Risk assessment and identification of factors influencing the historical concentrations of microcystin in Lake Taihu, China  

作　　者：Chen Cheng Alan D.Steinman Kaiye Zhang Qi Lin Qingju Xue Xing Wang Liqiang Xie 

机构地区：[1]State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Annis Water Resources Institute,Grand Valley State University,740 West Shoreline Drive,Muskegon,MI,USA [4]National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,Chinese Research Academy of Environmental Sciences,Beijing 100012,China [5]State Environmental Protection Key Laboratory of Drinking Water Source Protection,Chinese Research Academy of Environmental Sciences,Beijing 100012,China

出　　处：《Journal of Environmental Sciences》2023年第5期1-14,共14页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.41877486,41907326).

摘　　要：Understanding the history of microcystins(MCs)pollution in large lakes can help inform future lake management.We collected sediment cores from Lake Taihu to:investigate the long-term record of MCs(MC-LR,MC-YR,and MC-RR),explore the main environmental drivers of MCs,and assess their public health and ecological risks.Results showed that MCs content in all cores increased over time.The core from north Taihu had the highest MC concentrations,with an average total MCs(sum of MC-LR,MC-YR,and MC-RR=TMCs)content of(74.31±328.55)ng/g.The core from eastern Taihu showed the lowest average TMCs content of(2.91±3.95)ng/g.PCA showed that sediment MCs at the three sites were positively correlated with sediment chlorophyll-a.MC-LR and MC-YR in northern and western Taihu negatively correlated with both the sediment total organic carbon/sediment total nitrogen ratio(STOC/STN)andwater nitrate(NO_(3)^(−)-N)concentration,but three MC congeners at eastern Taihu showed positive correlations with water orthophosphate(PO_(4)^(3−)-P),NO_(3)^(−)-N,and STOC/STN.Generalized additive model analysis at each site revealed that NO_(3)^(−)-N was the main TMCs driver in northern andwestern Taihuwhere phytoplankton dominated,whereasPO_(4)^(3−)-P was the main TMCs driver in eastern Taihu where macrophytes dominated.At the whole lake scale,total phosphorus(TP)andPO_(4)^(3−)-P were the most important environmental drivers influencing MCs;TP explained 47.4%,44.2%,and 47.6%while orthophosphate explained 34.8%,31.2%,and 34.7%of the deviance on TMCs,MC-LR,and MC-YR,respectively.NO_(3)^(−)-N also showed a strong effect on MCs variation,especially on MC-YR.Risk assess-ment showed that both ecological and public health risk has increased in recent years.We conclude that while control of phosphorus and nitrogen input should be a major focus for future lake management,lake zone-specificmanagement strategiesmay also be important.

关 键 词：MICROCYSTINS Pollution history ORTHOPHOSPHATE NITRATE Risk assessment Lake Taihu 

分 类 号：X173[环境科学与工程—环境科学] X524