Anthropogenic input of polycyclic aromatic hydrocarbons into five lakes in Western China

The temporal distribution of polycyclic aromatic hydrocarbons (PAHs) was examined in dated sediments from five lakes in Western China. The surficial concentrations of seven carcinogenic PAHs (BaA, Chyr, BbF, BkF, BaP, DBA and INP, hereafter denoted as PAH(7)) were highly site-specific. The Sigma PAH(7) concentrations generally increased from the deep layers to surface sediments. The temporal trends of Sigma PAH(7) concentrations were clearly different from those reported in developed countries. From 1950s to 19805, which PAHs started to decrease in developed countries, is the right period that PAHs started to increase rapidly in Western China. The fluxes and mass inventories suggest that the PAH(7) input over the past three decades was much more rapidly than it was before the 1980s. Source identification indicates that the PAHs were primarily from biomass burning and domestic coal combustion, and increasing vehicular and/or industrial coal combustion emission was also found. (C) 2010 Elsevier Ltd. All rights reserved.