title: The Relationship between Occupation and Semen Quality.
abstract: BACKGROUND
  Infertility can be a major concern for couples trying to conceive, and occupational hazards may constitute a main cause of infertility in men. Studies conducted throughout the world indicate that physical and chemical hazards in the workplace can have a negative impact on male fertility. The main objective of this study was to determine the frequency of occupational categories of men who attended an infertility clinic, and to evaluate the differences in the semen quality parameters among occupational categories.
  
  
  METHODS
  This cross-sectional study was conducted on 1164 males who were referred to the Infertility Research Center in Tehran for treatment of infertility in order to evaluate the effects of certain occupations on infertility. The participants were divided into several categories according to their occupations and evaluated by means of a questionnaire for duration of infertility, BMI, sperm count, percentage of normal sperm morphology and percentages of sperm with class A and class B motilities. Descriptive statistics, analysis of variance, and correlations were conducted using SPSS 16.0 for Windows.
  
  
  RESULTS
  There were no statistically significant differences in the mean sperm count or sperm morphology between occupational categories. Assessment of the differences in the frequency of sperm motility classes between occupational categories revealed a significant difference only in the frequency of sperm with class B motility. The lowest mean percentages of sperm with class B motility were seen in those involved in the transportation industry, a finding in agreement with a number of other researches.
  
  
  CONCLUSIONS
  Our findings revealed an association between occupation and sperm motility. Since our study population was relatively small and in many cases exposures to work hazards were brief, a larger study group must be evaluated in order to support the preliminary results of this study.
authors: Faculty of Health, Safety and Environment (HSE), Shahid Beheshti University of Medical Sciences, Tehran, Iran ; Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Mohammad Hossein
authors: MH
authors: Vaziri
authors: Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Mohammad Ali
authors: MA
authors: Sadighi Gilani
authors: Faculty of Health, Safety and Environment (HSE), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Amir
authors: A
authors: Kavousi
authors: Faculty of Health, Safety and Environment (HSE), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Marjan
authors: M
authors: Firoozeh
authors: Faculty of Health, Safety and Environment (HSE), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Reza
authors: R
authors: Khani Jazani
authors: Department of Reproductive Imaging, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Ahmad
authors: A
authors: Vosough Taqi Dizaj
authors: Faculty of Health, Safety and Environment (HSE), Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors: Habibesadat
authors: H
authors: Mohseni
authors: Department of Epidemiology and Reproductive Health, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Narges
authors: N
authors: Bagery Lankarani
authors: Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Mohammad
authors: M
authors: Azizi
authors: Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
authors: Reza
authors: R
authors: Salman Yazdi
keywords: Male infertility; Occupational Exposure; Semen Quality