Development of mutagenicity during degradation of N-nitrosamines by advanced oxidation processes.
Development of mutagenicity of five N-nitrosamines (N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosopyrrolidine (NPYR) and N-nitrosodiphenylamine (NDPhA)) was investigated during oxidative processes involving UV-photolysis, ozone and OH radicals. The mutagenicity was detected by the Ames test with 3 different strains, TA98, TAMix and YG7108, a strain which is sensitive for N-nitrosamines, in presence and absence of metabolic activation (S9). UV photolysis of mutagenic N-nitrosamines (NDMA, NDEA, NDPA and NPYR) leads to the removal of their specific mutagenic activity as detected in YG7108 in the presence of S9. A formation of mutagens during UV photolysis was detected only in case of NDPhA in the strain TA98. Oxidation products of NDMA, NDEA and NDPhA did not show any significant mutagenicity in the strains used, whereas oxidation of NDPA and NPYR by hydroxyl radicals seems to lead to the formation of direct mutagens (mutagenic in the absence of S9) in YG7108 and TAMix. Oxidation by hydroxyl radicals of N-nitrosamines with chains longer than ethyl can mimic metabolic activation of N-nitrosamines in vivo.
['Mestankova|Hana|H|', 'Schirmer|Kristin|K|', 'Canonica|Silvio|S|', 'von Gunten|Urs|U|']
D004249:DNA Damage D017665:Hydroxyl Radical D009152:Mutagenicity Tests D009153:Mutagens D009154:Mutation D009602:Nitrosamines D010100:Oxygen D055668:Photochemical Processes D010782:Photolysis D012486:Salmonella typhimurium D013056:Spectrophotometry, Ultraviolet D014466:Ultraviolet Rays D014871:Water Microbiology D014873:Water Pollutants
Mutagenicity N-nitrosamines Ozone Ames test UV photolysis Hydroxyl radicals