title: Persistent organochlorines, sedentary occupation, obesity and human male subfertility.
abstract: BACKGROUND
  Studies have suggested that the quality of human semen has been declining over recent decades, presumably because of lifestyle or environmental factors.
  
  
  METHODS
  Polychlorinated biphenyls and organochlorine pesticides were analysed in the plasma of 25 men with poor semen quality, 20 men with normal semen quality and idiopathic subfertility and 27 men with normal semen quality and female factor subfertility. Samples of seminal fluid were also analysed to assess the relationship between the levels in blood and semen.
  
  
  RESULTS
  The results indicate no difference in the levels of organochlorines between the groups. The levels of organochlorines in seminal fluid were proportional to the levels in plasma, but approximately 40 times lower. Men with poor semen quality were three times more likely to be obese than men with normal semen quality. There was also a significant negative correlation between semen quality parameters and body mass index among men with normal semen quality. The prevalence of sedentary work was lowest among men with the best semen quality.
  
  
  CONCLUSIONS
  Poor semen quality was found to be associated with sedentary work and obesity but not with plasma levels of persistent organochlorines. More research is needed to assess whether sedentary lifestyle and obesity are causal factors in the decline of semen quality.
authors.affiliation: Department of Pharmacology and Toxicology, University of Iceland, Hofsvallagata 53, IS-107 Reykjavik, Iceland. elinmag@hi.is
authors.forename: Elin V
authors.initials: EV
authors.lastname: Magnusdottir
authors.forename: Tanja
authors.initials: T
authors.lastname: Thorsteinsson
authors.forename: Sigridur
authors.initials: S
authors.lastname: Thorsteinsdottir
authors.forename: Maria
authors.initials: M
authors.lastname: Heimisdottir
authors.forename: Kristin
authors.initials: K
authors.lastname: Olafsdottir
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood / Q000378:metabolism*; D007248:Infertility, Male / Q000097:blood / Q000209:etiology / Q000378:metabolism; D008019:Life Style; D008297:Male; D009765:Obesity / Q000150:complications; D009790:Occupations; D010575:Pesticides / Q000097:blood / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000097:blood / Q000378:metabolism; D012661:Semen / Q000378:metabolism*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011078:Polychlorinated Biphenyls