Urban Geochemistry: A study of the influence of anthropogenic activity on the heavy metal content of soils in traditionally industrial and non-industrial areas of Britain

Heavy metal concentrations have been determined in topsoils (0–15cm) in the London Borough of Richmond-upon-Thames, a non-industrial, mainly residential area of approximately 56 km2, and Wolverhampton an industrial city in the West Midlands of 70 km2. Soil samples were taken on a grid basis at a density of four per km2 and analysis for 25 elements was carried out by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Topsoils in Richmond were found to have significantly higher concentrations of heavy metals in developed locations compared to areas of open space, whilst in Wolverhampton topsoils a greater degree of contamination with Zn was found than with Pb. GIS-based mapping techniques used in conjunction with statistical analysis of the data have highlighted the influence of land-use on the heavy metal content of topsoils in these two urban areas. The highest concentrations of Pb in Richmond-upon-Thames (> 1000 μg/g) tend to occur close to major road junctions on roads with high traffic densities. High levels of Pb (approx. 500 μg/g) also occur in the areas where the oldest housing is located (> 100 a). In Wolverhampton the highest concentrations of heavy metals, Zn in particular, are generally located to the east of the city in areas of both historical and contemporary industrial activity.