The missing piece of the public health puzzle: Understanding the exposome

Can exposomics transform approaches to disease prevention, product regulation, and public health policies? Martine Vrijheid from the Barcelona Institute for Global Health (ISGlobal) highlights the importance of researching environmental exposures for healthier societies

Our environment makes all the difference when it comes to our health. Up to 90% of disease risk stems from our environment, rather than genetics. This presents both a challenge and an opportunity. These exposures are preventable, but they remain largely unmeasured and underregulated. This needs to change to truly protect our health.

How our environment shapes health

Chronic diseases are not only a major harm to health, but they are also expensive – cancer, cardiovascular conditions, and respiratory disorders account for a large part of healthcare costs and economic burdens worldwide. The Human Genome Project was a revolutionary step towards understanding the genetic causes of disease. Scientists decoded the entire human genome, helping account for roughly 10-30% of chronic disease risks. The rest comes from our environment.

Taking a step back to see the bigger picture, scientists coined the term exposome. The human exposome includes all environmental exposures an individual experiences in a lifetime and how they affect their health. Building a more comprehensive and systematic understanding of how these exposures shape our health will allow policymakers to shift from reactively treating disease to proactively protecting public health.

Why we need to consider the exposome now

It is a crucial moment to understand how what we’re exposed to influences our health. We encounter more synthetic chemicals than ever before. Over 350,000 synthetic chemicals are currently on the global market. Increasing plastic production and rampant plastic use worldwide have released micro- and nanoplastics into the environment. Meanwhile, our changing climate can create new stressors, such as wildfire smoke, extreme heat, and changing allergen patterns. These and other environmental factors disproportionately affect people, with vulnerable and marginalised communities facing greater impacts.

At the same time, we now have more power than ever to understand how these exposures impact our health. Over the past two decades, exposomics has evolved from a concept into a data-driven scientific field. Advances in analytical chemistry, geospatial tools, and artificial intelligence made this possible. Omic technologies allow scientists to detect thousands of chemicals in a single drop of blood, explain biological mechanisms, and predict future disease risks related to our environment. We can now map exposures to air pollutants and noise using satellites and track health using wearable sensors. AI and machine learning let us process more data and make more accurate predictions.

The exposome should drive public policy

By understanding how our environment interacts with our health, we can better address current public health challenges, prevent future disease, and create policies that improve our overall health and wellbeing. For policymakers, the exposome can be a valuable resource. It can explain how noise, air pollution, and green spaces affect our health, ensuring that the way cities are built works for those living in them. It can show health risks associated with different chemicals and chemical mixtures, advising policymakers on how they should be regulated. It can help predict how our shift to remote work will affect our overall health and wellbeing. These are only some of the ways that exposomics can influence public policy.

What we need for a new era of public health research

Exposome research is uncovering more about how our environment impacts our health every day. Yet to make full use of this information, we need continued funding and people to communicate and act on the findings.

Due to its complexity, understanding our exposome requires robust research infrastructure and cross-disciplinary collaboration. Researchers also need the resources to understand health impacts over longer periods. As it stands, most exposome research is conducted in high-income countries. More efforts are needed to support researchers in low- and middle-income countries, where the negative environmental impacts are most severe. Bringing together researchers, policymakers and other key people to discuss findings, resources, and funding is key to shedding light on how our environment influences our health.

Exposomics has the power to transform how we prevent disease, regulate products, and create new policies to protect public health. Addressing these exposures and how they interact could help us create a more sustainable, healthier society.