Brominated flame retardant migration into indoor dust

Brominated flame retardants (BFRs) are ubiquitous in indoor air and dust, leading to human exposure and resultant concerns about adverse impact on health. Despite elevated concentrations in dust, little is known about how BFRs transfer to dust from treated products. A test chamber was constructed to investigate pathways via which the polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) migrate from source materials to indoor dust. These were: (1) BFRs volatilise and subsequently partition to dust, (2) particles or fibres of the source abrade, transfering to dust directly (3) direct source-dust contact results in transfer. A HBCD treated textile curtain, and a PBDE TV casing were both tested. Partitioning post volatilisation was a less effective mechanism than abrasion. Direct source-dust contact resulted in effective and rapid transfer. A forensic microscopy investigation on ‘real world’ dust of elevated BFR content identified polymer particles containing BDE-209, likely originating from a BFR treated polymeric material indicating abrasion. An $in$ $vitro$ extraction test investigated the bioaccessibility of dust contaminated $via$ pathways (1) and (2). Results indicate bioaccessibility may be less efficient from samples containing elevated concentrations of BFRs, and from dusts contaminated primarily via abrasion. More detailed research is essential to confirm these findings

Challenges with Quantifying Tire Road Wear Particles: Recognizing the Need for Further Refinement of the ISO Technical Specification

Environmental monitoring data for tire road wear particles are vastly limited compared to those for other microplastics, primarily due to analytical challenges with quantification. Recently, two ISO technical specifications have been released using pyrolysis GC-MS for quantification. However, these methods have major assumptions, including that the content of natural and synthetic rubber in tire tread is constant across formulations and that the pyrolysis products chosen are selective. This study analyzed a wide range of commercially available tires from Australia and Norway, using pyrolysis GC-MS to test these assumptions. The percent mass of synthetic rubber in tires (n = 39) was highly variable, ranging from <0.05 to 28%, when using the ISO-recommended pyrolysis product 4-vinylcyclohexene. The content varied between brands and models, demonstrating that formulations are highly variable and unknown. The styrene butadiene dimer and trimer pyrolysis products were also assessed, and the calculated synthetic rubber content was higher, had an even greater variability, and had no correlation with concentrations calculated using 4-vinylcyclohexene. Using the ISO method has the potential to underreport environmental concentrations of TRWPs by a factor of at least 5, suggesting the specification requires further refinement, and there is an immediate need for large-scale analysis of commercial tire treads and assessments of suitable pyrolysis products.acceptedVersio

Test chamber and forensic microscopy investigation of the transfer of brominated flame retardants into indoor dust via abrasion of source materials

Brominated flame retardants (BFRs) have been detected in indoor dust in many studies, at concentrations spanning several orders of magnitude. Limited information is available on the pathways via which BFRs migrate from treated products into dust, yet the different mechanisms hypothesized to date may provide an explanation for the range of reported concentrations. In particular, transfer of BFRs to dust via abrasion of particles or fibers from treated products may explain elevated concentrations (up to 210 mg g(-1)) of low volatility BFRs like decabromodiphenyl ether (BDE-209). In this study, an indoor dust sample containing a low concentration of hexabromocyclododecane, or HBCD, (110 ng g(-1) Sigma HBCDs) was placed on the floor of an in-house test chamber. A fabric curtain treated with HBCDs was placed on a mesh shelf 3 cm above the chamber floor and abrasion induced using a stirrer bar. This induced abrasion generated fibers of the curtain, which contaminated the dust, and,HBCD concentrations in the dust increased to between 4020 and 52 500 ng g(-1) for four different abrasion experiment times. The highly contaminated dust (HBCD at 52 500 ng g(-1)) together with three archived dust samples from various UK microenvironments, were investigated with forensic microscopy techniques. These techniques included Micro X-ray fluorescent spectroscopy, scanning emission microscopy coupled with an energy dispersive X-ray spectrometer, Fourier transform infrared spectroscopy with further BFR analysis on LC-MS/MS. Using these techniques, fibers or particles abraded from a product treated with BFRs were identified in all dust samples, thereby accounting for the elevated concentrations detected in the original dust (3500 to 88 800 ng g(-1) Sigma HBCD and 24 000 to 1 438 000 ng g(-1) for BDE-209). This study shows how test chamber experiments alongside forensic microscopy techniques, can provide valuable insights into the pathways via which BFRs contaminate indoor dust

