Retention and maternal transfer of environmentally relevant polybrominated dibenzo‐p‐dioxins and dibenzofurans, polychlorinated dibenzo‐p‐dioxins and dibenzofurans, and polychlorinated biphenyls in zebrafish (Danio rerio) after dietary exposure

Abstract

High levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), mono- and non-ortho-polychlorinated biphenyls (PCBs), and polybrominated dibenzo-p-dioxins (PBDDs) are found in fish from coastal areas in the Baltic Sea, which may cause ecotoxicological effects. To increase our understanding of the persistency of the emerging pollutants polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), fish feed was spiked with 21 PBDD/Fs, 17 PCDD/Fs, and 30 PCBs and fed to zebrafish (Danio rerio). Concentrations in fish and eggs were examined during a 6- or 12-week uptake period, and a 6-week elimination period. Steady-state was reached for 2-, 3-, 7-, and/or 8-substituted tri- and tetra-BDD/Fs; 2,3,7,8-tetra-BDD (2,3,7,8-TeBDD) was the most strongly retained. Steady-state was not reached for tetra- to hexa-CDDs. Non-2,3,7,8 congeners showed little or no retention. Most PCBs had high retention and did not reach steady state. Half-lives decreased in the order PCBs > PCDD/Fs > PBDD/Fs. Concentrations of 2,3,7,8-substituted penta- to octa-CDD/Fs decreased with their degree of chlorination, suggesting that the rate-limiting factor for uptake is low bioavailability. Maternal transfer was observed for all retained compounds, with most transfer factors <1, indicating that transfer rates are affected by the poor water solubility of the compounds. The limited retention of the major PBDD congeners found in Baltic Sea fish suggests that they are exposed to high or very high concentrations via either food or water.

Development and Evaluation of a Database of Dietary Bioaccumulation Test Data for Organic Chemicals in Fish

“…59 A generally applicable screening criterion is that AEs > 1.0 (100%) are suspect indicating a source of error and are thus classified L. Plausible explanations for AE > 1.0 are the (bio)formation of the chemical in the organism (or perhaps the GIT) or additional unintentional exposure during the test or analytical errors. In some cases AE values >1.0 are reported for certain chemicals for which bioformation is not expected to occur 102 and there is no obvious explanation. Measured doses (quantities for C D and I) are required for H classification for most AE data (76% of the entries).…”

Complex Mixtures of Brominated/Chlorinated Diphenyl Ethers and Dibenzofurans in Soils from the Agbogbloshie e-Waste Site (Ghana): Occurrence, Formation, and Exposure Implications

“…Chronic exposure to PCDD/Fs resulted in high concentrations in blood of workers in Agbogbloshie . Meanwhile, despite the high contamination levels of PBDFs in Agbogbloshie, the contribution of these brominated dioxins to the total dioxin exposure risk is still unclear considering the potentially lower bioaccessibility and shorter half life. , Nevertheless, because significant dioxin-like activities were detected in the brominated dioxin fraction (rather than in the chlorinated dioxin fraction) of several randomly selected serum samples from Agbogbloshie e-waste workers (Table S6), further studies on the potential health effects of brominated dioxins in e-waste workers are warranted.…”

Atmospheric Emission of Polybrominated Dibenzo-p-dioxins and Dibenzofurans from Converter Steelmaking Processes

“…Although lower brominated PBDD/F congeners can naturally form through photochemical and biosynthetic pathways (Haglund, 2010;Arnoldsson et al, 2012), the major sources of PBDD/Fs are thermal industrial activities, such as metallurgical processes, solid waste incineration, and electronic waste dismantling (Du et al, 2010;Gullett et al, 2010;Wang et al, 2010b;Duan et al, 2011;Chang et al, 2013;Chang et al, 2014). Widespread use of brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A, provides an abundance of bromines for PBDD/F formation in industrial processes (Weber and Bertram, 2003;Wang et al, 2010a;Wyrzykowska-Ceradini et al, 2011).…”