Assessment of Radon Concentration in Groundwater with Associated Human-Health Implications around Bagwai and Shanono Artisan Gold Mining Site Kano State, Northwestern Nigeria

This study assesses the activity concentration of Radon in underground water around Bagwai and Shanono artisan gold mining Sites in Kano State, Northwestern Nigeria. A total of (39) underground water samples, including sixteen (16) from boreholes and twenty-three (23) from hand-dug wells, were randomly collected. The activity concentration of Radon was analyzed using a portable radon detector, Rad7, from DURRIDGE Company. The results show that the radon concentration in all the water samples ranges from 4.13 to 45.24 Bq/l, with an average value of 20.13 Bq/l. The calculated total annual effective dose due to both ingestion and inhalation for different age groups ranges from 42.40, 57.60 and 65.30 (µSv/y) to 457.10, 622.06 and 704.60 (µSv/y), with an average value of 203.32, 276.70 and 313.51 (µSv/y) for adults, children, and infants respectively. The total excess lifetime cancer risk for different age groups varies from 0.00149, 0.00202 and 0.0247 to 0.0160, 0.0220 and 0.0247 with mean values of 0.00703, 0.00956 and 0.0109 for adults, children, and infants. The obtained results are higher than the internationally recommended limits set by USEPA of 4 to 40Bq/l and the International Commission on Radiological Protection (ICRP) value of 0.1mS/y; thus, the water in the study area is not suitable for drinking and other domestic purposes. Hence, remedial action needs to be taken by the authorities to ensure the continuous utilization of water within the study area.