Physics Access (Jul 2024)
Assessment of Heavy Metals, Gross Alpha, Gross Beta and Radon Activity Concentration in Groundwater around Doguwa and its Environs, within Kano State, Nigeria
Abstract
This study assessed the activity concentrations of gross alpha, gross beta, Radon and heavy metals in groundwater sources from illegal mining areas in Doguwa Local Government, Kano State, Nigeria. Water samples from five distinct mining areas were analyzed for gross alpha and beta radioactivity using a portable single-channel gas-free proportional detector (MPC2000B-DP) via ISO9696 and ISO9697 methods, Radon levels with a Rad7 (DURRIDGE) detector, and heavy metals with atomic absorption spectroscopy. Gross alpha concentrations ranged from 0.0000238 to 0.00013 Bq/L, averaging 0.00008158 Bq/L, a value below the WHO limit of 0.5 Bq/L. Gross beta concentrations ranged from 0.536 to 2.78 Bq/L, averaging 1.7056 Bq/L, exceeding the WHO limit of 1.0 Bq/L. Radon levels varied from 0.12 to 1.7 Bq/L, averaging 1.102 Bq/L, below the WHO limit of 11.1 Bq/L. Annual effective doses from gross alpha ingestion were 4.10918E-05, 4.16874E-06, and 8.33748E-06 mSv/year for adults, infants, and children, respectively. Radon exposure doses were 1.61E-13 and 8.04E-14 mSv/year for adults and children, respectively, below the 0.1 mSv/year limit. However, beta radiation doses exceeded the 0.1 mSv/year limit, with values of 0.85911072, 0.21477768, and 0.42955536 mSv/year for adults, infants, and children, respectively. The average concentrations of heavy metals were 0.00058 mg/L for Cd, 0.012 mg/L for Cr, 0.00628 mg/L for Fe, 0.0046 mg/L for Mn, 0.09534 mg/L for Ni, 0.01214 mg/L for Pb, and 0.00582 mg/L for Zn. Children exhibited elevated cancer risks from heavy metal ingestion 0.004865 and dermal exposure 0.000069, with hazard quotient values of 0.740205 and 0.004882, respectively. The hazard index and lifetime cancer risk for children were 0.004882, exceeding USEPA recommended values. While gross alpha and radon levels were within safety limits, beta radiation levels and heavy metal hazard quotients exceeded maximum contamination levels, highlighting significant health risks, including DNA damage and increased cancer risks.
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