Dehalogenation of polychlorinated biphenyls and polybrominated diphenyl ethers using a hybrid bioinorganic catalyst

The environmentally prevalent polybrominated diphenyl ether (PBDE) #47 and polychlorinated biphenyls (PCBs) #28 and #118 were challenged for 24 hours with a novel biomass-supported Pd catalyst (BioPd0). Analysis of the products via GC/MS revealed the BioPd0 to cause the challenged compounds to undergo stepwise dehalogenation with preferential loss of the least sterically hindered halogen atom. A mass balance for PCB #28 showed that it is degraded to three dichlorobiphenyls (33.9 %), two monochlorobiphenyls (12 %), and biphenyl (30.7 %). The remaining mass was starting material. In contrast, while PCB #118 underwent degradation to yield five tetra- and five trichlorinated biphenyls; no less chlorinated products or biphenyl were detected, and the total mass of degraded products was 0.3 %. Although the BioPd0 material was developed for treatment of PCBs, a mass balance for PBDE #47 showed that the biocatalyst could prove a useful method for treatment of PBDEs. Specifically, 10 % of PBDE # 47 was converted to identifiable lower brominated congeners, predominantly the tribrominated BDE 17, and the dibrominated BDE 4, 75 % remained intact, while 15 % of the starting mass was unaccounted for

OPAL Water Centre Monitoring Report 2008-2012

One of the main aims of the Open Air Laboratories (OPAL) project was to promote a greater understanding of the state of the natural environment throughout England, but especially with people who, previously, may not have had the opportunity to become involved. As part of this objective, the OPAL Water Centre developed the OPAL Water Survey which aimed to encourage people to explore the ponds and lakes in their neighbourhoods and discover the animals and plants that live in and around them. However, we felt it was important to demonstrate that lakes and ponds are more than just charismatic beasts such as dragonfly larvae and diving beetles and that these animals exist within a fascinating interaction of aquatic chemistry, physics and biology. Furthermore, it is also important to show that lakes do not exist in isolation but are dependent on what happens around them in their catchments, what is deposited onto their surfaces from the atmosphere, and also how over-arching factors like seasonal changes and climate play important roles. To this end, the OPAL Water Centre set up a monitoring programme at a lake in each of the nine designated regions of England. This monitoring programme involved quarterly measurements over four years (April 2008 – April 2012) supplemented by other less frequent activities. This provided new data on a range of sites across the country; provided more information on some urban and disturbed environments and raised awareness of ecosystem health and how individual actions may affect lakes and ponds. Our monitoring programme included physical measurements such as water temperature, conductivity, dissolved oxygen, pH and light, chemicals such as nutrients as well as potentially toxic trace metals and persistent organic pollutants (POPs) and biological monitoring of zooplankton, phytoplankton and diatoms. These data allow us to see how lakes change over the seasons and inter-annually as well as the extent of any local impacts. We were very pleased that many of these lakes have local interest groups who have used these data in management plans and as a basis for other studies (e.g. Fleet Pond Society in Hampshire; Friends of Chapman’s Pond in York; field centres at Slapton Ley in Devon and Holt Hall in Norfolk) and as a way to get young people interested in their local environment (e.g. Junior Rangers at Marton Mere in Blackpool). Although monitoring can tell us a great deal about short-term changes, it takes a long time to see whether things are improving or getting worse. Lake sediment cores allow us to put seasonal monitoring into an historical context so we can observe changes over decadal and even centennial time-scales. We therefore also analysed sediment cores from each lake for chemical and biological parameters at each of our monitoring lakes to see these long-term changes. Each core was dated using radio-isotopes (210Pb; 137Cs) allowing us to see not only the direction of change (whether contamination or water quality is improving or deteriorating) but importantly the rate at which any change is occurring. This report describes the main results of all these monitoring activities and a brief interpretation of them on a site-by-site basis. Inevitably, given the large amount of data generated over the four years, this report is only a summary

Pre-operative experiences and post-operative benefits of ptosis surgery: A qualitative study

© 2017 Taylor & Francis. This qualitative study sought to explore the experiences of patients who had undergone successful ptosis correction surgery. Participants were recruited from Bristol Eye Hospital. Nine participants were interviewed using a semi-structured interview schedule and open ended questions. Data were analysed using inductive thematic analysis. Four major themes were identified from patient accounts. Patients described the psychosocial and functional difficulties they experienced living with ptosis, and the subsequent benefits of surgery. Patients reported experiencing appearance related anxiety pre-operatively due to their condition and engaging in behaviours to avoid social encounters. Gender differences were noted in the internalization of perceived negative reactions from others, with men describing fewer adverse impacts. Patients described perceived barriers to seeking surgery including a lack of awareness of ptosis as a treatable condition, the perception that being concerned with their appearance could be seen as vain and the view that ptosis surgery is synonymous with cosmetic surgery. Following successful surgery patients outlined positive impacts on their vision, appearance and psychosocial well-being after successful surgery. This qualitative study highlights the complexities of the factors and processes contributing to the psychosocial impacts of ptosis and the potential benefits of surgery and/or psychosocial support. An increased awareness amongst people with ptosis of the potential positive impacts of surgery and an enhanced understanding of the reasons why patients may not seek treatment amongst health care professionals are likely to benefit this often overlooked patient group

