Selenium levels

There are areas (22) where selenium levels in the soil are very low these include regions of volcanic activity like that adjacent to the Cascade mountains in the Pacific Northwest states of the United States and the central north island of New Zealand. There, because the heat of emption volatilized the selenium, the residual soil parent material is virtually devoid of selenium. Other areas of low soil-selenium reflect leaching of selenium out of the top soil, as in the Canterbury plain on New Zealand s south island. Areas of selenium deficiency have negative implications for animal and human health. 

There is considerable evidence to suggest that selenium compounds are anticarcinogens. For one thing, tests with laboratory animals show that the incidence and size of malignant tumors are reduced when a solution containing Na2Se03 is injected at the part per million level. Beyond that evidence, statistical studies show an inverse correlation between selenium levels in the soil and the incidence of certain types of cancer. 

Burger J. 1995. Heavy metal and selenium levels in feathers of herring gulls differences due to year, gender, and age at Captree, Long Island. Environ Monit Assess 38 37-50. 

Burger J, Gochfeld M. 1993. Heavy metal and selenium levels in feathers of young egrets and herons from Hong Kong and Szechuan, China. Arch Environ Contam Toxicol 25 322-327. 

Aaseth, J., Alexander, J., Thomassen, Y., Blomhoff, J.P. and Skrede, S. (1983). Serum selenium levels in liver diseases. Clin. Biochem. 15, 281-283. 

Dworkin, B., Rosenthal, W.S., Jankowski, R.H., Gordon, G.G. and Haldea, D. (1985). Low blood selenium levels in alcoholics with and without advanced liver disease. Correlation with clinical and nutritional status. Dig. Dis. Sci. 30, 838-844. 

E., Lachica, M., Abad-Lacruz, A., Gil, A., Humbert, P., Boix, J. and Gassull, M.A. (1990). Serum zinc, copper, and selenium levels in inflammatory bowel disease effect of total enteral nutrition on trace element status. Am. J. Gastroenterol. 85, 1584-1589. 

Burger, J. and M. Gochfeld. 1996. Heavy metal and selenium levels in Franklin s gull (Larus pipixcan) parents and their eggs. Arch. Environ. Contam. Toxicol. 30 487-491. 

Itano, K., S. Kawai, N. Miyazaki, R. Tatsukawa, and T. Fujiyama. 1984a. Mercury and selenium levels in striped dolphins caught off the Pacific coast of Japan. Agric. Biol. Chem. 48 1109-1116. 

Aerosol concentrations in excess of 4.0 jag Se/m3 are potentially harmful to human health (Harr 1978). Concentrations in excess of this value (6.0 pg Se/m3) were regularly encountered in the vicinity of the smeltery at Sudbury, Ontario, Canada (Nriagu and Wong 1983). It is not now known whether respiration rates of wildlife, particularly birds, are comparable to those of humans, whether selenium absorption energetics are similar, or whether wildlife species that frequent point sources of air contaminated by high selenium levels for protracted periods are at greater risk than humans. Until additional and more conclusive data become available, aerosol concentrations of less than 4.0 pg Se/m3 are recommended for the protection of sensitive wildlife species. 

Beal, A.R. 1974. A Study of Selenium Levels in Freshwater Fishes of Canada s Central Region. Canada Dep. 

Kaiser, I.I., P.A. Young, and J.D. Johnson. 1979. Chronic exposure of trout to waters with naturally high selenium levels effects on transfer RNA methylation. Jour. Fish. Res. Board Canada 36 689-694. 

Lorentzen, M., A. Maage, and K. Julshamn. 1994. Effects of dietary selenite or selenomethionine on tissue selenium levels of Atlantic salmon (Salmo salar). Aquaculture 121 359-367. 

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