The evaluation of heavy metals pollution in soils of the lower reaches of the Hengshi River within the Dabaoshan mining area based on fuzzy mathematics

Heavy metals combined pollution of soils is inevitable during the mining activity, and the contamination is complex, varied and ambiguous, conforming to the principle of fuzzy mathematics analysis. In this paper, six heavy metals of surface soils from Shangba Village in the lower reaches of the Hengshi River within the Dabaoshan mine were analyzed through construction of fuzzy mathematics pollution evaluation model in comparison with the traditional single factor pollution index and comprehensive pollution index evaluation method. The results show that the soils have been subjected to severe combined pollution from multiple heavy metals comprising Cd, Cu and As. The Cd pollution is most heavy, whereas the pollution of Cu and As is less. The traditional integrated pollution index and Nemerow pollution index show light and heavy pollution respectively. Therefore, the fuzzy mathematics pollution evaluation model can be used in the evaluation of heavy metals pollution of soils around the mining area by introducing appropriate impact factor, which is optimized and reformed based on the traditional pollution evaluation and can have good operability and broad applicability.