Abstract
Concentrations of particulate polycyclic aromatic hydrocarbons(PAHs) in ambient air were investigated every month during the period Apr. 2004 to Mar. 2006 at two sampling sites in Ehime Prefecture; Site-N in Niihama city industrial area and Site-U in Uwajima city nonindustrial area. The sampling was carried out by high volume air sampler on quarts filters, extracted with dichloromethane and analyzed by HPLC with programmable fluorescence detection. Heavy metals and water soluble ios in particulate samples and benzene in air samples were also analyzed in this study. Annual average of total PAHs concentrations ranged from 4.5 to 4.7 ng/m3 at Site-N, higher than in Site-U (2.0∼3.4 ng/m3). Estimated risks of each PAHs based on unit risk were in the order of 10-7∼10-5, but overall risk was higher than objective criteria suggested by Central Environmental Council, Japan. B[a]P contributed above 50 % followed by DB[a,h]A. To have a complete knowledge on PAHs in atmosphere, their levels in the gaseous phase should also be monitored. Major source of PAHs would be vehicles especially diesel cars because of their diagnostic ratios of B[ghi]P/IP, IP/(IP+B[ghi]P) and (B[b]F+B[k]F)/B[ghi]P ranged within values reported for diesel exhausts so far. This view can be substantiated by the observed high correlation of PAHs with benzene and carbon oxide. Indexes of sources were selected by hierarchical cluster analysis on datasets of PAHs, metals and ions at Site-U which has no significant sources from industries. Then temporal variations of them and back trajectories at points in time were analyzed. It appears that high concentrations of anthropogenic metals and NH4SO4 are observed when the air mass was originated and passed through low-altitudes on industrial regions of China. Although PAHs showed significant correlation with these metals, they would be increased mainly by the effect of atmospheric stability.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
