Abstract / Description of output
Potential ecological risk from perfluoroalkyl substances (PFASs) under changing exposure in large river systems is an emerging challenge. Based on systematic monitoring of PFASs at 43 hydrologic stations along a 4300 km continuum of the Yangtze River, we investigated the ecological risk of PFASs under changing exposure resulting from operation of the Three Gorges Dam (TGD). Importantly, perfluorooctanoic acid (PFOA) extensively occurred in most mainstream water
samples, accounting for about 90% of the total content of PFASs in both spring and autumn, while short-chain PFASs contributed more than PFOA in sediment. The significant inversion of long chain PFASs occurrence from sediment to water reflected a profound change in exposure due to loss of finer sediments resulting from long-distance, long-term scour of the riverbed downstream of the TGD. Coarsening of bed materials weakened sorption of long-chain PFASs in sediments and enhanced their exposure in water, resulting in substantial increase of ecological risk to representative aquatic organisms. In the long term, particular attention must be paid to reducing PFOA discharges downstream of the TGD from local industries. The paper also highlights the influence of huge dams on altering river exposure to persistent organic pollutants and the necessity for a new strategy for ecological risk management of large river systems.
samples, accounting for about 90% of the total content of PFASs in both spring and autumn, while short-chain PFASs contributed more than PFOA in sediment. The significant inversion of long chain PFASs occurrence from sediment to water reflected a profound change in exposure due to loss of finer sediments resulting from long-distance, long-term scour of the riverbed downstream of the TGD. Coarsening of bed materials weakened sorption of long-chain PFASs in sediments and enhanced their exposure in water, resulting in substantial increase of ecological risk to representative aquatic organisms. In the long term, particular attention must be paid to reducing PFOA discharges downstream of the TGD from local industries. The paper also highlights the influence of huge dams on altering river exposure to persistent organic pollutants and the necessity for a new strategy for ecological risk management of large river systems.
Original language | English |
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Article number | 115933 |
Journal | Water Research |
Early online date | 16 May 2020 |
DOIs | |
Publication status | E-pub ahead of print - 16 May 2020 |