Terrestrial animals environmental fate

A Terrestrial-Aquatic Model Ecosystem for Evaluating the Environmental Fate of Drugs and Related Residues in Animal Excreta... 

When farm animals are treated with drugs both as a prophylactic or curative measure, majority of the drug or drug related residues are eliminated in the excreta. Poultry as well as farm animal excreta is allowed to compost into manure and the manure is used on the farm land. The objective of the present study was to design a terrestrial-aquatic model ecosystem for evaluating the environmental fate of drugs and related residues in the animal excreta used as manure. 

The modified terrestrial-aquatic model ecosystem described here has been found to be a useful tool in studying the environmental fate of drugs and related residues present in animal excreta used as manure. The operation of the ecosystem is relatively simple and yet it allows one to study the complex metabolic transformations of a drug or related residues in its various components. Especially interesting is the study of the degradation of a compound in the soil in the presence of microorganisms found in the animal excreta. This information is important since it eventually determines whether a compound and/ or its metabolites will bioaccumulate in the various elements of the environment. 

Food Chain Bioaccumulation. There is information that barium bioconcentrates in certain plants and aquatic organisms (Bowen 1966 Schroeder 1970). However, the extent to which plants bioconcentrate barium from soil or to which uptake occurs in terrestrial animals is not well characterized. Further studies on the bioconcentration of barium by plants and terrestrial animals and on the biomagnification of barium in terrestrial and aquatic food chains would be useful to better characterize the environmental fate of barium and define the importance of food chain accumulation as a source of human exposure. 

Each tier employs different test species. Data on hazards to nontarget organisms proposed in Subdivision M cover the four areas terrestrial wildlife, aquatic animals, plants, and beneficial insects. The testing follows a tier scheme analogous to that for toxicological tests. Tier I represents the first level hazard test and Tier II consists of environmental fate studies that will be required only if indicated by the outcome of Tier I tests. 

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