Regional assessment of ambient volatile organic compounds in an industrial harbor area, Shizuoka, Japan

The regional distributions of, and inhalation cancer risks for, a group of volatile organic hydrocarbons (VOCs) consisting of aromatic hydrocarbons (AHCs), volatile organic halogenated compounds (VOHCs), and carbonyl compounds (CCs) were determined in an industrial harbor city (Shimizu, Japan) in the summer and winter of 2000. The concentrations of most of these VOCs tended to be higher in winter than in summer, but this trend was not observed for CCs. Significant correlations (p<0.05p<0.05) were observed between the concentrations of most of the AHCs in both summer and winter, and between the concentrations of certain AHCs and CCs in summer, which suggests common emission sources and similar atmospheric behavior for these compounds. The results of principal-component analysis indicated that vehicle exhaust and industrial activity were the predominant emission sources of the VOCs. To determine the local spatial distributions and emission sources for the VOCs, we created contour maps for the monitored VOCs. These maps indicated that the local distributions varied dramatically depending on the characteristics of the VOCs, such as their emission sources and fates. The lifetime cancer risks (LCRs) calculated from the corresponding VOC concentrations were significantly higher (p<0.0001p<0.0001) in winter than in summer. Risk was derived mainly from benzene, carbon tetrachloride, formaldehyde, and acetaldehyde in both summer and winter; the spatial distribution of high LCR levels was similar to the distribution of high benzene, formaldehyde, and acetaldehyde concentrations.