Socioeconomic isolation and exposure to air toxics in the St. Louis metropolitan area, USA

Abstract

Listen

Translate article

Background: A growing body of research has examined the association between neighborhood residential segregation and exposure to hazardous air pollutants in the United States. However, few studies have incorporated neighborhood-level measures of segregation that account for contextual factors throughout an entire study area. We used spatial analyses to investigate the relationship between socioeconomic isolation and exposure to carcinogenic air toxics in the St. Louis metropolitan area. Methods: We developed spatial measures of neighborhood-level poverty isolation and neighborhood-level unemployment isolation. To construct these isolation measures, we obtained census tract-level sociodemographic data from the US Census Bureau. Air pollution data were obtained from the US Environmental Protection Agency and spatial analyses, conducted in ArcGIS, were used to identify air pollution hotspots. We used multivariable logistic regression to examine the association between poverty isolation, unemployment isolation, and exposure to air pollutants. Results: We identified four distinct air toxic hotspots in the St. Louis metropolitan area. Census tracts in the highest quartile of poverty isolation were eight times more likely to be located in an air toxic hotspot than tracts in the lowest quartile (95% Confidence Interval, 4.8-11.9). Census tracts in the highest quartile of unemployment isolation were three times more likely to be located in an air toxic hotspot than tracts in the lowest quartile (95% Confidence Interval, 1.9-4.6). Conclusions: Spatial analyses revealed that poor neighborhoods are disproportionately exposed to air pollutants. Despite improvements in US air quality since the 1970s, racial and economic disparities in exposure to hazardous air pollutants persist. Future investigations are warranted to identify sources of hazardous air pollutants and inform public health efforts to advance environmental justice.