title: Dioxin exposure, from infancy through puberty, produces endocrine disruption and affects human semen quality.
abstract: BACKGROUND
  Environmental toxicants are allegedly involved in decreasing semen quality in recent decades; however, definitive proof is not yet available. In 1976 an accident exposed residents in Seveso, Italy, to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
  
  
  OBJECTIVE
  The purpose of this study was to investigate reproductive hormones and sperm quality in exposed males.
  
  
  METHODS
  We studied 135 males exposed to TCDD at three age groups, infancy/prepuberty (1-9 years), puberty (10-17 years), and adulthood (18-26 years), and 184 healthy male comparisons using 1976 serum TCDD levels and semen quality and reproductive hormones from samples collected 22 years later.
  
  
  RESULTS
  Relative to comparisons, 71 men (mean age at exposure, 6.2 years; median serum TCDD, 210 ppt) at 22-31 years of age showed reductions in sperm concentration (53.6 vs. 72.5 million/mL; p = 0.025); percent progressive motility (33.2% vs. 40.8%; p < 0.001); total motile sperm count (44.2 vs. 77.5 x 10(6); p = 0.018); estradiol (76.2 vs. 95.9 pmol/L; p = 0.001); and an increase in follicle-stimulating hormone (FSH; 3.58 vs. 2.98 IU/L; p = 0.055). Forty-four men (mean age at exposure, 13.2 years; median serum TCDD, 164 ppt) at 32-39 years of age showed increased total sperm count (272 vs. 191.9 x 10(6); p = 0.042), total motile sperm count (105 vs. 64.9 x10(6); p = 0.036), FSH (4.1 vs. 3.2 UI/L; p = 0.038), and reduced estradiol (74.4 vs. 92.9 pmol/L; p < 0.001). No effects were observed in 20 men, 40-47 years of age, who were exposed to TCDD (median, 123 ppt) as adults (mean age at exposure, 21.5 years).
  
  
  CONCLUSIONS
  Exposure to TCDD in infancy reduces sperm concentration and motility, and an opposite effect is seen with exposure during puberty. Exposure in either period leads to permanent reduction of estradiol and increased FSH. These effects are permanent and occur at TCDD concentrations < 68 ppt, which is within one order of magnitude of those in the industrialized world in the 1970s and 1980s and may be responsible at least in part for the reported decrease in sperm quality, especially in younger men.
authors.affiliation: University Department of Laboratory Medicine, Hospital of Desio, Milano, Italy. mocarelli@uds.unimib.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Mocarelli
authors.forename: Pier Mario
authors.initials: PM
authors.lastname: Gerthoux
authors.forename: Donald G
authors.initials: DG
authors.lastname: Patterson
authors.forename: Silvano
authors.initials: S
authors.lastname: Milani
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Limonta
authors.forename: Maria
authors.initials: M
authors.lastname: Bertona
authors.forename: Stefano
authors.initials: S
authors.lastname: Signorini
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Tramacere
authors.forename: Laura
authors.initials: L
authors.lastname: Colombo
authors.forename: Carla
authors.initials: C
authors.lastname: Crespi
authors.forename: Paolo
authors.initials: P
authors.lastname: Brambilla
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sarto
authors.forename: Vittorio
authors.initials: V
authors.lastname: Carreri
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Sampson
authors.forename: Wayman E
authors.initials: WE
authors.lastname: Turner
authors.forename: Larry L
authors.initials: LL
authors.lastname: Needham
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D052244:Endocrine Disruptors / Q000097:blood / Q000633:toxicity*; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis; D004785:Environmental Pollutants / Q000097:blood / Q000633:toxicity*; D004958:Estradiol / Q000097:blood; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007223:Infant; D007265:Inhibins / Q000097:blood; D007558:Italy; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D000072317:Polychlorinated Dibenzodioxins / Q000097:blood / Q000633:toxicity*; D011627:Puberty; D012661:Semen / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects
chemical_list: D052244:Endocrine Disruptors; D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; C422364:inhibin B; D004958:Estradiol; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone