title: Ambient manganese exposure is negatively associated with human sperm motility and concentration.
abstract: BACKGROUND
  Occupational and experimental animal studies indicate that exposure to high levels of manganese impairs male fertility, but the effects of ambient manganese in humans are not known.
  
  
  METHODS
  We measured blood levels of manganese and selenium in 200 infertility clinic clients in a cross-sectional study. Correlations between metals and semen variables were determined, adjusting for other risk factors. Outcomes were low motility (<50% motile), low concentration (<20 million/mL), or low morphology (<4% normal). We also investigated dose-response relationships between quartiles of manganese exposure and sperm parameters.
  
  
  RESULTS
  High manganese level was associated with increased risk of low sperm motility (odds ratio = 5.4; 95% confidence interval = 1.6-17.6) and low sperm concentration (2.4; 1.2-4.9). We saw a U-shaped dose-response pattern between quartiles of manganese exposure and all 3 sperm parameters.
  
  
  CONCLUSIONS
  Ambient exposure to manganese levels is associated with a reduction in sperm motility and concentration. No adverse effects were seen for high selenium.
authors.affiliation: Department of Epidemiology, Michigan State University, East Lansing, Michigan 48823, USA. wirthj@msu.edu
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Wirth
authors.forename: Mary G
authors.initials: MG
authors.lastname: Rossano
authors.forename: Douglas C
authors.initials: DC
authors.lastname: Daly
authors.forename: Nigel
authors.initials: N
authors.lastname: Paneth
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Puscheck
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Potter
authors.forename: Michael P
authors.initials: MP
authors.lastname: Diamond
mesh_terms: D000328:Adult; D001741:Black or African American; D003430:Cross-Sectional Studies; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects; D006306:Health Surveys; D006801:Humans; D007248:Infertility, Male; D008297:Male; D008345:Manganese / Q000009:adverse effects* / Q000097:blood*; D016017:Odds Ratio; D009845:Oligospermia / Q000139:chemically induced*; D012643:Selenium / Q000009:adverse effects / Q000097:blood*; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000002:abnormalities; D044465:White People
chemical_list: D008345:Manganese; D012643:Selenium