Groundwater metal pollution and health risk assessment in river valley heavy industrial cities of arid regions in China

Abstract

Xining, a river valley city in China’s arid region, serves as an important industrial hub with a fragile ecological environment. While groundwater heavy metal pollution in this area has drawn increasing concern, the sources and associated human health risks remain inadequately understood. This study analyzed 144 shallow groundwater samples from urban Xining for 14 heavy metals (Fe, Al, B, Mn, Ba, Zn, Pb, Cr⁶⁺, Ni, Cu, Co, Sb, Cd, and As) using the Nemerow comprehensive pollution index, correlation analysis, and the USEPA health risk assessment model. Results identified Fe, Al, B, Mn, Ba, Pb, Cd, and As as the primary pollutants, especially concentrated in river valley plains. These contaminants primarily originate from natural sedimentary conditions and human activities such as industrial and agricultural development. The pollution indices for Al, Pb, Mn, and Fe exceeded clean water thresholds, indicating serious contamination and the need for enhanced regulation. Health risk assessments revealed that children face greater exposure risks than adults, with arsenic and nickel being the main contributors to carcinogenic risk. Sensitivity analysis further showed that As, Fe, and Cd posed the greatest non-carcinogenic and carcinogenic risks, particularly in human-impacted areas such as the Nanchuan and Beichuan valleys and Ganhegou. These findings provide essential insights for groundwater safety management in plateau river valley cities and similar vulnerable regions.

Keywords

Groundwater / Heavy metals / Monte Carlo simulation / Health risk / Children and adult / Carcinogenic risks / Hydrogeological survey engineering / Xining City / Sustainable Development Goals (SDG 6)

CRediT authorship contribution statement

Shi-yu Liu, Bing Yi and Chun-yan Liu conceived of the present idea. Bing Yi and Chun-yan Liu carried out field investigation and sample collection. Shi-yu Liu, Bing Yi and Chun-yan Liu processed experiment data and drawed pictures. All authors discussed the results and contributed to the final manuscript.

Declaration of competing interest

The authors declare no conflicts of interest.

Acknowledgement

This research was supported by the projects of the Geological Survey (DD20240501104, DD20230422).

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