One-century sedimentary record, sources, and ecological risk of polycyclic aromatic hydrocarbons in Dianchi Lake, China

Abstract

In this study, the sedimentary records, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in Dianchi Lake were analyzed. The concentration ranges of ΣPAH 16 in the sediments of Dianchi Lake were 368-990 ng/g, with an average value of 572 ng/g, peaking in 1988. Economic development and rapid population growth, as well as the rapid growth of coal consumption, have a greater impact on the HMW PAHs than on the LMW PAHs in the sedimentary environment. The results of the diagnostic ratios and PCA model show that the main sources of PAHs were coal and biomass combustion, as well as fossil fuel combustion sources in individual years. The risk assessment results showed that the PAH concentrations in the sediment were within a safe range. In the past 100 years of sediment pore water, except for Phe, which reached chronic toxic pollution levels in some years, other 2-3 ring LMW PAHs have been within a safe range. With the development of industrialization and urbanization, the burning of fossil fuels such as coal and petroleum has increased, and some of the 4-6 ring HMW PAHs have reached chronic toxicity or even acute toxicity in the sediment pore water.