title: Semen quality in Peruvian pesticide applicators: association between urinary organophosphate metabolites and semen parameters.
abstract: BACKGROUND
  Organophosphates are broad class of chemicals widely used as pesticides throughout the world. We performed a cross-sectional study of associations between dialkylphosphate metabolites of organophosphates and semen quality among pesticide applicators in Majes (Arequipa), Peru.
  
  
  METHODS
  Thirty-one men exposed to organophosphate (OP) pesticides and 31 non-exposed were recruited (age, 20-60 years). In exposed subjects, semen and a blood sample were obtained one day after the last pesticide application. Subjects were grouped according to levels of OP metabolites in urine. Semen samples were analyzed for sperm concentration, percentage of sperm motility, percentage of normal morphology, semen leucocytes and concentrations of fructose and zinc. Exposure to OP was assessed by measuring six urinary OP metabolites (dimethyl and diethyl phosphates and thiophosphates) by gas chromatography using a single flame photometric detector.
  
  
  RESULTS
  Diethyldithiophosphate (p = 0.04) and diethylthiophosphate (p = 0.02) better reflected occupational pesticide exposure than other OP metabolites. Semen analysis revealed a significant reduction of semen volume and an increase in semen pH in men with OP metabolites. Multiple regression analysis showed that both occupational exposure to pesticides and the time of exposure to pesticides were more closely related to alterations in semen quality parameters than the single measurement of OP metabolites in urine.
  
  
  CONCLUSIONS
  The study demonstrated that occupational exposure to OP pesticides was more closely related to alterations in semen quality than a single measurement of urine OP metabolites. Current measurement of OP metabolites in urine may not reflect the full risk.
authors.affiliation: Department of Biological and Physiological Sciences, Faculty of Sciences and Philosophy, Universidad Peruana Cayetano Heredia, Lima, Peru. 23411@upch.edu.pe
authors.forename: Sandra
authors.initials: S
authors.lastname: Yucra
authors.forename: Manuel
authors.initials: M
authors.lastname: Gasco
authors.forename: Julio
authors.initials: J
authors.lastname: Rubio
authors.forename: Gustavo F
authors.initials: GF
authors.lastname: Gonzales
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects*; D062025:Organophosphate Poisoning; D009943:Organophosphorus Compounds / Q000652:urine*; D010568:Peru; D010575:Pesticides / Q000506:poisoning* / Q000652:urine; D012044:Regression Analysis; D012661:Semen / Q000187:drug effects*; D055101:Semen Analysis; D055815:Young Adult
chemical_list: D009943:Organophosphorus Compounds; D010575:Pesticides