Assessment of the soil quality by fuzzy mathematics in farmland around a uranium mill tailing repository in China

Based on statistical analysis of the concentrations of multiple contaminants such as radionuclides, heavy metals and organochlorine pesticides in soil samples, the soil quality of a large piece of farmland around a uranium mill tailing (UMT) pond was assessed by fuzzy mathematics. This study found that the concentrations of U, Th, Cd, Pb and DDT in all sampling sites and Cr in sites 1 and 2 were above the standard values, indicating the effects of the UMTs. We also detected residual OCPs in all soil samples in the study area. The fuzzy mathematics assessment showed that the farmland soil quality around the uranium mill tailing pond at site 1 belongs to class II, while sites 2-6 belong to class I. Based on the above conclusions, in the present study most of the farmland soils were suitable for growing crops except for the areas near the UMT pond (0-500 meters).