This work was initiated to extend the previous findings on the induction of xenobiotic metabolism by the halogenated benzenes. Particular interest was focused on studying further the relationship between their long-term induction and their storage in body fat. A second objective was to determine if the brominated benzenes caused hepatic porphyria similar to that observed with the fungicide hexachlorobenzene. A third aim was to extend the observations to other halogenated benzenes in the enhancement of esteratic pathways of xenobiotic metabolism. In contrast to hexachlorobenzene, the brominated benzenes, including the fully substituted hexabromobenzene, did not induce hepatic porphyria to any significant degree and did not cause increases in the secretion of porphyrins. Studies on the distribution and elimination of 1,2,4-trichlorobenzene and 1,2,4-tribromobenzene indicated that their prolonged inductive effects are related to their storage and slow release from body stores, particularly adipose tissue. The administration of Aroclor 1254 resulted in prolonged increases in xenobiotic metabolism which could also be enhanced by starvation.

Caption title. "January 1981." "EPA-600/1-81-010." Microfiche.