Natural radioactivity and trace metals in crude oils: implication for health

Abstract

Crude oil samples were collected from six different fields in the central Niger Delta in order to determine their natural radioactivity and trace element contents, with the aim of assessing the radiological health implications and environmental health hazard of the metals, and also to provide natural radioactivity baseline data that could be used for more comprehensive future study in this respect. The activity concentrations of the radionuclides were measured using a well, accurately calibrated and shielded vertical cryostat, Canberra coaxial high-purity germanium (HPGe) detector system, and the derived doses were evaluated. The metal concentrations were determined by the graphite furnace atomic absorption spectroscopic (GFAAS) method. The radionuclides identified with reliable regularity belong to the decay series of naturally occurring radionuclides headed by (238)U and (232)Th along with the non-decay series radionuclide, (40)K. The averaged activity concentrations obtained were 10.52 +/- 0.03 Bq kg(-1), 0.80 +/- 0.37 Bq kg(-1) and 0.17 +/- 0.09 Bq kg(-1) for (40)K, (238)U and (232)Th, respectively. The equivalent doses were very low, ranging from 0.0028 to 0.012 mSv year(-1) with a mean value of 0.0070 mSv year(-1). The results obtained were low, and hence, the radioactivity content from the crude oils in the Niger delta oil province of Nigeria do not constitute any health hazard to occupationally exposed workers, the public and the end user. The concentrations of the elements (As, Cd, Co, Fe, Mn, Ni, Se and V) determined ranged from 0.73 to 202.90 ppb with an average of 74.35 ppb for the oil samples analysed. The pattern of occurrence of each element agreed with the earlier studies from other parts of the Niger Delta. It was obvious from this study and previous ones that the Niger Delta oils have low metal contents. However, despite the low concentrations, they could still pose an intrinsic health hazard considering their cumulative effects in the environment. Also, various studies on the impact of oil spillage and activities of oil exploration and production on organisms in the immediate environment suggest this.

Investigation of Natural Radioactivity Levels and Evaluation of Radiation Hazards in Residential-Area Soil Near a Ras Tanura Refinery, Saudi Arbia

“…The variations in activity concentrations of 226 Ra, 232 Th, and 40 K in soil samples are based on the nature of its geological formations in the study area. Otherwise, naturally occurring radioactive materials encountered in oil and gas exploration, development, and production operations originate in subsurface formations that may contain radioactive materials such as uranium, thorium, and their daughter products [25]. This can be brought to the surface and contribute in the surface background.…”

Assessment of Radioactivity Contents and Associated Risks in Some Soil Used for Agriculture and Building Materials in Cameroon

“…Here in Nigeria, Tchokossa and his co-workers reported the results of many investigations on the distribution of radioactivity content in various environmental matrices [12][13][14][15][16][17][18][19], while in Cameroon, Makon et al carried out similar research in some edible vegetable cultivated and consumed worldwide [20]. Cameroon is located at the center of both operational and non-operational nuclear reactors and industries (Figure 1), and to the best of my knowledge, there is no published or on-going works on the survey of Cameroonian's soil.…”

Oil spills and community health: Implications for resource limited settings

“…A study on the natural radioactivity and trace elements in crude oils implications for health, noted that Niger Delta oil has low metallic contents but the cumulative effects of the radioactivity and metallic properties on human health is of concern (Ajayi et al, 2009). An incident that also readily comes to mind, showing the effect of environmental pollution on human health is the Minamata Bay incident in Japan, where more than 100 cases of central nervous system damage fish, as a result of toxic waste disposal on the bay by an industrial outside.…”