Abstract
BackgroundThe health-risk assessment paradigm is shifting from single stressor evaluation towards cumulative assessments of multiple stressors. Recent efforts to develop broad-scale public health hazard datasets provide an opportunity to develop and evaluate multiple exposure hazards in combination.MethodsWe performed a multivariate study of the spatial relationship between 12 indicators of environmental hazard, 5 indicators of socioeconomic hardship, and 3 health outcomes. Indicators were obtained from CalEnviroScreen (version 3.0), a publicly available environmental justice screening tool developed by the State of California Environmental Protection Agency. The indicators were compared to the total rate of hospitalization for 14 ICD-9 disease categories (a measure of disease burden) at the zip code tabulation area population level. We performed principal component analysis to visualize and reduce the CalEnviroScreen data and spatial autoregression to evaluate associations with disease burden.ResultsCalEnviroScreen was strongly associated with the first principal component (PC) from a principal component analysis (PCA) of all 20 variables (Spearman ρ = 0.95). In a PCA of the 12 environmental variables, two PC axes explained 43% of variance, with the first axis indicating industrial activity and air pollution, and the second associated with ground-level ozone, drinking water contamination and PM2.5. Mass of pesticides used in agriculture was poorly or negatively correlated with all other environmental indicators, and with the CalEnviroScreen calculation method, suggesting a limited ability of the method to capture agricultural exposures. In a PCA of the 5 socioeconomic variables, the first PC explained 66% of variance, representing overall socioeconomic hardship. In simultaneous autoregressive models, the first environmental and socioeconomic PCs were both significantly associated with the disease burden measure, but more model variation was explained by the socioeconomic PCs.ConclusionsThis study supports the use of CalEnviroScreen for its intended purpose of screening California regions for areas with high environmental exposure and population vulnerability. Study results further suggest a hypothesis that, compared to environmental pollutant exposure, socioeconomic status has greater impact on overall burden of disease.
Highlights
The health-risk assessment paradigm is shifting from single stressor evaluation towards cumulative assessments of multiple stressors
CalEnviroScreen 3.0 includes 12 environmental hazard variables: ozone levels, concentrations of particulate matter ≤ 2.5 μm in diameter, diesel particulate matter concentrations, traffic density, drinking water contamination, active pesticide mass used in agriculture, airborne toxic chemical releases, water body impairments, sites hazardous to groundwater, sites targeted for cleanup, hazardous waste sites, and solid waste sites
For Question 1, describing the multivariate structure of the CalEnviroScreen source data, we employ principal component analysis (PCA) to visualize which exposures are associated with each other and the prevailing patterns of overall exposure encountered in California
Summary
The health-risk assessment paradigm is shifting from single stressor evaluation towards cumulative assessments of multiple stressors. In order to protect vulnerable individuals and communities, environmental health science has broadened in emphasis from single-stressor evaluations to include integrated assessment of multiple stressors [1, 6,7,8,9,10] This integration among disparate exposures presents a significant methodological challenge, requiring qualitative and lessformal quantitative methods that address hazard as the potential for harm [3, 4, 6, 7, 11, 12]. These impact assessments use metrics of exposure and dose-response but lack the quantitative direct link of these two factors that is common in risk assessment Based on these methods, environmental justice advocates and health geographers have developed a variety of maps, indices, and tools that integrate environmental health hazards from multiple stressors at varying geographic scales. Some of these integration tools and methods consider the potential interaction between environmental contributors to risk and the preexisting vulnerability of exposed populations to environmental stressors [1, 8, 16, 19, 23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
