Source apportionment of PAHs in atmospheric particulates of Dalian: Factor analysis with nonnegative constraints and emission inventory analysis

Levels of 12 PAH species, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, perylene, indeno[1,2,3-cd]pyrene and benzo[ghi]perylene, in atmospheric particulates from urban area of Dalian, China, were determined. The sampling was performed at 15 sites in 1998. For wintertime and summertime, the summation of the 12 PAHs (ΣPAHs) averaged 167 (53.3–561) and 17.9 (1.6–48.9) ng m−3, respectively, which were much higher than the levels in other cities worldwide. Factor analysis with nonnegative constraints was used for source apportionment, which showed that PAHs originated from coal-related sources mainly (87%) and traffic emission as a second source (13%) in wintertime, and in summertime, coal-related sources (70%), traffic-related sources (27%), and wood burning (3%). The source apportionment results agree with the actual municipal and industrial layout well. Inventory analysis estimated the total amount of the 12 PAHs emitted by regulated stationary and mobile sources was 9940 kg in 1998. Qualitatively, consistent source apportionment results were obtained from the factor analysis with nonnegative constraints and inventory analysis.