title: Radioactive and chemical contamination of the water resources in the former uranium mining and milling sites of Mailuu Suu (Kyrgyzstan).
abstract: An assessment of the radioactive and chemical contamination of the water resources at the former uranium mines and processing sites of Mailuu-Suu, in Kyrgyzstan, was carried out. A large number of water samples were collected from the drinking water distribution system (DWDS), rivers, shallow aquifers and drainage water from the mine tailings. Radionuclides and trace metal contents in water from the DWDS were low in general, but were extremely high for Fe, Al and Mn. These elements were associated with the particle fractions in the water and strongly correlated with high turbidity levels. Overall, these results suggest that water from the DWDS does not represent a serious radiological hazard to the Mailuu Suu population. However, due to the high turbidities and contents of some elements, this water is not good quality drinking water. Water from artesian and dug wells were characterized by elevated levels of U (up to 10 μg/L) and some trace elements (e.g. As, Se, Cr, V and F) and anions (e.g. Cl(-), NO3(-), SO4(2-)). In two artesian wells, the WHO guideline value of 10 μg/L for As in water was exceeded. As the artesian wells are used as a source of drinking water by a large number of households, special care should be taken in order to stay within the WHO recommended guidelines. Drainage water from the mine tailings was as expected highly contaminated with many chemicals (e.g. As) and radioactive contaminants (e.g. U). The concentrations of U were more than 200 times the WHO guideline value of 30 μg/L for U in drinking water. A large variation in (234)U/(238)U isotopic ratios in water was observed, with values near equilibrium at the mine tailings and far from equilibrium outside this area (reaching ratios of 2.3 in the artesian well). This result highlights the potential use of this ratio as an indicator of the origin of U contamination in Mailuu Suu.
authors.affiliation: Federal Office for Civil Protection, Spiez Laboratory, Physics Division, Labor Spiez, CH-3700 Spiez, Switzerland. Electronic address: jose.corcho@babs.admin.ch.
authors.forename: J A
authors.initials: JA
authors.lastname: Corcho Alvarado
authors.affiliation: Federal Office for Civil Protection, Spiez Laboratory, Physics Division, Labor Spiez, CH-3700 Spiez, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Balsiger
authors.affiliation: Federal Office for Civil Protection, Spiez Laboratory, Physics Division, Labor Spiez, CH-3700 Spiez, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Röllin
authors.affiliation: Federal Office for Civil Protection, Spiez Laboratory, Physics Division, Labor Spiez, CH-3700 Spiez, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Jakob
authors.affiliation: Federal Office for Civil Protection, Spiez Laboratory, Physics Division, Labor Spiez, CH-3700 Spiez, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Burger
mesh_terms: D060766:Drinking Water / Q000032:analysis*; D004784:Environmental Monitoring; D005618:Fresh Water / Q000032:analysis; D060587:Groundwater / Q000032:analysis; D007707:Kyrgyzstan; D011834:Radiation Monitoring; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D060753:Water Quality; D014881:Water Supply / Q000032:analysis
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D014875:Water Pollutants, Radioactive
keywords: Former uranium mines; Kyrgyzstan; Mailuu Suu; Uranium contamination; Water resources