Evaluation of ground water quality using heavy metal pollution indices and estimation of health risk

Abstract

ABSTRACT This paper presents the monitoring of heavy metals, including cadmium (Cd), chromium (Cr), lead (Pb), copper (Cu), and zinc (Zn), in the groundwater of the Byrnihat Industrial Area and Guwahati City, which is located in close proximity to the Byrnihat Industrial Area. A total of 20 water samples were collected at distances approximately 1–2 km apart from each other. The pH and the TDS of the collected samples were analysed immediately after collecting samples using a digital pH and TDS meters. The collected samples were analysed using a Flame type Atomic Absorption Spectrophotometer. The highest observed values of Cd, Cr, Pb, Cu and Zn in mg/L were recorded to be 0.0526, 0.1438, 0.5175, 0.1060 and 0.0925, respectively. The average values of Cd, Cr, Pb, Cu and Zn were 0.0246 ± 0.0168 mg/L, 0.0282 ± 0.0421 mg/L, 0.4805 ± 0.0206 mg/L, 0.0653 ± 0.0276 mg/L, and 0.0642 ± 0.0098 mg/L, respectively. Cd and Pb concentrations were above the guideline values set by Bureau of Indian Standards (BIS) and the World Health Organisation (WHO) [WHO recommended values, Cd: 0.003 mg/L, Pb: 0.01 mg/L]. Though the average concentration of Cr was below the allowable limit, five samples within the Byrnihat industrial area were found to be above the limit. High values of pollution indices was observed for all the samples. The cumulative hazard index (HI) values for adults and children were found to be 8.56 and 9.37, respectively. The total cancer risk (TCR) was observed to be 7.87E-03 for adults and 8.54E-03 for children. The result obtained from the present investigation show significant contamination of ground water by heavy metals, particularly Pb, Cd, and Cr concentrations. The observed high values of hazard index and cancer risks indicate significant health risks, necessitating the need for immediate regulatory action.