Title: Non additive interactions in CALUX

Auteur(s): Windal I ; Schroijen C ; Van Wouwe N ; Carbonnelle S ; Van Overmeire I ; Brown D ; Clark G ; Baeyens W ; Goeyens L ;  ; 

Year: 2003

Journal: Organohalogen Compounds

Subject(s): CALUX ; Interaction ; analysis ; dioxin-like compounds ; TEQ ; PCDD/F ; PCB ; polychlorinated ; polychlorinated biphenyls ; Polychlorinated biphenyl ; TCDD ; dioxins ; dioxin ; clean-up ;  ; 

Summary: In chemical analysis of dioxin-like compounds, concentrations of the different congeners are multiplied by their corresponding TEF. The products expressed in TEQ are summed, assuming additive contribution of the PCDD/F and PCB. However, important non-additive interactions between halogenated aromatic hydrocarbons have been described (see Safe) for a review). These studies mainly focused on individual polychlorinated biphenyls (PCB 52, 108, 153, 156, 159) or Aroclor 1254, which are able to inhibit the biological response induced by TCDD. Similar non-additive interactions should be expected in CALUX analysis, since, in this methodology, a biological response is measured. However, little is known about the interactions between dioxins and other Ah ligand classes. Several questions can be raised. Which compounds are responsible for non-additive interactions? At what concentrations? Are these concentrations usually found in the samples? Are these compounds present in the extracts or are they degraded/discarded during the clean-up? The present paper tries to answer some of these questions for compounds known to be Ah ligands or known to interact. This study focuses on hexachlorobenzene (HCB), different kinds of PCB mixtures (Aroclor) which have been used as industrial products. The Aroclor 1254, 1242 and 1260 were selected here since they are the most widely used. The industrial mixture Halowax 1014 was used for polychloronaphthalene (PCN) and the industrial mixture Aroclor 5442 was used for polychloroterphenyls (PCT).