The Public Health Exposome (PHE)
Despite the huge investment that has been made in sequencing the human genome, recent research suggests that only 10 to 30% of the variance in cancer and chronic disease outcomes can be attributed to genetic factors while the remaining 70-90% is attributable to the environment. The exposome is a new exposure science paradigm developed to describe the effects of cumulative lifelong environmental exposures on health across the lifespan, from conception to death. The “exposome” suggests that health disparities result from the interaction of factors operating at multiple levels: from the individual to different forces of the environment in which he or she lives.
The public health exposome includes four environmental domains: the natural, built, social and policy. Health care data include the six primary areas of health disparities: cancer, cardio-metabolic disease, HIV/AIDS, injury, maternal & child health, and mental health/substance abuse. Health outcomes include morbidity, mortality, behavior, and screening data. All data have in common, spatial and temporal units of analysis at the county and annual level. The public health exposome data information system currently includes over 12,000 variables.
The public health exposome model has led us to develop a dynamic, multi-dimensional, longitudinal, data information system that promotes and supports research on the environmental context of health disparities and has led us to adopt trans-disciplinary methods for analyzing and visualizing data. The public health exposome model shifts the focus of the exposome paradigm from individual environmental exposures to that of a population in order to improve our understanding of the environmental etiology of disease. The public health exposome model moves the exposure science field ahead in four ways. First, it operationalizes environmental exposures into four primary elements: natural, built, social and policy. Second, it provides the potential for tracking longitudinal environmental exposures over the lifetime, from “in utero,” forward. Third, it captures nested complexities of exposures that operate across space, place, and time. And fourth, it integrates data on environmental exposures with health behaviors and outcomes data in both a GIS and a relational database and supports multiple methods of visualization and analysis.
Public Health Exposome Database
The public health exposome database currently integrates data on environmental exposures with health disparities indicators for populations for the United States for the period 1980 to 2010. The PHE data base currently is comprised of over 15,000 variables. The common unit of analysis for both environmental and health indicators is the county, although, where available, data for other geospatial units were collected (e.g., census tracts, zip codes, municipalities, legislative districts, etc.). While most data represent annual rates, data for some variables are available by other temporal units including day and month. Data are available in both ArcGIS and SQL Server. Like the human genome, once collected and sequenced, these steps will never have to be repeated.