Contamination of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River

To explore the occurrence, source, and risk of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River, eighty-nine surface water samples were collected in 8 field campaigns from July 2018 to November 2019. Fifteen of 16 PAHs except for dibenz(a,h)anthracene (DBA) were found in the water. Detection frequencies were observed between 53 and 72% for PAHs with 4 rings, while most of other PAHs were less detected, e.g., benzo(a)pyrene (BaP) in 31% of samples. The total concentrations of 16 priority PAHs reached up to 2.8 mu g center dot L-1 and increased during the tidal transitions from flood to ebb. The average concentrations of PAHs in ebb tides were higher than those in flood tides. PAH concentrations and compositions showed great variation with different sampling campaigns, and higher levels and more components were observed in the rainy months and cold months. Those priority PAHs in the tidal water source are mainly from combustion activities (especially fossil fuel combustion), but the contribution from oil spills/leakage is also important in rainy months. High-molecular-weight PAHs in this tidal water source may pose risks to aquatic life, while they pose no carcinogenic risk to human health via ingestion of drinking water.

Automated summary

This study investigated the occurrence, sources, and risks of 16 priority polycyclic aromatic hydrocarbons (PAHs) in urban source water at the tidal reach of the Yangtze River. The results showed that 15 out of 16 PAHs were detected in the water samples, with detection frequencies ranging from 53% to 72%. The total concentrations of PAHs reached up to 2.8 μg/L and increased during tidal transitions. The concentrations and compositions of PAHs varied with different sampling campaigns, with higher levels and more components observed in rainy and cold months. The priority PAHs in the tidal water source were mainly from combustion activities, but oil spills/leakage also made important contributions during rainy months. High-molecular-weight PAHs in this water source may pose risks to aquatic life, but they do not pose a carcinogenic risk to human health through ingestion of drinking water.