CADMIUM CONTAMINATION OF CHINESE AGRICULTURAL SOILS

Cadmium is one of the most serious soil pollutants and negatively affects human health. Due to the rapid industrial development, cadmium pollution of agricultural soils in China has received much attention. In this study, we applied a meta-analysis method to assess the current cadmium distribution in agricultural soils in China and assess its potential risk. A full dataset from 338 published studies with 76388 sampling points was compiled to systematically assess the cadmium content in Chinese agricultural soils by using spatial interpolation and geological accumulation index methods. The results showed that the mean cadmium content in agricultural soils in China was 0.35 mg/kg, which was higher than the currently known background cadmium content in Chinese soils (0.097 mg/kg). The spatial distribution of cadmium content in agricultural soils mainly showed that the cadmium content in southern China was greater than that in northern China. The highest cadmium content in agricultural soils was found in mining and smelting areas. This study implies that the increase in soil cadmium content since the 1990s is mainly based on the influence of human activities, especially mining activities. Our study suggests that stricter management should be performed to prevent cadmium pollution in agricultural soil in China in the future.