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Environmental Pollution



To prepare for ENVIRONMENT for any competitive exam, aspirants have to know about Environmental Pollution. Here we will study Environmental Pollution in details. It gives an idea of all the important topics for the IAS Exam and the Governance syllabus (GS-II.). Environmental Pollution terms are important from Environmental perspectives in the UPSC exam. IAS aspirants should thoroughly understand their meaning and application, as questions can be asked from this static portion of the IAS Syllabus in both the UPSC Prelims and the UPSC Mains exams. Even these topics are also highly linked with current affairs. Almost every question asked from them is related to current events. So, apart from standard textbooks, you should rely on newspapers and news analyses as well for these sections.


  • Pollution is any undesirable change in physical, chemical or biological characteristics of air, land, water or soil. Agents that bring about such an undesirable change are called as pollutants
  • Pollutants can be solid, liquid or gaseous substances present in greater concentration than in natural abundance and are produced due to human activities or due to natural happenings


Harmful effects of pollution

Pollution currently poses one of the greatest public health and human rights challenges, disproportionately affecting the poor and the vulnerable.

  • Pollution is not just an environmental issue, but affects the health and well-being of entire societies.
  • Despite the huge impacts on human health and the global economy, and the opportunity to apply simple and affordable solutions, pollution has been undercounted and insufficiently addressed in national policies and international development agendas.
  • Pollution of all kinds can have negative effects on the environment and wildlife and often impacts human health and well-being.



  • Commercial or Industrial waste:
  • Commercial waste consists of waste from premises used mainly for the general purposes of a business or trade or for the purpose of recreation, education, sport, or entertainment.
  • Rapid Urbanization:
  • The promise of jobs and prosperity, among other factors, pulls people to cities. Half of the global population already lives in cities, and by 2050 two-thirds of the world’s people are expected to live in urban areas.
  • Forest fires:
  • Wild fire, also called forest, bush or vegetation fire, can be described as any uncontrolled and non-prescribed combustion or burning of plants in a natural setting such as a forest, grassland, brush land or tundra, which consumes the natural fuels and spreads based on environmental conditions (e.g., wind, topography).
  • Wildfire can be incited by human actions, such as land clearing, extreme drought or in rare cases by lightning.
  • Increase in population:
  • The recent increase in the world’s population has magnified the effects of our agricultural and economic activities.
  • Hazardous waste:
  • Hazardous waste is a waste with properties that make it dangerous or capable of having a harmful effect on human health or the
  • Hazardous waste is generated from many sources, ranging from industrial manufacturing process wastes to batteries and may come in many forms, including liquids, solids gases, and sludge.
  • Improper agricultural practices and deforestation:
  • Agriculture, the very industry that sustains us, also threatens our continued existence as a species. This sector produces at least 23 percent of global greenhouse gas emissions (second only to the energy sector)-IPCC report.
  • Deforestation refers to the decrease in forest areas across the world that are lost for other uses such as agricultural croplands, urbanization or mining activities.




The classification of pollutants is done from different point of view:


  • Depending upon their existence in nature pollutants are of two types: namely quantitative and qualitative pollutants
  • Quantitative pollutants: These are those substances normally occurring in the environment, that acquire the status of a pollutant when their concentration gets increased due to the un-mindful activities of man. For example: carbon dioxide
  • Qualitative pollutants: These are those substances which do not normally occur in nature but are added by man, for example, insecticides.
  • Depending upon the form in which they persist after being released into the environment, the pollutants are categorized into two types, namely primary and secondary pollutants:
  • Primary Pollutants: These are those which are emitted directly from the source and persist in the form in which they were added to the environment. Examples: ash, smoke, fumes, dust, nitric oxide, sulphur dioxide, hydrocarbons etc.
  • Secondary Pollutants: These are those which are formed from the primary pollutants by chemical interaction with some constituents present in the atmosphere. Examples are Sulphur trioxide, nitrogen dioxide, aldehydes, ketones, ozone etc.
  • From the ecosystem point of view, i.e., according to their natural disposal, pollutants are of two types:
  • Non-degradable Pollutants: These are the substances that either do not degrade or degrade very slowly in the natural environment. Example: mercury salts, long chain phenolic chemicals, DDT and Aluminum cans etc.
  • Such non-degradable pollutants accumulate and are biologically magnified as they move in the biogeochemical cycle and along food chains in the ecosystem.
  • Bio-degradable Pollutants: These are the pollutants that are quickly degraded by natural means. Heat or thermal pollution, and domestic sewage are considered in this category as these can be rapidly decomposed by natural processes or by engineered systems such as municipal treatment, plants etc.

  • Air Pollution
  • Noise Pollution
  • Water Pollution
  • Soil Pollution
  • Radioactive Pollution
  • Light Pollution
  • Nitrogen pollution




  • Air pollution may be defined as the presence of any solid, liquid or gaseous substance including noise and radioactive radiation in the atmosphere in such concentration that may be directly and indirectly injurious to humans or other living organisms, plants, property or interferes with the normal environmental processes.
  • Air pollutants are of two types (1) suspended particulate matter, and (2) gaseous pollutants like carbon dioxide (CO2 ), NOx etc.
  • Air pollution is the world’s single greatest environmental risk to health, prematurely killing some 6.5 million people across the world every year and exposing nine out of ten people to unacceptable outdoor air pollution levels. It in particular affects women, children, the sick and elderly, and those in low-income groups.



  • Burning fossil fuels releases gases and chemicals into the air. Air pollution in the form of carbon dioxide and methane raises the earth’s temperature.
  • Smog or ground-level ozone occurs when emissions from combusting fossil fuels react with sunlight. Smog can irritate the eyes and throat and also damage the lungs.
  • Soot, or “particulate matter,” is made up of tiny particles of chemicals, soil, smoke, dust, or allergens, in the form of gas or solids that are carried in the air.
  • Hazardous air pollutants are emitted during gas or coal combustion.
  • Sulphur dioxide is produced from burning coal in thermal power plants.
  • Carbon monoxide is produced from the incomplete burning of carbon-based fuels.
  • Chloroflorocarbons are released mainly from air conditioning systems and refrigeration.



  • Notification of National Ambient Air Quality Standards 2009, forecasting 12 pollutants to indicate the level of air quality for protection of public health and sector-specific emission and effluent standards for industries.
  • Setting up of monitoring network for assessment of ambient air quality in different cities
  • Introduction of cleaner or alternate fuel like CNG, LPG etc and ethanol blending.
  • Launching of National Air Quality Index (AQI).
  • Pass over from BS-IV to BS-VI standards for vehicles by 1st April 2020.
  • Promotion of public transport network..
  • Environment audits have been made compulsory for all polluting Industry.



  • Greenhouse gases are another source of air pollution. Greenhouse gases such as carbon dioxide and methane occur naturally in the atmosphere. In fact, they are necessary for life on Earth. They absorb sunlight reflected from Earth, preventing it from escaping into space. By trapping heat in the atmosphere, they keep Earth warm enough for people to live. This is called the greenhouse effect.
  • But human activities such as burning fossil fuels and destroying forests have increased the amount of greenhouse gases in the atmosphere. This has increased the greenhouse effect, and average temperatures across the globe are rising.



Greenhouse gases


Carbon Dioxide

  • Burning of Fossil fuel
  • Land-use change (Deforestation)


  • Biomass burning
  • Rice paddies field

Nitrous Oxide

  • Biomass burning
  • Fossil-fuel combustion
  • Fertilizers


  • Photochemical reaction involving O2


  • Industrial production

Sulphur dioxide

  • Volcanoes
  • Coal based power plant
  • Biomass burning


  • Increase in worldwide average temperatures, caused in part by human activity, is called global warming.
  • Global warming is causing ice sheets and glaciers to melt. The melting ice is causing sea levels to rise at a rate of 2 millimeters (0.09 inches) per year.
  • The rising seas will eventually flood low-lying coastal regions. Entire nations, such as the islands of Maldives, are threatened by this climate change.

Lifetime and potential of GHG


Gas GWP (100-year) Lifetime (years)
Carbon Dioxide 1 100
Methane 21 12
Nitrous Oxide 310 120
Hydrofluorocarbons (HFCs) 140-11,700 1-270
Perfluorocarbons (PFCs) 6,500-9,200 8000-50,000
Sulfur hexafluoride (SF6) 23,900 3,200


  • Ocean Acidification:
  • Ocean acidificationis a direct consequence of increased human-induced carbon dioxide (CO2) concentrations in the atmosphere. CO2 dissolves in sea water it forms carbonic acid, thereby decreasing the ocean’s pH, leading to a suite of changes collectively known as ocean acidification
  • It has the potential to change marine ecosystemsand impact many ocean-related benefits to society
  • Changes in species growth and reproduction, as well as structural and functional alterations in ecosystems, will threaten food security, harm fishing industries anddecrease natural shoreline protection.
  • It will also increase the risk of inundation and erosionin low-lying areas, thereby hampering climate change adaptation and disaster risk reduction efforts.
  • Chloroflorocarbons (CFCs) damage the ozone layer, a region in Earth’s upper atmosphere. The ozone layer protects Earth by absorbing much of the sun’s harmful ultraviolet radiation. When people are exposed to more ultraviolet radiation, they are more likely to develop skin cancer, eye diseases, and other illnesses.


  • Which of the following are some important pollutants released by steel industry in India?

1) Oxides of sulphur

2) Oxides of nitrogen

3) Carbon monoxide

4) Carbon dioxide

Select the correct answer using the code given below.

  1. 1, 3 and 4 only
  2. 2 and 3 only
  3. 1 and 4 only
  4. 1, 2, 3 and 4

Answer: D

  • Excessive release of the pollutant carbon monoxide (CO) into the air may produce a condition in which oxygen supply in the human body decreases. What causes this condition?
  1. When inhaled into the human body, CO is converted into CO2
  2. The inhaled CO has much higher affinity for haemoglobin as compared to oxygen
  3. The inhaled CO destroys the chemical structure of haemoglobin.
  4. The inhaled CO adversely affects the respiratory center in the brain

Answer: B

  • The acidification of oceans is increasing. Why is this phenomenon a cause of concern?
  1. The growth and survival of calcareous phytoplankton will be adversely affected.
  2. The growth and survival of coral reefs will be adversely affected.
  3. The survival of some animals that have phytoplanktonic larvae will be adversely affected.
  4. The cloud seeding and formation of clouds will be adversely affected.

Which of statements given above is / are correct?

  1. 1,2 and 3 only
  2. 2 only
  3. 1 and 3 only
  4. 1,2,3 and 4


Answer: D


Acid Rain:

  • Normally rain water has a pH of 5.6 due to the presence of H+ ions formed by the reaction of rain water with carbondioxide present in the atmosphere.
  • When the pH of the rain water drops below 5.6, it is called acid rain.
  • It refers to the ways in which acid from the atmosphere is deposited on the earth’s surface. Oxides of nitrogen and sulphur which are acidic in nature can be blown by wind along with solid particles in the atmosphere and finally settle down either on the ground as dry deposition or in water, fog and snow as wet deposition
  • H2O (l) + CO2 (g) H2CO3 (aq)
  • H2CO3 (aq) H + (aq) + HCO3 – (aq)


Causes of acid rain:

  • Acid rain is a byproduct of a variety of human activities that emit the oxides of sulphur and nitrogen in the atmosphere.
  • The burning of fossil fuels (which contain sulphur and nitrogenous matter) such as coal and oil in power stations and furnaces or petrol and diesel in motor engines produce sulphur dioxide and nitrogen oxides.
  • SO2 and NO2 after oxidation and reaction with water are major contributors to acid rain, because polluted air usually contains particulate matter that catalyse the oxidation.


  • 2SO2 (g) + O2 (g) + 2H2O (l) → 2H2SO4 (aq)
  • 4NO2 (g) + O2 (g)+ 2H2O (l) → 4HNO3 (aq)


Sources of Acid Rain

Compounds Natural Sources Anthropogenic sources
Sulphur Dioxide Volcanoes


Decomposition of organic matters

Fossil fuel burning

Industrial processes

Thermal power plants based on coal

Nitrogen Oxides Volcanoes


Decomposition of organic matter

Forest fires

Fossil fuel burning

Biomass burning

Power plants based on coal

Formic Acid Forest fires Biomass burning
Carbon Dioxide Respiration


Fossil fuel burning

Industrial Processes

Carbon Monoxide Isoprene emission by plants Biomass burning

Industrial sources


Types of Acid Deposition-

Based on the moisture content acid eposition can be classified as

Wet Deposition Dry Deposition
  • Acid chemical are blown into areas where Atmospheric condition are wet. Eg: rain, snow, fog act as source of Wet acid deposition
  • Acid chemical are blown into area where Atmospheric condition are dry. Eg: dust particles, pollen grains act as locus for Dry acid deposition
  • Wet form of acid deposition is common in region of high moisture like East margin of Tropical region, west margin of temperate region and Polar region.
  • Wet form of acid deposition is common in west margin of Tropical region and east margin of temperate region.

Impact of acid rain


  • Effects of Acid Rain on Fish and Wildlife: The ecological effects of acid rain are most clearly seen in aquatic environments, such as streams, lakes, and marshes where it can be harmful to fish and other wildlife.
  • As it flows through the soil, acidic rain water can leach aluminum from soil clay particles and then flow into streams and lakes.
  • The more acid that is introduced to the ecosystem, the more aluminum is released.
  • Some types of plants and animals are able to tolerate acidic waters and moderate amounts of aluminum. Others, however, are acid-sensitive and will be lost as the pH declines.
  • Effects of Acid Rain on Plants and Trees: Dead or dying trees are a common sight in areas effected by acid rain.
  • Acid rain leaches aluminum from the soil. That aluminum may be harmful to plants as well as animals.
  • Acid rain also removes minerals and nutrients from the soil that trees need to grow.
  • Effects of Acid Rain on Materials: Not all acidic deposition is wet. Sometimes dust particles can become acidic as well, and this is called dry deposition.
  • When acid rain and dry acidic particles fall to earth, the nitric and sulfuric acid that make the particles acidic can land on statues, buildings, and other manmade structures, and damage their surfaces.
  • The acidic particles corrode metal and cause paint and stone to deteriorate more quickly. They also dirty the surfaces of buildings and other structures such as monuments.
  • The Taj Mahal in India has been affected by acid rain.
  • Effects on Human Health: When the pollutants that cause acid rain —SO2 and NOX, as well as sulfate and nitrate particles— are in the air, they can be harmful to humans.
  • SO2 and NOX react in the atmosphere to form fine sulfate and nitrate particles that people can inhale into their lungs.
  • It corrodes water pipes resulting in the leaching of heavy metals such as iron, lead and copper into the drinking water.
  • Many scientific studies have shown a relationship between these particles and effects on heart function, such as heart attacks resulting in death for people with increased heart disease risk, and effects on lung function, such as breathing difficulties for people with asthma.


  • Acid rain is caused by the pollution of environment by
    1. Carbon dioxide and nitrogen
    2. Carbon monoxide and carbon dioxide
    3. Ozone and carbon dioxide
    4. Nitrous oxide and sulphur dioxide

Answer: D


Indoor Air Pollution:

  • Indoor air pollution is caused by burning solid fuel sources – such as firewood, crop waste, and dung – for cooking and heating. The burning of such fuels, particularly in poor households, results in air pollution that leads to respiratory diseases which can result in premature death.
  • Air pollution is the cause of 7 million premature deaths worldwide. Out of this 7 million, 2.6 million premature deaths are caused by indoor air pollution.
  • Characteristics: IAP impacts are more prominent among low Socio Demographic Index (SDI) countries, within a country, the IAP is more likely to impact poor & rural households compared to affluent and urban households.
  • IAP affects women and children more than men.
  • 6% of deaths in low-income countries are attributed to indoor air pollution.
  • Sources of indoor air pollution:
  • Fuel-burning combustion appliances
  • Tobacco products
  • Building materials and furnishings
  • Products for household cleaning and maintenance, personal care, or hobbies
  • Central heating and cooling systems and humidification devices
  • Excess moisture
  • Outdoor sources such as:
  • Radon
  • Pesticides
  • Outdoor air pollution.

Short term effects:

  • Some health effects may show up shortly after a single exposure or repeated exposures to a pollutant.
  • These include irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. Such immediate effects are usually short-term and treatable.
  • Sometimes the treatment is simply eliminating the person’s exposure to the source of the pollution, if it can be identified.
  • Soon after exposure to some indoor air pollutants, symptoms of some diseases such as asthma may show up, be aggravated or worsened.

Long term effects:

  • Exposure to indoor air pollutants can lead to a wide range of adverse health outcomes in both children and adults, from respiratory illnesses to cancer to eye problems.
  • Members of households that rely on polluting fuels and devices also suffer a higher risk of burns, poisonings, musculoskeletal injuries and accidents.



  • Spreading awareness among people about the issue and the serious threat IAP poses to their health and wellbeing.
  • Promoting use of cleaner energy sources such as gobar gas, LPG, etc. is required.
  • Modification of design of cooking stove to make fuel efficient, smokeless and have an exit (e.g., chimney) for indoor pollutants.
  • Improvement in ventilation: measures such as a window above the cooking stove and cross ventilation though doors should be instituted.
  • Intersectoral coordination and global initiative


Status in India and govt steps

  • As per Census 2011, about 65.9 per cent of households depend on solid biomass, including firewood, crop residue and cow dung as primary fuel for cooking in India.
  • The Ministry of New and Renewable Energy (MNRE) is implementing following programmes to reduce dependence upon traditional biomass cooking:
  • The Unnat Chulha Abhiyan: It was launched in 2014 for promotion of improved biomass cook stove
  • National Biogas and Manure Management Programme (NBMMP) for setting up of family type household biogas plants
  • Promoting solar cookers to reduce the indoor air pollution.
  • Pradhan Mantri Ujjwala Yojana (PMUY): It was Launched in 2016 with a motto ‘Swachha Indhan, behtar Jeevan’ (Clean fuel, better life) by the Ministry of Petroleum and Natural Gas to safeguard the health of women & children by providing them with clean cooking fuel through LPG.



