[Distribution and sources of PAHs in soil from Liaohe estuarine wetland]

16 polycyclic aromatic hydrocarbons (PAHs) were measured by GC-FID for 31 surface soil samples collected from Liaohe estuary wetland in October of 2008 and May and August of 2009. The results showed that the total concentrations of PAHs in surface soil ranged from 293.4 ng x g(-1) to 1936.9 ng x g(-1) with a mean of 851.5 ng x ng(-1). The contents of PAHs were the highest in the oilwell reed field and the lowest in the beach. The total concentrations of PAHs and proportion of median and high molecular weight of samples collected in October was higher than those collected in May and August. The relative abundance of different benzene rings and the ratio analysis illustrated that pyrolysis was the main source in October, and the mixed pollution of pyrogenic and oil spill was the dominant source in May and August. The principle component analysis-multiple linear regression analysis (PCA-MLR) indicated that the major source in October was coal/vehicular emission (accounted for 45.5%), and the mixture of vehicular exhaust and oil spill was the major source in May and August (accounted for 75.2% and 42.2% respectively).