The atmospheric levels of 12 chlorinated polycyclic aromatic hydrocarbons (ClPAHs) associated with particulates at an urban site in Japan were investigated. Only 7 of the 12 species studied were detected in air samples collected monthly during 2002. 1-Chloropyrene (1-ClPy) was detected at the highest concentration (7.5 pg m -3 (annual mean)), followed by 6-chlorobenzo[a]pyrene (6-ClBaP; 5.6 pg m -3 ) and 9,10-dichlorophenanthrene (5.1 pg m -3 ). The concentrations of the ClPAHs tended to be higher in winter than in summer, with the exception of the 6-ClBaP concentration, which was high in both summer and winter. Correlation analysis also indicated that the behavior of 6-ClBaP differed significantly from that of the other ClPAHs. Comparison of the atmospheric ClPAH concentration profile normalized to 1-ClPy concentration with that for a traffic air sample revealed significant differences between the profiles. The behavior of the atmospheric ClPAHs was also influenced by the origin of the associated particulates, which varied according to season. The positions of chlorination in the detected ClPAHs were consistent with those where the frontier electron density was high. This means that the atmospheric ClPAHs were formed by secondary reactions with chlorine atoms. The photostabilities of the ClPAHs were also investigated in laboratory experiments using a chemical model system. The ClPAHs decayed according to first-order reaction rate kinetics, with photostabilities increasing in the order 6-ClBaP < 1-ClPy < 7-ClBaA < ClPhe < ClFluor, consistent with the trend for the parent PAHs. The photolyses of chlorophenanthrenes and 7-chlorobenz[a]anthracene were confirmed to proceed by initial abstraction of chlorine, followed by oxidative degradation. ES040433SFIGURE 4. Chemical structures of the ClPhe derivatives and 7-ClBaA used in the irradiation experiments.

No abstract

An analytical method was established for the simultaneous determination of 39 polycyclic aromatic hydrocarbons (PAHs) in air. The method was applied to a survey of gaseous and particulate PAHs in household indoor air. The survey was performed in 21 houses in the summer of 1999 and in 20 houses in the winter of 1999–2000 in Fuji, Japan. Thirty-eight PAHs were determined in indoor and outdoor air in the summer, and 39 PAHs were determined in indoor and outdoor air in the winter. The concentrations of gaseous PAHs in indoor air tended to be higher than those in outdoor air in the summer and winter. The concentrations of particulate PAHs in indoor air were the same as or lower than those in outdoor air in the summer and winter. PAH profiles, correlations between PAH concentrations, and multiple regression analysis were used to determine the factors affecting the indoor PAH concentrations. These results showed that gaseous PAHs in indoor air were primarily from indoor emission sources, especially during the summer, and that indoor particulate PAH concentrations were significantly influenced by outdoor air pollution.

An analytical method was established for the determination of benzene and 13 of its alkyl derivatives. The method was applied to a survey of indoor pollution that investigated the usefulness of the method, concentration levels, seasonal variations, profiles, correlations between compounds, and factors that affected indoor pollution by these compounds. The survey was performed in 21 houses in the summer of 1999 and 20 houses in the winter of 1999–2000 in Fuji, Japan. All the target compounds were detected in the indoor and outdoor air of all houses. Outdoor concentrations of benzene ranged from 0.779 to 3.17 μg/m3 in summer and from 1.35 to 6.04 μg/m3 in winter, whereas indoor concentrations of benzene ranged from 0.694 to 3.11 μg/m3 in summer and from 1.65 to 6.89 μg/m3 in winter. Indoor concentrations of the target compounds, except for benzene, were elevated, compared with outdoor concentrations. Because indoor and outdoor concentrations of benzene and its derivatives in summer were lower than in winter, the emission of these compounds may be increased by use of a heater and other variables present in winter. Profiles of the compounds, correlations between the compounds, and factors that affected indoor pollution (determined by multiple regression analysis) were investigated. These results suggested that indoor benzene predominantly penetrated from outdoors and that other benzene derivatives were emitted from indoor sources, such as paint solvents and kerosene heaters.