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

ABSTRACT

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 spatial distribution of trace metals, pollution sources, 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 spatial distribution of polluted metals in surface water and groundwater was correlated, indicating an irrigation-influenced spatial distribution 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 risk for individuals exposed to the water. Non-carcinogenic hazard and carcinogenic risk attributable to groundwater is serious in the regions traversed by the rivers in the study area.

Key Words:

• trace metal
• stable isotopes
• groundwater
• spatial distribution
• sources
• risk assessment

ACKNOWLEDGMENTS

The authors thank the editors and anonymous reviewers for their valuable comments and suggestions, which greatly improved this article.

Additional information

Funding

This research was financially supported by the National Natural Science Foundation of China (Grant Nos. 41271047 and 41201514), the 100-Talent Project of CAS, and the CAS visiting professorship for senior international scientists and Open Research Fund Program of the field stations of Institute of Geographic Sciences and Natural Resources Research, CAS.