  • The word smog is derived from smoke and fog. It is caused by the burning of large amounts of coal, vehicular emissionand industrial fumes(Primary pollutants), that react in the atmosphere with sunlight to form secondary pollutant.
  • This is the most common example of air pollution that occurs in many cities throughout the world.
  • There are two types of smog:
    • Classical smog occurs in cool humid climate. It is a mixture of smoke, fog and sulphur dioxide. Chemically it is a reducing mixture and so it is also called as reducing smog.
  • Photochemical smog occurs in warm, dry and sunny climate. The main components of the photochemical smog result from the action of sunlight on unsaturated hydrocarbons and nitrogen oxides produced by automobiles and factories.
  • Photochemical smog has high concentration of oxidising agents and is, therefore, called as oxidising smog.
  • These secondary pollutant combine with primary emission to form photochemical smog
  • Smog contains soot particulates like smoke, sulphur dioxide, nitrogen dioxideand other components.


Formation of photochemical smog

  • When fossil fuels are burnt, a variety of pollutants are emitted into the earth’s troposphere.
  • Two of the pollutants that are emitted are hydrocarbons (unburnt fuels) and nitric oxide (NO).
  • When these pollutants build up to sufficiently high levels, a chain reaction occurs from their interaction with sunlight in which NO is converted into nitrogen dioxide (NO2).
  • This NO2 in turn absorbs energy from sunlight and breaks up into nitric oxide and free oxygen atom.


Effects of photochemical smog

  • Photochemical smog causes serious health problems. Both ozone and PAN act as powerful eye irritants.
  • Ozone and nitric oxide irritate the nose and throat and their high concentration causes headache, chest pain, dryness of the throat, cough and difficulty in breathing.
  • Photochemical smog leads to cracking of rubber and extensive damage to plant life.
  • It also causes corrosion of metals, stones, building materials, rubber and painted surfaces


How to control photochemical smog

  • Many techniques are used to control or reduce the formation of photochemical smog. If we control the primary precursors of photochemical smog, such as NO2 and hydrocarbons, the secondary precursors such as ozone and PAN, the photochemical smog will automatically be reduced.
  • Usually catalytic converters are used in the automobiles, which prevent the release of nitrogen oxide and hydrocarbons to the atmosphere.
  • Certain plantsg., Pinus, Juniparus, Quercus, Pyrus and Vitis can metabolise nitrogen oxide and therefore, their plantation could help in this matter.


Gothenburg Protocol:

  • It is one of the Eight Protocols under UNECE Convention on Long Range Transboundary Air Pollution (CLRTAP or Air convention). It was adopted in 1999 to abate Acidification, Eutrophication and Groundlevel Ozone.
  • The revised Protocol (2012) sets national emission ceilings (up to 2020) for four pollutants: sulphur (SO2), nitrogen oxides (NOx), volatile organic compounds (VOCs) and ammonia (NH3).
  • It is also the first binding agreement to include emission reduction commitments for fine particulate matter.
  • Also, black carbon (or soot), a short-lived climate pollutant is included within particulate matter for policymaking.
  • Parties whose emissions have a more severe environmental or health impact and whose emissions are relatively cheap to reduce have to make the biggest cuts.



  • Photochemical smog is a resultant of the reaction among
  • NO2 , O3, and peroxyacetyl nitrate in the presence of sunlight
  1. CO, O2, and peroxyacetyle nitrate in the presence of sunlight
  2. CO, CO2, and NO2, at low temperature
  3. High concentration of NO2, O3, and CO in the evening

Answer: A

  • Brominated flame retardants are used in many household products like mattresses and upholstery, Why is there some concern about their use?

1) They are highly resistant to degradation in the environment.

2) They are able to accumulate in humans and animals.

Select the correct answer using the code given below.

  1. 1 only
  2. 2 only
  3. Both 1 and 2
  4. Neither 1 nor 2

Answer: C




National Air Quality Monitoring Programme (NAMP):

  • Central Pollution Control Board is executing a nation-wide programme of ambient air quality monitoring known as National Air Quality Monitoring Programme (NAMP).

The objectives of the NAMP are:

  • to determine status and trends of ambient air quality;
  • to ascertain whether the prescribed ambient air quality standards are violated;
  • to Identify Non-attainment Cities;
  • to obtain the knowledge and understanding necessary for developing preventive and corrective measures and
  • to understand the natural cleansing process undergoing in the environment through pollution dilution, dispersion, wind based movement, dry deposition, precipitation and chemical transformation of pollutants generated.
  • Under NAMP, four air pollutants viz., Sulphur Dioxide (SO2), Oxides of Nitrogen as NO2, Suspended Particulate Matter (SPM) and Respirable Suspended Particulate Matter (RSPM / PM10) have been identified for regular monitoring at all the locations.
  • The monitoring of meteorological parameters such as wind speed and wind direction, relative humidity (RH) and temperature were also integrated with the monitoring of air quality.


National Ambient Air Quality Standards (NAAQS):

  • National ambient air quality standards (NAAQS) have been established in the year 1982 for six “criteria” or major of outdoor air pollutants: lead, carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, and particulate matter.
  • The NAAQS have been revisited and revised in 2009 for 12 pollutants which include: SO2, NO2, PM10, PM2.5, Ozone, Lead, Carbon Monoxide, Arsenic, Nickel, Benzene, Ammonia and Benzopyrene.

National Clean Air Programme (NCAP):

  • The National Clean Air Programme or NCAP is a government programme launched by the Union Ministry of Environment, Forests and Climate Change in 2019.
  • Goal of NCAP is to meet the prescribed annual average ambient air quality standards at all locations in the country in a stipulated timeframe. The tentative national level target of 20%–30% reduction of PM2.5 and PM10 concentration by 2024 is proposed under the NCAP taking 2017 as the base year for the comparison of concentration.
  • Objectives:
  • To augment and evolve effective and proficient ambient air quality monitoring network across the country for ensuring comprehensive and reliable database
  • To have efficient data dissemination and public outreach mechanism for timely measures for prevention and mitigation of air pollution and for inclusive public participation in both planning and implementation of the programmes and policies of government on air pollution
  • To have feasible management plan for prevention, control and abatement of air pollution.


National Air Quality Index (NAQI):

  • NAQI was launched in 2014 with outline ‘One Number – One Color -One Description’ for the common man to judge the air quality within his vicinity.
  • It has been launched for monitoring the quality of air in major urban centers across the country on a real-time basis and enhancing public awareness for taking mitigative action.
  • The measurement of air quality is based on eight pollutants, namely, Particulate Matter (PM10), Particulate Matter (PM2.5), Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Carbon Monoxide (CO), Ozone (O3), Ammonia (NH3), and Lead (Pb).
  • AQI has six categories of air quality. These are: Good, Satisfactory, Moderately Polluted, Poor, Very poor and Severe.
  • It has been developed by the CPCB in consultation with IIT-Kanpur and an expert group comprising medical and air-quality professionals.
  • Vehicular pollution is kept under check by the use of CNG, LPG, ethanol blending from the universalisation of BS-IV in 2017 to BS-VI fuel standards by 1st April Along with this, the government is promoting carpooling and use of public transports.
  • Awareness campaigns like ‘Harit Diwali and Swasth Diwali’ have helped educate about the problem. In Delhi itself, 2000 schools participated making a total of over two lakh schools in the entire country.
  • The Graded Response Action Plan specifies the actions required to control and prevent PM10 and PM2.5.
  • Odd-Even scheme in Delhi to control air pollution.


Bharat Stage Norms (BS norms):

  • Bharat Stage Emission Standards have been instituted by the Central Pollution Control Board (CPCB), instituted within the Ministry of Environment Forests and Climate Change.
  • These are the standards set up by the Indian government which specify the amount of air pollutants from internal combustion engines, including those that vehicles can emit.
  • If these emit more pollutants than the prescribed limit, they don’t get a clearance to be sold in an open market.
  • Vehicle emission norms were introduced in India in 1991 for petrol and in 1992 for diesel vehicles. Since 2000, Euro norms are followed in India under the name Bharat Stage Emission Standards for four wheeled vehicles.
  • Bharat stage III norms have been enforced across India since October 2010.
  • Bharat stage IV norms were enforced throughout India since April 2017. Upgrading the emission norms requires the manufacturing companies to upgrade their technology, which in turn increases the cost of the vehicle. Cost is one of the main reasons for the slow upgrade of emission standards.
  • Recently, the central government has mandated that vehicle makers must manufacture, sell and register only BS-VI (BS6) vehicles from April 1, 2020 bypassing the BS-V norms altogether.


Difference Between BS-IV and BS-VI norms:

  • BS-VI emission norms are aimed at reducing the pollution in the country by cutting down the tail pipe emissions of all the new vehicles sold in the country. The new standard also puts an end to the sales and registration of BS 4 vehicles in India.
  • Particulate Matter (PM): BS 6 norms intend to bring down the emission of particulate matter by almost 80 per cent in case of petrol as well as diesel power-plants. Particulate Matter (PM) is a complex mixture of extremely small particles and droplets. The PM is infamous for causing severe lung ailments and has also been found to be carcinogenic in nature (cancer causing).
  • Nitrogen oxides (NOx): NOx gases in vehicles’ exhaust can cause health problems like lung infection and chronic respiratory problems. This is why, BS 6 emission standards want to reduce NOx in tailpipe emission by at least 25 per cent in case of petrol vehicles and 70 per cent in case of diesel vehicles as compared to their BS 4 counterparts.
  • Sulphur: BS 6-compliant vehicles cannot meet BS 6 emission standards unless they are run on BS 6 fuel. This is because BS 6 petrol and diesel are much cleaner and refined than BS 4 fuel. The biggest difference is that BS 6 fuel contain five times less sulphur — 50 ppm — as compared to 10 ppm in BS 4 fuel.


NITI Aayog ‘Decarbonising Transport in India” Project

  • The project is in collaboration with the International Transport Forum (ITF).
  • India’s Decarbonising Transport initiative is a part of the DTEE project.
  • DTEE stands for Decarbonising Transport in Emerging Economies.
  • DTEE is a project of ITF under which apart from India, currently Argentina, Morocco, and Azerbaijan are the participants.
  • The project will design a tailor-made transport emissions assessment framework for India.
  • It will provide the government with a detailed understanding of current and future transport activity and the related CO2 emissions as a basis for their decision-making.
  • ITF is a think tank for transport policy issues. It is headquartered in Paris,
  • It is an intergovernmental organization with the Organisation for Economic Co-operation and Development (OCED)


Current affairs


Oxygen Parlour opened at Nashik Railway Station to combat Air Pollution:

  • In a unique initiative to battle rising air pollution in cities, Indian Railways has opened an ‘Oxygen Parlour’ at Nashik railway station in Maharashtra. The initiative seeks to provide an experience of breathing clean air to the commuters.
  • The objective behind setting up Parlour is to expand this initiative to every railway station as well as every home.
  • The concept of Oxygen Parlour is based on recommendation of the National Aeronautics and Space Administration (NASA).


IndAIR: CSIR-NEERI’s web facility launched:

  • The Council of Scientific and Industrial Research-National Environmental Engineering Research Institute (CSIR-NEERI) has launched the country’s first interactive online repository, called IndAIR or Indian Air quality Interactive Repository.
  • The repository is one of few such facilities in the world and has the maximum number of studies-262 concerning Delhi-NCR.


WAYU (Wind Augmentation PurifYing Unit)-

  • It is an air pollution control device which can purify air in an area of 500m2.
  • It was developed by Council of Scientific and Industrial Research – National Environmental Engineering Research Institute (CSIR-NEERI) as a part of Technology Development Project being funded by Department of Science and Technology.



  • In a bid to resolve the crisis of air pollution, Council of Scientific and Industrial Research (CSIR) led by Nagpur-based National Environmental Engineering Research Institute (NEERI) developed green firecrackers.
  • The green crackers are named as Safe Water Releaser (SWAS), Safe Thermite Cracker (STAR) and Safe Minimal Aluminium (SAFAL) with 30% reduction in particulate matter on an average using Potassium Nitrate (KNO3) as oxidant.
  • These crackers have the unique property of releasing water vapour, air as a dust suppressant and diluents for gaseous emissions that match with the performance in sound with traditional conventional crackers.


Agriculture Residue:

  • Central Sector Scheme on ‘Promotion of Agricultural Mechanization for In-Situ Management of Crop Residue in the States of Punjab, Haryana, Uttar Pradesh and NCT of Delhi’ for the period from 2018-19 to 2019-20 has been launched to address air pollution and to subsidize machinery required for in-situ management of crop residue.
  • Torrefaction: India is testing this Swedish technology that can convert rice stubble into ‘bio-coal’. The technology involves heating up straw, grass, saw- mill residue and wood biomass to 250°C – 350°C. This changes the elements of the biomass into ‘coal-like’ pellets. These pellets can be used for combustion along with coal for industrial applications like steel and cement production.
  • Happy Seeder Machine: It is a tractor-operated machine developed by the Punjab Agricultural University (PAU) in collaboration with Australian Centre for International Agricultural Research (ACIAR), for in-situ management of paddy stubble (straw).
  • The National Green Tribunal has recently directed thermal power plants to take prompt steps toward the scientific disposal of fly ash.
  • Luxembourg: The First Country in the World to provide Free Public Transport:


Corporate Average Fuel Efficiency/Economy (CAFE) Regulation to curb the vehicular pollution:

  • It aims at lowering fuel consumption (or improving fuel efficiency) of vehicles by lowering carbon dioxide (CO2) emissions.
  • Corporate Average refers to sales-volume weighted average for every auto manufacturer. The norms are applicable for petrol, diesel, LPG and CNG passenger vehicles.
  • In India, CAFE regulations come into force into 2017, under which, average corporate CO2 emission from vehicle must be less than 130 gm per km till 2022 and below 113 gm per km thereafter.
  • CAFE norms require cars to be 30% or more fuel efficient from 2022 and 10% or more between 2017 and 2021.

NITI Aayog launches Nationally Determined Contributions Transport Initiative for Asia (NDC-TIA):

  • The initiative was launched to decarbonize transport and provide technical support on Green Gas emission reduction measures.
  • The initiative is supported by International Climate Initiative of German Ministry of Environment. The NDC-TIA team is to closely work with Government agencies, researchers, local decision makers, think tanks, industry experts, and civil society organizations.
  • The main objective of the programme is to support and regulate policies to promote electric vehicle charging infrastructure and smooth wide scale adoption of Electric Vehicles in India. Also, the programme will provide electric vehicle policy recommendations. It aims to support NDC targets through target sector.
  • The project will include three countries namely India, China and Vietnam for a period of 2020-24. It will provide a consistent strategy for effective policies of decarbonizing transport. It will make contributions and increase ambition in transport section.


ANTHURIUM: 10 Varieties of the high market value, AIR PURIFYING flower developed:

  • A woman innovator from Kerala, Vasini Bai has developed 10 varieties of Anthurium flower. The flower has high market value for its major usage as an indoor decorative.
  • The Anthurium flowers have gained their significance lately for their purification qualities. They purify the surrounding air.
  • Also, they remove harmful airborne chemicals such as ammonia, formaldehyde, toluene, allergens and xylene.


Smog Towers

  • Smog Towers are air purification structures that are designed to work as air purifiers. They are fitted with multiple air purifiers. These purifiers cleanses air as it passes through them.
  • It is a successful project and China has fitted two smog towers in the city of Beijing and Xi’an.


Anti-smog Gun

  • The anti-smog gunis a canon that sprays atomized water 50 metres into the air to bring down suspended pollutants.
  • The atomised water sprayed from the gun helps in bringing down the minute particles,which constitute the PM 2.5, the main pollutant.


Water and Nature Initiative (WANI)

  • WANI works in more than 12 river basin in over 30 countries worldwide.
  • WANI unlocks the potential for healthy river basin to build climate resilience and to sustain ecosystem and livelihood.
  • The IUCN – WANI work toward managing and protecting our water reserves and heritage for the future benefit of all.


Ozone Pollution

  • News- Delhi recorded an ozone pollution which is 1.22 times higher than the eight-hour average standard for ozone exposure that is 100 microgram per cubic meter.


Ozone is classified into two types:

  • Good ozone: Found in stratosphere, it protects the Earth’s surface from dangerous ultraviolet light.
  • Bad Ozone: Found in the troposphere (also known as ground level ozone), it is man-made. The released nitrogen oxide (NOx), carbon monoxide (CO) and volatile organic compounds (VOC), (NOx, CO, and VOCs are known as ozone precursors)


Health and Environmental impact of Ozone:

  • It is a highly reactive gas, even short-term exposure of an hour is dangerous for those with respiratory conditions and asthma.
  • Breathing ozone can cause chest pain, coughing, throat irritation and airway inflammation.
  • Increases the risk of respiratory infection and susceptibility to pulmonary inflammation (COPD).
  • Breathing ozone can shorten the life that is premature death.
  • It can cause cardiovascular diseases that inhaling ozone may affect the heart.
  • Ozone causes harm to vegetation and ecosystems including forests, parks, wildlife refuges etc.



