Effects on Microorganisms, Plants, Animals, and Humans

Ruminants require cobalt for the bacterial biosynthesis of vitamin B12 in the first stomach. Cobalt-deficient sheep or cattle show diminished feed intakes and weight loss. In cows, milk production declines and the fre- 

Whole blood (hard-metal workers), Italy 8845.6 1-245  

5 ig are lost per day, corresponding to 0.05% of the total vitamin B12 pool the biological half-life of the vitamin is in the order of 400 days (Herndon et al. 1980). 

Vitamin Bj2 deficiency gives rise to pernicious anemia. However, due to the small amounts required for the maintenance of health (3.5 pg per day per adult), genuine dietary deficiencies develop rarely, for example in strict vegetarians. Even in subjects with diminished or absent IE production, the first symptoms of vitamin Bj2 deficiency appear only in the fourth decade of life, due mainly to the long biological half-life of the 

Vitamin B12 is virtually nontoxic, even at high oral or injected doses excessive amounts are rapidly excreted. However, occasionally allergic responses to injected vitamin B12 occur (Fisher 1973), and adverse reactions to the combined administration of large injected doses of vitamin B12 and of oral vitamin C have been reported (Schrauzer 1979). Vitamin B12 is required for methionine biosynthesis and functions in conjunction with folic acid as the intermediate carrier of the methyl group. In its coenzyme form (5 -deoxyadenosylcobala-min), it is required for the conversion of methylmalonyl-CoA to succinyl-CoA. (Friedrich 1987). Bacteria utilize vitamin Bjj or its coenzyme in certain dehydrases, deaminases, and in methane biosynthesis. 

---

An Environmental Impact Report is also required for a notification. This is an assessment of the environmental compatibility made by the notifier, and is based on an evaluation of degradation, accumulation and mobility in the environment, effects on microorganisms, plants, animals and ecosystems and long-term indirect effects on humans via the environment. 

Yttrium is a non-essential element for microorganisms, plants, animals, and humans. However, no adverse effects of yttrium have been reported on plants and microorganisms, nor has any mechanism of yttrium detoxification in mammals been identified (Luckey and Venugopal 1978 Deuber and Heim 1991). 

Lead and lead compounds are classified as toxic chemicals that persist and bioaccumulate in the environment. Persistent, bioaccumulative toxic chemicals (PBTs) are of particular concern as they remain in the environment for significant periods, and accumulate in organisms exposed to them. Lead can cause damage to several systems in the human body. Children are particularly at risk from damage to the nervous system, endocrine system, cardiovascular system, and the kidneys. In addition, lead can have adverse effects on the environment, such as acute and chronic toxic effects on plants, animals, and microorganisms. 

Hader, D. P, Effects of enhanced solar ultraviolet radiation on aquatic ecosystems, in UV-B Radiation and Ozone Depletion Effects on Humans, Animals, Plants, Microorganisms, and Materials, Tevini, M., Ed. Lewis Publishers, Boca Raton, FL, 1993, 155. 

Alkaloids are an important class of compounds that have pharmacological effects on various tissues and organs of humans and other animal species. More than 16,000 are known and most are derived from higher plants. Alkaloids have also been isolated from microorganisms, from marine organisms such as algae, dinoflagellates, and puffer fish, as well as from terrestrial animals, such as insects, salamanders, and toads. 

Toxins. Metabolic products from microorganisms, plants, or animals with a poisonous effect on mammals, especially, humans. T. are mostly immunogenic, i.e., they can induce the formation of specific antibodies (antitoxins) as a result of their antigen character. They belong to widely differing classes of compounds such as proteins, lipopolysaccharides, alkaloids, terpenoids, steroids, aliphatic acids, biogenic amines, and guanine derivatives. 

Although PDHc can be foimd in microorganisms [12-15], plants [16-18], and mammals [19-21], the three-dimensional form and homology of the mammal s PDHc are different from their counterparts found in microorganisms and plants. Because of that, an effective herbicide that targets on plant PDHc should have no effect on animal PDHc and be safe for animals, including humans by biorational design. 

---