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Show - Ecological Risk Assessment North Oquirrh Mountains Appendix 2 2.8.3 Trophic Transfer Factors Trophic transfer factors for plants to herbivores are based on data from the house mouse, Transfer factors for Western harvest mouse, muskrat, and the California ground squirrel. terrestrial insectivores are based on data from the ornate shrew. Table 12. Trophic Transfer Factors for Selenium in Terrestrial Systems liver kidney muscle whole body Reference Clark, 1987 plants to 0.07 2.3 herbivores (0-293) (0-5) 1.9 0.57 _(0.15-2.5) (0.12-1.19) herbivores to carnivores soil to inverts inverts to insectivores insectivores to Clark, 1987 II carnivores II - Aquatic food chain transfer factors can be calculated from Saiki ana Lowe (1987) and Ohlendorf et el. (1993) as follows: Table 13. Aquatic Food Chain Transfer Factors for Selenium. Range Low Hioh water to seoirnent 267 303 water to detritus 515 1,333 water to rooted plants 76 136 water to invertebrates 515 1,000 1,121 2,693 water to mosouitoftsn 939 water to bird eoos 596 2.9 Zinc Zinc has been used by humans for over 2,000 years for utilitarian or ornamental purposes, particularly as a component of alloys (bronze, brass, and others) for galvanizing steel to prevent it from rusting, and dyes. Two fungicides (zineb and ziram) are organozinc compounds. Zinc is an important essential mineral, for most animal species dietary requirements range from 40 to 100 ppm. Signs of Zn toxicity include decreased growth rates, anemia, decreased bone mineralization, bone deformities, and decreased feather pigmentation. (NRC, 1980). 2.9.1 Toxic Effects 2.9.1.1 Domestic Animals Young cattle fed Zn-oxide or Zn-sulfate at 100, 200, 500, or 600 ppm showed no adverse effects efficiency were reduced at 900, 1,300, 1,700 and 2100 ppm diet during a 12 week exposure (Miller et al., 1970; Ott et a/., 1966a, c). Furthermore, cows fed diets amended with 372, 692, or 1,270 ppm Zn-oxide for six weeks showed no ill effects (Miller et al., 1965). Sheep (n=10) per group exhibited decreased feed intake at 1000 ppm and higher (1,500, while weight gain and feed 22 ecological planning and toxicology, inc. 1 |