  • Greenpeace has found that India is the largest emitter of Sulphur dioxide (SO2) in the world, contributing more than 15% of global anthropogenic emissions.
  • SO2emissions are a significant contributor to air pollution. High concentrations of SO2 in the air generally lead to the formation of other Sulphur Oxides (SOx).
  • SOx can react with other compounds in the atmosphere to form small particles. These particles contribute to Particulate Matter (PM) pollution.
  • Small particles may penetrate deeply into the lungs and in sufficient quantity can contribute to health problems.
  • The greatest source of SO2 in the atmosphere is the burning of fossilfuels in power plants and other industrial facilities.
  • Other sources include industrial processes such as extracting metal from ore, natural sources such as volcanoes, and locomotives, ships and other vehicles and heavy equipment that burn fuel with high sulphur content.


Fly Ash
  • News- The National Green Tribunal sought a report from the authorities on the current status of Fly ash management and disposal.
  • Fly ash is a fine powder, which is the by-product of burning coal in thermal power plants.
  • Fly ash includes substantial amounts micron sized earth elements of oxides of silica, aluminium and calcium. Element like Arsenic, Boron, Chromium, lead etc. are also found in trace concentrations.


Environmental Concerns Associated with Fly Ash
  • Fly ash is a major source of PM 2.5, fine, pollution particles, in summer it causes air pollution.
  • It becomes air borne, and gets transported to a radius of 10 to 20 kms. It can settle on water and other surfaces. It can also contaminate water and soil systems.
  • Fly ash contains heavy metals from coal, a large amount of PM 2.5 and black carbon (BC). Proper disposal of fly ash is still not happening in many places.
  • The wet disposal of Fly ash results in leaching of toxic heavy metals in ground water system.


Advantages of Fly Ash Utilization

  • Prevents Soil Erosion– Helps restrict usage of topsoil for manufacturing of bricks.
  • Used in variety of construction works– Fly ash is a proven resource material for many applications of construction industries, like Flyash bricks have been found to show better strength.
  • Fly ash can be used as a replacement for some of the Portland cement contents of concrete. It is environmentally beneficial because it reduces the Portland cement, a major contributor of CO2, required in concrete.
  • Fly ash is a proven resource material for many applications of construction industries and currently is being utilized in manufacturing of bricks/blocks/tiles.
  • Manufacturing of Absorbents that are suitable for purification of waste gases, drinking water purification, waste water treatment etc.
  • Used in Agriculture– as an agent for acidic soils, as soil conditioner — improving upon some important physio-chemical properties of the soil such as hydraulic conductivity, bulk density, porosity, water holding capacity, etc.
  • Use of Fly ash in agriculture can increase the yield of cereals, oil seeds, pulses, cotton and sugarcane by 10-15%, vegetables by about 20-25% and root vegetables by 30-40%.
  • Waste lands, degraded lands, saline alkaline soils, eroded soils etc., can be successfully reclaimed by fly ash.
  • Prevent Contamination of Water Resources– by preventing contamination of surface water through erosion, runoff, airborne particles landing on the water surface etc.


Government Measures to promote Fly Ash Utilization
  • Maharashtra has become the first state to adopt Fly Ash Utilization Policy, paving way for prosperity by generating “wealth from waste”, and environment protection.
  • The policy will create new employment opportunities in the power plant areas and also make available raw material for construction at low cost to help ‘Housing for All’ projects.
  • The policy seeks 100% use of fly ash generated from thermal power plants and biogas plants for construction activities.
  • Central Electricity Authority (CEA) has been monitoring the fly ash generation and its utilization in the country at coal/ lignite based thermal power stations since 1996-97.
  • The Ministry of Environment, Forests and Climate Change (MoEFCC) issued notifications on Fly Ash Utilization in 2016 that had following featureso Mandatory uploading of details of fly ash available on Thermal Power Station’s (TPS) website
  • Increase in mandatory jurisdiction of area of application from 100 km to 300 km;
  • Cost of transportation of fly ash to be borne entirely by TPS up to 100 km.
  • Mandatory use of fly ash based products in all Government schemes or programmes e.g. Pradhan Mantri Gramin Sadak Yojana, Mahatma Gandhi National Rural Employment Guarantee Act, 2005, Swachh Bharat Abhiyan, etc.
  • As per, 2019 government notification the existing red clay brick kilns located within 300 km shall be converted into fly ash-based bricks or blocks or tiles manufacturing unit within one year.
  • The GST rate on fly ash and fly ash aggregate with 90% or more of fly ash content was reduced from 18% to 5%.
  • A mobile app for ash management- ASH TRACK was created to help establish a link between fly ash users and power plant executives.
  • NTPC in collaboration with Institutes like IIT-Delhi and IIT-Kanpur has initiated manufacturing of prestressed railway concrete sleepers.
  • With the above measures in place, at present, 63% of the fly ash is being utilized in India.
  • Central Government has made it mandatory for use of fly ash bricks in construction activities happening 500 km around thermal power plants.


Two methods of scientific fly ash disposal

  • Dry Fly Ash Disposal system: Electrostatic precipitation (ESP) enables collection of dry Fly Ash which is then transported by trucks or conveyors at a site and disposed of by constructing a dry embankment.
  • Wet Fly Ash Disposal System: Fly Ash is mixed with water and transported as slurry through pipe and disposed of in ash ponds or dumping areas near the plants.


Delhi’s air pollution

  • According to a study conducted by The Energy and Resources Institute (TERI) in 2018, 36% of the pollution has its source in Delhi itself, 34% in National Capital Region while 30% comes from across international borders.
  • Vehicular Pollution: TERI’s study shows that vehicle pollution is the cause of 28 per cent of PM2.5 emissions.
  • Stubble burning: Crop residue burning during winter is one of the chief causes for rising air pollution levels in Delhi.
  • Industrial pollution: Industries contribute 30 per cent of PM2.5 levels, with 14 per cent from small industries.
  • The north-westerly winds that come into Delhi transport Sulphur dioxide (SO2) emitted from large power plants and refineries that are situated upwind of Delhi.


Factors responsible for Delhi’s pollution:

  • Lack of winds movement: The lack of winds that can carry away pollutants is one of the most important factors impacting air quality.
  • Delay in monsoon withdrawal: Late monsoon withdrawal is not good for air quality in north India as the time progresses towards winter. This marked by dry weather, clear skies and very low speed of surface winds. So, the particulate matter in the air, does not get dispersed and gets arrested in the atmosphere.
  • Geographical position of Delhi: Delhi lies to the north-east of the Thar Desert, to the north-west of the central plains and to the south-west of the Himalayas.
  • As winds arrive from the coasts, bringing with them pollutants picked up along the way, they get ‘trapped’ right before the Himalayas.
  • Dust storms: Delhi-NCR comes under a thick blanket of dust primarily due to dust storms from Rajasthan which is facing extremely dry weather conditions, with high temperatures and wind speeds.
  • Destruction of the Aravallis that protects north India from dust storms has increased this impact.
  • Also, a study in 2017 by the System of Air Quality and Weather Forecasting and Research (under the Ministry of Earth Sciences) and India Meteorological Department (IMD) “multi-day dust storm” in Iraq, Kuwait and Saudi Arabia was one of the main causes of Delhi’s smog.
  • Stubble burning: Stubble burning is the act of clearing agricultural fields by burning the residue that is left on the land after harvesting, to ready it for the next round of seeding.


Policy Response

  • National Green Tribunal (NGT) has banned crop residue burning in the states of Rajasthan, Uttar Pradesh, Haryana and Punjab.
  • Some of the laws that are in operation pertaining to crop residue burning are: The Section 144 of the Civil Procedure Code (CPC) to ban burning of paddy residue; The Air Prevention and Control of Pollution Act, 1981; The Environment Protection Act, 1986; The National Tribunal Act, 1995; and The National Environment Appellate Authority Act, 1997.
  • National Policy for Management of Crop Residue (NPMCR): launched by Ministry of Agriculture in 2014 to ensure prevention of burning of crop residues by incentivizing purchase of modern machineries to minimize left-over crop residue in the field
  • Central Sector Scheme on ‘Promotion of Agricultural Mechanization for In-Situ Management of Crop Residue in the States of Punjab, Haryana, Uttar Pradesh and NCT of Delhi’ for the period from 2018-19 to 2019-20 has been launched to address air pollution and to subsidize machinery


  • In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index?
  1. Carbon dioxide
  2. Carbon monoxide
  3. Nitrogen dioxide
  4. Sulfur dioxide
  5. Methane

Select the correct answer using the code given below.

  1. 1, 2 and 3 only
  2. 2, 3 and 4 only
  3. 1, 4 and 5 only
  4. 1,2, 3, 4 and 5

Answer: B

  • Consider the following;
    1. Carbon monoxide
    2. Methane
    3. Ozone
    4. Sulphur dioxide.

Which of the above are released into atmosphere due to the burning of crop/biomass residue?

  1. 1 and 2 only
  2. 2, 3 and 4 only
  3. 1 and 4 only
  4. 1, 2, 3 and 4

Answer: D

  • With reference to ‘ fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct?
  1. Fly ash can be used in the production of bricks for building construction.
  2. Fly ash can be used as a replacement for some of the Portland cement contents of concrete.
  3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any toxic elements.

Select the correct answer using the code given below:

  1. 1 and 2
  2. 2 only
  3. 1 and 3
  4. 3 only

Answer: A

Noise Pollution:


  • Unwanted or excessive sound that can have deleterious effects on human health and environmental quality
  • Noise pollutionis commonly generated inside many industrial facilities and some other workplaces, but it also comes from highway, railway, and airplane traffic and from outdoor construction activities.
  • However, exposure to excessive noise can affect your health and damage hearing. Harmful or annoying levels of noise are considered noise pollution or sound pollution.
  • Noise is measured in term of decibels (dB), as per WHO (World Health Organization) has prescribed optimum noise level as 45 dB by day to 35 dB at night.
  • Noise pollution (Control and regulation), 2000 define ambient noise levels for various area as follows:


Impacts of noise pollution:

  • Hypertension: a direct result of noise pollution caused elevated blood levels for a longer period of time.
  • Hearing loss: It can be directly caused by noise pollution, whether listening to loud music in your headphones or being exposed to loud drilling noises at work, heavy air or land traffic, or separate incidents in which noise levels reach dangerous intervals, such as around140 dB for adult or 120 dB for children.
  • Sleep disturbances are usually caused by constant air or land traffic at night, and they are a serious condition in that they can affect everyday performance and lead to serious diseases.
  • Child development: Children appear to be more sensitive to noise pollution, and a number of noise-pollution-related diseases and dysfunctions are known to affect children, from hearing impairment to psychological and physical effects.
  • Various cardiovascular dysfunctions: Elevated blood pressure caused by noise pollution, especially during the night, can lead to various cardiovascular diseases.
  • Dementia isn’t necessarily caused by noise pollution, but its onset can be favored or compounded by noise pollution.
  • Psychological dysfunctions and noise annoyance: Noise annoyance is, in fact, a recognized name for an emotional reaction that can have an immediate impact.


Effects of Noise Pollution on Wildlife and Marine Life:

  • Our oceans are no longer quiet. Thousands of oil drills, sonars, seismic survey devices, coastal recreational watercraft and shipping vessels are now populating our waters, and that is a serious cause of noise pollution for marine life.
  • Whales are among the most affected, as their hearing helps them orient themselves, feed and communicate. Noise pollution thus interferes with cetaceans’ (whales and dolphins) feeding habits, reproductive patterns and migration routes, and can even cause hemorrhage and death.
  • Other than marine life, land animals are also affected by noise pollution in the form of traffic, firecrackers etc., and birds are especially affected by the increased air traffic.


Measures to control noise pollution:

  • Strict imposition of noise limit over loudspeakers and automobiles.
  • Restrictions on burning firecrackers and honking in silent areas.
  • Construction of green mufflers by planting trees
  • Proper use of noise control equipment such as earplug, noise cancelling headphones etc.
  • Job rotation so as to reduce exposure time in noisy industrial places.


Laws Governing Noise Pollution

  • Air (Prevention and Control of Pollution) Act, 1981: It includes ‘Noise’ as an air pollutant.
  • Noise Pollution (Regulation and Control) Rules, 2000: It defines and regulates noise pollution and its sources.
  • Environment (Protection) Rules, 1986: It prescribes noise standards for motor vehicles, air- conditioners, refrigerators, diesel generators and certain types of construction equipment.
  • Noise emanating from industry is regulated by State Pollution Control Boards / Pollution Control Committees (SPCBs / PCCs) for states / Union territories under the Air (Prevention and Control of Pollution) Act, 1981.


Recent National Green Tribunal (NGT) direction on Noise pollution

  • The NGT has asked the CPCB to categories cities on the basis of their noise profile and identify the noisy hotspots.
  • The CPCB has also been asked to propose remedial plans for the noise pollution, within 3 months.
  • NGT has also called upon police departments in all states to procure sound monitoring devices.
  • They are also directed to assist the pollution control authorities in their efforts to mitigate noise pollution.
  • Manufacturers of public address systems and sound amplification equipment should provide inbuilt noise meters and data loggers in their products.
  • This would help regulators to establish violation and fix responsibility




  • Water pollution is the contamination of natural water present in lakes, rivers, streams, oceans, and groundwater due to inflow or deposition of pollutants directly or indirectly into the water systems.
  • Any modifications or change in the chemical, physical and biological properties of water that can cause any harmful consequences on living things and the environment is known as water pollution
  • Polluted water not only does this spell disaster for aquatic ecosystems, the pollutants also seep through and reach the groundwater, which might end up in our households as contaminated water we use in our daily activities, including drinking.
  • The United Nations estimates that 4,000 children die every day from drinking dirty water.


Causes of Water Pollution:

  • Industrial effluents: Industrial effluents have a complex nature of pollutants and include organic and inorganic substances like pharmaceutical residues, dyes, and metals, requiring treatment before discharge in wastewater streams.


  • Social and Religious Practices:
  • Among various types of anthropogenic actions religious activities like immersion of flour, oil, soap, ash, detergents, floral offerings, and mass bathing are also one of the important causes that affect the water quality of a water body.
  • The religious activities are deeply rooted in its cultural heritage; millions of people take holy bath and perform religious activities
  • Use of Detergents and Fertilizers: Water pollution by chemicals (such as detergents) is a big concern in the global context. Many laundry detergents contain approximately 35 percent to 75 percent phosphate salts. Over enrichment of phosphate can cause the water body to become choked with algae and other plants. Eutrophication deprives the water of available oxygen, causing the death of other organisms.
  • Agricultural run-offs- Use of insecticides and pesticides: Agricultural Runoff (non-point source) is water from farm fields due to irrigation, rain, or melted snow that flows over the earth that can absorb into the ground, enter bodies of waters or evaporate.
  • This runoff can contain pesticides, sediment (soil particles), nutrients (phosphorus, nitrogen and potassium from fertilizers) and metals, which can contaminate sources of water.
  • Mining activities: Mining activities emit several metal waste and sulphides from the rocks and is harmful for the water.
  • Acid mine drainage causes the acidity of water, which in turn disturb the chemical composition of water source by dissolving and freeing some harmful substances.
  • Marine dumping: In some countries the garbage produce by each household in the form of paper, aluminum, rubber, glass, plastic, food if collected and deposited into the sea.
  • Accidental leakage Marine pollution: Oil spill pose a huge concern as large amount of oil enters into the sea which does not dissolve with water; there by opens problem for local marine wildlife such as fish, birds and sea otters etc.
  • For example, a ship carrying large quantity of oil may spill oil if met with an accident and can cause varying damage to species in the ocean depending on the quantity of oil spill, size of ocean, toxicity of pollutant.
  • Burning of fossil fuels: Fossil fuels like coal and oil when burnt produce substantial amount of ash in the atmosphere. The particles which contain toxic chemicals (often of sulfur, which is present in coal) when mixed with water vapor result in acid rain.
  • Facilities handling radioactive materials:
  • The element that is used in production of nuclear energy is Uranium which is a highly toxic chemical.
  • Nuclear waste can have serious environmental hazards if not disposed-off properly.
  • Urban development and run off : As more cities and towns are developed, they have resulted in increased use of fertilizers to produce more food, soil erosion due to deforestation, increase in construction activities, inadequate sewer collection and treatment, landfills as more garbage is produced, increase in chemicals from industries to produce more materials.


Classification of water pollutants

  • Water pollutants can be divided into four major categories- Chemical, Physical, Physiological and Biological.
  • Though the physical and physiological pollutions are mainly outcomes of chemical pollutants, they are categorized separately because of their nature.

1.Chemical Pollutants: Chemical pollutants can further be divided into Organic pollutants and Inorganic pollutants. Organic pollutants:

  • Organic pollutants are the compounds those contain carbon atom in them and mainly of biological origin.
  • These are the oxygen depleting substances in water. They are carried to the water course from different sources like sewage, animal and human excreta, refineries, distillery, pulp and paper industry, tanneries, diary industry, textile industry, slaughter houses etc.
  • BOD and COD is common indicator of high organic content of waste water.
  • The organic pollutants could be further subdivided into two.


  • Biodegradable organic pollutants:
  • These are the organic materials which can be easily degraded by microorganisms.
  • Most of the naturally occurring organic compounds (originated from plants and animals) are biodegradable.
  • Examples: Proteins, fats, carbohydrates, alcohols, acids, aldehydes, esters, soaps etc.

  • Non-biodegradable organic pollutants:
  • These are the organic materials which are resistant to biological degradation.
  • Most of these are synthetic organics, which are of high concern.
  • Some naturally occurring organic compounds biodegrade so slowly that they are considered refractory.
  • For example, lignic acid, tannic acid, cellulose, and many of the organics associated with petroleum.
  • Pesticides (DDT, aldrin, dieldrin, endrin, endosulfan, lindane, toxaphene, mirex, heptachlor etc.), polychlorinated biphenyls (PCB’s), polyaromatic hydrocarbons (PAH’s), plastics, dioxins, furans, phenols, dyes, detergents etc.


