SUBLETHAL EFFECTS 



GENERAL 



PCBs elicit a variety of biologic and toxic effects including skin 

 lesions, a wasting syndrome, itmiunotoxicity, reproductive toxicity, genotoxic 

 and epigenetic effects, hepatomegaly and related liver damage, and the 

 induction of hepatic and extrahepatic drug-metabolizing enzymes. PCB 

 accumulations from the diet and from other sources are high, and retention is 

 lengthy in fatty tissues. Interspecies differences in sensitivity to PCBs are 

 large, even between species that are closely related taxonomically. 



TERRESTRIAL MACROPHYTES 



A 5X increase in somatic mutations was observed in ostrich ferns 

 ( Matteuccia struthiopteris ) growing near the Housatonic River in Pittsfield, 

 Massachusetts, on sediments containing mean PCB residues of 26 mg/kg (mostly 

 as Aroclor 1254), when compared to ostrich ferns from control areas (Klekowski 

 1982). No attempt was made to duplicate these observations under controlled 

 conditions, and no evidence of genetic damage to other plants of the 

 PCB-contaminated area was found (Klekowski 1982). 



AQUATIC ORGANISMS 



Bioconcentration of Aroclor 1254 from the medium by selected species of 

 freshwater and marine organisms varied from 60 to 340,000X (Table 5). Various 

 species of algae also concentrate PCBs over water levels by 10,000 to 100,000X 

 (Ernst 1984). Oysters ( Crassostrea virginica ) held for 65 days in seawater 

 solutions containing 0.0055 to 0.06 ug/1 of di-, tri-, tetra-, penta-, or 

 hexachlorobi phenyls had bioconcentration factors of 1,200 to 4,800X; uptake 

 was lowest for dichlorobiphenyls and became progressively higher with 

 increasing chlorination of PCB congeners (Ernst 1984). Similar results were 

 recorded for Daphnia magna exposed to five different C-14 labeled PCBs for 24 

 hours. BCFs varied from 473 to 11,232; formulations lowest in water solubilty 

 (highest chlorination) were accumulated most readily (Zhang et al . 1983). For 

 all PCBs, BCFs were generally higher with increasing exposure period, with 

 increasing PCB concentration, and with increasing chlorination of PCB 



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