skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mutagenic potential of binary mixtures of nitro-polychlorinated dibenzo-p-dioxins and related compounds

Journal Article · · J. Toxicol. Environ. Health; (United States)

The mutagenic potential of binary mixtures of nitro-polychlorinated dibenzo-p-dioxins and other environmentally related compounds was determined using Salmonella typhimurium strain TA98 in the standard plate incorporation assay. Samples tested included binary mixtures of 4-nitro-4'-chlorobiphenyl with 6-nitro-4,2',3',4',5'-pentachlorobiphenyl, 4-nitrobenzo-p-dioxin with 4-nitro-2,3,8-trichlorodibenzo-p-dioxin, and benzo(a)pyrene with either nitropentachlorobiphenyl or nitrotrichlorodibenzo-p-dioxin. Inhibition was the primary interaction observed for the mixtures of polyhalogenated dioxins or biphenyls with the direct-acting mutagens nitrodibenzo-p-dioxin or nitrochlorobiphenyl. At the highest dose tested, nitrotrichlorodibenzo-p-dioxin inhibited the bacterial mutagenicity of nitrodibenzo-p-dioxin by almost 50%, while pentachlorobiphenyl inhibited the mutagenicity of nitrobiphenyl by 34%. Conversely, synergism was the primary interaction observed for mixtures of halogenated aromatics with the promutagen benzo(a)pyrene. The addition of nitrotrichlorodioxin to benzo(a)pyrene enhanced the mutagenicity of the latter compound by as much as 70%, while the mutagenic potential of a mixture of benzo(a)pyrene and nitropentachlorobiphenyl was approximately 50% greater than the mutagenicity of benzo(a)pyrene alone. In summary, mixtures of nonmutagenic nitropolyhalogenated biphenyls or dibenzo-p-dioxins appear to inhibit the mutagenicity of direct-acting mutagens, while these same compounds seem to enhance the mutagenic potential of the promutagen benzo(a)pyrene.

Research Organization:
Texas A and M Univ., College Station (USA)
OSTI ID:
6834585
Journal Information:
J. Toxicol. Environ. Health; (United States), Vol. 24:3
Country of Publication:
United States
Language:
English