Concentration Levels and Potential Ecological Risks of Polycyclic Aromatic Hydrocarbons in Chinese Rivers

Polycyclic aromatic hydrocarbons (PAHs) are one of the most important persistent organic pollutants (POPs) and are widespread in surface waters in China. Based on the literature surveyed, concentration levels and geographic distribution of 16 PAHs in major Chinese rivers were summarized. The results showed that 2-3-ring PAHs were predominated in water, 4-ring PAHs were abundant in suspended particular matter (SPM), and 3-6 ring PAHs were the main chemical forms in sediment. In general, concentration levels of PAHs in rivers from northern China were higher than those from southern China. There existed a significant difference between concentration level of PAHs from the north and from the south. In comparison with concentration levels of PAHs in the world rivers, level of PAHs in dissolved phase in Chinese rivers was higher than those from other countries, while PAHs concentration in SPM and sediment of Chinese rivers was in the middle range. The quotient method was used to screen the potential risk of PAHs to aquatic organisms. It appeared that 7 among 16 PAHs, i.e., phenanthrene, anthracene, fluoranthene, pyrene, benzo[a] anthracene, chrysene and benzo[a] pyrene, might have potential adverse effects to aquatic system, which should be particularly concerned.