title: Decreased serum free testosterone in workers exposed to high levels of di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP): a cross-sectional study in China.
abstract: BACKGROUND
  Observations of adverse developmental and reproductive effects in laboratory animals and wildlife have fueled increasing public concern regarding the potential for various chemicals to impair human fertility.
  
  
  OBJECTIVE
  Our objective in this study was to assess the effect of occupational exposure to high levels of phthalate esters on the balance of gonadotropin and gonadal hormones including luteinizing hormone, follicle-stimulating hormone, free testosterone (fT), and estradiol.
  
  
  METHODS
  We examined urine and blood samples of 74 male workers at a factory producing unfoamed polyvinyl chloride flooring exposed to di-n-butyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) and compared them with samples from 63 male workers from a construction company, group matched for age and smoking status.
  
  
  RESULTS
  Compared to the unexposed workers, the exposed workers had substantially and significantly elevated concentrations of mono-n-butyl phthalate (MBP; 644.3 vs. 129.6 microg/g creatinine, p < 0.001) and mono-2-ethylhexyl phthalate (MEHP; 565.7 vs. 5.7 microg/g creatinine, p < 0.001). fT was significantly lower (8.4 vs. 9.7 microg/g creatinine, p = 0.019) in exposed workers than in unexposed workers. fT was negatively correlated to MBP (r = -0.25, p = 0.03) and MEHP (r = -0.19, p = 0.095) in the exposed worker group. Regression analyses revealed that fT decreases significantly with increasing total phthalate ester score (the sum of quartiles of MBP and MEHP; r = -0.26, p = 0.002).
  
  
  CONCLUSIONS
  We observed a modest and significant reduction of serum fT in workers with higher levels of urinary MBP and MEHP compared with unexposed workers.
authors.affiliation: Department of Environmental Epidemiology, Liaoning Provincial Center for Disease Prevention and Control, Shenyang, People's Republic of China.
authors.forename: Guowei
authors.initials: G
authors.lastname: Pan
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Hanaoka
authors.forename: Mariko
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Shujuan
authors.initials: S
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tsukino
authors.forename: Koichi
authors.initials: K
authors.lastname: Inoue
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
authors.forename: Ken
authors.initials: K
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000633:toxicity*; D002681:China; D003430:Cross-Sectional Studies; D003993:Dibutyl Phthalate / Q000633:toxicity*; D004051:Diethylhexyl Phthalate / Q000031:analogs & derivatives / Q000633:toxicity* / Q000652:urine; D004784:Environmental Monitoring; D004958:Estradiol / Q000097:blood; D005430:Floors and Floorcoverings; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis; D010795:Phthalic Acids / Q000652:urine; D010968:Plasticizers / Q000633:toxicity*; D011143:Polyvinyl Chloride; D013739:Testosterone / Q000097:blood*
chemical_list: D000395:Air Pollutants, Occupational; D010795:Phthalic Acids; D010968:Plasticizers; D003993:Dibutyl Phthalate; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D011143:Polyvinyl Chloride; D004051:Diethylhexyl Phthalate; C016599:mono-(2-ethylhexyl)phthalate; C028577:monobutyl phthalate