This research uses neighborhood characteristics (at the zipcode level) to explain changes in toxic releases between 1990 and 1993. It combines the Toxics Release Inventory data with demographic data from the 1990 US Census. We first analyze the location of manufacturing facilities in a particular neighborhood using a sample selection model, and then attribute changes in the level of emissions between 1990 and 1993 to the demographic and socio-economic characteristics of the neighborhood in 1990. The results indicate that variables likely to affect the propensity for communities to engage in political action significantly influence environmental performance. Economic characteristics of neighborhoods (such as income levels and unemployment) also affect changes in releases. Release changes in the Southeastern US exhibit a pattern consistent with racial injustice.