Exposome Research

Using improved systems for data analysis, artificial intelligence, and machine learning allows us to bring all of these datasets together to study the exposome at a level we couldn’t just a few years ago. Gary Miller, Ph.D., co-lead of the Network for Exposomics in the U.S.

Across UC Davis, interdisciplinary teams are redefining how we measure and understand environmental exposures. These projects and labs are pushing exposome science into the future.

Environmental Exposure and Brain Health Study

UC Davis COEH researchers are leading a new multi-cohort study to uncover how environmental exposures across the lifespan influence both day-to-day cognitive performance and long-term dementia risk. This project integrates cutting-edge exposure science with two of the most influential aging and women’s health cohorts in the nation: the Nurses’ Health Study II and the Rush University cohorts.

By linking smartphone GPS data and repeated cognitive tests with high-resolution models of temperature, air pollution, greenspace, and neighborhood walkability, investigators will be able to evaluate how short-term environmental conditions affect thinking and memory in real time.

Longitudinal residential histories coupled with cognitive testing, dementia incidence data, and brain-autopsy information will further reveal whether chronic exposures shape cognitive decline, dementia onset, and dementia-related neuropathology. Findings will identify environmental risk and resilience factors that can be improved through community design, climate adaptation, and environmental health policy — helping protect brain health across aging populations.

Built Environment Assessment through Computer visiON (BEACON)

The BEACON research project uses deep-learning analysis of street-level and satellite imagery to systematically characterize the built environment (streets, green spaces, walkability, urban form) across U.S. communities and examine how variation in built environments contributes to cardiovascular disease (CVD) risk.

By combining environmental exposures, spatial data, and health outcomes, BEACON aims to clarify how neighborhood design and urban infrastructure influence disease. With more than 80% of the U.S. population living in urban areas, the findings could inform urban planning, public health, and policy strategies to reduce cardiovascular risk at a population scale.

Nationwide Spatial Nature Data Repository

COEH is partnering with REI to accelerate research on the connections between nature and health. Together, we are building a first-of-its-kind, publicly accessible platform that brings together spatial datasets representing nature across the United States. This resource will allow users to easily explore, download, and connect nature-related data with health information — expanding research possibilities and supporting more equitable access to nature’s benefits.

Quantifying Greenspace Benefits for Californians

As California faces widening health disparities, growing mental health concerns, and the escalating impacts of climate change, the critical role of greenspaces in shaping health outcomes is becoming increasingly clear.  Working with the California Air Resources Board and local communities, COEH is using large-scale spatial and health datasets to understand how greenspace access and quality influence health across California — especially in underserved areas.

By modeling how changes to trees, parks, and other natural spaces impact health outcomes and related costs, this project will help guide equitable, evidence-based investments that support climate resilience and improve well-being statewide.

Evidence That Informs Regulation, Response, and Resilience

Public Health

Workplace Chemicals & Occupational Exposures

Many industries expose workers to hazardous chemicals, solvents, heavy metals, or other toxic substances. Regulatory programs aim to manage these risks through safety standards (e.g., by labeling hazards, limiting airborne concentrations, requiring protective equipment, etc.).

For instance, when chemical exposure poses excessive risk, regulatory agencies require engineering controls, restricted use, or personal protective equipment to reduce harmful exposures. These frameworks exemplify how studying the “occupational exposome” — especially cumulative or repeated exposures — is critical to preventing chronic disease and protecting worker health over time.

Wildfire Smoke

As climate change intensifies wildfires globally, smoke has emerged as a major exposome hazard. Smoke contains fine particulate matter (PM_2.5) and a mixture of hazardous air pollutants including volatile organic compounds, heavy metals, and combustion byproducts. Health impacts span respiratory (asthma, COPD, reduced lung function), cardiovascular (heart disease, stroke), immune system strain, and even neurological stress.

Chronic and repeated smoke exposure also shows potential long-term effects, including increased mortality and, in some studies, associations with cognitive decline. Communities thousands of miles downwind of fires — not just those near the blaze — are often affected, making smoke a broad, population-level environmental exposure.

Extreme Weather and Environmental Exposures

Beyond wildfires, weather shapes environmental exposures via heat extremes, shifting pollution patterns, and increased frequency of natural disasters. These exposures affect broad populations and disproportionately impact vulnerable communities — tying together physical, chemical, and social exposures.

Pesticides and Environmental Chemicals

Widespread use of pesticides means many people are exposed to chemical mixtures, whether in agricultural communities, as consumers, or through water/soil contamination. Regulatory review and worker-safety standards attempt to mitigate risk.

Chronic exposures — often through inhalation, ingestion, or skin contact — can accumulate over time, especially in populations living near treated fields or working in agriculture, potentially affecting reproductive, developmental, immune, or neurological health. Efforts to spatially map and monitor pesticide exposure (for example, using parcel-level data tied to crop and application records) are important steps toward quantifying cumulative exposure across communities.

Policy Changes, Protections, and Guidelines

• Smoke-reduction strategies: In response to mounting evidence about wildfire smoke toxicity, agencies such as U.S. Environmental Protection Agency (EPA) now fund and run studies — like the ASPIRE Study — to evaluate indoor air filtration systems and offer guidance for reducing indoor/outdoor smoke exposure during wildland fire events.
• Occupational chemical regulation: Under laws such as the Toxic Substances Control Act (TSCA), EPA recently released a compliance guide for the Workplace Chemical Protection Program (WCPP), setting requirements for industries that manufacture, process, or use hazardous chemicals.
• Worker safety standards: Organizations like Occupational Safety and Health Administration (OSHA) enforce hazard-communication standards, require safety-data sheets (SDS), limit airborne exposures, and mandate engineering controls or personal protective equipment to reduce chemical exposures at work.
• Pesticide use oversight: Through regulatory review under Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), EPA periodically evaluates and restricts pesticide uses found harmful to humans or the environment, balancing agricultural needs with public health.
• Public health guidance & community awareness: Health departments, environmental agencies, and advocacy groups increasingly issue air-quality alerts, smoke-event advisories, and recommendations (e.g., staying indoors, using air filtration, limiting strenuous outdoor activity) — especially during wildfire seasons or high-pollution episodes.