Cumulative Exposures to Environmental and Socioeconomic Risk Factors in
Milwaukee County, Wisconsin
Abstract
The environmental justice literature demonstrates consistently that
low-income and minority communities are disproportionately exposed to
environmental hazards. In this case study, we examined cumulative
multipollutant, multidomain, and multimatrix environmental exposures in
Milwaukee County, Wisconsin. We identified spatial hot spots in
Milwaukee County both individually and through clusters across a profile
of environmental pollutants that span regulatory domains and matrices of
exposure, as well as socioeconomic indicators. The most sensitive
cluster within the urban area was largely characterized by low
socioeconomic status (SES) and an overrepresentation of the Non-Hispanic
Black (NHB) population relative to the county as a whole. In this
cluster, average pollutant concentrations were equivalent to the 78th
percentile in county-level blood lead levels, 67th percentile in
county-level NO2, 79th percentile in county-level CO, and 78th
percentile in county-level air toxics while simultaneously having an
average equivalent to the 62nd percentile in county-level unemployment,
70th percentile in county-level population rate lacking a high school
diploma, 73rd percentile in county-level poverty rate, and 28th
percentile in county-level median household income. The spatial patterns
of pollutant exposure and SES indicators suggested that these
disparities were not random but were instead structured by socioeconomic
and racial factors. Our case study, which combines environmental
pollutant exposures, sociodemographic data, and clustering analysis,
provides a roadmap to identify and target overburdened communities for
interventions that reduce environmental exposures and consequently
improve public health.