  • Inorganic pollutants:
  • Inorganic pollutants include inorganic acids, alkalis, salts, anions, cations, free chlorine, ammonia etc.
  • They are added a result of industrial effluents, sewage, household cleansers and surface run-off from urban and agricultural field etc.
  • They affect the physical and chemical quality of water.

Table: Common inorganic pollutants found in water

2 Physical Pollutants: These are the pollutants which deteriorate the physical parameters of water quality. These include color, turbidity, suspended matter, radioactivity, froth and thermal pollutants

3 Physiological Pollutants: Physiological pollution, as said earlier, is caused by presence of some chemicals. Physiological pollutions are of two types- taste and odour.

4 Biological Pollutants: The biological pollution occurs due to introduction and growth of micro and macro organisms in water body, which adversely affect the quality of water, human health and ecosystem. Various biological pollutants include bacteria, algae, weeds, viruses, protozoa and worms.

Sources of water pollution:

  • Classifications of water pollution according to identifiability, can be either a Point or a Non-point source

Point Source:

When contamination originates from a single source, it’s called point source pollution.

Point source pollution can include:

  • on-site septic systems
  • leaky tanks or pipelines containing petroleum products
  • municipal landfills
  • livestock wastes
  • industrial/factory wastewater
  • municipal sewage treatment plants

Non-point source:

  • Nonpoint source pollution is contamination derived from diffuse sources.
  • Nonpoint source pollution is the leading cause of water pollution, but it’s difficult to regulate, since there’s no single, identifiable culprit.
  • These include:
  • Excess fertilizers, herbicides and insecticides from agricultural lands and residential areas
  • Oil, grease and toxic chemicals from urban runoff and energy production
  • Sediment from improperly managed construction sites, crop and forest lands, and eroding stream banks
  • Salt from irrigation practices and acid drainage from abandoned mines
  • Bacteria and nutrients from livestock, pet wastes and faulty septic systems
  • Atmospheric deposition and hydro modification


Types of water pollution:

Dissolved Oxygen:

Dissolved Oxygen (DO) is a measure of the amount of free oxygen available in river systems. Presence of organic and inorganic wastes in water decreases the dissolved oxygen content of the water. DO below 8 ppm (Parts Per Million) indicates pollution and below 4 ppm indicates heavy pollution. In unpolluted water, DO should be about 14 ppm.

Biological Oxygen Demand (BOD):

BOD is the amount of oxygen that will be consumed by bacteria or other aerobic microorganisms while decomposing organic matter under aerobic conditions. As tested, it is expressed in milligrams of oxygen consumed per liter of sample during a fixed incubation period. It is generally used as an indicator of the amount of organic pollution in a water sample. So, the BOD in polluted waters will generally be higher than in clean water. The higher value of BOD indicates low DO content of water. Since BOD is limited to biodegradable materials only. Therefore, it is not a reliable method of measuring pollution in water.

Chemical Oxygen Demand (COD):

COD is a slightly better mode used to measure pollution load in water. COD measures the amount of oxygen that will be consumed by the chemical breakdown, or oxidation (degeneration) of organic pollutants in water. The measurement of COD is also expressed in milligrams per liter under a specific oxidizing agent, temperature and time and can be completed in hours. This measurement looks for the oxygen consumed by a specific chemical oxidation process, and is not a substitute for BOD, or DO. It also is an indicator of the amount of organic pollution in a water sample. The COD is less specific than BOD as it measures the oxygen consumption for any pollutant that can be chemically oxidized, versus BOD which is only that portion which is biodegradable.
Invasive species Invasive plant species water hyacinth aquatic weed, also called ‘Terror of Bengal’ destroy micro environment to their advantage by producing allelochemicals which cause the destruction of native species and local biodiversity.


Agricultural Pollution:

  • Around the world, agriculture is the leading cause of water degradation.
  • Agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes. It’s also a major contributor of contamination to estuaries and groundwater.
  • Every time it rains, fertilizers, pesticides, and animal waste from farms and livestock operations wash nutrients and pathogens—such bacteria and viruses—into our waterways.
  • Nutrient pollution, caused by excess nitrogen and phosphorus in water or air, can cause algal blooms, a toxic soup of blue-green algae that can be harmful to people and wildlife.


Thermal Pollution:

Fig. Effect of thermal pollution on dissolved oxygen in water

  • The main sources of thermal pollution are the thermal and nuclear power plants.
  • Power plants – thermal and nuclear, chemical and other industries use a lot of water for cooling purposes, and the used hot water is discharged into rivers, streams or oceans.
  • Discharge of hot water may increase the temperature of the receiving water by 10 to 15 °C above the ambient water temperature. This is thermal pollution.
  • Increase in water temperature decreases dissolved oxygen in the water.
  • One of the best methods of reducing thermal pollution is to store the hot water in cooling ponds, allow the water to cool before releasing into any receiving water body.

Dead Zones

  • When these dense algal blooms eventually die, microbial decomposition severely depletes dissolved oxygen, creating a hypoxic or anoxic ‘dead zone’ lacking sufficient oxygen to support most organisms.
  • Dead zones are found both in freshwater lakes and Oceans.


Fish Kills

  • It is the sudden and unexpected death of a number of fish or other aquatic animals such as crabs or prawns over a short period of time and often within a particular area in the wild.
  • Most fish kills occur as a result of fluctuations in the natural environment with the most common cause being algal blooms and resulting water quality issues such as low oxygen or production of toxins.


Underground water pollution:


  • Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use.
  • Materials from the land’s surface can move through the soil and end up in the groundwater. For example, pesticides and fertilizers can find their way into groundwater supplies over time.
  • Road salt, toxic substances from mining sites, and used motor oil also may seep into groundwater.
  • In addition, it is possible for untreated waste from septic tanks and toxic chemicals from underground storage tanks and leaky landfills to contaminate groundwater.
  • Factors affecting ground water pollution- The extent of ground water pollution depends on the following factors : 1. Rainfall pattern 2. Depth of water table. 3. Distance from the source of contamination and 4. Soil properties such as texture , structure and filtration rate.


Causes for ground water Contamination

  • Discharge of toxic elements from industries and landfills and diffused sources of pollution like fertilisers and pesticides over the years has resulted in high levels of contamination of groundwater with the level of nitrates exceeding permissible limits in more than 50% districts in India.
  • Industries Manufacturing and other chemical industries require water for processing and cleaning purposes. This used water is recycled back to water sources without proper treatment. Also industrial waste is dumped in certain areas, the seepage of which results in groundwater contamination.
  • Agriculture- the fertilizers, pesticide and other chemicals used in growing plants contaminate groundwater.
  • Residential areas- These generate pollutants (microorganisms and organic compounds) for groundwater contamination
  • Mining- Mine drain discharge, oilfield spillage, sludge and process water also contaminate groundwater.
  • Coastal areas- Saltwater intrusion increases the salinity of groundwater in nearby areas.
  • Excessive extraction– It increases the concentration of minerals in the extracted areas, thus making it contaminated.


Ground water contamination in India:

Uranium Contamination:

  • Uranium is weakly radioactive and remains so because of its long physical half-life. The biological half-life (the average time it takes for the human body to eliminate half the amount in the body) for uranium is about 15 days.
  • The pollution of Groundwater by Uranium in India is one of the causes of worry. The World Health Organization (WHO) has set a provisional safe drinking water standard of 30 micrograms of uranium per litre for India, but many of the states have uranium much above the prescribed the limit.
  • According to the findings published in the journal “Environmental Science & Technology”, there is uranium contamination in groundwater in the aquifers across 16 states in India.
  • While the primary source of uranium is geogenic (naturally occurring), anthropogenic (human-caused) factors such as groundwater table decline and nitrate pollution may further enhance uranium mobilization.
  • Human activities, especially the over-exploitation of groundwater for agricultural irrigation, may contribute to the problem.
  • Exposure to uranium may lead to numerous adverse health impacts including bone toxicity and impaired renal function.


Arsenic Contamination:

  • Arsenic contamination in groundwater is one of the most crippling issues in the drinking water scenario of India. According to the latest report of the Central Ground Water Board (CGWB), 21 states across the country have pockets with arsenic levels higher than the BIS stipulated permissible limit of 0.01 milligram per litre (mg/l).
  • The states along the Ganga-Brahmaputra-Meghna (GBM) river basin — Uttar Pradesh, Bihar, Jharkhand, West Bengal and Assam — are the worst affected by this human-amplified geogenic occurrence.
  • In India, arsenic contamination was first officially confirmed in West Bengal in 1983.
  • Effects: Long-term exposure to arsenic in drinking water can cause cancer in the skin, lungs, bladder and kidney. It can also cause other skin changes such as thickening and pigmentation.
  • Increased risks of lung and bladder cancer and skin changes have been reported in people ingesting arsenic in drinking water at concentrations of 50 µg / litre, or even lower.
  • Recent research says arsenic contamination in groundwater has penetrated the food chain. It eventually causes photo-accumulation of arsenic in the food crops, especially in the leaves, can emanate from contaminated water sprayed on them.
  • Yet the focus remained on drinking water, and the affected regions became the primary stake-holder in the mitigation approach.

Nitrate and fluoride contamination:

  • The nitrate contamination and enrichment of fluoride in groundwater is a very common problem observed worldwide.
  • Nitrate contamination in groundwater occurs due to leaching of nitrate from agriculture lands, sewage effluent or fertilizer sink.
  • India is also suffering from nitrate contamination and fluoride enrichment problems.
  • According to UNICEF, India possesses 1% of total fluoride deposits present in the earth’s crust and its 17 states are endemic in fluorosis. Fluoride is necessary for teeth up to 1.50 mg/L. High concentration of fluoride in groundwater has been reported in central-western India and this enrichment occurs through geogenic sources.


Government Efforts to control the Ground Water Pollution

  • “A Master Plan for Artificial Recharge of Groundwater” has been developed by the Central Ground Water Board (CGWB) in 2013.
  • According to this plan, over 85 billion cubic metres will be recharged in rural and urban areas in a phased manner by 2023.
  • Legislations and programmes to protect groundwater : Water (Prevention and Control of Pollution) Act, 1974; Environmental Protection Act, 1986; the creation of Arsenic task force in West Bengal in 2005 and the launch of Salinity Ingress Prevention Scheme in Gujarat in 2008.
  • Atal bhujal Yojna, a central sector scheme to improve groundwater management and restore the health of country’s acquifers.
  • National Project on Aquifer Management (2016): The project proposes to cover 1.4 million sq km under aquifer mapping between 2017 and 2022.
  • National Water Policy 2012 which proposes a framework for creation of a system of laws and institutions and for a plan of action with a unified national perspective.
  • National Aquifer Mapping and Management Programme: It was initiated as a part of the Ground Water Management and Regulation scheme to delineate and characterize the aquifers to develop plans for ground water management.
  • Atal Jal Yojana: It aims to conserve groundwater in seven states facing the biggest declines in aquifer levels mainly due to over-extraction for water-intensive crops. These are Maharashtra, Haryana, Karnataka, Rajasthan, Madhya Pradesh, Uttar Pradesh and Gujarat.
  • Paani Bacho, Paise Kamao” (save water, earn money) scheme: It was launched by Punjab State Power Corporation Limited (PSPCL) to provide direct benefit transfer for electricity to agricultural consumers. Farmers get Rs 4 as direct benefit for each unit of electricity saved.



  • Which of the following can be found as pollutants in the drinking water in some parts of India?
  1. Arsenic
  2. Sorbitol
  3. Fluoride
  4. Formaldehyde
  5. Uranium

Select the correct answer using the codes given below.

  1. 1 and 3 only
  2. 2, 4 and 5 only
  3. 1, 3 and 5 only
  4. 1, 2, 3, 4 and 5

Answer: C


Marine pollution:
  • As per UNEP Report 2015, India dumped 0.6 tons of plastic waste into oceans annually and ranked 12th among the top 20 countries responsible for marine pollution.
  • The sewerage and garbage of coastal cities are also dumped into the sea.
  • The other sources of oceanic pollution are navigational discharge of oil, grease, detergents, sewage, garbage and radioactive wastes, offshore oil mining, oil spills.



  • On marine environment: Ingestion, suffocation and entanglement of hundreds of marine species such as seabirds, whales, fishes and turtles.
  • On food and health: Toxic contaminants accumulate on the surface of plastic materials which when ingested by marine organisms, enter their digestive systems, and overtime accumulate in the food web and leads to the transfer of contaminants between marine species and humans through consumption of seafood.
  • Carcinogenic chemicals present in the plastic materials interfere with the body’s endocrine system, causing developmental, reproductive, neurological, and immune disorders in both humans and wildlife.
  • On tourism: Plastic waste damages the aesthetic value of tourist destinations, leading to decreased tourism related incomes and major economic costs related to the cleaning and maintenance of the sites.



  • Long residual period of plastic: once the plastic waste enters into the ocean, there is very little we can do to collect it at a meaningful scale, particularly on the ocean floor several kilometres deep.
  • Lack of compliance with laws and conventions partly due to limited financial resources to enforce them.
  • The most important are the 1972 Convention on the Prevention of Marine Pollution by Dumping Wastes and Other Matter (or the London Convention), the 1996 Protocol to the London Convention (the London Protocol), and the 1978 Protocol to the International Convention for the Prevention of Pollution from Ships (MARPOL).
  • Structural flaws: Under linear plastic system, 95 per cent of the aggregate value of plastic packaging is lost to the economy after a single use cycle and that many plastic products are placed in markets that lack the capacity to collect and treat them economically after use.
  • Globally, only 71 per cent of plastic produced is formally collected, and less than 15 per cent is actually recycled.
  • Lack of data: Consistent definitions and conventions for plastic waste data and metrics are lacking, and there is insufficient transparency regarding the plastic being placed on the global market (type, chemical additives, etc.), trade flows, waste production, consumption, and post-use patterns.


Oil Spills:

  • Contamination of seawater due to an oil pour, as a result of an accident or human error, is termed an oil spill.
  • Oil is among the most important energy sources in the world and because of its uneven distribution, it is transported by ships across the oceans and by pipelines across the lands.
  • This has resulted in several accidents in the past while transferring the oil to vessels, during transportation, breaking of pipelines, as well as while drilling in the earth’s crust.




  • Recently, Russia declared a state of emergency in its Krasnoyarsk Region after a power plant fuel leaked causing 20,000 tonnes of diesel oil to escape into the Ambarnaya River.


  • Recently, a Japanese ship named M V Wakashio struck a coral reef resulting in an oil spill of over 1,000 tonnes into the Indian Ocean.

Chennai oil spill in 2017:

  • On 28 January 2017 two ships collided off Kamarajar Port Limited’s (KPL) harbour and resulted in a major oil spill disaster. The Chennai Oil Spill resulted in irreversible environmental damage.


Effects of oil spills:

On Marine life:

  • The immediate impact of an oil slick is the mass death of fish and turtles and of birds because they cannot fly with wings coated by heavy oil.
  • It reduces the amount of light and oxygen passing into the water. This suffocates marine life or causes it to go into a state of “heat coma“.
  • The oil destabilises the entire marine food chain, beginning with plankton, microscopic organisms that live in ocean depths, being deprived of the sunlight they need to make food.
  • Toxic chemicals leached from the oil and some of the oil itself sink to the seabed, damaging coral reefs and endangering the fish.

On human beings:

  • Tourism industry is greatly affected by oil spills and oil pollution. Due to increasing oil pollution on beaches and shorelines, recreational activities of tourists like boating, swimming, diving, adventure sports are taking a back seat.
  • The shore lines and sandy beaches in coastal areas may also be an indirect victim of oil water pollution.


Methods to clean the oil spill:

  • Containment Booms: Floating barriers, called booms are used to restrict the spread of oil and to allow for its recovery, removal, or dispersal.
  • Skimmers: They are devices used for physically separating spilled oil from the water’s surface.
  • Sorbents: Various sorbents (e.g., straw, volcanic ash, and shavings of polyester-derived plastic) that absorb the oil from the water are used.
  • Dispersing agents: These are chemicals that contain surfactants, or compounds that act to break liquid substances such as oil into small droplets. They accelerate its natural dispersion into the sea.
  • Biological agents: Nutrients, enzymes, or microorganisms such as Alcanivorax bacteria or Methylocella silvestris that increase the rate at which natural biodegradation of oil occurs are added.


Regulation of Marine pollution in India

  • India is a signatory to MARPOL (International Convention on Prevention of Marine Pollution).
  • Indian policy is restricted only to the banning of single use plastic. Prevention of Marine Pollution is dealt with by Merchant Shipping Rules, 2009 (under the Merchant Shipping Act, 1958), Environment (Protection) Act 1986, Air (Prevention and control of pollution) Act 1981 and rules made under CPCB.
  • Automated Ocean Pollution Observation System: Indian National Centre for Ocean Information Services (INCOIS) has established the system in 2018 to keep a tab on ocean pollution levels and offer insights on how the marine system is changing.
  • Algal Bloom Information Service (ABIS): INCOIS has developed a service for “Detection and Monitoring of Bloom in the Indian Seas”.
  • Periodic surveys of Indian flag vessels to ensure compliance to the above rules. Foreign vessels are likewise inspected under Port State Inspection regime and heavy penalty is levied in case of noncompliance.
  • Steering committee with stakeholders from all the concerned Ministers and Departments has been constituted by the Ministry of Environment, Forests and Climate Change. The Committee will coordinate the activities, examine proposals and provide guidance to Ministries, State and UT Governments with regard to research, policy planning, deployment of technology, public outreach and education and other facets of the problem of marine plastic littering.
  • The government has announced a number of steps to phase out single-use plastics with the eventual goal of stopping all usage to reduce the country’s plastic footprint under the Plastic Waste Management (Amendment) Rules 2018.
  • BIS has come out with an Indian standard according to which plastic microbeads of diameter 5 mm or less, that are insoluble in water, and solid plastic particles used to exfoliate or cleanse in personal care products are banned.
  • State level practice: Kerala’s Suchitwa Mission, under which fishermen are engaged in finding and collecting plastic from the oceans.


