A critical physical geography of urban soil contamination

Anthropogenic lead (Pb) is ubiquitous in urban soils given its widespread deposition over the course of the 19th and 20th centuries from a range of point- and non-point sources, including industrial waste and pollution, leaded paint, and automobile exhaust. While soil scientists and urban ecologists have documented soil Pb contamination in cities around the world, such analyses usually focus on proximal mechanisms but rarely consider more distal factors, notably the social processes mediating Pb accumulation in particular places. In this paper, I articulate a critical physical geography of urban soil Pb contamination that considers the dialectical co-production of soil processes and social processes. Using soil Pb contamination in the flatlands of Oakland, California as an empirical case, I integrate conventional quantitative geochemical mapping with theory and qualitative methods regularly employed in urban political ecology to explain the various spatio-temporal processes that bifurcated the city into flatlands and hills, a topography that is as much social as it is physical, and one that is fundamental to differentiated soil Pb concentrations and their disproportionate impact on low-income people of color. I demonstrate how understanding soil contamination through the lens of social metabolism - with particular attention to the materialitY of the socio-natural hybrids emerging from processes of capitalist urbanization - can complement conventional analyses, while contributing to a "material politics of place" to support struggles for environmental justice. (C) 2015 Elsevier Ltd. All rights reserved.