title: Groundwater contamination by microcystin from toxic cyanobacteria blooms in Lake Chaohu, China.
abstract: Lake Chaohu is a eutrophic lake that experiences massive cyanobacterial blooms. The high concentrations of microcystin observed in this lake are the result of the bloom's high proportion of toxic cyanobacteria strains. Groundwater is the important source of water for drinking, washing, and irrigation in the watershed of Lake Chaohu. This study examines the space-time distribution of microcystins and related environmental factors in wells near Lake Chaohu. All collected groundwater samples from the Lake Chaohu region had detectable concentrations of microcystins. The highest concentration of microcystins, 1.07 μg L(-1), occurred in a well hundreds of meters from the western coast of the lake in September. The distance from the lake shore to the well was significantly and positively correlated with the microcystin concentration in the groundwater. Moreover, a correlation analysis shows that the microcystin concentration in the groundwater was positively correlated with the total dissolved phosphorus (TDP) and microcystin concentration of the nearby lake water. Therefore, the microcystin in the groundwater likely originates from penetration by nearby lake water. Our results suggest that the groundwater near Lake Chaohu poses a significant health risk for the local residents when used for drinking water.
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China. zhyang@niglas.ac.cn.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
authors.forename: Fanxiang
authors.initials: F
authors.lastname: Kong
authors.affiliation: State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
mesh_terms: D002681:China; D000458:Cyanobacteria / Q000254:growth & development*; D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry / Q000382:microbiology*; D057097:Harmful Algal Bloom; D060106:Lakes / Q000382:microbiology*; D052998:Microcystins / Q000032:analysis*; D010758:Phosphorus / Q000032:analysis; D014873:Water Pollutants / Q000032:analysis
chemical_list: D052998:Microcystins; D014873:Water Pollutants; D010758:Phosphorus; C078588:microcystin
keywords: Cyanobacteria blooms; Groundwater; Lake Chaohu; Microcystin