The geochemistry of selenium in groundwaters in Finland

Inorganic selenium speciation in groundwaters by solid phase extraction on Dowex 1X2

“…Epidemiological studies show that mortality from cardiovascular diseases and cancer might increase as the serum Se level decreases [5,6]. In Finland, sodium selenate has been added into fertilizers nationwide in order to improve the dietary Se intake since 1985 [7]; therefore, it has become a potential source of Se in the groundwaters. The difference between the required and toxic amount is small [8], and the toxic dose also depends on the selenium species.…”

Estimation of the Behaviors of Selenium in the Near Field of Repository

“…Since the sorption of ions on the sorbent can be greatly dependent on their concentration [17] and the concentration of selenium in the repository is anticipated to be low, the sorption behavior of selenite in the low concentration has to be examined. Actually the concentration of selenium in the natural water or groundwater is found at around 10 -9 mol/L [18]. Thus, Se-75 isotope (added 100 µg/mL Se carrier) as a selenious acid in 0.1M HCl, purchased from EcKert & Ziegler Isotope Products, was used for the sorption test in the low selenite concentration with less than 1x10 -6 mol/L.…”

The effect of catch crop species on selenium availability for succeeding crops

“…Wang et al (1994) showed that in Finland the Se fertilisers might have temporarily increased the Se concentration in river waters and headwater streams, by surface runoff of selenate after rainfall. However 6 years after the establishment of the nationwide Se fertilisation in Finland, Se concentrations in natural ground-waters and wells were below the health-based limit of 10 μg L −1 set for drinking water (Alfthan et al 1995). The amount of Se lost through leaching depends on the form of Se present and its mobility, which is a function of soil pH, the presence of competing ions (sulphate, phosphate, oxalate, and molybdate), climate and organic matter (Eich-Greatorex et al 2007;Mayland et al 1991).…”