A therapeutic regimen for purging dieldrin from adulterated individuals
SummaryIn four feedlots 1013 steers had become contaminated by being fed over 50% of their diet as cull seed potatoes containing 0.1 to 0.2 ppm dieldrin (dry weight basis), developing residues of up to 0.76 ppm (rendered fat). These residues were in excess of federal guidelines (0.30 ppm, rendered fat), but considered non-pathological and without physiological effect. Application of a therapeutic regimen, consisting of an initial injection of testosterone propionate and vitamins A, D and E and of daily oral doses of phenobarbital (first 20 days only) and activated charcoal in a finishing ration, resulted in marked reductions in dieldrin residues within 30 days. The rate of dieldrin loss was increased six-fold and the residual half-life reduced from a reported 150 to 250 days to about 25 to 80 days. The effectiveness of individual components or combinations was not evaluated, but the rate of charcoal feeding appeared most important.
Insecticide interactions affecting residue accumulation in animal tissues.
Abstract Interactions among the insecticides DDT, methoxychlor, and dieldrin were studied in terms of their residues stored in rats' adipose tissue. A commercial rat diet was treated with the three compounds using three dose levels of each (DDT: 0, 5, 50 ppm; methoxychlor: 0, 50, 500 ppm; dieldrin: 0, 1, 10 ppm) in a factorial arrangement that permitted preparation of all 27 possible compound and dose level combinations. Female rats were fed the treated diets for 10 weeks and then sacrificed. Adipose tissue was analyzed for lipid content and residual insecticide concentrations. As reported in a previous paper, dieldrin storage was markedly reduced when DDT was present in the treatment combination. Further statistical analysis of the data has indicated a significant influence of dieldrin treatment on storage of DDT. DDT storage, when fed at the 50 ppm level, was increased by the high dieldrin treatment. Methoxychlor storage was not affected by the other treatments; however, methoxychlor caused a small, but significant, reduction in dieldrin storage. The DDE:DDT storage ratio in tissue was not influenced by either dieldrin or methoxychlor. The DDT effect is postulated to result from enhanced dieldrin metabolism by liver microsomal enzymes.
The decontamination of animal feeds.
Pesticides have become essential to the economical production of most animal feedstuffs, including also the by-products of other agricultural industries, for example almond hulls, seed screenings, fruit pomaces, and other materials. The treatment which results in contamination may be intentional such as acaricide applications to almond hulls, or incidental such as drift onto alfalfa fields, but an increasing proportion of feed samples contain unacceptable levels of pesticide residues.