title: Health status and plasma dioxin levels in chloracne cases 20 years after the Seveso, Italy accident.
abstract: BACKGROUND
  The Seveso, Italy accident of 1976 exposed a large population to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or simply dioxin). The accident resulted, mostly among children, in one of the largest ever-reported outbreaks of chloracne, the typical skin disorder due to halogenated-hydrocarbon compounds.
  
  
  OBJECTIVE
  Approximately 20 years after the accident, we conducted an epidemiological study in Seveso to investigate (a) the health status of chloracne cases; (b) TCDD-chloracne exposure-response relationship; and (c) factors modifying TCDD toxicity.
  
  
  METHODS
  From 1993 to 1998, we recruited 101 chloracne cases and 211 controls. Trained interviewers administered a structured questionnaire assessing, among other epidemiological variables, information on an extensive list of diseases. During the interview, individual pigmentary characteristics were determined. We measured plasma TCDD levels using high-resolution gas chromatography/mass spectrometry.
  
  
  RESULTS
  Plasma TCDD was still elevated (> 10 ppt) in 78 (26.6%) of the 293 subjects with adequate plasma samples, particularly in females, in subjects who had eaten home-grown animals, and in individuals with older age, higher body mass index and residence near the accident site. After 20 years, health conditions of chloracne cases were similar to those of controls from the Seveso area. Elevated plasma TCDD was associated with chloracne [odds ratio (OR) = 3.7, 95% confidence interval (CI) 1.6-8.8, adjusted for age, sex and residence]. Chloracne risk was higher in subjects younger than 8 years at the accident (OR = 7.4, 95% CI 1.8-30.3) and, contrary to previous hypotheses, did not increase at puberty onset or in teenage years. Subjects with elevated TCDD levels and light hair colour had higher relative odds of chloracne (OR = 9.2, 95% CI 2.6-32.5).
  
  
  CONCLUSIONS
  Dioxin toxicity in chloracne cases was confined to the acute dermatotoxic effects. Chloracne occurrence appeared related to younger age and light hair colour. Age-related dioxin elimination or dilution must be taken into account in interpreting these results.
authors.affiliation: Genetic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, DHHS, Behtesda, MD 20892-7236, USA.
authors.forename: A
authors.initials: A
authors.lastname: Baccarelli
authors.forename: A C
authors.initials: AC
authors.lastname: Pesatori
authors.forename: D
authors.initials: D
authors.lastname: Consonni
authors.forename: P
authors.initials: P
authors.lastname: Mocarelli
authors.forename: D G
authors.initials: DG
authors.lastname: Patterson
authors.forename: N E
authors.initials: NE
authors.lastname: Caporaso
authors.forename: P A
authors.initials: PA
authors.lastname: Bertazzi
authors.forename: M T
authors.initials: MT
authors.lastname: Landi
mesh_terms: D000062:Accidents, Occupational; D000152:Acne Vulgaris / Q000139:chemically induced* / Q000453:epidemiology; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000032:analysis; D005260:Female; D006200:Hair Color; D006304:Health Status; D006801:Humans; D007223:Infant; D007558:Italy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*; D000072317:Polychlorinated Dibenzodioxins / Q000097:blood / Q000633:toxicity*; D012307:Risk Factors
chemical_list: D000072317:Polychlorinated Dibenzodioxins