Determination of Animal Hazards from PCB-Contaminated Air and Soil Samples from Crab Orchard: Draft Report

Three matrices were sampled from the Sangamo Electric Landfill located on the Crab Orchard National Wildlife Refuge in Southern Illinois. The samples were extracted and refined for biological testing. The refined soil extract contained 4 7, 0. 7 6 and 0. 05 mg/ ml polychlorinated biphenyls (PCBs), dibenzofurans (PCDFs) and dibenzodioxins (PCDDs), respectively. The PCB congener profiles neither resembled commercial mixtures nor were limited to congeners normally considered to be present in the food chain. Tri- and tetraCBs dominated the PCB profile in the soil and air extracts, while the dust extract contained a higher proportion of tetra- and pentaCBs. The summed TCDD equivalencies (TEQs) of the soil, dust and air extracts were 0.62, 0.51 and 0.11 μg TCDD per mg PCB, respectively. The air and soil extracts were most effective in causing head loss and dopamine depletion in planarians, while the air and dust extracts caused an increase in whole body serotonin. In the female rat integrated endocrine disruption assay (FRIEDA), all extracts induced P450s and depressed serum thyroxine to similar degrees. The low TEQ air extract had a mild biphasic uterotropic effect, while the soil extract was uterotropic only at twice the highest PCB dose of the air extract. When the TCDD-like compounds were partially removed from the soil extract, this extract also had a mild uterotropic effect at lower doses. TCDD TEQs are valuable predictors of a specific set of responses, but the risk assessment of environmental mixtures of chlorinated aromatic compounds must consider multiple mechanisms and histories of exposures to labile compounds which may cause persistent or delayed effects.Ope