05 Jun 2025 : Exposomics for better environmental health

Editorial 1: Exposomics for better environmental health

Context

Scientific progress in exposomics will help us better understand the causes of diseases and create more complete ways to prevent them.

Introduction

The focus of World Environment Day 2025 (June 5) is to stop plastic pollution. Micro-plastics are just one of many harmful chemical, physical, and biological dangers found in the air, water, and our surroundings. We cannot easily detect or measure how much we are exposed to them or the health risks they cause. Because of this, reducing diseases caused by the environment remains a big challenge for public health.

Tackling Environmental Health in India

• Economic Growth and Environment: Rapid growth in India is increasing the scale and complexity of environmental exposures and their links to lifestyles.
• High Disease Burden and New Approaches: India faces 25% of global environmental diseases, needing integrated health risk assessments for better management.
• Need for Complete Environmental Factors: Including all environmental factors in disease studies is crucial to avoid worsening health inequalities and rising costs.
• Exposomics for Better Prevention: Using exposomics helps understand disease causes fully and develop holistic prevention.
• Investing in Health Surveillance: Long-term environmental health monitoring combined with digital health and data science is vital.

Environmental disease burden

• WHO and Global Burden of Disease (GBD) Study:
  The WHO started estimating the environmental disease burden in 2000, forming the base for the GBD study. The latest GBD cycle (2021) analyzed 88 risk factors, highlighting the biggest contributors to global health burden.

• Environmental Health Burden in India:
  • Nearly 3 million deaths and 100 million DALYs are linked to occupational and environmental health (OEH) risks.
  • OEH risks cause over 50% of non-communicable diseases such as heart disease, stroke, lung diseases, asthma, diabetes, and kidney disease.
  • Lead exposure affects child development, with India accounting for 154 million IQ points lost in children under five (about 20% globally).

• Limitations of Current GBD Environmental Burden Estimates
  • Only around 11 categories of environmental risk factors are included due to limited human exposure data.
  • Missing risks include chemical exposures, micro-plastics, solid waste, and environmental noise.
  • Interactions between environmental, metabolic (e.g., high blood pressure), behavioural (e.g., smoking), genetic, and socio-economic factors are complex and not fully studied.
  • Risk assessments usually focus on single factors, not mixtures or lifetime exposures.
• Climate change worsens environmental risks:
  • Increases heat, air pollution, vector-borne diseases, storms, floods, and wildfires.
  • Affects crop yields, worker productivity, food security, and supply chains.
  • Drives mental health issues like depression and anxiety related to ecological stress and pollution.
  • Can cause compound effects where multiple hazards occur together, amplifying health risks.
  • Vulnerable populations with poor access to healthcare and nutrition are most affected.
• Need for Better Data and Holistic Strategies:
  • Current estimates are conservative underestimates of the true environmental health burden.
  • There is a lack of data and methods to include many important risk factors in GBD assessments.
  • Holistic and scalable prevention strategies require improved understanding and integration of multiple environmental, social, and health factors.

Understanding the Human Genome Project and the Exposome

• The Global Human Genome Project (1990-2003) significantly advanced our understanding of the genetic basis of diseases.
• However, it revealed that genetic variation alone has limited predictive power for many common diseases.
  • For example, genetics contributes to less than 50% of the risk for heart disease, a major cause of death worldwide.
• The success of genome mapping led to the development of the “exposome” concept:
  • Exposome: The totality of all environmental exposures an individual encounters throughout their lifetime and how these exposures affect health.
• Traditional environmental health studies are usually hypothesis-driven and focus on:
  • One or a small set of exposures
  • At limited time points
• These traditional methods fail to capture the complex interactions of multiple exposures over a lifetime and their impact on human health.
• Exposomics aims to fill this gap by:
  • Studying interactions between external exposures (physical, chemical, biological, psycho-social)
  • Considering diet, lifestyle, and internal factors like genetics, physiology, and epigenetics
  • Creating a comprehensive atlas of Exposure-Wide Associations (EWAS) to complement Genome-Wide Associations Studies (GWAS)
• Achieving this requires integrating multiple interdisciplinary technologies, such as:

• Challenges:
  • Limited capacity and resources globally to generate exposomic data.
  • Urgent need to develop a harmonised data ecosystem for:
    • Storing, accessing, and sharing exposomic data
    • Ensuring data interoperability through sustained repositories

Mainstream environment within health

• Implementing environmental health management programmes in India faces significant challenges and hurdles.
• At first glance, exposome frameworks may appear implausible or irrelevant given these challenges.
• However, adopting technology and data-driven approaches in the health sector is already a familiar strategy in India.
• Exposomics presents unique opportunities to:
  • Integrate environmental risk factors into public health programmes more effectively.
  • Develop more precise predictive models for chronic diseases.
  • Enable advancements in precision medicine tailored to individual exposures and genetics.
• Success depends on:
  • Strong investments in capacity building to develop expertise and infrastructure.
  • Synchronizing existing analytical, environmental, and public health systems.
• This integrated approach promises to:
  • Address public health concerns with unprecedented cost-effectiveness.
  • Improve health outcomes by targeting environmental risks comprehensively.

Conclusion

The time is ripe for the Indian environmental health community to actively engage with and contribute to the growing global momentum surrounding the science of exposomics. Looking ahead, future World Environment Day celebrations may increasingly emphasize the significance of the Human Exposome Project as a powerful framework for holistic prevention strategies that aim to preserve and promote health equity worldwide.