Spatial inequality and the distribution of industrial toxic releases: Evidence from the 1990 TRI

Objective. This research investigates environmental justice activists' claims that pollution is unevenly distributed across communities in the United States. We examine three possible explanations for environmental inequity: racial discrimination, economic stratification, and urban ecology. Methods. To assess pollution levels, we use the U.S. Environmental Protection Agency's 1990 Toxics Release Inventory (TRI), a data set which contains information on permitted and accidental releases of over 300 toxic chemicals from manufacturing facilities. We combine this information with county-level data from the 1990 U.S. Census and the 1990 County Business Patterns. Results. In support of activists' claims, the regression analysis reveals a positive relationship between proportion Black and toxic releases to air, which is partly explained by urbanization and industrial location. The effect of economic status is revealed to be curvilinear, with lower- and higher-income counties experiencing lower levels of toxic releases than middle-income counties. Conclusions. Our results suggest that processes such as urbanization and industrial location, which are often treated as control variables, may best be regarded as mechanisms through which disadvantaged residents and toxic pollution come together in space.