for selected species of aquatic organisms and Aroclor PCBs, with one 

 exception, varied from 0.1 to 5.4 ug/1 for the no effect level, and from 0.4 

 to 15.0 ug/1 for measurable effects (Table 6). The exception was larvae of 

 the sheepshead minnow (which was especially sensitive) with an MATC of 0.06 to 

 0.16 ug/1 for Aroclor 1254 (Table 6). 



BIRDS 



Among sensitive avian species, PCBs disrupt normal patterns of growth, 

 reproduction, metabolism, and behavior. In general, PCB accumulation is rapid 

 and depuration is lengthy. Diet is an important route of PCB accumulation. 

 Concentrations in liver (mg/kg fresh weight) were highest (900) in birds that 

 fed on fish, followed by species that feed on small birds and mammals (50), 

 worms and insects (0.65), and lowest (0.2) in herbivorous species (NAS 1979). 



Delayed reproductive impairment was documented in ringed turtle-doves 

 given 10 ppm of dietary Aroclor 1254 for 3 months; residues in the fat of 

 adults was 736 ppm, and in their eggs 16 ppm fresh weight (as quoted in Heinz 

 et al. 1984). Hatchability of ringed turtle-dove eggs from the first clutch 

 was not reduced by consumption of Aroclor by the adults. However, 6 months 

 later, the hatchability of the second clutch (accompanied by abnormal 

 incubation behavior) was reduced to 10% of controls; embryos also contained 

 chromosomal aberrations (Peakall et al. 1972). Mourning doves ( Zanaida 

 ma cr our a carol inensis ) given dietary Aroclor 1254 for 6 weeks at 0, 10, or 40 

 ppm were observed for courtship behavior and reproductive effort during days 

 14 to 44 posttreatment (Tori and Peterle 1983). Doves fed 10 ppm spent twice 

 as much time as controls in the courtship phase (billing, cooing, nest site 

 selection), but only 50% of these pairs completed the courtship phase and 

 progressed into nest building and incubation; of those that nested, nest 

 Initiation was significantly delayed. Doves fed 40 ppm spent the 30 days 

 posttreatment in courtship without nesting; most of this group, especially 

 females, did not respond normally to the presence of a mate. Tori and Peterle 

 (1983) suggested that the disrupted reproductive behavior observed in 

 PCB-treated doves was due to reduced estrogen and androgen levels. PCBs have 

 been shown to degrade estrogens and androgens by increasing the activity of 

 hepatic microsomal enzymes (as quoted in Tori and Peterle 1983). Hatchability 

 of chicken eggs was reduced when hens were fed diets containing 20 ppm of 

 various Aroclor PCBs (1232, 1242, 1248, or 1254). PCB residues in samples of 

 fat from treated hens varied from 45 to 125 ppm, and in their eggs from 3 to 

 14 ppm (as quoted in Heinz et al. 1984). Reproductive impairment in chickens 

 was recorded at Aroclor dietary levels as low as 5 ppm; effects at the 2 ppm 

 level were not significant (Heinz et al. 1984). American kestrels ( Falco 

 sparverius ) given 33 ppm of dietary Aroclor 1254 for 62 to 69 days (equivalent 

 to 9 to 10 mg/kg body weight/daily), showed a significant decline in sperm 

 concentration, but no compensatory increase in semen volume (Bird et al. 

 1983). PCB residues in treated kestrels, in ppm lipid weight, were 107 in 

 muscle and 128 in testes; for controls, these values were 0.4 in muscle and 

 1.0 in testes. These results suggest that migratory flesh-eating birds 



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