The bacterial mutagenicity of 2-nitrodibenzo-p-dioxin, a mixture of 2-nitro-7-chloro-and 2-nitro-8-chlorodibenzo-p-dioxin, 7-nitro-2,3-dichloro-, 8-nitro-2,3,7-trichloro-, 2-nitro-1,3,7,8-tetrachloro- and 3-nitro-1,2,4,7,8-pentachlorodibenzo-p-dioxin was determined using Salmonella typhimurium tester strains TA98 and TA100 with and without rat hepatic S9 for metabolic activation. The activities of these compounds were dependent on several factors including the dose level of compound per plate, the presence or absence of the S9 fraction, the tester strain used and the structure of the nitro-polychlorinated dibenzo-p-dioxin (PCDDs). All the nitro-PCDDs exhibited some direct acting mutagenicity with both tester strains, however, the activity was significantly lowered in the presence of exogenous S9 and the compounds were more mutagenic to tester strain TA98. The mutagenicity of the nitro-PCDDs was also dependent on structure since there was a marked decrease in activity with increasing chlorine content. Since nitro-PCDDs have recently been identified as incomplete combustion products of municipal waste, this study confirms that this new class of compounds are also bacterial mutagens. Several nitro polychlorinated biphenyls (PCB) were also shown to be mutagenic.
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Health, Toxicology and Mutagenesis