Mapping Where Health Happens: GIS Data Bring Place Into the Exposome

For decades, the search for the roots of chronic disease has focused inward, on genomes, transcripts, proteins, and metabolites. Yet the environment that surrounds every person, from the air they breathe to the heat of their neighborhood and the distance to the nearest clinic, shapes biology just as powerfully as any DNA sequence. A new commentary published in the Journal of Exposure Science & Environmental Epidemiology argues that the tools to capture that environmental dimension are finally maturing, and that publicly available geographic information systems (GIS) datasets may be the key to making the exposome a routine part of human health research.

The exposome, a concept first articulated to complement the genome, encompasses the totality of environmental exposures an individual experiences across a lifetime. In principle, it is the environmental mirror of the genome: where genes catalog inherited potential, the exposome catalogs the accumulated external and internal pressures that regulate health and disease. In practice, however, measuring the exposome has proven far harder than sequencing DNA. Genomic and multiomic technologies now deliver extraordinarily deep characterizations of biological systems, but the ability to characterize the external environment with comparable depth and rigor remains comparatively limited. Questionnaires, the traditional workhorse of exposure assessment, capture only what participants remember, notice, and are willing to report, leaving vast swaths of the chemical, physical, and social environment unmeasured.

A new study by MacNell and colleagues, examined in the commentary by R. Keith Reeves of Duke University School of Medicine, demonstrates a practical route forward. The researchers systematically integrated multiple publicly available geospatial datasets within an exposome-wide association study, or ExWAS, framework. Their platform was the Personalized Environment and Genes Study, known as PEGS, a research cohort that has already proven unusually versatile. Using residential information from more than 7,500 participants, the team linked each participant’s location to environmental indicators derived from geospatial datasets and then evaluated associations between those indicators and a range of common disease phenotypes. The approach effectively turns a participant’s address into a dense, multidimensional exposure profile, one assembled at low cost from data that already exist.

The technical logic of the ExWAS framework deserves attention. Analogous to genome-wide association studies, which scan hundreds of thousands of genetic variants for statistical links to disease, an ExWAS scans a broad panel of environmental exposures for associations with health outcomes. The challenge has always been assembling a sufficiently rich panel of exposures. GIS-based linkage addresses this by drawing on satellite-derived air pollution estimates, proximity to hazardous sites, temperature surfaces, and other spatially referenced data layers, then assigning each participant values based on where they live. Because these datasets are public and standardized, the same exposure panel can be reconstructed for almost any cohort with residential addresses, enabling retrospective and prospective analyses across studies at relatively low cost.

One of the most significant findings highlighted in the commentary is that geospatial information does more than reproduce what questionnaires already capture. In the MacNell analysis, GIS-based measures identified associations that overlapped with prior PEGS findings, including relationships between environmental exposures and cardiovascular and metabolic phenotypes. Critically, the geospatial approach also surfaced potential associations with exposures that had not previously been captured by survey-based assessments. That combination, confirming known signals while revealing new ones, is exactly what a maturing exposure science should deliver, and it suggests that place-based data can genuinely complement rather than merely duplicate self-reported measures.

PEGS has become a proving ground for this kind of integrative work. Beyond the new GIS-linked ExWAS, the cohort has supported exposome-wide studies of common diseases, the development of polyexposure risk scores for type 2 diabetes, investigations of air-pollution mixtures and inflammatory skin disease, and studies that combine geographic exposures with genetic susceptibility to immune-mediated disease. A dedicated dataset resource now provides genomic, exposomic, and geospatial data together, allowing researchers to test how environmental and genetic risk factors interact. Earlier questionnaire-based ExWAS analyses in PEGS had already revealed both expected and novel risk factors associated with cardiovascular outcomes, establishing the statistical machinery that the geospatial extension now enriches.

The broader opportunity, as Reeves frames it, could extend well beyond any single association. A partly standardized geospatial exposome would provide an environmental data infrastructure applicable across cohorts, retrospective and prospective alike. Exposure questionnaires could be complemented and streamlined, while environmental measures could be updated dynamically as participants move or as new data layers become available. This is a subtle but important shift in study design: rather than freezing exposure history at enrollment, researchers could maintain living exposure profiles that track participants through time. In a mobile society, where people change neighborhoods, cities, and even countries, that flexibility addresses one of the most persistent weaknesses of static exposure assessment.

The scope of what can be measured geospatially is also expanding. Air pollution and hazardous waste sites were the natural first targets, since both have well-developed national datasets and established health links. But the commentary points toward a much wider canvas: extreme heat, water quality, healthcare access, and other environmental and social determinants of health could all be layered into a geospatial exposome. Each addition broadens the range of exposures captured and opens new hypotheses about how the places people live shape chronic disease. Heat exposure, for instance, intersects with cardiovascular strain; healthcare access intersects with disease management and outcomes; water quality intersects with a growing list of chemical exposures of concern. Integrating these layers transforms the address from a simple demographic variable into a rich exposure summary.

The end goal, according to the commentary, is for environmental exposure information to become a routine component of phenotyped cohorts, integrated alongside genomic, molecular, clinical, and social determinants of health data. In that vision, a participant in a large biobank would carry not only a genome sequence and a set of lab values but also a standardized, continuously updated environmental profile derived from where they have lived. Disease association studies could then interrogate genes and environment in a single unified framework, something that has been promised conceptually for years but has been difficult to deliver because environmental data lagged so far behind biological data in depth and standardization.

Challenges remain, of course. Geospatial datasets are proxies, not personal monitors, and they capture exposure at residential locations rather than wherever a person actually spends their day. Spatial resolution, temporal coverage, and the comparability of datasets across regions all impose limits on how finely the exposome can be resolved. Yet the direction of travel is clear. As public geospatial data grow in quality and coverage, and as frameworks like ExWAS provide disciplined ways to test thousands of exposures against thousands of health outcomes, the environment is moving from the margins of epidemiology toward its center. The commentary on the MacNell study makes the case that putting place into the exposome is no longer an aspiration but an operational reality, one that could reshape how scientists understand, and ultimately prevent, the diseases that define modern life.

Subject of Research: Integration of geographic information systems data into exposome-wide association studies for human health research

Article Title: Putting place into the exposome for human health. Comment on: ‘Applying geographic information systems data linkages for an exposome-wide association study in the Personalized Environment and Genes Study’

Article References: Reeves, R. K. (2026). Putting place into the exposome for human health. Comment on: ‘Applying geographic information systems data linkages for an exposome-wide association study in the Personalized Environment and Genes Study’. Journal of Exposure Science & Environmental Epidemiology. https://doi.org/10.1038/s41370-026-00980-6

Image Credits: AI Generated

DOI: 10.1038/s41370-026-00980-6

Keywords: exposome, GIS, ExWAS, PEGS study, environmental epidemiology, air pollution, geospatial data, cardiovascular disease, type 2 diabetes, exposure assessment, public health, genomics