Occurrence of halogenated flame retardants in commercial seafood species available in European markets

PBDEs (congeners 28, 47, 99, 100, 153, 154, 183, 209), HBCD (α, β, γ), emerging brominated flame retardants (PBEB, HBB and DBDPE), dechloranes (Dec 602, 603, 604, syn- and anti-DP), TBBPA, 2,4,6-TBP and MeO-PBDEs (8 congeners) were analysed in commercial seafood samples from European countries. Levels were similar to literature and above the environmental quality standards (EQS) limit of the Directive 2013/39/EU for PBDEs. Contaminants were found in 90.5% of the seafood samples at n. d.-356 ng/g lw (n. d.-41.1 ng/g ww). DBDPE was not detected and 2,4,6-TBP was detected only in mussels, but at levels comparable to those of PBDEs. Mussel and seabream were the most contaminated species and the Mediterranean Sea (FAO Fishing Area 37) was the most contaminated location. The risk assessment revealed that there was no health risk related to the exposure to brominated flame retardants via seafood consumption. However, a refined risk assessment for BDE-99 is of interest in the future. Moreover, the cooking process concentrated PBDEs and HBB.

Òscar Aznar-Alemany, Laura Trabalón, Silke Jacobs and al., Food and Chemical Toxicology, Volume 104, June 2017, Pages 35–47

The article

NORMAN interlaboratory study (ILS) on passive sampling of emerging pollutants

A chemical monitoring on site (CM Onsite) organised by NORMAN Association and JRC in support of the Water Framework Directive

Passive samplers can play a valuable role in monitoring water quality within a legislative framework such as the European Union’s Water Framework Directive (WFD). The time-integrated data from these devices can be used to complement chemical monitoring of priority and emerging contaminants which are difficult to analyse by spot or bottle sampling methods, and to improve risk assessment of chemical pollution. In order to increase the acceptance of passive sampling technology amongst end users and to gain further information about the robustness of the calibration and analytical steps, several inter-laboratory field studies have recently been performed in Europe. Such trials are essential to further validate this sampling method and to increase the confidence of the technological approach for end users. An inter-laboratory study on the use of passive samplers for the monitoring of emerging pollutants was organised in 2011 by the NORMAN association (Network of reference laboratories for monitoring emerging environmental pollutants; http://www.norman-network.net) together with the European DG Joint Research Centre to support the Common Implementation Strategy of the WFD. Thirty academic, commercial and regulatory laboratories participated in the passive sampler comparison exercise and each was allowed to select their own sampler design. All the different devices were exposed at a single sampling site to treated waste water from a large municipal treatment plant. In addition, the organisers deployed in parallel for each target analyte class multiple samplers of a single type which were subsequently distributed to the participants for analysis. This allowed an evaluation of the contribution of the different analytical laboratory procedures to the data variability. The results obtained allow an evaluation of the potential of different passive sampling methods for monitoring selected emerging organic contaminants (pharmaceuticals, polar pesticides, steroid hormones, fluorinated surfactants, triclosan, bisphenol A and brominated flame retardants). In most cases, between laboratory variation of results from passive samplers was roughly a factor 5 larger than within laboratory variability. Similar results obtained for different passive samplers analysed by individual laboratories and also low within laboratory variability of sampler analysis indicate that the passive sampling process is causing less variability than the analysis. This points at difficulties that laboratories experienced with analysis in complex environmental matrices. Where a direct comparison was possible (not in case of brominated flame retardants) analysis of composite water samples provided results that were within the concentration range obtained by passive samplers. However, in the future a significant improvement of the overall precision of passive sampling is needed. The results will be used to inform EU Member States about the potential application of passive sampling methods for monitoring organic chemicals within the framework of the WFD. (2016)

The report

Are whale sharks exposed to persistent organic pollutants and plastic pollution in the Gulf of California (Mexico)? First ecotoxicological investigation using skin biopsies

