PCDDS, PCDFS, AND PCBS IN HUMAN BLOOD IN RELATION TO CONSUMPTION OF CRABS FROM A CONTAMINATED FJORD AREA IN NORWAY

Consumption of fish and shellfish from contaminated areas may be an im portant source of human exposure to persistent organohalogen compounds such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-d ioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs). We determin ed concentrations of 2,3,7,8-substituted PCDDs and PCDFs and 19 PCB co ngeners in whole blood samples from three groups of men, 40-54 years o f age, with different consumption levels of crabs from a fjord area in southern Norway polluted with organochlorine compounds from a magnesi um production plant. A significant increase of many PCDD/PCDF congener s was found in the blood when comparing the referents, moderate-, and high-intake groups. The greatest difference as observed for several of the PCDFs that are characteristic for the contamination of the marine biota of the fjord. PCBs, in general, play a minor role in the contam ination of the fjord by the magnesium production process, except for t he highly chlorinated congeners such as PCB-209. Nevertheless, almost all PCBs increased from the referents to the high-intake group. Howeve r, the relative concentrations of several highly chlorinated PCBs (par ticularly PCB-209) in blood are unexpectedly low compared to their abu ndance in crabs, indicating low uptake of these congeners. The exposur e to PCDDs/PCDFs from crab consumption calculated from individual body burdens of these compounds were in good agreement with the intake est imated from previously measured concentrations in crabs, reported fish ing sites, and consumption. Almost all subjects in the high-intake gro up exceeded the tolerable weekly intake of 35 pg TEQ/kg body weight/we ek proposed by a Nordic Expert Group.