2-Nitrofluoranthene, 1-, 2- and 4-Nitropyrenes and 6-Nitrochrysene in Diesel-Engine Exhaust and Airborne Particulates

抄録

Diesel-engine exhaust and airborne particulates were collected in downtown and suburban areas and five mutagenic nitroarenes (2-nitrofluoranthene (NF), 1-, 2- and 4-nitropyrenes (NPs) and 6-nitrochrysene (NC) in benzene-ethanol extracts were determined by high-performance liquid chromatography with chemiluminescence detection. 1- and 4-NPs and 6-NC were found in diesel-engine exhaust particulates, however, 2-NF and 2-NP were not detected. On the other hand, all five nitroarenes were found in airborne particulates. Diurnal concentration patterns of 4-NP and 6-NC in the downtown area were similar to the pattern of 1-NP, but the patterns of 2-NF and 2-NP were different from the pattern of 1-NP. These results strongly suggested that 2-NF and 2-NP are formed in the atmosphere. Of the five nitroarenes, 2-NF had the largest suburban / downtown concentration ratio. 2- and 4-NPs and 6-NC all showed larger ratios than did 1-NP. These results showed that 2-NF and 2-NP were formed in the atmosphere, but that the secondary formation of 4-NP and 6-NC were not known. Taking mutagenic activity and the atmospheric concentration into consideration, the mutagenic contribution of 2-NF was estimated to be comparable with that of 1-NP in the downtown area, and more than that of 1-NP in the suburban area. This result suggested that the mutagenic contribution of the minor nitroarenes formed in urban air might not be negligible.