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

► The 50 year trend of PAHs in a reservoir in Northeast China was established. ► The decrease of the 16 PAHs since 1990s could be attributed to the energy structure change in the region. ► The increase of 5 + 6 ring PAHs in the reservoir could be partly due to the contribution from vehicle emissions. ► The PAH time trend in this study is different from that in the U.S. and European countries, and other areas of China.