Exposure to flame retardant chemicals on commercial airplanes

Background: Flame retardant chemicals are used in materials on airplanes to slow the propagation of fire. These chemicals migrate from their source products and can be found in the dust of airplanes, creating the potential for exposure. Methods: To characterize exposure to flame retardant chemicals in airplane dust, we collected dust samples from locations inside 19 commercial airplanes parked overnight at airport gates. In addition, hand-wipe samples were also collected from 9 flight attendants and 1 passenger who had just taken a cross-country (USA) flight. The samples were analyzed for a suite of flame retardant chemicals. To identify the possible sources for the brominated flame retardants, we used a portable XRF analyzer to quantify bromine concentrations in materials inside the airplanes. Results: A wide range of flame retardant compounds were detected in 100% of the dust samples collected from airplanes, including BDEs 47, 99, 153, 183 and 209, tris(1,3-dichloro-isopropyl)phosphate (TDCPP), hexabromocyclododecane (HBCD) and bis-(2-ethylhexyl)-tetrabromo-phthalate (TBPH). Airplane dust contained elevated concentrations of BDE 209 (GM: 500 ug/g; range: 2,600 ug/g) relative to other indoor environments, such as residential and commercial buildings, and the hands of participants after a cross-country flight contained elevated BDE 209 concentrations relative to the general population. TDCPP, a known carcinogen that was removed from use in children’s pajamas in the 1970’s although still used today in other consumer products, was detected on 100% of airplanes in concentrations similar to those found in residential and commercial locations. Conclusion: This study adds to the limited body of knowledge regarding exposure to flame retardants on commercial aircraft, an environment long hypothesized to be at risk for maximum exposures due to strict flame retardant standards for aircraft materials. Our findings indicate that flame retardants are widely used in many airplane components and all airplane types, as expected. Most flame retardants, including TDCPP, were detected in 100% of dust samples collected from the airplanes. The concentrations of BDE 209 were elevated by orders of magnitude relative to residential and office environments

Predictors of human PBDE body burdens for a UK cohort

Human exposure to polybrominated diphenyl ethers (PBDEs) was investigated in a cohort of 20 UK adults along with their anthropometric covariates and relevant properties such as room surveys, lifestyle, diet and activity details. Selected PBDE congeners were measured in matched samples of indoor dust (n = 41), vehicles (n = 8), duplicate diet (n = 24), serum (n = 24) and breast milk (n = 6).Combined exposure estimates via dust and diet revealed total PBDE intakes of 104 to 1,440 pg kg−1 bw d−1 for ΣBDEs3–7 and 1,170 to 17,000 pg kg−1 bw d−1 for BDE-209. These adult intakes are well within health reference doses suggested by the European Food Safety Authority (EFSA) and the US EPA. Diet was the primary source of intake of BDE3–7 congeners for the majority of the cohort, with dust the primary source of BDE-209. Primary sources of PBDE exposure vary between countries and regions with differing fire prevention regulations. Estimated infant exposures (ages 1.5–4.5 years) showed that BDE-99 intake for one of the households did not meet EFSA's recommended margin of exposure, a further two households had borderline PBDE exposures for high level dust and diet intake.Males and those having a lower body fat mass had higher serum BDE-153. Higher meat consumption was significantly correlated with higher BDEs3–7 in serum. A reduction in dietary BDEs3–7 would therefore result in the greatest reduction in BDE-99 exposure. Rooms containing PUF sofas or armchairs over 20 years old had more BDEs3–7 in their dust, and rooms with carpets or rugs of that age had higher dust BDE-209. Dusting rooms more frequently resulted in significantly lower concentrations of all major congeners in their dust. Correlation between BDE-209 body burden and dust or diet exposure was limited by its low bioaccessibility. Although vehicle dust contained the highest concentrations of BDEs3–7 and BDE-209, serum BDEs3–7 correlated most strongly with bedroom dust

Direct contact between dust and HBCD-treated fabrics is an important pathway of source-to-dust transfer

