Metal contamination of groundwater in the mica mining areas of Jharkhand: assessing seasonal variation, sources and human health risk

ABSTRACT

The concentrations of metals in the groundwater were assessed on a seasonal basis to evaluate the possible risk on the local populace via the drinking water pathway in the mica mining areas of Jharkhand in India. Significant temporal variations were observed in the concentration of metals with the highest values being in the post-monsoon season. Spatial variations were also illustrated with higher metals observed in the areas with mining and vehicular activities. Al, Fe and Mn were the metals of major concern, which surpassed the drinking water quality standards at many locations. Considering all the seasons, Al, Fe and Mn exceeded the standards in 72%, 47% and 33% of samples, respectively. The metal concentrations in groundwater of the area can be ascribed to both natural sources and human activities as is depicted from principal component analysis, which resulted in extraction of four factors explaining 66.6% of data variance. For the evaluation of the non-carcinogenic human health risk, Hazard Quotients (HQ) and Hazard index (HI) were calculated as per United States Environmental Protection Agency methodology. Taking into account the geometric mean of the metal concentration in the groundwater, the hazard quotients did not exceed unity for any metal in any season advocating that the metals individually did not pose risk to the consumers of the groundwater. However, the cumulative risk of all the considered the metals as depicted by the Hazard Index suggests appreciable risk to the child population in the pre-monsoon (HI = 1.17) and post monsoon (HI = 1.18) seasons. The health risk assessment identified the child population being more vulnerable to non-carcinogenic risk as compared to the adults. Also, the risk was highest during the post-monsoon season as weighed against the other two seasons. Location-wise HI suggests the groundwater being unfit for drinking in more than 50% of the locations.

KEYWORDS:

• Koderma
• mica mining areas
• groundwater
• metals
• risk assessment
• principal component analysis

Acknowledgments

The authors are grateful to the Department of Science and Technology, Government of India, for providing the necessary funding for the study under the DST – Women Scientist Scheme-A (WOS-A) (Grant No. SR/WOS-A/EA-28/2018). Authors are also thankful to IUAC for extending Q-ICPMS established under the National Geochronology Facility funded by the Ministry of Earth Science (MoES) with project reference number MoES/P.O.(Seismic)8(09)-Geochron/2012.

Authors contribution

Dr Soma Giri: Sample analysis, data compilation, statistical analysis, conceptualization, project administration, manuscript writing, revising and editing. Mr Abhishek Pandey Bharat: analysis, writing and revising. Dr Abhay Kumar Singh: supervision, review and editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Department of Science and Technology, Government of India [SR/WOS-A/EA-28/2018].