Occupationally related exposures and reduced semen quality: a case-control study.
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.
Tielemans
E
E
Department of Environmental Sciences, Wageningen Agricultural University, The Netherlands.
Burdorf
A
A
te Velde
E R
ER
Weber
R F
RF
van Kooij
R J
RJ
Veulemans
H
H
Heederik
D J
DJ
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
D000395:Air Pollutants, Occupational; D004391:Dust; D008670:Metals; D010575:Pesticides; D012997:Solvents; D002104:Cadmium; D002857:Chromium