National Oil Spill Disaster Contingency Plan:

  • India promulgated National oil spill Disaster contingency plan (NOS-DCP) in the year 1996. Coast guard was designated as central coordination authority.


The objectives of the plan are:

  • To develop appropriate and effective systems for the detection and reporting of spillage of oil.
  • To ensure prompt response to prevent, control, and combat oil pollution.
  • To ensure that adequate protection is provided to the public health and welfare, and the marine environment.
  • To ensure that appropriate response techniques are employed to prevent, control, and combat oil pollution, and dispose off recovered material in an environmentally accepted manner.

To ensure that complete and accurate records are maintained of all expenditure to facilitate cost of recovery.


Effects of Water Pollution:

Effects on Human beings:

  • Waterborne pathogens, in the form of disease-causing bacteria and viruses from human and animal waste, are a major cause of illness from contaminated drinking water.
  • Diseases spread by unsafe water include cholera, giardia, and typhoid. Even in wealthy nations, accidental or illegal releases from sewage treatment facilities, as well as runoff from farms and urban areas, contribute harmful pathogens to waterways.
  • Heavy metals such as arsenic and mercury to pesticides and nitrate fertilizers—are getting into our water supplies. Once they’re ingested, these toxins can cause a host of health issues, from cancer to hormone disruption to altered brain function. Children and pregnant women are particularly at risk.
  • The compounds of lead cause anaemia, headache, loss of muscle power.
  • Water contaminated with cadmium can cause itai itai disease.
  • According to WHO, nitrate in drinking water can cause methaemoglobinaemia or blue baby syndrome or the decreased ability of blood to carry vital oxygen around the body.
  • Excess fluoride in drinking water causes neuromuscular disorders, gastrointestinal problems, teeth deformity, hardening of bones and stiff and painful joints (skeletal fluorosis). Pain in bones and joint and outward bending of legs from the knees is called Knock-Knee syndrome.
  • Fluorosis is a common problem in several states of the country due to the intake of high fluoride content water.

Effects on environment:

  • In order to thrive, healthy ecosystems rely on a complex web of animals, plants, bacteria, and fungi—all of which interact, directly or indirectly, with each other. Harm to any of these organisms can create a chain effect, imperiling entire aquatic environments.
  • When water pollution causes an algal bloom in a lake or marine environment, the proliferation of newly introduced nutrients stimulates plant and algae growth, which in turn reduces oxygen levels in the water. This dearth of oxygen, known as eutrophication, suffocates plants and animals and can create “dead zones,” where waters are essentially devoid of life.
  • In certain cases, these harmful algal blooms can also produce neurotoxins that affect wildlife, from whales to sea turtles.
  • Marine ecosystems are also threatened by marine debris, which can strangle, suffocate, and starve animals. Much of this solid debris, such as plastic bags and soda cans, gets swept into sewers and storm drains and eventually out to sea, turning our oceans into trash soup.
  • Meanwhile, ocean acidification is making it tougher for shellfish and coral to survive. Though they absorb about a quarter of the carbon pollution created each year by burning fossil fuels, oceans are becoming more acidic. This process makes it harder for shellfish and other species to build shells and may impact the nervous systems of sharks, clownfish, and other marine


Government initiatives to control water pollution in India:

  • Water (Prevention and Control of Pollution) Act (1974): It established Pollution Control Boards at the Central and State levels and bestowed them with powers to prevent and control water pollution and to advise governments on matters pertaining to such pollution.
  • Namami Gange programme for effective abatement of pollution, conservation and rejuvenation of National River Ganga.
  • National Water Policy, 2012: One of its important provision includes conservation of river corridors and water bodies and ensuring that the industrial effluents, local cesspools, residues of fertilisers and chemicals etc. do not reach the water source.
  • In budget 2019-2020, Government unveiled vision for 2030 which includes clean rivers, with safe drinking water to all Indians, sustaining and nourishing life and efficient use of water in irrigation using micro-irrigation techniques.
  • To assess the efficacy of river cleaning programmes, the CPCB has been ordered by NGT to launch a nationwide programme on biodiversity monitoring and indexing of the rivers.


National River Conservation Plan (NRCP)

  • One of the important steps undertaken by the government to reduce river pollution is the National River Conservation Plan (NRCP), a national, top-down programme targeting the domestic pollution that goes into the surface water.
  • Launched in 1985, NRCP started its work with the Ganga Action Plan.

National Water Quality Monitoring Programme:

  • The Central Pollution Control Board (CPCB) in association with State Pollution Control Boards (SPCBs) / Pollution Control Committees (PPCs) is monitoring the quality of water bodies at 2500 locations across the country under National Water Quality Monitoring Programme (NWQMP) which indicate that organic pollution is the predominant cause of water pollution. Based on the magnitude of organic pollution, CPCB in 2008 identified 150 polluted river stretches which increased to 302 in 2015.
  • Implementation of National Lake Conservation Plan (NLCP) and National Wetland Conservation Programme (NWCP) for conservation and management of identified lakes and wetlands in the country which have been merged in February, 2013 into an integrated scheme of National Plan for Conservation of Aquatic Eco-systems (NPCA) to undertake various conservation activities including interception, diversion and treatment of waste water, pollution abatement, lake beautification, biodiversity conservation, education and awareness creation, community participation etc.


Industrial water treatment:

  • Before raw sewage can be safely released back into the environment, it needs to be treated correctly in a water treatment plant. In a water treatment plant, sewage goes through a number of chambers and chemical processes to reduce the amount and toxicity of the waste.



  • Denitrification is an ecological approach that can be used to prevent the leaching of nitrates in soil, this in turn stops any ground water from being contaminated with nutrients.


Septic tanks and sewage treatment:

  • Septic tanks treat sewage at the place where it is located, rather than transporting the waste through a treatment plant or sewage system. Septic tanks are usually used to treat sewage from an individual building.


Ozone wastewater treatment:

  • Ozone wastewater treatment is a method that is increasing in popularity. An ozone generator is used to break down pollutants in the water source.
  • The generators convert oxygen into ozone by using ultraviolet radiation or by an electric discharge field.



  • Either chlorine gas or certain chlorine compounds are added to water to complete the purification process. Extremely small amounts of chlorine, about 0.3 parts per million, are usually adequate to kill almost all the microorganisms (certainly all the pathogens) remaining in the water. At the same time, chlorine neutralizes many odors and tastes in the water.



  • Phytoremediation is a bioremediation process that uses various types of plants to remove, transfer, stabilize, and/or destroy contaminants in the soil and groundwater.


Current Topics in News


  • The Union Minister for Finance while presenting the budget announced Jal Jeevan Mission to ensure HarGharJal (piped water supply) to all rural households by 2024.


  • This Mission will focus on integrated demand and supply side management of water at the local level, including creation of local infrastructure for source sustainability like rainwater harvesting, groundwater recharge and management of household wastewater for reuse in agriculture.
    The Mission will converge with other Central and State Government Schemes to achieve its objectives of sustainable water supply management across the country.


  • NITI Aayogin association with Ministry of JAL Shakti and Ministry of Rural Development released Composite Water Management Index 2.0
  • NITI Aayogfirst launched and conceptualized the Composite Water Management Index in 2018 as a tool to instil a sense of cooperative and competitive federalism among the states.
  • It provided actionable guidanceto States on where they were doing well absolutely and relatively and what they needed to focus on to secure their water.
  • The index comprises 9 themes:


Radioactive Pollution


  • The radioactive pollution is defined as the physical pollution of living organisms and their environment as a result of release of radioactive substances into the environment during nuclear explosions and testing of nuclear weapons, nuclear weapon production and decommissioning, mining of radioactive ores, handling and disposal of radioactive waste, and accidents at nuclear power plants.
  • Radioactivity is a phenomenon of spontaneous emission of particles such as protons (alpha particles), electrons (beta particles), and gamma rays (short wave electromagnetic radiation) due to the disintegration of atomic nuclei of some elements.
  • It’s generated by uranium mining, nuclear power plants, and the production and testing of military weapons, as well as by universities and hospitals that use radioactive materials for research and medicine.
  • Radioactive waste can persist in the environment for thousands of years, making disposal a major challenge. Accidentally released or improperly disposed of contaminants threaten groundwater, surface water, and marine resources.


Sources of Radioactive Radiations

  • Natural Sources: They include cosmic rays from space and terrestrial radiations from radio-nuclides present in earth’s crust such as radium-224, uranium-238, thorium-232, potassium-40, carbon-14 etc.
  • Man-made Sources:
  • Nuclear power plants
  • Nuclear weapons
  • Transportation of nuclear material
  • Disposal of nuclear waste
  • Uranium mining
  • Radiation therapy


Types of Radiation:

  • Non-ionizing radiation: It affects only those components which absorb them and have low penetrability.
  • Ionizing radiation: It has high penetrability and causes the breakage of macro-molecules.



  • Effects of ionizing radiation:
  • They include x-rays, gamma rays, cosmic rays and other atomic radiations caused by the emissions of radioactive elements.
  • Ionizing radiation has high penetration power and can cause a breakage of macro-molecules
  • The molecular damage may produce short range (immediate) and long range (delayed) effects.
  • Short range effects include burns, impaired metabolism, dead tissues and death of several organisms.
  • Long range effects include mutations leading to increased incidence of tumours and cancers, shortening of life-span and developmental The mutated gene can persist in living organisms and may affect their progeny.

Effects of non-ionizing radiation:

  • They include short-wave radiations such as the ultraviolet rays which form a part of solar radiation.
  • They have a low penetrating power and affect only the cells and molecules which absorb them.
  • They can damage eyes which may occur due to reflection from coastal sand, snow (known as snow blindness) or by directly looking at the sun during an eclipse.
  • They can injure the cells of skin and blood capillaries producing blisters and reddening. This condition is known as sunburn.




  • Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
  • In the case of contaminants which occur naturally in soil, even when their levels are not high enough to pose a risk, soil pollution is still said to occur if the levels of the contaminants in soil exceed the levels that should naturally be present.
  • Soil contamination or soil pollution can occur either because of human activities or because of natural processes. However, mostly it is due to human activities.
  • The soil contamination can occur due to the presence of chemicals such as pesticides, herbicides, ammonia, petroleum hydrocarbons, lead, nitrate, mercury, naphthalene, etc in an excess amount.


Causes of Soil pollution:

  • There are two main causes through which soil pollution is generated: anthropogenic (man-made) causes and natural causes.

Man-Made Pollutants:

  • Anthropogenic (man-made) soil pollution originates in several types of processes, some deliberate (industrial) and some accidental. Human-caused soil pollution can work in conjunction with natural processes to increase the toxic contamination levels in the soil.
  • Accidental spills and leaks during storage, transport or use of chemicals (e.g. leaks and spills of gasoline and diesel at gas stations);
  • Foundry activities and manufacturing processes that involve furnaces or other processes resulting in the possible dispersion of contaminants in the environment;
  • Mining activities involving the crushing and processing of raw materials, for instance, heavy metals, emitting toxic substances;
  • Construction activities;
  • Agricultural activities involving the diffusion of herbicides, pesticides and/or insecticides and fertilizers;
  • Transportation activities, releasing toxic vehicle emissions
  • Chemical waste dumping, whether accidental or deliberate – such as illegal dumping;
  • The storage of waste in landfills, as the waste products may leak into groundwater or generate polluted vapors
  • Cracked paint chips falling from building walls, especially lead-based paint.


Natural Pollutants:

  • Natural accumulation of compounds in soil due to imbalances between atmospheric deposition and leaking away with precipitation water (e.g., concentration and accumulation of perchlorate in soils in arid environments)
  • Natural production in soil under certain environmental conditions (e.g., natural formation of perchlorate in soil in the presence of a chlorine source, metallic object and using the energy generated by a thunderstorm)
  • Leaks from sewer lines into subsurface (e.g., adding chlorine which could generate trihalomethanes such as chloroform).


Effects of soil pollution:


  • Reduced soil fertility
  • Reduced nitrogen fixation
  • Increased erodibility
  • Larger loss of soil and nutrients
  • Deposition of silt in tanks and reservoirs
  • Reduced crop yield
  • Imbalance in soil fauna and flora



  • Dangerous chemicals entering underground water
  • Ecological imbalance
  • Release of pollutant gases
  • Release of radioactive rays causing health problems
  • Increased salinity
  • Reduced vegetation



  • Clogging of drains
  • Inundation of areas
  • Public health problems
  • Pollution of drinking water sources
  • Foul smell and release of gases
  • Waste management problems



  • Soil becomes unavailable to grow food.
  • If contaminated soil is used to grow food, the land will usually produce lower yields.
  • Can cause even more harm because a lack of plants on the soil will cause more erosion.
  • The pollutants will change the makeup of the soil and the types of microorganisms that will live in it.
  • Thus it’s possible for soil pollution to change whole ecosystems.


Measures to control soil pollution:

  • Soil erosion can be controlled by a variety of forestry and farm practices. For example:
  • Planting trees on barren slopes.
  • Contour cultivation and strip cropping may be practiced instead of shifting cultivation
  • Terracing and building diversion channels may be undertaken.
  • Reducing deforestation and substituting chemical manures by animal wastes also helps arrest soil erosion in the long term.
  • Proper dumping of unwanted materials:
  • Excess wastes by man and animals pose a disposal problem. Open dumping is the most commonly practiced technique.
  • Nowadays, controlled tipping is followed for solid waste disposal. The surface so obtained is used for housing or sports field.
  • Production of natural fertilizers:
  • Bio-pesticides should be used in place of toxic chemical pesticides. Organic fertilizers should be used in place of synthesized chemical fertilizers.
  • Ex: Organic wastes in animal dung may be used to prepare compost manure instead of throwing them wastefully and polluting the soil.
  • Recycling and Reuse of wastes:
  • To minimize soil pollution, the wastes such as paper, plastics, metals, glasses, organics, petroleum products and industrial effluents etc should be recycled and reused. Ex: Industrial wastes should be properly treated at source. Integrated waste treatment methods should be adopted.
  • Ban on Toxic chemicals:
  • Ban should be imposed on chemicals and pesticides like DDT, BHC, etc which are fatal to plants and animals. Nuclear explosions and improper disposal of radioactive wastes should be banned.


Land Degradation:
  • Land is a vital resource to humankind, like air and water.
  • Land degradation—the deterioration or loss of the productive capacity of the soils for present and future—is a global challenge that affects everyone through food insecurity, higher food prices, climate change, environmental hazards, and the loss of biodiversity and ecosystem services.
  • Land degradation is caused by multiple forces, including extreme weather conditions particularly drought, and human activities that pollute or degrade the quality of soils and land utility negatively affecting food production, livelihoods, and the production and provision of other ecosystem goods and services.
  • India faces a severe problem of land degradation. About 32% of the Total Geographical Area of the country is undergoing the process of desertification/land degradation.
  • A 2016 report by the ISRO found that about 29% of India’s land (in 2011-13) was degraded, this being a 0.57% increase from 2003-05.
  • At the COP-13, India had committed to restoring 13 million hectares of degraded and deforested land by the year 2020 and an additional 8 million hectares by 2030.
  • Land degradation is happening at an alarming pace, contributing to a dramatic decline in the productivity of croplands and rangelands worldwide.


Threats to land integrity:

  • Land degradation has accelerated during the 20th century due to increasing and combined pressures of agricultural and livestock production (over-cultivation, overgrazing, forest conversion), urbanization, deforestation, and extreme weather events such as droughts and coastal surges which salinate land.

  1. Desertification:
  • Desertification is a type of land degradation in which a relatively dry land region becomes increasingly arid.
  • Desertification leads to losing bodies of water as well as vegetation and wildlife.
  • Out of the total 328.72 MHA of India’s total geographical area, 4 million hectares (MHA) are under desertification.
  • In the past 10 years, 26 of 29 Indian states have reported an increase in the area undergoing desertification. Around 40 to 70 per cent of the land has undergone desertification in eight states, Rajasthan, Delhi, Goa, Maharashtra, Jharkhand, Nagaland, Tripura and Himachal Pradesh.
  • The highest increase in land degradation is observed in Lunglei district of Mizoram (5.81 percent increase from 2003-05 to 2011-13).
  • Loss of soil cover, mainly due to rainfall and surface runoff, is one of the biggest reasons for desertification. It is responsible for 10.98 percent of desertification in the country.
  • Other main reasons include, wind erosion (5.55 per cent), human-made or settlements (0.69 per cent), vegetation degradation (8.91 per cent) and salinity (1.12 per cent).
  • India was the signatory to United Nations Convention to Combat Desertification in Paris on June 17, 1994. The main agenda of this convention is to achieve land degradation neutrality by 2030.
  • But despite all this, India has witnessed an increase of 1.87 million hectares undergoing the process of desertification between 2003-05 and 2011-13.
  • Land degradation and desertification can affect human health through complex pathways. As land is degraded and in some places deserts expand, food production is reduced, water sources dry up and populations are pressured to move to more hospitable areas. The potential impacts of desertification on health include:
  • higher threats of malnutrition from reduced food and water supplies;
  • more water- and food-borne diseases that result from poor hygiene and a lack of clean water;
  • respiratory diseases caused by atmospheric dust from wind erosion and other air pollutants;
  • the spread of infectious diseases as populations migrate.

