Composite assessment of human health risk from potentially toxic elements through multiple exposure routes: A case study in farmland in an important industrial city in East China

Accumulation of potentially toxic elements (PTEs) in farmland soils and agricultural products is an issue of considerable concern related to food safety and human health. Assessment of composite health risks caused by exposure to PTEs through different pathways and the spatial probability of these risks could help in soil management and reduction in the corresponding human health risk. In this study, we collected 932 soil samples and corresponding samples of rice planted at the same locations in an industrial city in eastern China. The composite human health risk, including the health risks caused by Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni from soil inhalation, ingestion, and dermal contact combined with the consumption of rice were assessed. Sequential Gaussian stochastic simulation and probability kriging were employed to explore the spatial pattern of the composite health risk. The results showed that 13.52%, 5.47%, 2.68%, 2.58%, 1.61%, 0.86%, and 0.21% of soil samples collected from the study area were polluted by Hg, Cd, Pb, Cu, Zn, Ni, and Cr, respectively. Furthermore, 65.02%, 20.28%, 10.94%, 4.72%, 0.75%, 0.11%, and 0.11% of rice samples were polluted by high levels of Ni, Cr, As, Cd, Pb, Hg, and Zn, respectively. Children had a higher hazard index than adults for non-carcinogenic health risks. Both children and adults had potential carcinogenic risks. The largest contributor to non-carcinogenic health risks was As, whereas Ni was the largest contributor to carcinogenic risk. Consumption of contaminated rice accounted for> 90% of the total non-carcinogenic and carcinogenic health risks, suggesting that PTEs accumulation in rice could exert harmful effects on human health. In terms of their spatial patterns, both non-carcinogenic and carcinogenic risks were associated with areas with a high density of anthropogenic activities. Residents in most areas in the study region have a high probability of experiencing significant carcinogenic and non-carcinogenic health effects caused by exposure to PTEs. Children have a higher probability of non-carcinogenic health risk than adults across the study area. The results revealed that consumption of contaminated crops poses essential potential health risks to humans. Measures should be undertaken to reduce the content of contaminated PTEs in farmland soils and rice, and children should be listed as a priority for protection from exposure to PTEs.