Distribution of volatile organic compounds in ambient air of Kaohsiung, Taiwan.

Automobile emissions have created a major hydrocarbon pollution problem in the ambient air of Taiwan. The aim of this study was to determine the volatile organic compounds (VOCs) in the ambient air of Kaohsiung, Taiwan. The spatial distribution, temporal variation, and correlations of VOCs at three study sites, selected based on traffic densities and distances from a freeway, were discussed. Sixty-four hydrocarbons were identified in the ambient air. Among all of the VOC species, acetone, aromatic and aliphatic compounds constituted the major constituents. Higher concentrations of VOCs existed further away from major arteries as compared to those found near the freeway. Therefore, the distance from the freeway may not be a sufficient index for reflecting actual air quality in the study area. Weather conditions, wind speed and direction did not affect the distribution of VOC concentrations in the three study sites. Other factors, such as the height and density of buildings, traffic conditions or commercial activities, might affect the distribution of VOCs.