  1. Deforestation:
  • Deforestation is the permanent removal of trees to make room for something besides forest. This can include clearing the land for agriculture or grazing, or using the timber for fuel, construction or manufacturing.
  • Forests cover more than 30% of the Earth’s land surface, according to the World Wildlife Fund.
  • Multiple factors, either of human or natural origin, cause deforestation. Natural factors include natural forest fires or parasite-caused diseases which can result in deforestation. Nevertheless, human activities are among the main causes of global deforestation.
  • According to the Food and Agriculture Organization (FAO), the expansion of agriculture caused nearly 80% of global deforestation, with the construction of infrastructures such as roads or dams, together with mining activities and urbanization, making up the remaining causes of deforestation.
  • WWF has been working to protect forests for more than 50 years. WWF works with governments, companies, communities and other stakeholders to promote certification for responsible forest management practices, combat illegal logging, reform trade policies, protect forested areas, and more.


  1. Overgrazing:
  • Overgrazing occurs when the consumption of vegetation biomass by livestock and other grazers (e.g., wildlife) exceeds the vegetation’s ability to recover in a timely fashion, thus exposing the soil and reducing the vegetation’s productive capacity.
  • Overgrazing reduces the usefulness, biodiversity, and productivity of the land and is one cause of desertification and erosion. It’s also considered to be a cause of the spread of invasive species of non-native plants and weeds.


Causes of Overgrazing:

  • Lack of Proper Animal/Wildlife Management
  • Socio-economic Conditions of the Farmer
  • Drought or Decline in Precipitation
  • Improper Land Use
  • Overstocking of land with more animals
  • Poor Irrigation Methods in Arid and Semi-arid Areas


Effects of overgrazing:

  • Soil erosion
  • Land Degradation
  • Loss of Valuable Species
  • Food Shortage/Famine
  • Death of People and Livestock
  • Deforestation
  • Global warming


Solutions to Overgrazing:

  • Proper Management of Animals
  • Land Use Management
  • Sustainable Pasture Practices
  • Shifting to Other Ways of Feeding Livestock


  1. Soil Salinity:
  • Soil salinity is a measure of the concentration of all the soluble salts in soil water.

Factors affecting soil salinity:

Several factors affect the amount and composition of salts in soils:

  • Irrigation water quality – The total amount of dissolved salts in the irrigation water, and their composition, influence the soil salinity. Therefore, various parameters, such as source water EC (electrical conductivity) and its minerals content should be tested.
  • Fertilizers applied – The type and amount of fertilizers applied to soil, affect its salinity. Some fertilizers contain high levels of potentially harmful salts, such as potassium chloride or ammonium sulphate. Overuse and misuse of fertilizers leads to salinity buildup, and should be avoided.
  • Irrigation regimen and type of irrigation system – The higher the water quantity applied, the closer soil salinity is to irrigation water salts concentration. When the soil dries, the concentration of salts in the soil solution is increased.
  • Field’s characteristics and agricultural history – A poorly drained soil might reach salinity level that is harmful to the plants and to the whole crop. A soil that was not flushed after a previous growing cycle might contain high level of accumulated salts.


  1. Soil Erosion:
  • Soil erosion is a naturally occurring process that affects all landforms. In agriculture, soil erosion refers to the wearing-away of a field’s topsoil by the natural physical forces of water and wind or through forces associated with farming activities such as tillage.
  • Erosion, whether it is by water, wind or tillage, involves three distinct actions – soil detachment, movement and deposition.
  • Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere “on-site” where it builds up over time or is carried “off-site” where it fills in drainage channels.
  • Soil erosion reduces cropland productivity and contributes to the pollution of adjacent watercourses, wetlands and lakes.
  • Soil erosion can be a slow process that continues relatively unnoticed or can occur at an alarming rate, causing serious loss of topsoil. Soil compaction, low organic matter, loss of soil structure, poor internal drainage, salinisation and soil acidity problems are other serious soil degradation conditions that can accelerate the soil erosion process.


Causes of soil erosion:

  • Farming: Agriculture is probably the most significant activity that accelerates soil erosion.
  • Grazing: Grazing animals wander over large areas of pasture or natural grasslands eating grasses and shrubs. Grazers expose soil by removing the plant cover for an area.
  • Logging and Mining: Surface mining disturbs the land and leaves the soil vulnerable to erosion. Logging removes trees that protect the ground from soil erosion. The tree roots hold the soil together and the tree canopy protects the soil from hard falling rain. Logging results in the loss of leaf litter, or dead leaves, bark, and branches on the forest floor. Leaf litter plays an important role in protecting forest soils from erosion.
  • Construction: Constructing buildings and roads churns up the ground and exposes soil to erosion. In some locations, native landscapes, such as forest and grassland, are cleared, exposing the surface to erosion (in some locations the land that will be built on is farmland).
  • Recreational Activities: Recreational activities may accelerate soil erosion. Off-road vehicles disturb the landscape and the area eventually develops bare spots where no plants can grow.


Why preventing and stopping soil erosion is so important?

According to the UN’s Food and Agriculture Organization (FAO), some key roles of soils are:


  • Soils help fight and adapt to climate change by collecting and storing carbon and reducing greenhouse gas emissions (GHG) in the atmosphere;
  • Resilient soils allow for water infiltration through the soil, filtering pollutants and preventing them from leaching into the groundwater;
  • Soils capture and store water for crops, whereas degraded soils retain less water;
  • Reducing surface evaporation and increasing water use efficiency and productivity are also processes enhanced by healthy soils;
  • Soils provide fiber, fuel, medicinal products, and other ecosystem services;
  • Soils are home to 1/4 of biodiversity and they are a key part of the global cycles that make all life possible.


Impacts of land degradation:

  • Pollution and clogging of waterways from land degradation:
  • Most of the soil eroded from the land together with the chemical fertilisers and pesticides utilised in agricultural fields are discharged into waterways and streams.
  • With time, the sedimentation process can clog waterways, resulting in water scarcity. The agricultural fertilisers and pesticides also damage marine and freshwater ecosystems and the limits the domestic uses of the water for the populations that depend on them for survival.
  • Increased flooding risk from land degradation:
  • Land degradation leads to the removal of soil composition which plays a role in water retention and absorptions.
  • For this reason, the transformed land is unable to soak up water, making flooding more frequent.
  • In other words, soil degradation takes away the soil’s natural capability of holding water thus contributing to more and more cases of flooding.
  • Loss of arable land from soil depletion:
  • Because soil degradation contributes to land degradation, it also means that it creates a significant loss of arable land. The literal translation of arable land is “able to be ploughed”.
  • About 40% of the world’s agricultural land is lost on the account of soil quality depreciation caused by agro-chemicals and soil erosion.
  • Most of the crop production practices result in the topsoil loss and the damage of soil’s natural composition that make agriculture possible.
  • Drought and aridity caused by land degradation:
  • Drought and aridity are problems highly influenced and amplified by soil degradation. As much as it’s a concern associated with natural environments in arid and semi-arid areas, the United Nations recognizes the fact that drought and aridity are man-made (anthropogenic) factors especially as an outcome of soil degradation.
  • Hence, the contributing factors to soil quality decline such as overgrazing, poor tillage methods, and deforestation are also the leading causes of desertification characterized by droughts and arid conditions. In the same context, soil degradation may also bring about loss of biodiversity.
  • Soil quality reduction from land degradation:
  • Soil quality decline is one of the main causes of land degradation and is considered to be responsible for 84% of the ever diminishing acreage. Year after year, huge acres of land lost due to soil erosion, contamination and pollution. About 40% of the world’s agricultural land is severely diminished in quality because of erosion and the use of chemical fertilisers, which prevent land from regenerating.
  • The decline in soil quality as a result of agricultural chemical fertilisers also further leads to water and land pollution thereby lowering the land’s worth on earth.
Land conservation initiatives



14th Conference of Parties (CoP14) of the UNCCD was convened in India for the first time.

Outcomes :

  • Adoption of Delhi Declaration: Commitment for a range of issues, including gender and health, ecosystem restoration, taking action on climate change, private sector engagement, Peace Forest Initiative and recovery of five million hectares of degraded land in India.
  • Drought Toolbox: It is a sort of knowledge bank which contains tools that strengthen the ability of countries to anticipate and prepare for drought effectively and mitigate their impacts.
  • International coalition for action on Sand and Dust storms (SDS): SDS source base map will be developed with the goal of improving monitoring and response to these storms.
  • Sustainability, Stability and Security (3S) initiative: Launched by 14 African countries to address migration driven by land degradation and aims at restoring land and creating green jobs for migrants and vulnerable groups.
  • Youth Caucus on Desertification and Land convened its first official gathering in conjunction with the UNCCD COP14 to bring together youth advocates from different parts of the world, to build their capacity, share knowledge, build networks and to engage them meaningfully in the UNCCD processes.

United Nations Convention to Combat Desertification (UNCCD)

  • It is one of the three Conventions that came out of the historic 1992 Earth Summit in Rio de Janeiro including UN Framework Convention on Climate Change and Convention on Biological Diversity.
  • It was established in 1994, it is sole legally binding international agreement that links environment & development to sustainable land management.
  • The convention obliges national governments to take measures to tackle the issue of desertification and focuses on having a bottom-up approach to achieve its goals, by involving the local communities.
  • The 2018 – 2030 Strategic Framework of convention is a comprehensive international commitment to attain Land Degradation Neutrality (LDN) aiming for:
  • Restoration of productivity of degraded land.
  • Enhancing the livelihoods of people dependent on them.
  • Mitigating the impact of droughts on vulnerable populations.
  • India ratified the Convention to Combat Desertification in 1996 and Ministry of Environment, Forest and Climate Change is the nodal ministry for the convention.
  • India is also a part of the Bonn Challenge, which is an international effort to bring 150 million hectares of the world’s degraded and deforested land into restoration by 2020, and 350 million hectares by 2030.


Land Degradation Neutrality (LDN)

  • UNCCD defines LDN as a state whereby the amount and quality of land resources which is necessary to support ecosystem functions and enhance food security, remains stable or increases within specified temporal and spatial scales and ecosystems.
  • It is a unique approach that counterbalances the expected loss of productive land with the recovery of degraded areas.
  • Land cover and land cover change, land productivity and soil organic carbon are the three indicators used by the pilot countries to set the land degradation baseline, identify potentially negative trends and formulate corrective measures.


Steps taken to achieve LDN

  • LDN Target Setting Programme: Under this, UNCCD is supporting interested countries in the national land degradation neutrality (LDN) target setting process, including the definition of national baselines, targets and associated measures to achieve LDN.
  • Creation of an LDN fund to invest in bankable projects on land rehabilitation and sustainable land management worldwide including sustainable agriculture, sustainable livestock management, agroforestry, etc.
  • Global Land Outlook by UNCCD demonstrates the central importance of land quality to human wellbeing, assesses current trends in land conversion, degradation and loss, identifies the driving factors and analyzes the impacts etc.
  • In India:
  • National Action Plan (NAP) to combat desertification was launched in 2001 for 20 years.
  • Desertification and Land Degradation Atlas (2016) of entire country was prepared by ISRO and 19 other partners using Indian remote sensing satellites data in GIS environment.
  • Schemes like Integrated Watershed Development Program, Per Drop More Crop, National Afforestation Program, National Green Mission, etc. have components to tackle Land degradation.


UPSC Previous Year Questions


  1. Causes of soil erosion and its control in India (2005)
  2. Examine the cause and the extent of ‘desertification’ in India and suggest remedial measures. (2012)


  1. Consider the following pairs: (2014)

Programme/ Project Ministry

1 Drought-Prone Area Programme: Ministry of Agriculture

  1. Desert Development Programme: Ministry of Environment and Forests
  2. National Watershed Development Project for Rainfed Areas: Ministry of Rural Development

Which of the above pairs is/are correctly matched?

(a) 1 and 2 only

(b) 3 only

(c) 1, 2 and 3

(d) None

Answer: (D)





  • Solid waste” means any garbage or refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility and other discarded material, resulting from industrial, commercial, mining, and agricultural operations, and from community activities.
  • It is important to note that the definition of solid waste is not limited to wastes that are physically solid. Many solid wastes are liquid, semi-solid, or contained gaseous material.


Types of Solid Waste:

It can be classified into different types depending on their source:

  • Municipal Solid Waste (MSW): It consists of household waste, construction and demolition debris (CnD), sanitation residue, and waste from streets, generated mainly from residential and commercial complexes.
  • As per the MoEF it includes commercial and residential waste generated in municipal or notified areas in either solid or semi-solid form excluding industrial hazardous wastes but including treated bio-medical wastes;
  • Industrial Solid Waste (ISW): In a majority of cases it is termed as hazardous waste as they may contain toxic substances, are corrosive, highly inflammable, or react when exposed to certain things e.g. gases.
  • Biomedical waste or hospital waste: It is usually infectious waste that may include waste like sharps, soiled waste, disposables, anatomical waste, cultures, discarded medicines, chemical wastes, etc., usually in the form of disposable syringes, swabs, bandages, body fluids, human excreta, etc. These can be a serious threat to human health if not managed in a scientific and discriminate manner.
  • Hazardous Waste: “Hazardous waste” means any waste which by reason of any of its physical, chemical, reactive, toxic, flammable, explosive or corrosive characteristics causes danger or is likely to cause danger to health or environment, whether alone or when in contact with other wastes or substances.



  • Bioremediation technologies utilize naturally occurring microorganisms, such as bacteria, fungi, and yeast, to degrade hazardous substances into non-toxic or less toxic substances.
  • There are several advantages of using bioremediation processes compared with other remediation technologies:

(1) Biologically-based remediation detoxifies hazardous substances instead of merely transferring contaminants from one environmental medium to another;

(2) Bioremediation is generally less disruptive to the environment than excavation-based processes; and

(3) The cost of treating a hazardous waste site using bioremediation technologies can be considerably lower than that for conventional treatment methods.

  • Bioremediation applications are categorized as either in situ or ex situ.
  • In situ applications treat contaminated soil or water in the location in which they are found.
  • Ex situ bioremediation requires excavation or pumping of contaminated soil or groundwater, respectively, before treatment is initiated.
  • In situ techniques are generally less expensive, generate less dust and debris, and release less contaminants than ex situ techniques because no excavation processes are required.
  • On the other hand, ex situ techniques are generally easier to control, faster, and able to treat a wider range of contaminants and soil types than in situ techniques.


Bioremediation related technologies

  • Bioventing – an in situ remediation technology that uses microorganisms to biodegrade organic constituents in the groundwater system.
  • Bioleaching – extraction of metals from their ores through the use of living organisms instead of using harmful chemical substances such as cyanide etc.,
  • Land farming– ex-situ waste treatment process that is performed in the upper soil zone or in biotreatment cells. Contaminated soils, sediments, or sludges are transported to the Landfarming site, incorporated into the soil surface and periodically turned over to aerate the mixture
  • Composting – Aerobic bacteria and fungi decompose the organic matter into compost used as fertilizer.
  • Bio-augmentation – the addition of Achaea or bacterial cultures required to speed up the rate of degradation of a contaminant.
  • Bio-stimulation – modification of the environment to stimulate existing bacteria capable of bioremediation.


Solid waste management:

  • Centralized method: This method involves collection of municipal waste from all over the local area and by means of landfilling, dump outside the city/nagar panchayat limit
  • This process looks at door-to-door collection of solid waste by waste pickers who hand over to the collection team who then discard the collected waste in the landfill.
  • The waste pickers are employees of the Municipal Corporation or Nagar Panchayat. The collection team is generally contracted out by a tendering process.
  • De-centralized method: This is a model seen in a few places like Suryapet in Andhra Pradesh and Bangalore in Karnataka.
  • The waste is collected ward-wise and is segregated at source into bio-degradable and non-biodegradable.
  • The biodegradable waste is composted at a nearby facility by different methods of aerobic and anerobic composting.
  • The non-biodegradable waste is further categorized into paper, plastic, metal and other waste and then further collected by recyclers for up-cycling or down-cycling of products.


Treatment methods for solid waste:

  • Thermal treatment: Incineration is the combustion of waste in the presence of oxygen, so that the waste is converted into carbon dioxide, water vapour and ash. Also labeled Waste to Energy (WtE) method, it is a means of recovering energy from the waste.
  • Pyrolysis and gasification: In this method, thermal processing is in complete absence of oxygen or with less amount of air.
  • Biological treatment methods: This involves using micro-organisms to decompose the biodegradable components of waste. The 2 types of processes:
  • Aerobic: This needs the presence of oxygen and includes windrow composting, aerated static pile composting & in-vessel composting, vermiculture
  • Anaerobic digestion: Takes place in the absence of oxygen.
  • Landfills and open dumping:
  • Sanitary landfills: It is the controlled disposal of waste on land in such a way that contact between waste and the environment is significantly reduced and the waste is concentrated in a well defined area.
  • Dumps are open areas where waste is dumped exposing it to natural elements, stray animals and birds. With the absence of any kind of monitoring and no leachate collection system, this leads to the contamination of both land and water resources.
  • 4 R principle: Waste reduction strategy
  • Reduce: reduce the use of plastics.
  • Reuse: buy rechargeable items rather than disposable ones.
  • Recycle: Segregate your waste for better disposal and purchase recycled/ green products.
  • Recovery or reclaim: Various mechanical, biological and caloric systems and technologies can convert, reprocess or break up waste into new materials or energy. This means turning waste into fuel for manufacturing processes or equipment designed to produce energy.


