D, CD Sandau, P Ayotte, E Dewailly, J Duffe, and RJ Norstrom. 2000.
Analysis of Hydroxylated Metabolites of PCBs (OH-PCBs) and Other
Chlorinated Phenolic Compounds in Whole Blood from Canadian Inuit.
Health Perspectives 108:611-616.
PCBs enter the human body, many are converted by enzymatic processes
to derivative compounds, or "metabolites," called hydroxylated
PCBs (OH-PCBs). OH-PCBs can be significantly more powerful biologically
than the original PCB from which they are derived.
et al. compared blood levels of PCBs and OH-PCBs, in Inuit
living in the Canadian arctic (Nunavik, Quebec) with blood sampled
in the general Canadian population living in the south of the country.
work is of high interest because of:
known transport of persistent organic pollutants, including PCBs
into arctic ecosystems (OSF chapter 7);
Inuit diet, which often contains significant proportions of fat-laden
meat from seals, whales, polar bears and other species near the
top of the food chain and thus often burdened with high levels
of bioaccumulative contaminants; and
potency of certain PCBs and related compounds in interfering with
thyroid and retinoid hormone systems. Some of these contaminants
are more powerful than even thyroxin, the natural thyroid prohormon,
at binding with thyroid hormone transport proteins.
found that arctic living Inuit carried blood levels of contaminants
ranged widely among individuals but that the arctic people's PCB
and OH-PCB concentrations overall were up to 70x greater
than the pooled sample from the southern part of Canada. This pattern
did not hold for all compounds measured. "The geometric mean
PCB [pentachlorophenol] concentration in the Inuit samples was 2.02
ng/g, approximately 3 times lower than in the southern Quebec pooled
had lower mean concentrations of all phenolic compounds quantitated
than men. The generally lower levels in women may result from the
loss of OH-PCBs and PCBs through lactation because both have been
identified in milk (36-38). Both OH-PCBs and PCBs were significantly
correlated with age (r = 0.68 and 0.78, respectively; p < 0.05).
The increase of both PCB and OH-PCB concentrations with age may
be due to the increased exposure with age (elders' preference for
traditional foods), a slow excretion rate of PCBs that prevents
steady state from being achieved, or both."