Potentially hazardous residues of non-ortho chlorine substituted coplanar PCBs in human adipose tissue.
The non-ortho chlorine substituted coplanar polychlorinated biphenyls (PCBs), namely, 3,3',4,4'-tetra-(T4CB), 3,3'4,4',5-penta-(P5CB), and 3,3',4,4',5,5', hexachlorobiphenyl (H6CB) are found to be the most toxic congeners of PCBs eliciting toxic and biological responses typical of 2,3,7,8-tetrachloro dibenzo-p-dioxin (T4CDD). Analyses of human adipose tissues for these congeners revealed 94-860 pg/g of T4CB, 120-730 pg/g of P5CB, and 36-200 pg/g of H6CB on wet weight basis. These were significantly higher than 2,3,7,8-T4CDD detected in the same samples (less than 1-18 pg/g). On the basis of in vitro and in vivo induction of hepatic microsomal benzo(a)pyrene hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD), "T4CDD toxic equivalents" were calculated for coplanar PCBs in humans. "T4CDD toxic equivalent" for 3,3',4,4',5-P5CB was one order of magnitude higher than 2,3,7,8-T4CDD. Considering the extreme toxic potential and persistence of coplanar PCBs, their presence in the human body may pose a greater toxic threat than dioxins and dibenzofurans.
Kannan
N
N
Department of Environment Conservation, Ehime University, Matsuyama, Japan.
Tanabe
S
S
Tatsukawa
R
R
D000273:Adipose Tissue / Q000032:analysis*; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000032:analysis*; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000032:analysis; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug / Q000032:analysis
D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D011955:Receptors, Drug; D011078:Polychlorinated Biphenyls; C027309:3,4,5,3',4',5'-hexachlorobiphenyl; C023035:3,4,5,3',4'-pentachlorobiphenyl; C028451:3,4,3',4'-tetrachlorobiphenyl