The effects of arid climate on PAE accumulation in organic films on an impervious surface

Abstract

Impervious surfaces play an important role in the circulation of urban pollutants. We analyze the influence of arid climate factors on phthalate ester (PAE) accumulation in the organic films on an impervious surface (windows) in the city of Changji, Xin Jiang, China. Different sampling sites in Changji were selected based on their land uses (high traffic, residential/educational, and industrial areas). The samples were analyzed using gas chromatography. The results showed that the average concentrations of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and di-2-ethylhexyl phthalate (DEHP) were 26.68 μg/g (range ND–203.03 μg/g), 16.93 μg/g (ND–102.43 μg/g), 220.85 μg/g (ND–1458.46 μg/g), and 42.99 μg/g (ND–267.23 μg/g), respectively. These results indicate that DBP and DEHP were the main PAE pollutants present on the impervious surfaces. The seasonal concentrations of the four PAEs varied consistently: levels were higher in spring, autumn, and winter, and lower in summer. There was clear seasonal variation in the concentrations of DMP, DBP, and DEHP, but less notably in those of DEP. Furthermore, seasonal variation in PAE levels was consistent between high traffic and residential/educational areas and Changji as a whole. However, seasonal levels of PAE concentrations in industrial areas were unique, and the concentration of DEP was higher in summer in these areas. Our results will aid understanding of the circulation mechanisms and enrichment of PAEs in organic films on typical impervious surfaces in arid climates. Moreover, we provide baseline data for accurately predicting PAE levels and developing local environmental protection policies.