Selenium volatilizes from soils at rates that are modified by temperature, moisture, time, season or year, concentration of water soluble selenium, and microbiological activity. Conversion of inorganic and organic selenium compounds to volatile selenium compounds (such as dimethyl selenide, dimethyl diselenide, and an unknown compound) by microorganisms has been observed in lake sediments of the Sudbury area of Ontario. This conversion may have been effected by pure cultures of Aeromonas, Flavobacterium, Pseudomonas, or an unidentified fungus, all of which are found in methylated lake sediments. Production of volatile selenium is temperature dependent. Compared with the amount of dimethyl Se produced at an incubation temperature of 20 deg C, 25% less was produced at 10 deg C and 90% less at 4 deg C.
Literature: Eisler R; Selenium hazards to fish, wildlife and invertebrates: a synoptic review. U.S. Fish and Wildlife Service Biological Report 85 (1.5) p.4 (1985)
The Kd values measured in unamended, manure-amended and gluten-amended Hanford sandy loam at 4 deg C were 0.038, 0.091 and 0.045, respectively; there was no detection at temperatures of 21 and 40 deg C, or in Losthill clay loam under the same conditions(1).
Literature: (1) Guo L et al; Environ Sci Technol 33: 2934-8 (1999)