Mass transfer of PBDEs from plastic TV casing to indoor dust via three migration pathways - A test chamber investigation

Polybrominated diphenyl ethers (PBDEs) are widely detected in humans with substantial exposure thought to occur in indoor environments and particularly via contact with indoor dust. Despite this, knowledge of how PBDEs migrate to indoor dust from products within which they are incorporated is scarce. This study utilises an in-house designed and built test chamber to investigate the relative significance of different mechanisms via which PBDEs transfer from source materials to dust, using a plastic TV casing treated with the Deca-BDE formulation as a model source. Experiments at both room temperature and 60 degrees C revealed no detectable transfer of PBDEs from the TV casing to dust via volatilisation and subsequent partitioning. In contrast, substantial transfer of PBDEs to dust was detected when the TV casing was abraded using a magnetic stirrer bar. Rapid and substantial PBDE transfer to dust was also observed in experiments in which dust was placed in direct contact with the source. Based on these experiments, we suggest that for higher molecular weight PBDEs like BDE-209; direct dust: source contact is the principal pathway via which source-to-dust transfer occurs

Temporal trends in radiometrically dated sediment cores from English lakes show polybrominated diphenyl ethers correlate with brominated but not mixed bromo/chloro dioxins and furans

This paper reports concentrations between ~1950 and present, of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), in radiometrically-dated sediment cores from three English lakes. Mixed bromo/chloro dibenzo-p-dioxins and furans (PXDD/Fs) were measured in two of the same lakes. Concentrations of PXDD/Fs decreased over time to the present. To our knowledge, this is the first report of temporal trends of PXDD/Fs in the environment. In contrast, concentrations of PBDEs increased towards the present and were significantly correlated (R = 0.88–0.98; p < 0.05) with concentrations of PBDFs in all three lakes. These observations suggest that the sources of PXDD/Fs are not related to PBDEs and differ from those of PBDFs. We also report for the first time the presence of octabromodibenzofuran (OBDF) in the two most recent core slices at one lake. The source of OBDF in these samples is unclear. While OBDF has been reported previously as a significant contaminant of some commercial formulations of Deca-BDE, it is also present in Octa-BDE products and in emissions from a variety of combustion activities. Overall, while the positive correlation between PBDEs and PBDFs suggests increased use of PBDEs has contributed substantially to environmental contamination with PBDFs; examination of PBDF homologue patterns implies emissions from combustion activities are likely also important

Novel Insights into the Dermal Bioaccessibility and Human Exposure to Brominated Flame Retardant Additives in Microplastics

Supporting Information is available online at: https://pubs.acs.org/doi/10.1021/acs.est.3c01894#_i23 .Copyright © 2023 The Authors. In this study, we optimized and applied an in vitro physiologically based extraction test to investigate the dermal bioaccessibility of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD), incorporated as additives in different types of microplastics (MPs), and assess human dermal exposure to these chemicals. The dermal bioaccessibility of PBDEs in polyethylene (PE) MPs was significantly higher (P < 0.05) than in polypropylene (PP) MPs. Both log Kow and water solubility influenced the dermal bioaccessibility of PBDEs. For HBCDDs in polystyrene MPs, the dermally bioaccessible fractions were 1.8, 2.0, and 1.6% of the applied dose for α-, β-, and γ-HBCDDs, respectively. MP particle size and the presence of cosmetic formulations (antiperspirant, foundation, moisturizer and sunscreen) influenced the bioaccessibility of PBDEs and HBCDDs in MP matrices at varying degrees of significance. Human exposure to ∑PBDEs and ∑HBCDDs via dermal contact with MPs ranged from 0.02 to 22.2 and 0.01 to 231 ng (kg bw)−1 d–1 and from 0.02 to 6.27 and 0.2 to 65 ng (kg bw)−1 d–1 for adults and toddlers, respectively. Dermal exposure to PBDEs and HBCDDs in MPs is substantial, highlighting for the first time the significance of the dermal pathway as a major route of human exposure to additive chemicals in microplastics.European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Individual Fellowship Grant Agreement Number 101026229

Historical trends of PBDEs and HBCDs in sediment cores from Sydney estuary, Australia

This paper presents the first historical data on the occurrence of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDs) in estuarine sediment from Australia. Sediment cores and surficial sediment samples were collected from four locations within Sydney estuary, Australia. Large increases in concentrations were observed for all compounds between 1980 and 2014, especially for BDE-209 (representative usage of Deca-BDE commercial mixture), which was found in surficial sediment at an average concentration of 42 ng/g thy wt (21-65 ng/g dry wt). PBDE congeners representative of both the Penta- and Octa-BDE commercial mixtures (Sigma 6PBDEs) were also found in their highest concentrations in surficial sediments (average: 1.3 ng/g dry wt; range: 0.65-2.5 ng/g dry wt). PBDE concentrations in surficial sediments were relatively high when compared with those presented in the available literature. This suggests that their input into the Sydney estuary has not decreased since their bans almost a decade earlier. After a sharp increase in the 1990s, HBCD concentrations peaked at an average of 3.5 ng/g dry wt (1.8-53 ng/g dry wt) in surficial samples. With global legislation on HBCDs allowing its usage for the next 10 years, it is expected that its input into the estuary is likely to continue. (C) 2015 Elsevier B.V. All rights reserved