Source identification and risk assessment of potentially toxic elements in surface soil of townships in the northwest Hebei region
Soil environmental quality in rural areas is not only crucial to the implementation of the rural revitalisation strategy, but also directly impacts the smooth progress of integrated urban-rural development. However, it faces an increasing risk of contamination from PTEs. Consequently, systematically identifying sources of contamination and assessing their ecological and health risks is essential to ensuring soil safety and sustainable development in rural areas. The results showed that the mean content of eight PTEs in the study area was lower than the background value of the soil environment in Hebei Province only for the elements As, Pb, Zn and Hg, and the exceeding rate of Cr, Cu, Cd and Ni was higher than 55%. APCS-MLR model identified five categories of pollution sources with the following sources and contributions: industrial pollution sources (47.1%), transportation sources (24.3%), natural sources (13.8%), agricultural sources (3.8%), and atmospheric deposition sources (11.0%). Ecological risks are mainly attributed to Cd and Hg, with high-risk areas concentrated in the central part of the study area. Probabilistic health risks indicate that adult and pediatric THI values are within the safe range at the 95% confidence interval and that 16.98% children have some significant carcinogenic risk. Source contribution to health risk indicates that industrial and transportation sources are important sources of control for cancer risk, yet elemental As are less enriched, so there is no need to pay much attention to the impact of natural sources on health risk. In conclusion, this study provides a reference for risk prevention and potential source identification of PTEs in the top soil of the township.