Natural and anthropogenic soil geochemical characteristics of Belfast, Glasgow, Cardiff and east London, in the United Kingdom

The British Geological Survey's Geochemical Baseline Survey of the Environment (G-BASE) project is responsible for the systematic geochemical mapping of the land surface of Great Britain. Samples of soils, stream sediments and stream waters collected at an average density of 1 sample per 1.5 km2 are determined for up to 46 elements/parameters. Concerns over land quality in population centres have raised interest in the concentrations and behaviour of chemical substances within the urban environment. This prompted the G-BASE project to expand the geochemical survey into urban areas. The sampling strategy of urban areas differs to that of the regional survey as only soil samples are collected, but at a much higher density of 4 samples per km2. Top (5 - 20 cm) and deeper (35 - 50 cm) samples are collected at each site. 22 urban centres from different parts of the UK have been surveyed so far, giving an extensive dataset of over 16000 samples. This provides a unique picture of the status of UK urban soil chemistry.