Monitoring and Risk Assessment on Heavy Metals in Soil at a Mining Area in Fujian

Accumulation and health risks of heavy metals in the soils around a mine in Fujian were studied. Contents of Cd, Pb and Cr in the agricultural fields nearby were determined. Heavy metal pollution on the soil and damages to the ecology were evaluated based on various indices, and the health risks to humans were assessed using a probability assessment model. The results showed that the soils in the surveyed areas were contaminated by Cd, Pb and Cr to varying extents. The average individual pollutant index on the metals ranked in the order of Cd > Pb > Cr, and the over-all pollution index was 1.21 implying that the soils were under a lightly polluted condition. The average potential ecological risk was Cd > Pb > Cr with a comprehensive ecological risk index of 226 indicating a medium level of ecological hazard. The Cd in the soils was assessed to belower than 10^-4, a level less likely to risk cancers in humans as suggested by experts. The non-carcinogen risks index on Pb did not exceed the accepted limit of 1, which ought not to cause any health concerns. On the other hand, the Cr contamination in the soils made the carcinogenic risk index 12.9% greater than the threshold value of 10^-4 that could post a thread to human health.