title: High levels of uranium in groundwater of Ulaanbaatar, Mongolia.
abstract: Water samples collected from 129 wells in seven of the nine sub-divisions of Ulaanbaatar were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) using Clean Lab methods. The levels of many trace elements were found to be low with the average concentrations (ranges in brackets) being 0.9 (<0.1-7.9) μg/L for As; 7.7 (0.12-177) μg/L for Mn; 0.2 (<0.05-1.9)μg/L for Co; 16 (<0.1-686) μg/L for Zn; 0.7 (<0.1-1.8) μg/L for Se; <0.1 (<0.02-0.69) μg/L for Cd; and 1.3 (<0.02-32) μg/L for Pb. The levels of uranium were surprisingly elevated (mean, 4.6 μg/L; range <0.01-57 μg/L), with the values for many samples exceeding the World Health Organization's guideline of 15 μg/L for uranium in drinking water. Local rocks and soils appear to be the natural source of the uranium. The levels of uranium in Ulaanbaatar's groundwater are in the range that has been associated with nephrotoxicity, high blood pressure, bone dysfunction and likely reproductive impairment in human populations. We consider the risk associated with drinking the groundwater with elevated levels of uranium in Ulaanbaatar to be a matter for some public health concern and conclude that the paucity of data on chronic effects of low level exposure is a risk factor for continuing the injury to many people in this city.
authors.affiliation: Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI 48109, United States. stoten@umich.edu
authors.forename: Jerome
authors.initials: J
authors.lastname: Nriagu
authors.forename: Dong-Ha
authors.initials: DH
authors.lastname: Nam
authors.forename: Titilayo A
authors.initials: TA
authors.lastname: Ayanwola
authors.forename: Hau
authors.initials: H
authors.lastname: Dinh
authors.forename: Erdenebayar
authors.initials: E
authors.lastname: Erdenechimeg
authors.forename: Chimedsuren
authors.initials: C
authors.lastname: Ochir
authors.forename: Tsend-Ayush
authors.initials: TA
authors.lastname: Bolormaa
mesh_terms: D002947:Cities; D004781:Environmental Exposure / Q000032:analysis*; D060587:Groundwater / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D019216:Metals, Heavy / Q000032:analysis; D008986:Mongolia; D018570:Risk Assessment / Q000379:methods; D014501:Uranium / Q000032:analysis*; D060986:Water Wells / Q000737:chemistry*
chemical_list: D019216:Metals, Heavy; D014501:Uranium