Recent Changes in Atmospheric Polycyclic Aromatic Hydrocarbons (PAHs) and Nitropolycyclic Aromatic Hydrocarbons (NPAHs) in Shenyang, China

Airborne particulates were collected in three size fractions by using Anderson low-volume air samplers in Shenyang, China, in winter and summer in 2007. Compared with data obtained in 2001 at the same sites, the total concentrations of nine polycyclic aromatic hydrocarbons (PAHs) in winter decreased by 67% at one site and decreased by 40% at the other site, while the total concentrations of four nitropolycyclic aromatic hydrocarbons (NPAHs) did not decrease. This suggests that environmental countermeasures begun in 2001 were effective in decreasing the concentration of PAHs. However, in summer, the concentrations of PAHs and NPAHs rose by the factors of 4 and 5, respectively, possibly because of an increase in the number of motor vehicles. © 2011 Taylor and Francis Group, LLC.