indicators of PCB exposure. For example, Japanese quail fed 1,000 ppm of 

 Aroclor 1260, and that subsequently died, contained 780 ppm in brain; treated 

 survivors contained 250 ppm (as quoted in Heinz et al. 1984). Also, various 

 species of small birds that were killed by dietary exposure to Aroclor 1254 

 had PCB brain residues of 349 to 763 ppm (Heinz et al . 1984). 



PCBs are associated with a variety of biochemical, histopathological , and 

 behavioral responses in birds. PCBs affect zinc and calcium metabolism in 

 chickens, disrupt vitamin A use in quail, and potentiate vitamin A deficiency 

 in chickens by interfering with selenium use (Roberts et al . 1978). Body 

 temperature, serum chemistry, and thyroid function of ringed turtle-doves was 

 significantly altered by 3,4,3' ,4'-tetrachlorobiphenyl (Spear and Moon 1985). 

 Metabolism of various respiratory pigments was disrupted by PCBs in birds and 

 mammals (Roberts et al . 1978). PCBs are good inducers of drug-metabolizing 

 enzymes that are vital in detoxification processes. Aroclor 1254 injected 

 once into liver parenchymal tissue of the barn owl ( Tyto alba ), at 30 mg/kg 

 body weight, produced increases in the levels of liver cytochrome P-450 

 activities (Rinzky and Perry 1983). Ringed turtle-doves fed 10 or 100 ppm of 

 dietary Aroclor 1254 showed depressed levels of dopamine and norepinepherine; 

 PCB residues in the brains of these doves averaged 2.8 in the 10 ppm group, 

 and 18.3 ppm in the 100 ppm group (Heinz et al . 1984). Pelicans ( Pelecanus 

 sp.) fed 100 ppm of dietary Aroclor 1254 for 10 weeks showed increased liver 

 histopathology (NAS 1979). Certain PCB congeners produce acute 

 histopathologic changes in chick embryo liver, and these same congeners 

 selectively induce cytochrome P-448 mediated mixed function oxidases; adverse 

 effects were noted within 24 hours at concentrations as low as 146 mg of 

 3,4,3' ,4'-tetrachlorobiphenyl and 3,4,5,3' ,4' ,5 '-hexachlorobiphenyl on a whole 

 egg fresh weight basis (Rifkind et al. 1984). PCBs also have been associated 

 with abnormal behavior in European robins ( Erithacus nubecula ), pheasants, 

 quail, and other avian species according to Heinz et al. (1984). 



MAMMALS 



The mink is one of the most sensitive mammalian species to PCBs (Aulerich 

 and Ringer 1977; Ringer 1983; Hornshaw et al . 1983; Aulerich et al. 1985). 

 Signs of PCB poisoning in mink include anorexia, weight loss, lethargy, and 

 unthrifty appearance; prior to death, dark fecal stools indicative of the 

 presence of blood from the upper gastrointestinal tract (confirmed by 

 necropsy) was observed. Enlarged livers of mink given PCB diets were typical; 

 a similar pattern has been associated in practically all species studied. PCB 

 residues (10 to 15 ppm whole body fresh weight) within Great Lakes fish 

 incorporated into the diet of mink caused reproductive problems and death in 

 commercially ranched mink as long ago as 1965. Diets supplemented with as 

 little as 2 ppm of Aroclor 1254 for 8 months, or 5 ppm for 4 months, resulted 

 in near reproductive failure--with normal breeding and whelping, but a high 

 death rate of kits; reproduction was not affected at dietary levels of 1 ppm 

 of Aroclor 1254. Certain hexachlorobiphenyl isomers can produce death and 

 reproductive toxicity in mink at dietary concentrations as low as 0.1 mg/kg. 



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