Pollution characteristics of volatile organic compounds in the atmosphere of Haicang District in Xiamen City, Southeast China
The compositions, spatial distributions, seasonal variations as well as ozone formation potential (OFP) of volatile organic compounds (VOCs) were investigated in the atmosphere of Haicang District, Xiamen City, Southeast China. Twenty-four VOCs were detected in this study, and alcohol, methylene chloride, toluene, ethyl acetate, and isopropyl alcohol were the abundant species. The concentrations of total VOCs (TVOCs) in industrial areas were higher than those in residential and administrative areas and background site. For industrial areas, the TVOCs concentrations in summer were higher than those in winter, which might result from the higher ambient temperature in summer led more evaporation of organic compounds from industrial activities. In contrast, non-industrial areas showed higher concentrations in winter while lower concentrations in summer due to the unfavorable meteorological conditions in winter. The spatial distribution of BTEX (benzene, toluene, ethylbenzene and xylene) followed the order of industrial areas > residential and administrative areas > background site, and the concentrations in summer were lower than those in winter for most sites. The higher ratios (8.9–14.0) of T/B in this study indicated that industrial emissions were the main sources in this District. X/B ratios were used to assess the ages of air parcels and provided evidences of transport of air parcels among these sites. Total OFP (TOFP) showed the trend of increase with the increase of TVOCs, and toluene was found as the major contributor to TOFP.