Historical evolution of polycyclic aromatic hydrocarbon pollution in Chaihe Reservoir from 1863 to 2018

Pollution from polycyclic aromatic hydrocarbons (PAHs) spreads and changes worldwide. The pollution evo-lution in the regional water environment evolves in response to multiple factors, requiring considerable atten-tion. PAH heterogeneity in the sediment core from Chaihe Reservoir was investigated to indicate dynamic changes in PAH pollution levels and sources and propose recommendations for controlling PAHs. Dynamic PAH patterns showed that the overall decline in PAH pollution was in association with local anthropogenic activities, temperature, and precipitation over the period 1863-2018. Nevertheless, coal, oil, and natural gas consumptions still played significant roles in transferring PAHs to the reservoir. Meanwhile, there were dominant local origins, including grass, wood, and coal combustion. The results highlight that the joint action of natural and anthro-pogenic interventions mitigated PAH pollution in the reservoir. Promoting improved fuels, new energy vehicles, and cleaner energy may further lower PAH pollution.

Automated summary

This study investigated the heterogeneity of PAHs in the sediment core of Chaihe Reservoir to assess the dynamic changes in pollution levels and sources, and proposed recommendations for controlling PAHs. The results showed an overall decline in PAH pollution in the reservoir, but coal, oil, and natural gas consumption still played significant roles in transferring PAHs. Local sources such as grass, wood, and coal combustion were also identified. The study highlights the importance of both natural and anthropogenic interventions in mitigating PAH pollution.