title: Occupationally related exposures and reduced semen quality: a case-control study.
abstract: OBJECTIVE
  To determine whether there is an association between abnormal semen parameters and occupational exposures to organic solvents, metals, and pesticides.
  
  
  METHODS
  Case-control study using three case groups based on different cutoff values for semen parameters and one standard reference group.
  
  
  METHODS
  University Hospital Utrecht and University Hospital Rotterdam, the Netherlands.
  
  
  METHODS
  Male partners of couples having their first consultation at the two infertility clinics (n = 899).
  
  
  METHODS
  Men provided at least one semen sample. Occupational exposure was assessed with use of job-specific questionnaires, a job exposure matrix, and measurements of metals and metabolites of solvents in urine.
  
  
  METHODS
  Standard clinical semen analyses were used to define case groups and controls.
  
  
  RESULTS
  An association between aromatic solvents and reduced semen quality was demonstrated, irrespective of the exposure assessment method used. The associations were stronger if the case definition was based on stricter cutoff values for semen parameters. Risk estimates were higher if the analysis was restricted to primary infertile men. Exposure to other pollutants at the workplace was not associated with impaired semen quality.
  
  
  CONCLUSIONS
  The findings indicated an association between aromatic solvent exposure and impaired semen parameters.
authors: Department of Environmental Sciences, Wageningen Agricultural University, The Netherlands.
authors: E
authors: E
authors: Tielemans
authors: A
authors: A
authors: Burdorf
authors: E R
authors: ER
authors: te Velde
authors: R F
authors: RF
authors: Weber
authors: R J
authors: RJ
authors: van Kooij
authors: H
authors: H
authors: Veulemans
authors: D J
authors: DJ
authors: Heederik
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects; D002104:Cadmium / Q000652:urine; D016022:Case-Control Studies; D002857:Chromium / Q000652:urine; D004391:Dust / Q000009:adverse effects; D005260:Female; D006801:Humans; D007248:Infertility, Male / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008670:Metals / Q000009:adverse effects / Q000652:urine; D016273:Occupational Exposure; D010575:Pesticides / Q000009:adverse effects; D012307:Risk Factors; D012661:Semen / Q000502:physiology*; D012907:Smoking / Q000652:urine; D012997:Solvents / Q000009:adverse effects
chemical_list: D000395:Air Pollutants, Occupational; D004391:Dust; D008670:Metals; D010575:Pesticides; D012997:Solvents; D002104:Cadmium; D002857:Chromium