Polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in fish from the Netherlands: concentrations, profiles and comparison with DR CALUX® bioassay results

Abstract

Fish from Dutch markets were analysed for concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DLPCBs) and compared with the new European maximum residue levels (MRLs), set in 2006. In a first study on 11 different fish and shellfish from various locations, concentrations of PCDD/Fs were nearly all below the MRL for PCDD/Fs [4 pg toxic equivalents (TEQ) per gram wet weight (ww)] and nearly all below 8 pg total TEQ/g ww, the new MRL for the sum of PCDD/Fs and DL-PCBs. Some samples exceeded the total TEQ MRL, such as anchovy, tuna and sea bass. Furthermore, 20 (out of 39) wild eel samples exceeded the specific MRL for eel (12 pg total TEQ/g ww), as the study revealed PCDD/F TEQ levels of 0.2-7.9 pg TEQ/g ww and total TEQ values of 0.9 to 52 pg/g ww. TEQ levels in farmed and imported eel were lower and complied with the MRLs. Smoking eel, a popular tradition in the Netherlands, only had marginal effects on PCDD/F and DL-PCB concentrations. Owing to volatilization, concentrations of lowerchlorinated PCBs were reduced to below the limit of quantification after smoking. DL-PCBs contributed 61-97% to the total TEQ in all eel samples. This also holds for other fish and shellfish (except shrimps): DL-PCB contributed (on average) from 53 (herring) to 83% (tuna) to the total TEQ. Principal-component analysis revealed distinctive congener profiles for PCDD/Fs and non-ortho PCBs for mussels, pikeperch, herring and various Mediterranean fish. The application of new TCDD toxic equivalency factors (TEFs) set by the World Health Organization in 2006 (to replace the 1997 TEFs) resulted in lower TEQ values, mainly owing to a decreased mono-ortho PCB contribution. This decrease is most pronounced for eel, owing to the relative high monoortho PCB concentrations in eel. Consequently, a larger number of samples would comply with the MRLs when the new TEFs are applied. The DR CALUX® assay may be used for screening total TEQ levels in eel, in combination with gas chromatography-high resolution mass spectrometry confirmation of suspected samples. An almost 1:1 correlation was found when the 1997 TEFs were applied, but, surprisingly, a 1.4-fold overestimation occurred with application of the 2006 TEFs.

Brominated flame retardants in fish and shellfish – levels and contribution of fish consumption to dietary exposure of Dutch citizens to HBCD

“…Furthermore, emphasis was placed on eel by sampling a large number of freshwater locations in order to assess the contamination of Dutch fresh waters. Eel has proven to be a valuable indicator of the contamination of Dutch freshwaters with persistent organic pollutants (POP) like polychlorinated biphenyls (PCB) and chlorinated dioxins and furans [16,17]. Finally, two samples of flounder were obtained from the Western Scheldt to monitor (i) the production of BFR (by a chemical industry) in Terneuzen, The Netherlands, and (ii) the effects of the utilization of BFR in the textile industry in Antwerp and further upstream the river Scheldt in Belgium.…”

Prolonged ELS test with the marine flatfish sole (Solea solea) shows delayed toxic effects of previous exposure to PCB 126

“…Therefore, a very sensitive in vitro reporter gene assay for dioxin-like toxic potency in H4IIE rat hepatoma cells (Murk et al, 1998) was applied for the direct quantification of the in vitro TCDD-equivalent (TEQ) levels on a lipid basis in these very small samples. This DRE-H4IIE.Luc assay (sometimes also referred to as DR CALUX) has been chemically validated before and produces a response that is linear with the concentration of compounds with dioxin-like toxicity (Murk et al, 1998;Stronkhorst et al, 2002;Besselink et al, 2004;Hoogenboom et al, 2006;Van Leeuwen et al, 2007).…”

“…In vitro reporter gene assays based on Ah-receptor activation have been developed and chemically validated for the direct quantification of the dioxin-like potency of mixtures of contaminants in sediments and biota (Murk et al, 1996a(Murk et al, , 1998Stronkhorst et al, 2002;Hoogenboom et al, 2006;Van Leeuwen et al, 2007). In these in vitro reporter gene assays the relative potency of compounds to activate the Ah-receptor is related to that of TCDD, not the toxicity compared to that of TCDD.…”

PCDD/Fs and PCBs in Soils: a Study of Case in the City of Belo Horizonte‑MG

“…20,21 All standards were purchased from Cambridge Isotope Laboratories (Tewksbury, MA, USA) and are listed in Table S1 (Supplementary Information section). All solvents used (n-hexane, dichloromethane, ethylacetate and toluene) were purchased from Actu-All Chemicals (Randmeer, The Netherlands) and were of PEC grade.…”