Sedimentary record of polycyclic aromatic hydrocarbons in a reservoir in Northeast China.

A sediment core from the Dahuofang Reservoir in Northeast China was (210)Pb and (137)Cs dated and analyzed for polycyclic aromatic hydrocarbons (PAHs) to track the regional PAH pollution in the past 50 years. The 2-4 ring PAHs peaked in the early 1990s, reflecting the historical role of coal usage in the energy structure in this area. More recently, vehicle emissions caused the continuous increase of the 5+6 ring PAHs. However, the sixteen US EPA priority PAHs showed a significant decline since the early 1990s. This PAH temporal trend is different from the U.S., the European countries and Japan, and is also different from the other areas of China, which could be attributed to the switch from coal to oil or natural gas as the main energy, and the large-scale elimination of outdated combustion facilities and techniques in Northeast China. Copyright Â