QUANTIFICATION AND HEALTH RISK ASSESSMENT OF HEAVY METALS IN GROUNDWATER AROUND MINING SITES IN JEMA’A LOCAL GOVERNMENT AREA, KADUNA STATE, NIGERIA

Abstract

Jema’a Local Government Area is notable for decades of mining activities in Kaduna State, Nigeria. This mining activity increases the potentials for groundwater contamination and health risk impact. This study quantifies and assessed health risk of physico-chemical parameters (with respect to heavy metals) in groundwater around mining sites in Jema’a LGA from April to September 2024. Water and sediment samples were collected bimonthly and analyzed for physico-chemical parameters namely temperatures, pH, salinity, conductivity, Total dissolve solids, dissolve oxygen, transparency, nitrate, phosphate, copper, cadmium, lead and zinc. Measurements were done using electronic meter and Atomic Absorption Spectrophotometer (AAS). Data obtained were subjected to analysis of variance (ANOVA), Duncan multiple range test and Pearson correlation coefficient.All parameters measured were within WHO permissible limit. Results revealed that air temperature ranged from 23.7-31.9°C; surface water temperature, 25.5-31.9°C; pH, 6.60-8.22; salinity, 122-150.5 ppm; conductivity, 254.4-312.67 µmhoS/cm; total dissolve solids, 205.05-219.33 ppm; dissolve oxygen, 3.59-11.04 mg/L; transparency, 26.4-49.11 cm; nitrate, 0.06-8.12 mg/L; phosphate, 0.22-0.35 mg/L and copper, 0.002-0.04 mg/L showed significant (p<0.05) mean temporal variation, while zinc in surface water 0.025-0.30 mg/L; lead 0.04-0.06 mg/kg; copper 0.03-0.04 mg/kg and zinc in sediment 0.12-0.17 mg/kg did not show significant (p>0.05) temporal difference. Cadmium and lead were below detectable limit in groundwater during this study. There were high negative correlation between water transparencies and total dissolve solids content (r = -.76). The result suggest that groundwater around mining sites in Jema’a LGA showed early signs of pollution while health risk assessment showed low health risk, underscoring the need for frequent and comprehensive health risk assessment to evaluate potential bioaccumulation and biomagnification of this pollutants.