Hexabromocyclododecanes (HBCDs) are a class of brominated flame retardant that have found extensive application in consumer products used widely in indoor environments. Although uncertainty remains about the human health impacts of HBCDs, ingestion of HBCD-contaminated indoor dust has been shown to be a particularly significant exposure pathway for young children. Despite this, understanding of the mechanisms via which HBCD transfer from products to indoor dust remains incomplete. In this study, an in-house test chamber was used to investigate transfer of HBCDs from a treated textile sample to indoor dust via direct textile: dust contact. Results were compared with previous data using the same test chamber to examine other pathways via which HBCDs transfer from products to dust, and highlighted HBCD transfer via direct source: dust contact as being particularly important. This novel finding was corroborated by complementary experiments that examined HBCD transfer via direct contact, from other treated textiles to three major components of indoor dust: artificial indoor dust, soil particles, and cotton linters. (C) 2015 Elsevier B.V. All rights reserved

The message on the bottle:Rethinking plastic labelling to better encourage sustainable use

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordPlastic pollution continues to worsen globally in volume and complexity. The complexity in plastic production, use and disposal is significant, highlighting the importance of clear communication to consumers. Yet despite this, poor plastic labelling is clear, evident from poor waste management metrics even in the most equipped countries. Plastic labelling must change to contribute to a holistic intervention on global plastic mismanagement. Discussion on this topic leads to three key recommendations: 1. An accurate and clear “sustainability scale” to empower consumers to make decisions informed by environmental and human health implications; 2. Directions for appropriate disposal action in the region of purchase; 3. A comprehensive list of plastic composition, including additives.Natural Environment Research Council (NERC)QUEX InstituteQueensland Health, AustraliaMinderoo Foundation, Australi

A preliminary investigation into the use of Red Pine (Pinus Resinosa) tree cores as historic passive samplers of POPs in outdoor air

The suitability of Red Pine trees (Pinus Resinosa) to act as passive samplers for persistent organic pollutants (POPS) in outdoor air and to provide historic information on air concentration trends was demonstrated in this preliminary investigation. Red Pine tree cores from Toronto, Canada, were tested for polycyclic aromatic hydrocarbon (PAHs), alkylated-PAHs, nitro and oxy-PAHs, polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (novel BFRs). The PBDEs and novel BFRs demonstrated a similar relative contribution in cores representing 30 years of tree growth, to that reported in contemporary air samples. Analysis of tree ring segments of 5-15 years resulted in detectable concentrations of some PAHs and alk-PAHs and demonstrated a transition from petrogenic sources to pyrogenic sources over the period 1960-2015. A simple uptake model was developed that treats the tree rings as linear -phase passive air samplers. The bark infiltration factor, IFBANK, is a key parameter of the model that reflects the permeability of the bark to allow chemicals to be transferred from ambient air to the outer tree layer (cambium). An IFBARK of about 2% was derived for the Red Pine trees based on tree core and air monitoring data

Poly- and perfluoroalkyl substances (PFASs) in indoor dust and food packaging materials in Egypt: Trends in developed and developing countries

PFASs concentrations in dust samples collected from three microenvironments in Cairo ranged from 1.3 to 69 ng g(-1) with FTOHs being dominant. The 8:2 FTOH was detected in all samples. Among the FOSAs and FOSEs the MeFOSE was dominant while among ionic PFASs, PFOS and PFOA were most prominent. The concentrations of PFASs were among the lowest worldwide. Correlations between worldwide concentrations of PFOS + PFOA and country development indexes highlight higher usage and human exposure in more developed countries. Food packaging was analyzed for PFSAs, PFCAs and PAPs. The 6:2 and 8:2 monoPAPs were found to be above the MDL in 18% of the samples. PFOA was detected in 79% of the samples with median concentration of 2.40 ng g(-1). PFOS was detected in 58% of the samples with median concentration of 0.29 ng g(-1) while PFHxS and PFDS were below detection limit. Different human exposure scenarios were estimated

A critical review on passive sampling in air and water for per- and polyfluoroalkyl substances (PFASs)

Passive sampling methods have been widely used for monitoring pollutants in different environments due to their advantages including simplicity to use and time-integrated sampling. Despite the advantages, challenges still exist and are associated with the calibration and implementation of passive sampling, in particular for per- and polyfluoroalkyl substances (PFASs) due to their unique physicochemical properties. In the current review, we focus on the calibration and use of passive samplers for PFASs in air and water. The comparison of the sampling rates generally showed a higher variability for the aqueous passive samplers compared to the passive air samplers. A better standardization for calibration methods for PFASs in air and water is needed. Nevertheless, passive samplers are an ideal tool for monitoring PFASs in air and water and can identify spatial or temporal trends and pollution sources, variations in water quality and ultimately improve our understanding of the global distribution of PFASs