title: Polybrominated dibenzo-p-dioxins, dibenzofurans, and biphenyls: inclusion in the toxicity equivalency factor concept for dioxin-like compounds.
abstract: In 2011, a joint World Health Organization (WHO) and United Nations Environment Programme (UNEP) expert consultation took place, during which the possible inclusion of brominated analogues of the dioxin-like compounds in the WHO Toxicity Equivalency Factor (TEF) scheme was evaluated. The expert panel concluded that polybrominated dibenzo-p-dioxins (PBDDs), dibenzofurans (PBDFs), and some dioxin-like biphenyls (dl-PBBs) may contribute significantly in daily human background exposure to the total dioxin toxic equivalencies (TEQs). These compounds are also commonly found in the aquatic environment. Available data for fish toxicity were evaluated for possible inclusion in the WHO-UNEP TEF scheme (van den Berg et al., 1998). Because of the limited database, it was decided not to derive specific WHO-UNEP TEFs for fish, but for ecotoxicological risk assessment, the use of specific relative effect potencies (REPs) from fish embryo assays is recommended. Based on the limited mammalian REP database for these brominated compounds, it was concluded that sufficient differentiation from the present TEF values of the chlorinated analogues (van den Berg et al., 2006) was not possible. However, the REPs for PBDDs, PBDFs, and non-ortho dl-PBBs in mammals closely follow those of the chlorinated analogues, at least within one order of magnitude. Therefore, the use of similar interim TEF values for brominated and chlorinated congeners for human risk assessment is recommended, pending more detailed information in the future.
authors.affiliation: Institute for Risk Assessment Sciences-IRAS and WHO Collaborating Centre for Environmental Health Risk Assessment, Utrecht University, Utrecht, The Netherlands. m.vandenberg@uu.nl
authors.forename: Martin
authors.initials: M
authors.lastname: van den Berg
authors.forename: Michael S
authors.initials: MS
authors.lastname: Denison
authors.forename: Linda S
authors.initials: LS
authors.lastname: Birnbaum
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Devito
authors.forename: Heidelore
authors.initials: H
authors.lastname: Fiedler
authors.forename: Jerzy
authors.initials: J
authors.lastname: Falandysz
authors.forename: Martin
authors.initials: M
authors.lastname: Rose
authors.forename: Dieter
authors.initials: D
authors.lastname: Schrenk
authors.forename: Stephen
authors.initials: S
authors.lastname: Safe
authors.forename: Chiharu
authors.initials: C
authors.lastname: Tohyama
authors.forename: Angelika
authors.initials: A
authors.lastname: Tritscher
authors.forename: Mats
authors.initials: M
authors.lastname: Tysklind
authors.forename: Richard E
authors.initials: RE
authors.lastname: Peterson
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000493:pharmacokinetics / Q000633:toxicity*; D004147:Dioxins / Q000493:pharmacokinetics / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D011075:Polybrominated Biphenyls / Q000493:pharmacokinetics / Q000633:toxicity*; D018570:Risk Assessment; D012989:Soil Pollutants / Q000493:pharmacokinetics / Q000633:toxicity*; D018675:Toxicity Tests
chemical_list: D001572:Benzofurans; D004147:Dioxins; D011075:Polybrominated Biphenyls; D012989:Soil Pollutants; C023614:dibenzofuran; C020887:dibenzo(1,4)dioxin
keywords: biomarkers.; dioxin; halogenated hydrocarbon; persistent organic chemicals; polychlorinated biphenyls; regulatory/policy