title: Exposure to persistent organochlorine pollutants associates with human sperm Y:X chromosome ratio.
abstract: BACKGROUND
  During the last decades, there has been concern that exposure to endocrine disruptors, such as persistent organochlorine pollutants (POPs), may contribute to sex ratio changes in offspring of exposed populations.
  
  
  METHODS
  To investigate whether exposure to 2,2'4,4'5,5'-hexachlorobiphenyl (CB-153) and dichlorodiphenyl dichloroethene (p,p'-DDE) affect Y:X chromosome proportion, semen of 149 Swedish fishermen, aged 27-67 years, was investigated. The men provided semen and blood for analysis of hormone, CB-153 and p,p'-DDE levels. The proportion of Y- and X-chromosome bearing sperm in semen samples was determined by two-colour fluorescence in situ hybridization (FISH) analysis.
  
  
  RESULTS
  Log transformed CB-153 as well as log transformed p,p'-DDE variables were both significantly positively associated with Y chromosome fractions (P-values = 0.05 and <0.001, respectively). Neither age, smoking nor hormone levels showed any association with Y-chromosome fractions.
  
  
  CONCLUSIONS
  This is the first study to indicate that exposure to POPs may increase the proportion of ejaculated Y-bearing spermatozoa. These data add to the growing body of evidence that exposure to POPs may alter the offspring sex ratio.
authors.affiliation: Fertility Centre, Scanian Andrology Centre, Malmö University Hospital, Lund University, SE 205 02 Malmö, Sweden. Tarmo.Tiido@kir.mas.lu.se
authors.forename: Tarmo
authors.initials: T
authors.lastname: Tiido
authors.forename: Anna
authors.initials: A
authors.lastname: Rignell-Hydbom
authors.forename: Bo
authors.initials: B
authors.lastname: Jönsson
authors.forename: Yvonne Lundberg
authors.initials: YL
authors.lastname: Giwercman
authors.forename: Lars
authors.initials: L
authors.lastname: Rylander
authors.forename: Lars
authors.initials: L
authors.lastname: Hagmar
authors.forename: Aleksander
authors.initials: A
authors.lastname: Giwercman
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D041321:Chromosomes, Human, X / Q000187:drug effects*; D041322:Chromosomes, Human, Y / Q000187:drug effects*; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood / Q000633:toxicity; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D005260:Female; D005399:Fishes; D005506:Food Contamination; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000633:toxicity*; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000633:toxicity; D012744:Sex Ratio; D013094:Spermatozoa / Q000187:drug effects* / Q000648:ultrastructure*; D013548:Sweden
chemical_list: D004785:Environmental Pollutants; D006843:Hydrocarbons, Chlorinated; D003633:Dichlorodiphenyl Dichloroethylene; D011078:Polychlorinated Biphenyls; C014024:2,4,5,2',4',5'-hexachlorobiphenyl