Human Health Risk Assessment of Heavy Metals in Groundwater in the Luan River Catchment within the North China Plain

The Luan River catchment within the North China plain has been famous for the development of its iron mineral resources since the 1950s. At the same time, it is also the main grain-producing area, known as the granary of eastern Hebei Province. Groundwater plays an important role in this region, and thus, it is imperative for us to improve our understanding of the heavy metal groundwater contamination in this catchment. Therefore, a total of 144 groundwater samples were collected for chemical analysis from 16 operational private wells of local residents in the study area, over eight consecutive periods from December 2016 to May 2017. Each shallow groundwater sample was analyzed for 39 heavy metals including among others, As, B, Ba, Be, Cd, Cr, Cu, Fe, Li, Mn, Mo, Ni, Sb, Se, Sn, Sr, V, and Zn. However, subsequent analyses only focused on three heavy metals (Cd, Cr, and Ni) that exceeded the Groundwater Quality Standard III. Spatial and temporal variations of Cd, Cr, and Ni in the shallow groundwater were analyzed. Cr was found to have the highest concentrations, followed by Ni and Cd. A human health risk assessment was conducted where carcinogenic risks and Hazard Quotients (HQs) were evaluated separately. The results indicate that both the carcinogenic risks and HQs of Ni and Cr are higher than the recommended standard value. Therefore, the prevention and control of heavy metal contamination in the Luan River catchment should focus on Ni and Cr