Spatiotemporal Perspectives on Air Pollution and Environmental Justice in Hamilton, Canada, 1985–1996

Abstract This article addresses two questions: (1) How do spatiotemporal changes in air pollution levels—specifically, total suspended particulates (TSP)—rise or fall with socioeconomic status? (2) A critical equity interpretation of environmental policy then motivates this question: does the pursuit of average regional reductions in pollution benefit those who need improvements least, benefit those who need improvements most, or maintain the status quo? TSP data are drawn from networks of monitoring stations operated in 1985, 1990, and 1995. The monitoring data are interpolated with a kriging algorithm to produce estimates of likely pollution distribution throughout Hamilton. Exposure is related to socioeconomic status (SES) variables at the census tract level for corresponding years—1986, 1991, and 1996—and associations are tested with ordinary least squares (OLS) and spatial regression models. The results show that whether TSP rises or falls, injustice persists but becomes less pronounced over time. Among all SES indicators, dwelling value consistently predicts TSP levels for all years, suggestive of a land-rent/spatial-externalities dynamic. As we move forward in time, it becomes increasingly difficult to differentiate air-pollution exposure among Hamilton neighborhoods, as industrial TSP sources become more dispersed in the region and transportation pollution becomes relatively more important. We conjecture that more equitable distributions of air pollution have resulted more from post-Fordist industrial and spatial restructuring than from environmental policy intervention. Injustice in Hamilton and its apparent relationship with changing industrial structure appear similar to results in the United States and speak to a continental, intraurban environmental-justice experience.