RADIOLOGICAL IMPLICATIONS OF ARTISANAL GOLD MINING ACTIVITIES IN GABABIYU, MINNA METROPOLIS, NIGERIA

Abstract

Radiological contaminations of the human environment due to anthropogenic activities have been associated with significant human health challenges. Forty surface soil samples collected at random from Gababiyu artisanal gold mining site in Minna were assessed for their radiological contents using gamma spectrometric technique which employs NaI (Tl) detector. Radiological hazard parameters were also computed from the measured activity concentrations in order to assess the level of exposure of the miners and the public to ionising radiation. Specific activities of 226Ra, 232Th and 40K ranged from 10.27±2.88 to 152.60±3.80 Bq.kg-1, 32.67±1.93 to 185.90±6.06 Bq.kg-1 and 35.18±1.45 to 947.50±7.51 Bq.kg-1 respectively, with mean values of 65.06±4.20, 87.63±2.89 and 267.94±4.29 Bq.kg-1 in sequence. The mean values for 226Ra and 232Th were above the UNSCEAR stipulated global averages. Thus, indicating that the soil bears significant concentrations of 226Ra and 232Th. Computed average absorbed dose rate at 1 m above ground was 94.16 nGy.h-1 with corresponding mean annual dose equivalent of 0.22 mSv.y-1 and average excess lifetime cancer risk of 0.76×10-3. These values were all below respective safety limits set by UNSCEAR. The results of this investigation therefore indicated minimal radiological risk associated with artisanal gold mining activities in the studied area.