Browsing by Author "Shammah, K."

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    ASSESSMENT OF RADIOLOGICAL HAZARDS FROM MINING ACTIVITIES OF MBAYION LIMESTONE MINE IN GBOKO LOCAL GOVERNMENT AREA, BENUE STATE, NIGERIA
    (Department of Environmental Management, Nasarawa State University Keffi, 2018-02-11) Shammah, K.; Ekpo, Salamatu Abraham; Emmanuel, Ozim Chukwunonso
    7i/s study assessed the radiological hazards to members of the public and workers from naturally occurring radioactivity due to limestone mining activities in Mbayiom District. Soil samples were collected and analyzed for the activity concentrations of the three major primordial radionuclides; Uranium - 238 (mU), Thorium -232 (232Th) and Potassium -40 (*°K) using direct gamma spectrometry. Mean activity concentrations (47.1Bq/kg, and 607.6bq/kg) higher than the world averages were recorded for 23HU and 40K respectively in the study area. They were however, lower than the IAEA average values and fell within the worldwide ranges of 11 - 110 and 140 - 850 respectively- Conversely, the mean concentration (18.3 Bq/kg) of232Th was lower than world average and satisfied IAEA safety standard. In comparing the absorbed gamma dose rate and the annual effective dose (AED) owed to the three NORMs in the study area, it was found that the total dose rate (64.24nGy/h) was above the worldwide rate (60 nGy/h) though within the global range of 18 - 93 nGy/h. However, the total AED (0.022 nGy/h) due to 23HU, 232Th and40K was below the worldwide average (0.48 nGy/h). Gamma absorbed dose obtained in this study showed higher dose in line with of Kazakhstan, India, Luxembourg. Sweden. Norway, Malaysia and China as against countries like Ghana. Iran, Algeria and USA which had lower dose than the global average. The average radium equivalent activity (151.6 Bq/kg) and the average external hazard index (0.409) had values lesser than the acceptable level of370 Bq/kg and <1. Although the average internal hazard index (1.115) was higher than the permissible limit of <1, it was still within the worldwide range of 1.015 - 1.30. It was concluded that the NORMs activity concentration due to 238U and 40K at Mbayion limestone mine is relatively high. Therefore, these high activity concentrations of the nuclides will influence background radiation in the Mbayion environment by increasing the exposure of background radiation emanating from the significant levels of natural radionuclides. However, considering the average radium equivalent activity values for the analyzed samples, soil or rocks from the study area could be utilized for building purposes without causing any substantial radiological hazards. Appropriate radioactivity monitoring project should be carried out on the mining site in order to check for conceivable rise in radioactivity level due to buildup of mineral from numerous quarry sites; and workers should be provided with personal monitoring service (Thermoluminescent dosimeter equipment like safety glasses, dust masks, safety boots, and gloves.