China: China is drawing the geochemical reference map (or map of human contamination) which covers 81 chemical indicators (including 78 kinds of elements). The measurement will be based on deep samples and surface samples. Deep samples will be collected from 1 meter under earth which are undisturbed by human pollutions; surface samples are from 25 cm under earth which will be used to measure the pollution caused by human activities. The human pollution would be measured based on the pollution differences between the surface samples and the respective deep samples.
Source: China about