Selenium and drinking water quality indicators in Mongolia

Abstract

Mongolia is characterized by restricted sources of drinking water and intensive water pollution due to high rates of urbanization, mining industry development, enormous amount of livestock, and ever-growing attempts in domestic production of cereals and vegetables. Among others, Se is the least studied element in Mongolian water resources. Based on fluorimetric method of analysis, the first results on Se levels in drinking water of five aimags, Ulaanbaatar, and Erdenet were obtained. Uneven distribution of Se in Mongolia was manifested, the highest Se concentrations being typical for the southern resources (up to 18,600 μg/L) and the lowest, for the Northern ones (up to 0.022 μg/L). ICP-MS data of Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, Hg, I, K, Li, Mg, Mn, Na, Ni, P, Pb, Si, Sn, Sr, V, and Zn contents indicate poly-microelementosis existence in the South of Mongolia (Dorno-Gobi aimag) where ground water is characterized by elevated levels of As and extremely high levels of Se, Li, Na, F, Cl, B, and nitrates ions, exceeding maximum permissible levels by 1.86; 4.3; 3.1; 3.1; 2.7; 3.4; and 1.8 times respectively. Toxic concentrations of Se in groundwater of Dorno-Gobi aimag contradict with the published low human serum Se and low content of the element in horseflesh that suggests the possible effect of the above pollutants on Se bioavailability. Revealed phenomenon and mosaic distribution of heavy metals in areas with high and low Se content in water resources indicate the need of direct search for Se and other pollutant transfer in food chain in various ecological loading conditions, creation of a map of Se distribution in water resources of other Mongolian regions, and large-scale evaluation of the human poly-elemental status.

Assessing of Heavy Metals in Serum of Barki Sheep in Rainfed Area at Matrouh Governorate

“…These findings could be explained by the fact that selenium can be reached to soils or an aquatic environment through weathering of rocks, aeolian deposition, fluvial input, suspension load and biological effect (El-Badry and Khalifa, 2017). Recently, high levels of selenium are steadily found in groundwater and drinking water around the world (Golubkina et al, 2018).…”

Occurrence and Health Risks of Organic Micro-Pollutants and Metals in Groundwater of Chinese Rural Areas

“…2017 ; Edet et al. 2004 ; Giri and Singh 2015 ; Golubkina et al. 2018 ; Iqbal and Shah 2012 ; Kavanagh et al.…”

“…Two metals, As (49:2% ± 37:6%) and Cr (25:5% ± 32:3%), were significant contributors to the CR T values. Among the three metals with high contributions to RQ T , Li and Sr were indispensable trace elements to humans (Liu et al 2018;Schrauzer 2002) and have been widely detected in groundwater worldwide (Duggal et al 2017;Edet et al 2004;Giri and Singh 2015;Golubkina et al 2018;Iqbal and Shah 2012;Kavanagh et al 2017;Kent and Landon 2016;Purushotham et al 2017;Qi et al 2019;Toccalino et al 2012;Voutchkova et al 2018). Previous studies have indicated that the levels of Li or Sr in groundwater were not associated with noncarcinogenic risks (Duggal et al 2017;Edet et al 2004;Giri and Singh 2015;H Zhang et al 2018).…”

The Problem of Selenium for Human Health—Removal of Selenium from Water and Wastewater

“…Under these conditions, Se is predominantly present in the form of labile selenate [20]. High nitrate concentrations are known to create weak oxidation conditions that inhibit microbial Se fixation, which can also cause increased Se concentrations in water [21]. The differences in selenium content between raw and drinking water in individual months were statistically insignificant (p < 0.05) except in June, July, August, and October.…”