Urban geochemistry: research strategies to assist risk assessment and remediation of brownfield sites in urban areas

Urban geochemical maps of Wolverhampton and Nottingham, based on multielement analysis of surface soils, have shown distribution patterns of "total" metals concentrations relating to past and present industrial and domestic land use and transport systems. Several methods have been used to estimate the solubility and potential bioavailability of metals, their mineral forms and potential risks to urban population groups. These include sequential chemical extraction, soil pore water extraction and analysis, mineralogical analysis by scanning electron microscopy, source apportionment by lead isotope analysis and the development of models to predict metal uptake by homegrown vegetables to provide an estimate of risk from metal consumption and exposure. The results from these research strategies have been integrated with a geographical information system (GIS) to provide data for future land-use planning.