Exposure to high background radiation level in the tin mining area of Jos Plateau, Nigeria

Abstract

The present work deals with the radioactivity of samples of tin tailings collected from a mining site in Jos, Nigeria. The activity concentrations of the samples were measured using a gamma-ray spectrometer with a hyper-pure germanium detector. In situ dose rates at the site were also measured using a precalibrated survey meter. Potassium-40 was not detected in any of the studied samples. The activity concentrations of (238)U and (232)Th ranged from 17.1 x 10(2) to 16.6 x 10(3) Bq kg(-1) and from 52.9 x 10(2) to 47.5 x 10(3) Bq kg(-1), with mean values of 72.2 x 10(2) and 16.8 x 10(3) Bq kg(-1), respectively. The absorbed dose rates were between 4.0 and 36.3 microGy h(-1), with a mean value of 13.5 microGy h(-1), which is much higher than the world average of 0.06 microGy h(-1) for soil. The calculated effective dose rates varied between 2.8 and 25.4 microSv h(-1), with a mean value of 9.4 microSv h(-1), whereas the effective dose rates obtained for the in situ measurement varied between 6.0 and 28.0 microSv h(-1). The annual gonadal dose equivalent was calculated as 92.4 mSv. This is much higher than the world average dose equivalent rate to individuals from soil (0.30 mSv y(-1)).

Occupational exposure to natural radionuclides due to mining activities in Ibadan, Southwestern Nigeria

“…It is apparent that miners in the pit are equally exposed to the same dose irrespective of their work in the pit that is, whether digging or handling while miners that work at the heap are less exposed. When compared with the result obtained for tin tailings at mining area in Jos, Nigeria (9.4 µSv h -1 ) (Ademola, 2008), the results obtained in this work are very low. Though some of the doses are high, all of the effective doses calculated in this work are below the annual global effective dose of 2.7 mSv due to natural source for miner (UNSCEAR, 2000), however the UNSCEAR annual global effective dose also considered exposure to radon gas.…”

“…Mining is one of such activities that enhance the natural radioactivity level of the environment, thus working activities that involves natural radioactive material is source of radiation exposure (UNSCEAR, 2000). Ademola (2008) reported high activity concentrations of natural radionucldes in tin tailings.…”

Radioactivity concentrations and dose assessment for bitumen and soil samples around a bituminous deposit in Ondo State, Nigeria

“…To represent the activity concentrations of 40 K, 226 Ra and 232 Th, a common index which takes into account the radiation hazards associated with all three radionuclides has been introduced and is called radium equivalent activity, Ra eq . The relation is given as (Beretka and Mathew, 1985;Ademola, 2008a) Ra eq = 0. 232 Th deliver the same gamma dose rate.…”

Radioecological impacts of tin mining

“…Mining of minerals involves the removal of large amounts of soil which contain radioactive materials (Ibeanu 2003), and the radioactive materials in the excavated soil may find their way into the food chain and hence to humans. The unceasing release of mining waste (tailings) into the biosphere may result in a build-up of radionuclides in the air, water, and soil, which will impact both human and nonhuman biota (Ademola 2008).…”

“…Attempts have been made in the past to assess the human health impacts of tin mining in the Jos Plateau, Nigeria (e.g., Ibeanu 2003;Funtua and Elegba 2005;Ademola and Farai 2006;Jibiri and Agomuo 2007;Jibiri et al 2007aJibiri et al , b, 2009Ademola 2008;Ajayi 2008;Arogunjo et al 2009;Olise et al 2010Olise et al , 2014, but few studies have considered non-human biota (but see Møller and Mousseau, 2013). Recently, international standards have also been set to protect non-human biota from the effects of exposure to ionizing radiation (ICRP 2003;UNSCEAR 2008;ICRP 2009;IAEA 2011).…”