Solid Waste Management Rules, 2016:

  • The Union Ministry of Environment, Forests and Climate Change (MoEF&CC) has notified the new Solid Waste Management Rules (SWM), 2016. These will replace the Municipal Solid Wastes (Management and Handling) Rules, 2000, which have been in place for the past 16 years.
  • These rules are the sixth category of waste management rules brought out by the ministry, as it has earlier notified plastic, e-waste, biomedical, hazardous and construction and demolition waste management rules.
  • According to Union Minister of State for Environment, Forests and Climate Change, 62 million tonnes of waste is generated annually in the country at present, out of which 5.6 million tonnes is plastic waste, 0.17 million tonnes is biomedical waste, hazardous waste generation is 7.90 million tonnes per annum and 15 lakh tonnes is e-waste.


Highlights of SWM rules, 2016:

  • Segregation at source: The new rules have mandated the source segregation of waste in order to channelise the waste to wealth by recovery, reuse and recycle. Waste generators would now have to now segregate waste into three streams- Biodegradables, Dry (Plastic, Paper, metal, Wood, etc.) and Domestic Hazardous waste (diapers, napkins, mosquito repellants, cleaning agents etc.) before handing it over to the collector.
  • Collection and disposal of sanitary waste: The manufacturers or brand owners of sanitary napkins are responsible for awareness for proper disposal of such waste by the generator and shall provide a pouch or wrapper for disposal of each napkin or diapers along with the packet of their sanitary products.
  • Collect Back scheme for packaging waste: As per the rules, brand owners who sale or market their products in packaging material which are non‐biodegradable, should put in place a system to collect back the packaging waste generated due to their production.
  • User fees for collection: The new rules have given power to the local bodies across India to decide the user fees. Municipal authorities will levy user fees for collection, disposal and processing from bulk generators. As per the rules, the generator will have to pay “User Fee” to the waste collector and a “Spot Fine” for littering and non-segregation, the quantum of which will be decided by the local bodies.
  • Waste processing and treatment: As per the new rules, it has been advised that the bio-degradable waste should be processed, treated and disposed of through composting or bio-methanation within the premises as far as possible and the residual waste shall be given to the waste collectors or agency as directed by the local authority. The developers of Special Economic Zone, industrial estate, industrial park to earmark at least 5 per cent of the total area of the plot or minimum 5 plots/ sheds for recovery and recycling facility.
  • Promoting use of compost: As per the rules, the Department of Fertilisers, Ministry of Chemicals and Fertilizers should provide market development assistance on city compost and ensure promotion of co‐marketing of compost with chemical fertilisers in the ratio of 3-4 bags is to 6-7 bags by the fertiliser companies to the extent compost is made available for marketing to the companies.
  • Promotion of waste to energy: The rules mandate all industrial units using fuel and located within 100 km from a solid waste-based Refuse-Derived Fuel (RDF) plant to make arrangements within six months from the date of notification of these rules to replace at least 5 per cent of their fuel requirement by RDF so produced.
  • Revision of parameters and existing standards: As per the new rules, the landfill site shall be 100 metres away from a river, 200 metres from a pond, 500, 200 metres away from highways, habitations, public parks and water supply wells and 20 km away from airports/airbase. Emission standards are completely amended and include parameters for dioxins, furans, reduced limits for particulate matters from 150 to 100 and now 50. Also, the compost standards have been amended to align with Fertiliser Control Order.
  • Management of waste in hilly areas: As per the new rules, construction of landfills on hills shall be avoided. Land for construction of sanitary landfills in hilly areas will be identified in the plain areas, within 25 kilometers. However, transfer stations and processing facilities shall be operational in the hilly areas.
  • Constitution of a Central Monitoring Committee: The government has also constituted a Central Monitoring Committee under the chairmanship of Secretary, MoEF&CC to monitor the overall implementation of the rules.



As per the Solid Waste Management Rules, 2016in India, which one of the following statements is correct?

(a) Waste generator has to segregate waste into five categories.

(b) The Rules are applicable to notified urban local bodies, notified towns and all industrial townships only.

(c) The rules provides for exact and elaborate criteria for the identification of sites for landfills and waste processing facilities

(d) It is mandatory on the part of waste generator that the waste generated in one district cannot be moved to another district.

Answer: C




  • Biomedical waste comprises human & animal anatomical waste, treatment apparatus likeneedles, syringes and other materials used in health care facilities in the process of treatment and research. This waste is generated during diagnosis, treatment or immunisation in hospitals, nursing homes, pathological laboratories, blood bank, etc.
  • According to a report filed by the Central Pollution Control Board (CPCB), India generates about 101 Metric Tonnes per day of COVID-19 related bio-medical waste in addition to the regular bio-medical waste generation of about 609 MT per day.


Proper Bio-medical waste management

  • Scientific disposal of Biomedical Waste through segregation, collection and treatment in an environmentally sound manner minimises the adverse impact on health workers and on the environment.
  • The hospitals are required to put in place the mechanisms for effective disposal either directly or through common biomedical waste treatment and disposal facilities.
  • The hospitals servicing 1000 patients or more per month are required to obtain authorisation and segregate biomedical waste in to 10 categories, pack five colour backs for disposal.
  • There are 198 common bio-medical waste treatment facilities (CBMWF) are in operation and 28 are under construction. 21,870 HCFs have their own treatment facilities and 1,31,837 HCFs are using the CBMWFs.


Problems of unscientific Bio-medical waste disposal

  • The quantum of waste generated in India is estimated to be 1-2 kg per bed per day in a hospital and 600 gm per day per bed in a clinic.
  • 85% of the hospital waste is non-hazardous, 15% is infectious/hazardous. Mixing of hazardous results in to contamination and makes the entire waste hazardous. Hence there is necessity to segregate and treat.
  • Improper disposal increases risk of infection; encourages recycling of prohibited disposables and disposed drugs; and develops resistant microorganisms
  • Lack of segregation: Municipalities pick up COVID-19 biomedical waste from houses, but it often has other household waste mixed in it. This decreases the efficiency of the incinerators at waste treatment plants as it results in greater emissions and unburnt ash.
  • Guidelines not being followed: Due to the gravity of the situation, some states are not following the CPCB guidelines on Covid-19 related waste and the existing bio medical waste management rules further increasing the risk.
  • Overburdened Capacity: PPE are being used everywhere, from hotels to hospitals, railway stations to airports, crematoriums to burial grounds so, the disposal mechanisms available in the cities are not equipped to deal with this huge volume.
  • Investment in incinerators is also a problem, as this infection (COVID-19) is episodic, the machines may not be useful once cases start decreasing.


Key features of Bio-medical Waste Management Rules 2016 (amended in 2018)

  • Pre-treatment of waste: Waste generated in laboratories, microbiological waste, blood samples and blood bags to be pre-treated through disinfection or sterilisation on-site in the manner as prescribed by WHO.
  • Phasing out of use of chlorinated plastic bags, gloves and blood bags.
  • Better segregation: Bio-medical waste has been classified into 4 categories: Untreated human anatomical waste, Animal anatomical waste, Soiled waste and Biotechnology waste.
  • Storage of waste: Provision within the premises for a safe, ventilated and secured location for storage of segregated biomedical waste.
  • Regular Training and Immunisation of all health care workers.
  • Ensure proper Transportation and handling of waste without any adverse effect to the human health and the environment.
  • Record maintenance and monitoring of the activities related to bio-medical waste management.
  • Establish GPS and Bar-coding facility at Common biomedical waste treatment facility.


Wastewater management
  • United Nations University – Institute for Water, Environment and Health (UNU-INWEH), noted that efficiently treating wastewater can help meet SDGs.
  • The world generates about 380 trillion litres (tl) wastewater every year, which is projected to rise roughly 51 per cent by 2050 to 574 tl.
  • Asia contributed the most at 42 per cent of global wastewater generation, followed by Europe and North America (18 per cent each) in 2015.
  • As per NITI Aayog’s composite water management index, India is facing one of its major and most serious water crises. Its water demand is projected to be twice the available supply by 2030. While almost 80% of water supply flows back into the ecosystem as wastewater.
  • In India, 70% of states treat less than half of their waste water.
  • Scarcity of water in most of the cities (due to rise in population and fall in water vailability), can be addressed by waste water management. E.g. According to a study, waste water recycling can meet more than 20 per cent of the Bangalore’s daily needs.


Steps taken for waste water management

  • NITI Aayog’s Composite Water Management Index which ranks state includes water treatment capacity as parameter to enable effective water management.
  • NITI Aayog under Urban Management Programme on ‘Water Recycling and Reuse’ is working on capacity building for Urban Water Cycle Management for Sustainable and Resilient Water Infrastructure and Healthy Cities.
  • National Policy on Faecal Sludge and Septage Management (FSSM) to be implemented under Swachh Bharat Mission, AMRUT and Smart City Mission.
  • Construction of Sewage Treatment plants (STPs) to treat sewage generated by domestic and industrial waste. Also, Common Effluent Treatment Plants (CETPs) for cluster of smallscale industries.
  • ‘Namami Gange Programme’ under ‘Ganga action plan’ was launched for effective abatement of pollution, conservation and rejuvenation of National River Ganga and Yamuna Action Plan’ to restore river Yamuna.
  • Ministry of Jal Shakti has initiated the ‘National Water Mission Awards’ to recognize excellence in water conservation, efficient water use and sustainable water management practices.


Best practices:

  • Avadi Sewage Treatment Plant: Tamil Nadu Police Housing Corporation has successfully constructed an off-grid sewage treatment plant that not only solved the problem of sewage disposal but also provided a pond of treated water for fishing, vegetable cultivation and recharging of groundwater.
  • Sewage-fed aquaculture system of Kolkata: Farmers around Kolkata city in India developed a technique of using domestic sewage for fish culture and other agricultural purposes.
  • Singapore’s NEWater is reclaimed water, purified using dual-membrane (via microfiltration and reverse osmosis) and ultraviolet technology, can be used for potable and non-potable purpose


Plastic Pollution:


  • Single-use plastics, often also referred to as disposable plastics, are commonly used for plastic packaging and include items intended to be used only once before they are thrown away or recycled.
  • These include, among other items, grocery bags, food packaging, bottles, straws, containers, stirrers, styrofoam cups or plates etc.
  • According to Un-Plastic Collective Report, an estimated 8.3 billion tonnes of plastic has been produced since the early 1950s, about 60% of which has ended up either in a landfill or the natural environment
  • India alone generates 9.46 million tonnes of plastic waste every year, around 43% of which comprises single-use plastic.
  • India generates close to 26,000 tonnes of plastic a day, according to a CPCB estimate from 2012. Worse, a little over 10,000 tonnes a day of plastic waste remains uncollected.

Impacts of single use plastic (SUP)

  • Uncollected plastic waste eventually ends up in the natural environment — in our seas and oceans or piling up on our lands.
  • By 2050, the amount of plastic in seas and oceans across the world will weigh more than the fishes, says a headline-grabbing estimate by the Ellen MacArthur Foundation. At less than 11 kg, India’s per capita plastic consumption is nearly a tenth of the US, at 109 kg.
  • It is non-biodegradable instead they slowly break down into smaller pieces of plastic called microplastics which again causes more issues. It can take up to thousands of years for plastic bags and Styrofoam containers to decompose.
  • The toxins, poisons and persistent pollutants present in some of these plastic products leach and enter human bodies where they cause several diseases, including cancer and can damage nervous systems, lungs and reproductive organs.
  • Humans may be consuming anywhere from 39,000 to 52,000 microplastic particles a year through fish (contaminated with microplastics) alone.
  • Plastic kills an estimated 1 million sea birds every year and affects around 700 species which get infected by ingesting plastics.
  • Single-use plastics make up on average 49% of beach litter.
  • If the production, disposal and incineration of plastic continues on its present day growth trajectory, by 2030 these global emissions could reach 1.34 gigatonne per year — equivalent to more than 295 coal-based power plants of 500-MW capacity.
  • The ubiquitous plastic seems to be a curse for the third world countries, because poor countries, especially in Asia, not only have their own plastic dump to deal with but also the plastic trash that lands on their shores from developed countries.
  • India has imported 99,545 MT plastic flakes and 21,801 MT plastic lumps from South America, Africa, Middle East, Europe and Asia.

Global steps

  • United Nations Environment Program (UNEP) had declared the theme for World Environment Day 2018 as ‘Beat Plastic Pollution’.
  • G20 Implementation Framework for Actions on Marine Plastics Litter which is aimed at facilitating further concrete action on marine waste, though on a voluntary basis.


Challenges with banning single use plastic

  • It is difficult as no one takes the responsibility for the single use plastic thrown by them and behaviour change towards the shift from non-using of single use plastic is difficult
  • It is difficult to ban the product which is of immense use to the public, without thinking of a sustainable and equally utilitarian alternative product. For e.g. Single-use plastic helps keep medical equipment sterile and safe to use.
  • It impacts most industries since SUP forms part of packaging and hence is linked to all industries directly or indirectly.
  • India’s plastic industry officially employs around 4 million people across 30,000 processing units, out of which 90% are small to medium-sized businesses.
  • If plastic sachets made from multi-layered packaging are banned, it can disrupt supplies of key products such as biscuits, salt and milk etc
  • Ban will increase the price of most FMCG products as manufacturers would try and shift to alternative packaging (which can be costlier).
  • Ban can lead to loss of revenue as well as job loss in the plastic manufacturing industry.
  • Solutions & Alternatives Taken By India and world To Beat Plastic Pollution:
  • In 2018 on World Environment Day, India went big in their commitment to beat plastic pollution with an announcement that ‘India pledges to eliminate all single-use plastic in the country by 2022.
  • India’s Airports Turned Single-Use Plastic Free: Reaffirming India’s pledge to become a plastic-free country, the Airports Authority of India (AAI) in January 2019, made an announcement that 129 airports across the country will be made single-use plastic-free.
  • Kumbh, Celebrated as India’s Cleanest Festival in 2019,
  • Parliamentary Elections Made Green: Ministry of Environment, Forests and Climate Change laid down standard guidelines for use of alternative materials for election campaign.
  • India Paved the Way to Combat Marine Pollution with New Partnerships: The Ministry of Environment, Forest and Climate Change announced two major collaborations with developed countries like Norway and Germany to help combat marine pollution.
  • PM Modi Kick-Started ‘Plastic-Free’ Campaign on Independence Day: In his Independence Day speech, PM Modi initiated a ‘Plastic-Free’ campaign.
  • Conversion into fuel: Council of Scientific and Industrial Research (CSIR) in 2014, developed a unique process of converting plastic waste like polyethylene and polypropylene to either gasoline or diesel.
  • Degrading plastic: IIT Madras has demonstrated an environment-friendly strategy to degrade the chemically inert and physically stable plasticpolytetrafluoroethylene (PTFE) by continuous stirring it in water containing glucose and metal ions for about 15 days at 700C.
  • Ireland: They introduced a tax on plastic bags at points of sale, known as the “PlasTax’’.
  • Norway deposit refund system: Since 1999 Norway has used a deposit refund system for its beverage bottles and cans where public can return them at reverse vending machines to receive the deposit back.
  • Plastic Ban: Major big states of India such as Maharashtra, Odisha, Tamil Nadu, Himachal Pradesh, and Telangana have imposed a ban on single-use plastics at the state level.
  • Food in Exchange of Plastic Waste: Chhattisgarh became India’s first state to open up one-of-its-kind garbage café, wherein food to the poor and homeless is being provided free of cost in lieu of plastic waste. Example- café in Chhattisgarh’s Ambikapur, Odisha’s Kotpad Notified Area Council (NAC) etc.
  • Andhra Pradesh launched ‘Rice for Plastic’ drive to eradicate single-use plastic while feeding the hungry
  • India’s Cleanest City Indore Introduces a Separate Bag for Plastic Waste: The Indore Municipal Corporation announced a separate collection bag for all kinds of plastic waste like carry bags, milk pouches, water bottles, discarded buckets, mugs, tetra-packs, pens and plastic packaging items.
  • Tiles Made Using Plastic Waste: Apart from building roads using plastic waste, many states are also making pavements tiles. In cities like Bengaluru, Hyderabad, tiles made out of plastic have already been put to use.


Plastic Waste Management Rules 2016 (amended in 2018)

  • Defines minimum thickness of plastic carry bags i.e. 50 microns. This would increase the cost and the tendency to provide free carry bags would come down.
  • Responsibility of local bodies: Rural areas are brought under the rules since plastic has reached rural areas as well. The gram sabhas have been given responsibility of implementation.
  • Extended Producer Responsibility: Producers and brand owners have been made responsible for collecting waste generated from their products.
  • Producers are to keep a record of their vendors to whom they have supplied raw materials for manufacturing. This is to curb manufacturing of these products in unorganized sector.
  • Responsibility of waste generator: All institutional generators of plastic waste shall segregate and store their waste as per Solid Waste Management Rules, and handover segregated wastes to authorized waste disposal facilities.
  • Responsibility of street vendors and retailers: Not to provide such carry bags or fine would be imposed. Only the registered shopkeepers on payment of a registration fee to local bodies would be allowed to give out plastic carry bags on charge.
  • Promote the use of plastic for road construction or energy recovery.
  • A Central Registration System for the registration of the producer/ importer/ owner.
  • Phasing out of Multi-layered Plastic (MLP) that are “nonrecyclable or non-energy recoverable or have no alternate use”.



