Fonofos toxicosis in dairy cows: an accidental poisoning (1977).

An accidental poisoning (in 1977) of 28 Holstein cows occurred when approximately 0.9 kg of 25% active ingredient fonofos, O-ethyl S-phenyl ethylphosphonothiolothionate, was spilled onto bulk feed in a delivery truck. Eight cows died within 2 days; the remaining 20 were necropsied 29 days later. Of the 8 fatally poisoned, 7 were being fed a high-grain diet and 1 was fed a medium-grain diet. Fonofos concentrations in feed cart and storage bin samples were 100 micrograms/g and 61 micrograms/g, respectively. Tissues from 6 animals were analyzed extensively for fonofos concentrations: 2 had died immediately; the other 4 were in the recovery state when they were necropsied. Rumen contents and liver, kidney, brain, heart, and milk samples were analyzed. Fonofos concentrations in these samples were significantly higher in the cows fatally affected than in the cows necropsied 3 weeks later. The oral acute LD50 and LD1 of fonofos in Holstein cows were calculated by the Litchfield and Wilcoxon method to be 1.30 and 0.84 mg/kg, respectively, with a 95% confidence range of +/- 0.20 mg/kg.

Residues of polychlorinated biphenyls, DDT, and DDT metabolites in Pennsylvania streams, community water supplies, and reservoirs, 1974--76.

Pennsylvania streams, community water supplies, and open water reservoirs were analyzed for PCB mixtures, DDT, and DDT metabolites. Streams were sampled in 1974 and again in 1975. Only 4 of 19 stream locations were contaminated. Maximum concentrations in community supplies of Aroclor 1242 (2 locations), Aroclor 1254 (3 locations), and sigmaDDT (2 locations) were 350, 260, and 620 ng/kg, respectively. Of the 110 community water supplies sampled in 1975 and 1976, only 7 contained residues. Maximum concentrations in community supplies of Aroclor 1242 (4 locations) and sigmaDDT (2 locations) were 460 ng/kg and 75 ng/kg, respectively. The seventh contained 0.7 ng/kg of dieldrin. None of the three open water reservoirs contained detectable residues of the compounds of interest. Essentially no correlation was found between PCB and DDT analogs in streams and those in fish from streams which had been samples at similar locations in a related study in 1976.

Chlorinated hydrocarbon and PCB residues in tissues and lice of northern fur seals, 1972.

DDT, dieldrin, and PCB contents of tissues and the sucking lice of the northern fur seal (Callorhinus ursinus) were studied in samples collected in July 1972 in the Pribilof Islands, Alaska. They included the analyses of two nursing cows and their two newborn pups, three 2-month-old pups, and the sucking lice inhabiting these animals, Antarctophthirus callorhini and Proechinophthirus fluctus. The sigmaDDT content of fat tissue was 5.2, 5.6 and 63 mug/g (-/x) for cows, newborns, and 2-month-old pups, respectively. Dieldrin appeared at trace levels. PCB residues (Aroclor 1254) were 5.8, 5.5, and 33 mug/g (-/x), respectively. The sigmaDDT content of blood was less than 0.01 mug/g for cows and newborns and 4.6 mug/g for 2-month-old pups. PCB's were found only in trace amounts in the blood of all animals except one 2-month-old pup which contained 3.4 mug/g. Lice contained 0.2-6 percent, respectively, of the sigmaDDT and PCB's detected. All residues were expressed on a wet-weight basis. Two-month-old pups had far higher residue levels than had cows. A high percentage of sigmaDDT occurred as the DDE metabolite: 60 percent in cows and newborn pups and 90 percent in 2-month-old pups.