Insight User Guide: Soil chemistry

Estimated Background Soil Chemistry

The estimated values provide the likely background concentration of the potentially harmful elements Arsenic (As), Cadmium (Cd), Chromium (Cr), Lead (Pb) and Nickel (Ni) in topsoil. The values are estimated primarily from rural topsoil data collected at a sample density of approximately 1 per 2 km². In areas where rural soil samples are not available, estimation is based on stream sediment data collected from small streams at a sampling density of 1 per

2.5 km²; this is the case for most of Scotland, Wales and southern England. The stream sediment data are converted to soil-equivalent concentrations prior to the estimation.

Estimated Urban Soil Chemistry

Estimated topsoil chemistry of Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), Tin (Sn) and Zinc (Zn) and bioaccessible Arsenic (As) and Lead (Pb) in 23 urban centres across Great Britain. These estimates are derived from interpolation of the measured urban topsoil data referred to above and provide information across each city between the measured sample locations (4 per km²).

Measured Urban Soil Chemistry

The locations and measured total concentrations (mg kg-1) of Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), Tin (Sn) and Zinc (Zn) in urban topsoil samples from 23 urban centres across Great Britain. These are collected at a sample density of 4 per km².

For sites in certain urban areas like London, it is common to not have all of the available soil chemistry data. This is because there is a lack of suitable geochemical data and is a limitation of this dataset.