Selenium - Mercury Antagonism in Human Blood Samples from Residents of Wassa West District, a Mining Area in Ghana

Abstract

This paper sought to evaluate Se to Hg (Se:Hg) molar  ratio in  human blood samples from residents of Wassa West district of Ghana, a region which has a long history of gold mining. Determining Hg levels alone in either environmental samples or human body fluids or tissues is necessary but not essential enough to assess the health risk of a given population. The levels of Se in such matrices are the fundamental factor in health risk assessment of Hg exposure and toxicity. Fifty blood samples were collected from volunteers from Wassa West District and were analysed for Hg and Se concentrations. The molar concentrations of each element was calculated and the corresponding Se:Hg molar ratios were determined. The results indicated that, the molar concentrations of Se ranged from 0,35 nM to 62.38 nM with a mean value of 25.26 nM, while Hg molar concentrations ranged from 0.05 nM to 4.65 nM with a mean value of 0.38 nM. The ratios ranged from 0.97 to 958 with a mean value of 155.40. Apart from, one subject, all the Se:Hg molar ratios were above one, which may imply that the residents have enough Se (well nourished) to prevent Hg toxicity.The precision and accuracy of the analytical methods were determined by the standard reference materials,  DORM-2 and GBW 09101. The measurement precision which was determined using relative standard deviation fell within 4%.The results of the analysed samples were within ±5% of the certified values of the standard reference materials.