Particulate Polycyclic Aromatic Hydrocarbons and Their Nitrated Derivatives in Three Cities in Liaoning Province, China

Abstract

Airborne particulates were collected in nine size fractions by using Andersen low-volume air samplers in the cities of Shenyang, Fushun, and Tieling, Liaoning Province, in northeast China, during the period from July 2001 through December 2003. Nine polycyclic aromatic hydrocarbons (PAHs) and seven nitropolycyclic aromatic hydrocarbons (NPAHs) in the airborne particulates were determined. The mean concentrations of the sums of the nine PAHs and seven NPAHs were highest in Fushun, which is an industrial city, and lowest in Shenyang, which is a commercial city, although the consumption of petroleum and coal were largest in Shenyang. The nine fractions were grouped into three groups: > 7 μ m, 2.1–7 μ m and < 2.1 μ m. In each city, more than 50% of the total PAHs and total NPAHs were found in the fine particulate fraction (< 2.1 μ m). In each city, all PAHs and all NPAHs were clearly higher in winter than in summer. The concentration ratio of 1-nitropyrene to pyrene, which is a suitable indicator to identify diesel engine and coal combustion as proposed by our previous study, showed that the major contributors of PAHs and NPAHs in the airborne particulates were coal-combustion systems both in summer and winter in Fushun and Tieling. In Shenyang, atmospheric PAHs and NPAHs also seemed to be affected by coal combustion systems in winter, whereas gasoline engine vehicles seemed to be a major contributor in summer by the larger concentration ratio of 1-nitropyrene to pyrene. Cluster analysis and other diagnostic ratios such as benz[a]anthracene to chrysene, benzo[ghi]perylene to benzo[a]pyrene supported these results.