Source-based health risk assessment of heavy metal contamination in Soil: A case study from a polymetallic mining region in Southeastern Hubei, Central China

Abstract

To conduct a precise health risk assessment of heavy metals (HMs) in soil, it is imperative to ascertain the primary sources of potential health risks. To achieve this objective, we conducted comprehensive measurements of HMs, including Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Ti, V, and Zn, in soil extracted from the polymetallic mining area. A method combining the positive matrix factorization with the health risk assessment model was used to quantify the source-specific health risks. Results indicate that when compared to the local background values, the accumulation of Cd, Cr, Cu, Mn, Pb, Sb, and Zn in the local soil appears to be influenced by anthropogenic activities. Among these sources, local industrial-related activities contributed the largest proportion of HMs to the soil at 34.7%, followed by natural sources at 28.7%, mining and metallurgy-related activities at 28.2%, and traffic-related activities at 8.40%. Although the non-carcinogenic and carcinogenic risks associated with individual heavy metal elements were found to be below safety thresholds, the cumulative health risks stemming from total heavy metals exceeded safety limits for children. Moreover, the unacceptable health risks for children originating from industrial-related activities, natural sources, and mining and metallurgy-related activities were primarily concentrated in proximity to mining sites and industrial areas within the local region. This investigation furnishes valuable insights that can aid governmental authorities in formulating precise control policies to mitigate health threats posed by soils in polymetallic mining areas.