Organic Contaminants in Urban Soils

Abstract

AbstractOrganic pollutants are predominantly synthetic compounds made or extracted by humans, and it is therefore not surprising that they are common contaminants in urban soils. This chapter provides details of the immense range of potential organic pollutants in urban soils, including their types, physical properties, chemical structures, and sources. The behaviour of non-polar, polar, and ionic organic compounds in soils is explained in terms of their key chemical reactions, including abiotic and biological degradation, and transport phenomena are also addressed, before a brief discussion of toxicity. Sampling, extraction, and chemical analysis methods are covered briefly, together with background concentrations, regulatory contamination thresholds, and contamination indices. A comprehensive case study is focused on polycyclic aromatic hydrocarbons (PAH) in the highly urbanised Pearl River Delta region of China. This case study uses the PAH family of compounds to illustrate many of the concepts needed to understand the behaviour of persistent organic pollutants in urban soils, concluding with their fluxes and a conceptual PAH cycle.KeywordsOrganic contaminantsUrban soilsHydrocarbonsPersistent organic pollutantsPAHPearl River Delta