The whale shark (Rhincodon typus) is an endangered species that may be exposed to micro- and macro-plastic ingestion as a result of their filter-feeding activity, particularly on the sea surface. In this pilot project we perform the first ecotoxicological investigation on whale sharks sampled in the Gulf of California exploring the potential interaction of this species with plastic debris (macro-, micro-plastics and related sorbed contaminants). Due to the difficulty in obtaining stranded specimens of this endangered species, an indirect approach, by skin biopsies was used for the evaluation of the whale shark ecotoxicological status. The levels of organochlorine compounds (PCBs, DDTs), polybrominatediphenylethers (PBDEs) plastic additives, and related biomarkers responses (CYP1A) were investigated for the first time in the whale shark. Twelve whale shark skin biopsy samples were collected in January 2014 in La Paz Bay (BCS, Mexico) and a preliminary investigation on microplastic concentration and polymer composition was also carried out in seawater samples from the same area. The average abundance pattern for the target contaminants was PCBs > DDTs > PBDEs > HCB. Mean concentration values of 8.42 ng/g w.w. were found for PCBs, 1.31 ng/g w.w. for DDTs, 0.29 ng/g w.w. for PBDEs and 0.19 ng/g w.w for HCB. CYP1A–like protein was detected, for the first time, in whale shark skin samples. First data on the average density of microplastics in the superficial zooplankton/microplastic samples showed values ranging from 0.00 items/m3 to 0.14 items/m3. A Focused PCA analysis was performed to evaluate a possible correlation among the size of the whale sharks, contaminants and CYP1A reponses. Further ecotoxicological investigation on whale shark skin biopsies will be carried out for a worldwide ecotoxicological risk assessment of this endangerd species.

Maria Cristina Fossi, Matteo Baini, Cristina Panti and al., Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, Available online 6 March 2017, In Press

The article

Tracing the Biotransformation of PCBs and PBDEs in Common Carp (Cyprinus carpio) Using Compound-Specific and Enantiomer-Specific Stable Carbon Isotope Analysis

Compound-specific and enantiomer-specific carbon isotope composition was investigated in terms of biotransformation of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) as well as atropisomers of chiral PCB congeners in fish by exposing common carp (Cyprinus carpio) to certain PCB and PBDE congeners. The calculated carbon isotope enrichment factors (εC) for PCB 8, 18, and 45 were −1.99, −1.84, and −1.70‰, respectively, providing evidence of the metabolism of these congeners in fish. The stable carbon isotopic compositions of PBDE congeners clearly reflect the debromination of PBDEs in carp. Significant isotopic fractionation was also observed during the debromination process of BDE 153 (εC = −0.86‰). Stereoselective elimination of chiral PCB congeners 45, 91, and 95 was observed, indicating a stereoselective biotransformation process. The similar εC values for E1-PCB 45 (−1.63‰) and E2-PCB 45 (−1.74‰) indicated that both atropisomers were metabolized by the same reaction mechanisms and stereoselection did not occur at carbon bond cleavage. However, the εC values of (+)-PCB 91 (−1.5‰) and (−)-PCB 95 (−0.77‰) were significantly different from those of (−)-PCB 91 and (+)-PCB 95, respectively. In the latter, no significant isotopic fractionations were observed, indicating that the stereoselective elimination of PCB 91 and 95 could be caused by a different reaction mechanism in the two atropisomers.

Bin Tang, Xiao-Jun Luo, Yan-Hong Zeng, and Bi-Xian Mai, Environ. Sci. Technol., Article ASAP, February 16, 2017

The article

Statistical Survey of Persistent Organic Pollutants: Risk Estimations to Humans and Wildlife through Consumption of Fish from U.S. Rivers

