High resolution gas chromatographic analysis of cytochrome P-448 inducing polychlorinated biphenyl congeners in hazardous waste.

Polychlorinated biphenyls (PCBs), which have been commercially manufactured since 1929, are complex mixtures of many congeners and several homologues. They have been used in a variety of industrial and non-industrial applications which has allowed large quantities to be released into the workplace and environment1-6. Based on a 198 1 estimate, as many as 17 million pounds of PCBs were entering land disposal sites in the U.S.A. annually (for a total of 385 million pounds)5,7. While their toxicity varies among isomer and toxicity test species, PCBs have been sufficiently implicated in animal and human toxicity to warrant their ban in the U.S.A.‘. Most of the early methods of analysis of PCBs were directed toward commercial products (such as Aroclors). It is still common to report results as ppm PCB-as Aroclor 1242, 1254, etc.s,9. Disposal of PCBs is based on a generic classification as PCB type and quantitated as > 50 or > 500 ppm. This is at best an approximation when the sample matches the standard, and is not applicable when microbial degradation and/or mammalian metabolism preclude visual matchingslO,l l. The problem of PCB analysis has become more complex with the discovery of specific congener toxicities10~12-1 8, with special concerns arising over the health effects of populations exposed to PCBs through contamination of the food chain19-22, in the workplaceZ3-26, and most recently to the questions of by-product PCBs2v2’ and incinerator and chemical destruction method residues28-29. Until recently the results of body burden studies have been reported as ppm of Aroclor X with no mention made as to the presence of specific PCB congeners. A recent study has reported the results with quantitation of specific congeners30. The importance of the quantitation of specific PCBs is underscored by studies that have demonstrated differences between mechanisms and degree of toxicity for individual PCB congeners6~10~12-1s. F or example, induction of cytochrome P-448 hepatic mixed function oxidase is effected only by certain PCBs. The P-448 is a fraction of the native hepatic enzyme system that metabolizes polycyclic aromatic hydrocarbons, such as