Spatial Distribution, Potential Sources, and Risk Assessment of Trace Metals of Groundwater in the North China Plain

National Natural Science Foundation of China 41271047 41201514；100-Talent Project of CAS；CAS visiting professorship for senior international scientists；Open Research Fund Program of the field stations of Institute of Geographic Sciences and Natural Resources Research, CAS<p class="FR_field"> Diversion of water for irrigation from the Yellow River has impacted groundwater quality in the North China Plain (NCP). In this study, by using geochemical and isotope methods, groundwater origin, the <span class="hitHilite">spatial</span> <span class="hitHilite">distribution</span> of trace metals, pollution <span class="hitHilite">sources</span>, and health risks were evaluated. Groundwater is recharged from surface water. The primary pollution components in surface water were B, Al, Se, Zn, Mn, and Ni-with concentrations exceeding standards by 100%, 84.4%, 64.4%, 31.1%, 20%, and 2.2%, respectively. In groundwater, exceeding standard rates for those elements were 100%, 100%, 61%, 25.7%, 39%, and 4.9%, respectively. The <span class="hitHilite">spatial</span> <span class="hitHilite">distribution</span> of polluted metals in surface water and groundwater was correlated, indicating an irrigation-influenced <span class="hitHilite">spatial</span> <span class="hitHilite">distribution</span> of trace metals in the groundwater. The trace metals were introduced via anthropogenic and geogenic activities. Zinc poses the most serious non-carcinogenic hazard for local residents. The ingestion pathway is much more likely to lead to zinc toxicity than the dermal absorption pathway. The carcinogenic Cd and Pb could result in an increased cancer <span class="hitHilite">risk</span> for individuals exposed to the water. Non-carcinogenic hazard and carcinogenic <span class="hitHilite">risk</span> attributable to groundwater is serious in the regions traversed by the rivers in the study area.