Researchers at the University of Michigan, School of Natural Resources and Environment published a paper last month that examines an important question about environmental disparities: Which came first – The people or the pollution? More specifically, are present-day disparities around hazardous sites the result of a pattern of placing hazardous waste sites, polluting industrial facilities, and other locally unwanted land uses disproportionately where poor people and people of color live? Or are they the result of demographic changes that occur after the facilities have been sited? Their answer published in the December issue of the journal Environment Research Letters points to a clear pattern of disproportionately placing hazardous waste facilities in people of color communities at the time of siting.

The authors used a national database of commercial hazardous waste facilities sited from 1966 to 1995 and examined the demographic composition of host neighborhoods at the time of siting and demographic changes that occurred after siting. They found strong evidence of disparate siting for facilities sited in all time periods, though they did find some evidence of post-siting demographic changes. According to the authors, these changes “were mostly a continuation of changes that occurred in the decade or two prior to siting, suggesting that neighborhood transition serves to attract noxious facilities rather than the facilities themselves attracting people of color and low income populations. Our findings help resolve inconsistencies among the longitudinal studies and builds on the evidence from other subnational studies that used distance-based methods. We conclude that racial discrimination and sociopolitical explanations (i.e., the proposition that siting decisions follow the ‘path of least resistance’) best explain present-day inequities.”

This study examined the processes by which racial and socioeconomic disparities in the location of polluting industrial facilities can occur. According to the authors, “prior studies have had mixed results … principally because of methodological differences, that is, the use of the unit-hazard coincidence method as compared to distance-based methods.” This is the first national-level environmental justice study to conduct longitudinal analyses using distance-based methods.

The authors came to conclude that “Our findings show that rather than hazardous waste TSDFs ‘attracting’ people of color, neighborhoods with already disproportionate and growing concentrations of people of color appear to ‘attract’ new facility siting. The body of distance-based research suggests that government policies, industry practices and community empowerment measures are needed to ensure fairness in the siting process and to address disparities in risks associated with existing facilities. In addition, more studies that use reliable methods to assess such racial and socioeconomic disparities in the location of other types of environmental hazards could also improve our understanding of the processes and factors that contribute to environmentally unjust conditions in the United States and around the world.”

The authors also published a review paper in the same issue of this journal that summarized previous environmental justice studies that demonstrated the existence of racial and socioeconomic disparities in relation to a wide range of environmental hazards.