U.S. EPA conducted a national statistical survey of fish tissue contamination at 540 river sites (representing 82 954 river km) in 2008–2009, and analyzed samples for 50 persistent organic pollutants (POPs), including 21 PCB congeners, 8 PBDE congeners, and 21 organochlorine pesticides. The survey results were used to provide national estimates of contamination for these POPs. PCBs were the most abundant, being measured in 93.5% of samples. Summed concentrations of the 21 PCB congeners had a national weighted mean of 32.7 μg/kg and a maximum concentration of 857 μg/kg, and exceeded the human health cancer screening value of 12 μg/kg in 48% of the national sampled population of river km, and in 70% of the urban sampled population. PBDEs (92.0%), chlordane (88.5%) and DDT (98.7%) were also detected frequently, although at lower concentrations. Results were examined by subpopulations of rivers, including urban or nonurban and three defined ecoregions. PCBs, PBDEs, and DDT occur at significantly higher concentrations in fish from urban rivers versus nonurban; however, the distribution varied more among the ecoregions. Wildlife screening values previously published for bird and mammalian species were converted from whole fish to fillet screening values, and used to estimate risk for wildlife through fish consumption.

Angela L. Batt, John B. Wathen, James M. Lazorchak, Anthony R. Olsen, and Thomas M. Kincaid,  Environ. Sci. Technol., Article ASAP, February 23, 2017

Kinetics of Brominated Flame Retardant (BFR) Releases from Granules of Waste Plastics

Plastic components of e-waste contain high levels of brominated flame retardants (BFRs), whose releases cause environmental and human health concerns. This study characterized the release kinetics of polybrominated diphenyl ethers (PBDEs) from millimeter-sized granules processed from the plastic exteriors of two scrap computer displays at environmentally relevant temperatures. The release rate of a substitute of PBDEs, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), from the waste plastics, was reported for the first time. Deca-BDE was the most abundant PBDE congeners in both materials (87–89%), while BTBPE was also present at relatively high contents. The release kinetics of BFRs could be modeled as one-dimensional diffusion, while the temperature dependence of diffusion coefficients was well described by the Arrhenius equation. The diffusion coefficients of BFRs (at 30 °C) in the plastic matrices were estimated to be in the range of 10–27.16 to 10–19.96 m2·s–1, with apparent activation energies between 88.4 and 154.2 kJ·mol–1. The half-lives of BFR releases (i.e., 50% depletion) from the plastic granules ranged from thousands to tens of billions of years at ambient temperatures. These findings suggest that BFRs are released very slowly from the matrices of waste plastics through molecular diffusion, while their emissions can be significantly enhanced with wear-and-tear and pulverization.

Bingbing Sun, Yuanan Hu, Hefa Cheng, and Shu Tao, Environ. Sci. Technol., 2016, 50 (24), pp 13419–13427

The article

Chemical Pollutants Sorbed to Ingested Microbeads from Personal Care Products Accumulate in Fish

The prevalence of microplastics (<5 mm) in natural environments has become a widely recognised global problem. Microplastics have been shown to sorb chemical pollutants from their surrounding environment, thus raising concern as to their role in the movement of these pollutants through the food chain. This experiment investigated whether organic pollutants sorbed to microbeads (MBs) from personal care products were assimilated by fish following particle ingestion. Rainbow fish (Melanotaenia fluviatilis) were exposed to MBs with sorbed PBDEs (BDE-28, -47, -100, -99, -153, -154, -183 200 ng g-1; BDE-209 2000 ng g-1) and sampled at 0, 21, 42 and 63 days along with two control treatments (Food Only and Food + Clean MBs). Exposed fish had significantly higher ∑8PBDE concentrations than both control treatments after just 21 days, and continued exposure resulted in increased accumulation of the pollutants over the experiment (ca. 115 pg g-1 ww d-1). Lower brominated congeners showed highest assimilation whereas higher brominated congeners did not appear to transfer, indicating they may be too strongly sorbed to the plastic or unable to be assimilated by the fish due to large molecular size or other factors. Seemingly against this trend, however, BDE-99 did not appear to bioaccumulate in the fish, which may be due to partitioning from the MBs or that it was metabolised in vivo. This work provides evidence that MBs from personal care products are capable of transferring sorbed pollutants to fish that ingest them.

Peter Wardrop, Jeff Shimeta, Dayanthi Nugegoda, Paul D Morrison, Ana Miranda, Min Tang, and Bradley Owen Clarke, Environ. Sci. Technol., Vol. 50 (7), pages 4037-4044, April 2016