Quantifying ecological and human health risks of metal(loid)s pollution from non-ferrous metal mining and smelting activities in Southwest China

Abstract

The environmental release and transfer of heavy metal(loids) from natural and anthropogenic sources to neighboring habitats can pose an ecological threat to the exposed biota and habitat, as well as a human health risk to the residents. However, analytical tools to identify the potential contamination source(s) and assess the impact of this transfer have not been well described. Soil samples were collected from affected areas proximal to non-ferrous metal(loid)s mining and smelting facilities. Two integrated assessment methods, based on soil total metal(loid) content, included: (1) the potential ecological risk index combined with positive matrix factorization (PMF) and (2) human health risk assessment combined with PMF. Results indicated that there were four generic sources of pollution (based on PMF analyses of 115 replicated samples collected from four study areas): agricultural and industrial activities, traffic emissions, and natural sources. For ecological risk, the contribution of these metal(loid)s pollution sources were industrial activities (20.34–70.76 %), traffic emissions (18.73–56.93 %), natural sources (3.69–27.02 %), and agricultural activities (3.79–21.43 %). Health risks were higher for children than for adults. Industrial activity was a major source of non-carcinogenic risk to children (32.10–74.62 %) and adults (31.33–73.78 %), and carcinogenic risk to children (22.53–67.27 %) and adults (20.69–64.76 %). Total metal analysis indicated that As and Cd were highly enriched in the soil, but chemical fractionation revealed low As mobility. Total Cd and possibly As were the main pollutants causing the ecological risks at these contaminated sites. This study demonstrates that ecological and human health risks could be quantified to prioritize the pollution sources for reasonable contaminated site risk management.