title: Half-lives of tetra-, penta-, hexa-, hepta-, and octachlorodibenzo-p-dioxin in rats, monkeys, and humans--a critical review.
abstract: The elimination half-lives (t1/2) in Sprague-Dawley rats for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2, 3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) and 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD) were estimated in long-term studies by Schlatter, Poiger and others. Furthermore, there are some published half-lives of TCDD in adult humans. The average half-life of TCDD in adult humans is approximately 2840 days, while in Sprague-Dawley rats the average t1/2 of TCDD is 19 days. The t1/2 of TCDD in humans is about 150 times that of rats. This factor was used to calculate the t1/2 values of the other polychlorinated dibenzo-p-dioxins (PCDDs) in humans from the rat data. Furthermore, the terminal t1/2 values of PCDDs in adult humans were calculated from the regression equation: logt1/2H = 1.34 logt1/2R + 1.25 which was recently established for 50 xenobiotics (t1/2H = terminal half-lives in days for humans, t1/2R = terminal half-lives in days for rats). The following terminal half-lives in adult humans were obtained: 12.6 years for 1,2,3,7,8-PeCDD, 26-45 years for 1,2,3,4,7,8-HxCDD, 80-102 years for 1,2,3,4,6,7,8-HpCDD and ca. 112-132 years for OCDD. These half-lives of PCDDs are critically compared with measured t1/2 values of PCDDs and other persistent organic pollutants in rats, monkeys and humans.
authors.affiliation: GSF-National Research Center for Environment and Health, Institute of Ecological Chemistry, Neuherberg, Germany.
authors.forename: Harald J
authors.initials: HJ
authors.lastname: Geyer
authors.forename: Karl-Werner
authors.initials: KW
authors.lastname: Schramm
authors.forename: Ernst Anton
authors.initials: EA
authors.lastname: Feicht
authors.forename: Akbar
authors.initials: A
authors.lastname: Behechti
authors.forename: Christian
authors.initials: C
authors.lastname: Steinberg
authors.forename: Rainer
authors.initials: R
authors.lastname: Brüggemann
authors.forename: Hermann
authors.initials: H
authors.lastname: Poiger
authors.forename: Bernhard
authors.initials: B
authors.lastname: Henkelmann
authors.forename: Antonius
authors.initials: A
authors.lastname: Kettrup
mesh_terms: D000818:Animals; D004147:Dioxins / Q000493:pharmacokinetics*; D004785:Environmental Pollutants / Q000633:toxicity*; D006207:Half-Life; D000882:Haplorhini; D006801:Humans; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004147:Dioxins; D004785:Environmental Pollutants