Exposomics for Better Environmental Health

World Environment Day (WED) is a global observance, celebrated annually on June 5th, to raise awareness and encourage action for the protection of our environment.

World Environment Day 2025

• Theme: The theme for World Environment Day 2025 (June 5) is “Ending Plastic Pollution.”
• Microplastics: Microplastics are among thousands of unseen chemical, physical, and biological hazards present in our environment.
• Challenge of Measurement: Most of these hazards remain undetectable due to lack of sensing technologies. This makes exposure assessment and risk evaluation extremely difficult.

India’s Environmental Health Crisis

• High Global Burden: India contributes nearly 25% of the global environmental disease burden. Rapid economic growth has intensified environmental exposures.
• Integrated Risk Assessments: Current approaches are piecemeal, exacerbating health inequities and costs. Emphasis is needed on integrated environmental health frameworks.
• WHO and GBD Insights: WHO began tracking the environmental disease burden in 2000. he 2021 GBD study included 88 risk factors.
• Key Findings: Environmental and occupational health (EOH) risks caused 18.9% of global deaths (~12.8 million) and 14.4% of all DALYs
• Top contributors: PM2.5 air pollution: 4.2% DALYs, 4.7 million deaths, household air pollution: 3.9% DALYs, 3.1 million deaths
• Rising Health Impacts: India sees nearly 3 million deaths due to OEH risks.Over 100 million DALYs are attributable to environmental causes.
• Link to Non-Communicable Diseases: Over 50% of burden for diseases like IHD, stroke, COPD, lung cancer, and diabetes are from environmental exposures.
• Impact on Children: Lead exposure has led to 154 million IQ points lost in Indian children under 5 — 20% of global total.

Challenges Associated with Environment Policies

• Narrow Risk Categories: Current GBD assessments include only ~11 environmental risk factors. There is a lack of human exposure data for chemical, physical, and complex risks.
• Missing Synergistic Interactions: Environmental risks interact with metabolic, behavioural, and genetic factors. Current models fail to capture complex life-course interactions.
• Compound Hazards: Climate change worsens exposure to Heat, vector-borne diseases, air pollution, Floods, storms, wildfires. It also affects food security and mental health (e.g., depression, anxiety).
• Vulnerable Populations: Populations with limited access to health and food systems are most at risk. Compound effects and synergies are inadequately captured in current data.

Exposome

• About: The total lifetime exposure of an individual to physical, chemical, biological and psycho-social factors that influence health.  
  • The exposome encompasses all exposures and individual experiences from conception throughout their life, including environmental factors like air pollution, chemicals, and lifestyle choices, as well as biological and social factors that can impact health. 
• Role of Exposomics: Exposomics can help track disease origins over a life course. It provides a comprehensive view of the environment–health interactions.
• Digital Integration: Investment is needed in long-term environmental health surveillance. It should integrate biomonitoring with digital health and data platforms.
• Genome to Exposome: The Human Genome Project (1990–2003) transformed our understanding of genetic diseases. However, for many common diseases like heart disease, genetics alone explains less than 50% of the risk.
• Beyond Genes: The limited predictive power of genes led to the concept of the “exposome.” It refers to all exposures across a person’s lifetime and their impact on health.
• Limitations of Traditional Methods: Conventional studies often target single exposures at specific points in time. They fail to capture the complex, cumulative nature of lifetime environmental exposures.
• Multifactorial Understanding: Exposomics explores interactions between:
  • External exposures (chemical, biological, psycho-social)
  • Internal traits (genetics, physiology, epigenetics)
  • And lifestyle factors like diet and behaviour
• GWAS to EWAS: Just as Genome-Wide Association Studies (GWAS) reveal genetic links to disease, Exposure-Wide Association Studies (EWAS) aim to map environmental influences.
• Interdisciplinary Integration: Requires tools like wearable sensors for real-time personal monitoring, untargeted chemical analysis of biomonitoring samples, organs-on-a-chip to simulate biological response, AI and Big Data to synthesize complex datasets
• Perceived Challenges: The exposome framework may appear implausible or irrelevant in India. This is due to implementation hurdles in environmental health programmes.

Way Forward

• Harmonised Data Ecosystem: A sustainable, interoperable data system is critical. It should enable access, sharing, and harmonisation of exposomics data.
• Technology: India has shown the ability to leapfrog using technology and data-driven approaches in healthcare. Exposomics can follow a similar pathway for integration.
• Public Health Integration: Exposomics enables predictive modelling for chronic diseases. It supports precision medicine by mapping individual exposure histories.
• Smart Investments: Unbridled investments in capacity building and infrastructure synchronisation are key. This can ensure cost-effective solutions for India’s health burden.

Conclusion

The time is ripe for India’s environmental health community to engage in the global exposomics movement. This will enable India to contribute actively to shaping future global health paradigms. Future World Environment Days may champion the human exposome project. It can emerge as the best prescription for holistic prevention and health equity.