  • Define single use plastic: It will help to categorise items according to both their “qualitative and quantitative aspects” as well as “technical attributes”.
  • Segregation, collection and recycling: India uses about 14 million tonnes of plastic annually but lacks an organised system for management of plastic waste, leading to widespread littering.
  • Investment: There is a need to invest heavily in improving source segregation of waste and supporting end-to-end segregation of waste to strengthen processing.
  • Policy framework: There is need for a National Action Plan or guidelines that focus on implementing plastic ban in a phase-wise manner in terms of urgency.
  • Simultaneously reinforcing research and development funding for different alternatives and eco-friendly products.
  • Effectively implement of laws and policies: There is need to clear about which items should be included in EPR
  • Focus on innovation in designs: Government should invest money in encouraging the setting up of ventures that provide sustainable products as an alternative to current non-recyclable products.


Current Issue

  • Palau Bans Sunscreen Harmful to corals
  • Pacific Island, Palau has become the first country to ban sun cream that is harmful to corals.
  • The country has banned common ingredients used in cosmetics including oxybenzone.
  • Research show that the oxybenzone could stunt the growth of baby, cause corals to bleach at lower temperature and it reduces their resilience to climate change.



Micro-plastics in Deep Oceans
  • Researchers have observed that deep sea hotspots of biodiversity are also likely to be micro-plastic hotspots.
  • Although micro-plastics are known to spread on the global seafloor, the processes that control their dispersal and concentration in the deep sea remain largely unknown.
  • The researchers have studied the spatial distribution and ultimate settling position of the micro-plastics and its effects on the biodiversity hotspots in the deep oceans.

Note- Plastic debris those are less than five millimetres in length are called micro-plastics


Why is there a great concern about the ‘microbeads’ that are released into environment?

  1. They are considered harmful to marine ecosystems.
  2. They are considered to cause skin cancer in children.
  3. They are small enough to be absorbed by crop plants in irrigated fields.
  4. They are often found to be used as food adulterants.

Answer: A



  • E-waste is any electrical or electronic equipment that’s been discarded. This includes working and broken items that are thrown in the garbage or donated to a charity reseller like Goodwill. Often, if the item goes unsold in the store, it will be thrown away.
  • E-waste is particularly dangerous due to toxic chemicals that naturally leach from the metals inside when buried.
  • India is generating about eight lakh tonnes of e-waste annually. In December, 2017, the United Nations reported that the world generated 44.7 million tonnes of electronic waste in 2016, India’s contribution to this was a significant 2 million tonnes, being amongst top five countries in E -waste generation.
  • The Ministry of Environment, Forests and Climate Change (MoEFCC) is the nodal agency for the planning of e- waste management and sustainable environmental issues.
  • Department of Telecommunications, Ministry of Communication in National Telecom Policy 2012 (NTP), puts emphasizes on Periodic disposal of all electronic waste as E-waste, Strengthening the framework to address the environmental and health related concerns pertaining to the telecom sector.
  • National Telecom Policy 2012 and NTP 2018, promotes the use of energy efficient equipment and renewable energy technologies to achieve long term sustainability.

Constituents and Effects of E-Wastes

Substances Impact
Arsenic Effect lungs and kidney

Long duration exposer has carcinogenic effects

Barium Breathing problem


Slowdown in nerve reflexes

Beryllium Causes lung cancer
Cadmium Affects kidney

Muscles weakness

Central Nervous system disorder

Lead Diarrhea

Appetite loss



Impact of elements released from e-waste:


  • Improper handling of e-waste is detrimental to the environment and mankind. Since this waste is nothing but a combination of plastics and toxic chemicals, these get released into the environment.
  • Pollutants such as dioxins and furans from polyvinyl chloride, lead, beryllium, cadmium, mercury, etc. get into our environment and cause the following health hazards:
  • Reproductive issues
  • Developmental problems
  • Damage to the immune system
  • Interference with regulatory hormones
  • Damage to the nervous system
  • Kidney damage
  • Hamper’s brain development in children
  • May lead to lung cancer
  • Chronic beryllium disease
  • Skin ailments
  • Cadmium accumulations on liver and kidney
  • Asthmatic bronchitis
  • DNA damage
  • Muscle weakness
  • Endocrine system disruption
  • Exposure to harmful chemicals present in e-waste can lead to severe health hazards that are at times fatal. These toxins enter our body through inhalation, skin absorption, or ingestion.
  • Environmental effects: The toxic materials from electronic devices are released into bodies of water, groundwater, soil and air, affecting both land and sea animals.
  • Improper management of e-waste also contributes to global warming. A total of 98 Mt of CO2- equivalents were released into the atmosphere from discarded fridges and air-conditioners that were not managed in an environmentally sound manner.
  • Low recycling capacity: Almost all e-wastes contain some form of recyclable material, including plastic, glass, and metals; however, due to improper disposal methods and techniques these materials cannot be retrieved for other purposes.
  • Only 17.4% of the total e-waste was collected and recycled globally.
  • Dumping in Developing countries: A large amount of E-waste from developed countries is dumped into developing countries impacting the environment the health of the people there.


E-Waste (Management) Rules 2018:

  • According to the new E-Waste (Management) Amendment Rules, 2018 the manufacturer, producer, importer, transporter, refurbisher, dismantler and recycler shall be liable to pay financial penalties as levied under the Provisions of the Environment (Protection) Act.
  • According to the latest amendment, the Central Pollution Control Board (CPCB) may conduct random sampling of electrical and electronic equipment placed in the market to monitor and verify the compliance of reduction of hazardous substances provisions and the cost for sampling and testing shall be borne by the government, which was not the case in the previous amendment. Previously, the cost was borne by the producers.

Extended Producer Responsibility (EPR):

  • The EPR is a policy approach under which producers are given a significant responsibility— financial or physical—for the treatment or disposal of post-consumer products.
  • Responsibility of the producer for collection of waste Electrical and Electronic Equipment from the Electrical and Electronic Equipment placed on the market earlier, such as through dealer, collection centers, through buy-back arrangement, exchange scheme, Deposit Refund System, etc.
  • Whether directly or through any authorized agency and channelizing the items so collected to authorized recyclers.


Benefits of EPR

  • The closed loop approach under EPR, waste generated is used to produce another product. This reduces cost of production for the new product by using waste.
  • It helps in lowering the hazardous environmental impact of the waste generated.
  • EPR has shifted the burden of waste disposal to these product manufacturers, thus it has driven the adoption of innovative production techniques etc.
  • EPR policies will be instrumental in ensuring 3R principle (Reduce-Reuse-Recycle) hence facilitating a circular economy, extending life cycle of product.


Concerns about EPR

  • It has high regulatory cost and fines on companies for non-adherence to guidelines.
  • There is a lack of formalized reverse logistics system; hence setting up a collection network could be extremely complex and expensive.
  • The informal sector manages around 90% of waste management streams and upgrading them into the formal sector while ensuring their adherence to compliances will be challenging.
  • Social awareness and responsibility are key concerns in successfully managing waste.
  • Segregation of waste at source will be challenging due to lack of technological methods and involvement of unorganized and unaware manpower.

Basel Convention on the Control of Transboundary Movements of Hazardous Wastes

  • It was adopted in 1989 and it came into force in 1992.
  • The Convention aims to protect human health and the environment against the adverse effects resulting from the generation, transboundary movements and management of hazardous wastes and other wastes.
  • Best practice: In October 2019, the EU adopted new Right to Repair standards, which means that from 2021 firms will have to make appliances longer-lasting, and will have to supply spare parts for machines for up to 10 years.



  • Adoption of Circular Economy, which aims to eliminate waste, not just from recycling processes, but throughout the lifecycles of products and packaging it maximize value and eliminate waste.
  • Provide incentives to industry by introducing tax rebates or other conditions to support its transition to phase out use of plastic.
  • Need to integrate the informal sector, and increase citizens’ environmental awareness and promote efficient coordination and communication between stakeholders involved.


Current Topics


  • India first e-waste clinic for segregating, processing and disposalof waste from household and commercial units will soon be set-up in Bhopal, Madhya Pradesh.
  • Recently, government released draft of ‘uniform framework for Extended Producers Responsibility (EPR) under Plastic Waste Management Rules (PWMR) 2016.
  • About draft EPR framework
  • EPR framework under PWMR 2016 has proposed three models:
  • Plastic credit model: In this producer is not required to recycle their own packaging, but to ensure that an equivalent amount of packaging waste has been recovered and recycled to meet their obligation. Producers and processors/ exporters may exchange plastic credits for a financial transaction at a price and other terms as negotiated between them.
  • Producer Responsibility Organisations (PROs): Under this an organisation will manage the waste on behalf of producers. Municipal bodies can also register as PRO or waste collector. There will be a National PRO Advisory Committee to govern plastic waste management in the country.
  • Fee-based mechanism: Under this, the producers will contribute to the EPR corpus fund at the central level, each producer contributes based on generation of plastic waste vis-a-vis efforts required.
  • It also has provisions to impose penalties on producers if they fail to meet their targeted collection.
  • This money shall be used for creating infrastructure for plastic waste management.
  • It recommends a graded approach for achieving the targets, starting with 30% in the first year and moving up to 90% in five years.
  • It provides for Information, Education and Communication (IEC) to achieve an effective waste segregation, collection, transportation and recycling.
  • A single national registry will be created to enlist all stakeholders to improve monitoring and help bring transparency in plastic waste management system.
  • The monitoring of the entire mechanism of the EPR will be the responsibility of the Central Pollution Control Board (CPCB).


In India, ‘extended producer responsibility’ was introduced as an important feature in which of the following?

  1. The Bio-medical Waste (Management and Handling)Rules,1998
  2. The Recycled Plastic (Manufacturing and Usage)Rules,1999
  3. The e-Waste (Management and Handling) Rules, 2011
  4. The Food Safety and Standard Regulations, 2011

Answer: C



  • Light pollution is the presence of anthropogenic and artificial light in the night environment.
  • Excessive light on the retina causes extreme discomfort to the eyes.
  • It is exacerbated by excessive, misdirected or obtrusive use of light, but even carefully used light fundamentally alters natural conditions.
  • Effects of Light Pollution
  • Disturbs the reproductive cycles of some animals and loss of biodiversity due to change in predation and migration pattern of wildlife animal
  • In humans, it disturbs circadian rhythms that regulate hormones and other bodily functions like Psychological Behaviour change
  • Excessive blue light emitted form LEDs directly affects sleep pattern in Human by suppressing the production of the hormone melatonin, which mediates the sleep-wake cycle in humans.
  • It also threatening 30 percent of vertebrates that are nocturnal and over 60 percent of invertebrates that are nocturnal, artificial light also affects plants and microorganisms.


Nitrogen Pollution


  • In an automobile engine, (at high temperature) when fossil fuel is burnt, dinitrogen and dioxygen combine to yield significant quantities of nitric oxide (NO) and nitrogen dioxide ( NO2 ) as given below:


  • N2 (g) + O2 (g) → 2NO(g)

NO reacts instantly with oxygen to give NO2


  • 2NO (g) + O2 (g) → 2NO2 (g)


Rate of production of NO2 is faster when nitric oxide reacts with ozone in the stratosphere.


  • NO (g) + O3 (g) → NO2 (g) + O2 (g)
  • The irritant red haze in the traffic and congested places is due to oxides of nitrogen.
  • Higher concentrations of NO2 damage the
  • leaves of plants and retard the rate of photosynthesis.
  • Nitrogen dioxide is a lung irritant that can lead to an acute respiratory disease in children.
  • It is toxic to living tissues also. Nitrogen dioxide is also harmful to various textile fibres and metals.
  • Nitrogen compounds running off farmland have led to water pollution problems around the world, while nitrogen emissions from industry, agriculture and vehicles make a big contribution to air pollution.
  • Nitrogen becomes a pollutant when it escapes into the environment and reacts with other organic compounds. It is either released into the atmosphere, gets dissolved in water sources such as rivers, lakes or groundwater, or remains in the soil.
  • While it might lead to favourable growth of species that can utilise this nutrient, nitrogen as a pollutant is often detrimental to the environment and health.


Colombo Declaration on Sustainable Nitrogen Management

  • The aim of the Declaration is to halve nitrogen waste by 2030
  • Environment ministers and officials from more than 30 countries attended the event.
  • The event endorsed UN plans for a campaign called “Nitrogen for Life”.
  • The Declaration was developed with technical support from International Nitrogen Management System (INMS).
  • INMS is a joint activity of UNEP and International Nitrogen Initiative Multiple pollution threats results from Reactive nitrogen in Air, Water , Terrestrial and acquatic ecosystem , Eutrophication etc.
  • There is need to reduce reactive nitrogen which will help to reduce Eutrophic zones that are affecting fishing and tourism.
  • Need for Carbon like framework


Previous Years UPSC Questions



  1. Justify with necessary logic “Biological clean-up methods can be cheaper than the conventional physical and chemical pollution treatments”.(2006)
  2. Comment on the spatial components in urban solid waste management in the country. (2010)
  3. Enumerate the National Water Policy of India. Taking river Ganges as an example, discuss the strategies which may be adopted for river water pollution control and management. What are the legal provisions of management and handling of hazardous wastes in India? (2013)
  4. Mumbai, Delhi and Kolkata are the three Mega cities of the country but the air pollution is much more serious problem in Delhi as compared to the other two. Why is this so? (2015)
  5. What are the impediments in disposing the huge quantities of discarded solid wastes which are continuously being generated? How do we remove safely the toxic wastes that have been accumulating in our habitable environment? (2018)



Consider the following: (2019)

  1. Carbon monoxide
  2. Methane
  3. Ozone
  4. Sulphur dioxide

Which of the above are released into atmosphere due to the burning of crop/biomass residue?

(a) 1 and 2 only

(b) 2, 3 and 4 only

(c) 1 and 4 only

(d) 1, 2, 3 and 4

Answer: D

In India, the use of carbofuran, methyl arathion, phorate and triazophos is viewed with apprehension. These chemicals are used as (2019)

(a) Pesticides in agriculture

(b) Preservatives in processed foods

(c) fruit-ripening agents

(d) Moisturizing agents in cosmetics

Answer: A


Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds? (2018)

  1. Decreased salinity in the river
  2. Pollution of groundwater
  3. Lowering of the water-table

Select the correct answer using the code given below.

(a) 1 only

(b) 2 and 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: B


How is the National Green Tribunal (NGT) different from the Central Pollution Control Board (CPCB)? (2018)

  1. The NGT has been established by an Act whereas the CPCB has been created by an executive order of the Government.
  2. The NGT provides environmental justice and helps reduce the burden of litigation in the higher courts whereas the CPCB promotes cleanliness of streams and wells, and aims to improve the quality of air in the country.

Which of the statements given above is/are correct?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: B


With reference to ‘fly ash’ produced by the power plants using coal as fuel, which of the following statements is/are correct? (2015)

  1. Fly ash can be used in the production of bricks for building construction.
  2. Fly ash can be used as a replacement for some of the Portland cement concrete.
  3. Fly ash is made up of silicon dioxide and calcium oxide only, and does not contain any

toxic elements.

Select the correct answer using the code given below.

(a) 1 and 2

(b) 2 only

(c) 1 and 3

(d) 3 only

Answer: A


Which of the following can be found as pollutants in the drinking water in some parts of India? (2013)

  1. Arsenic
  2. Sorbitol
  3. Fluoride
  4. Formaldehyde
  5. Uranium

Select the correct answer using the codes given below.

(a) 1 and 3 only

(b) 2, 4 and 5 only

(c) 1, 3 and 5 only

(d) 1, 2, 3, 4 and 5

Answer: C


Which of the following are some important pollutants released by steel industry in India?


  1. Oxides of sulphur
  2. Oxide of nitrogen
  3. Carbon monoxide
  4. Carbon dioxide

Select the correct answer using the code given below.

(a) 1, 3 and 4 only

(b) 2 and 3 only

(c) 1 and 4 only

(d) 1, 2, 3 and 4

Answer: D

Due to improper / indiscriminate disposal of old and used computers or their parts, which of the following are released into the environment as e-waste?

1) Beryllium

2) Cadmium

3) Chromium

4) Heptachlor

5) Mercury

6) Lead

7) Plutonium

Select the correct answer using the codes given below.

  1. 1, 3, 4, 6 and 7 only
  2. 1, 2, 3, 5 and 6 only
  3. 2, 4, 5 and 7 only
  4. 1, 2,3,4,5,6 and 7


There is some concern regarding the nanoparticles of some chemical elements that are used by the industry in the manufacture of various products. Why? (2014)

  1. They can accumulate in the environment and contaminate water and soil.
  2. They can enter the food chains.
  3. They can trigger the production of free radicals.

Select the correct answer using the code given below.

(a) 1 and 2 only

(b) 3 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: D

Brominated flame retardants are used in many household products like mattresses and upholstery. Why is there some concern about their use? (2014)

  1. They are highly resistant to degradation in the environment.
  2. They are able to accumulate in humans and animals.

Select the correct answer using the code given below.

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2


Answer: C


There is a concern over the increase in harmful algal blooms in the seawaters of India. What could be the causative factors for this phenomenon? (2011)

  1. Discharge of nutrients from the estuaries.
  2. Run-off from the land during the monsoon.
  3. Upwelling in the seas.

Select the correct answer from the codes given below:

(a) 1 only

(b) 1 and 2 only

(c) 2 and 3 only

(d) 1, 2 and 3

Answer: D

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 Career Development Program 2023 Result PDF     Download UPSC Mains 2023 Question Papers PDF  Free Initiative links -1) Download Prahaar 3.0 for Mains Current Affairs PDF both in English and Hindi 2) Daily Main Answer Writing  , 3) Daily Current Affairs , Editorial Analysis and quiz ,  4) PDF Downloads  UPSC 2022 Final Result🔥5 out of Top 10 from PW OnlyIAS Community. UPSC Prelims 2023 Trend Analysis cut-off and answer key