title: A cross-sectional investigation of chronic exposure to microcystin in relationship to childhood liver damage in the Three Gorges Reservoir Region, China.
abstract: BACKGROUND
  Microcystin-producing Microcystis bloom is a severe water problem in the world. Some reports indicate that chronic exposure to microcystin may result in liver damage in adults, but information on effects in children is limited.
  
  
  OBJECTIVE
  We investigated the relationship between microcystin exposure and liver damage in children.
  
  
  METHODS
  We measured microcystin concentrations in drinking water and aquatic food (carp and duck) from two lakes and four wells. Participants were 1,322 children 7-15 years of age who obtained drinking water from one of the tested sources, completed questionnaires, and provided blood samples for serum liver enzymes [alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT)] and serum microcystin analysis. Multivariable logistic regression was used to identify risk factors associated with liver damage (two or more abnormal serum enzyme levels in ALT, AST, ALP, or GGT).
  
  
  RESULTS
  Microcystin was detected in most samples of water and aquatic food from two lakes. Children who drank water from the lake with the highest microcystin concentrations had a total estimated daily microcystin intake of 2.03 μg, a value much higher than the tolerable daily intake (0.40 μg) proposed by the World Health Organization for children. Hepatitis B virus (HBV) infection, use of hepatotoxic medicines, and microcystin exposure were associated with liver damage. AST and ALP levels were significantly higher in high-microcystin-exposed children than in low-exposed children and unexposed children when participants who were HBV-positive or hepatotoxic medicine users were excluded from the analysis.
  
  
  CONCLUSIONS
  These results suggest that chronic exposure to microcystin may be associated with liver damage in children in the Three Gorges Reservoir Region.
authors.affiliation: Department of Environmental Hygiene, College of Preventive Medicine, Third Military Medical University, Chongqing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Ji-an
authors.initials: JA
authors.lastname: Chen
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhao
authors.forename: Chaowen
authors.initials: C
authors.lastname: Pu
authors.forename: Zhiqun
authors.initials: Z
authors.lastname: Qiu
authors.forename: Renping
authors.initials: R
authors.lastname: Zhang
authors.forename: Weiqun
authors.initials: W
authors.lastname: Shu
mesh_terms: D000293:Adolescent; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D002648:Child; D002681:China; D005260:Female; D006801:Humans; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008107:Liver Diseases / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D052998:Microcystins / Q000097:blood* / Q000633:toxicity*; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D052998:Microcystins; C078588:microcystin; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase