Normal background concentrations of contaminants in the soils of England : results of the data exploration for Cd, Cu, Hg and Ni

The British Geological Survey (BGS) has been commissioned by the Department for Environment, Food and Rural Affairs (Defra) to give guidance on what are normal levels of contaminants in English soils in support of the Part 2A Contaminated Land Statutory Guidance. This has initially been done by studying the distribution of four contaminants – arsenic (As), lead (Pb), benzo[a]pyrene (BaP) and asbestos – in topsoils from England. The work was extended further to include cadmium (Cd), copper (Cu), nickel (Ni) and mercury (Hg) enabling methodologies developed by the project to be tested on a larger range of contaminants. This report serves to record the information collected on the additional four contaminants (Cd, Cu, Ni and Hg) that was undertaken in order to define their Normal Background Concentrations (NBCs). Other earlier Project reports should be consulted for the full background to methods used to analyse these data, in particular Work package 1&2, and Work package 3 reports. The Technical Guidance Sheets, and Technical Guidance Sheet Supplementary Information for each of these additional contaminants provide the final synthesis of this exploratory data analysis, and should be considered as the definitive resource for the Normal Background Concentrations.