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Children’s Car Seats Contain Legacy and Novel Flame Retardants

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... In recent years, reports have emerged about the presence of a variety of halogenated flame retardants (HFRs) in childcare items such as cot mattresses and child car seats (Cooper et al., 2016;Stapleton et al., 2011;Wu et al., 2019). HFRs have found application as additives to polyurethane and polystyrene foams and fabric covers used in these and other items to help meet fire safety regulations in various jurisdictions. ...
... In contrast, a more recent study of 10 foam samples from childcare articles (changing pads, sleep positioners, and bath products) collected in the USA in 2015, did not detect either PBDEs or HBCDD above the detection limit of 1 mg/kg (Gloekler et al., 2021). Likewise, in 18 child car seats purchased in the USA in 2018, only BDEs 28, 47, and 49 were detected, with the maximum concentration being 5.9 mg/kg of BDE-49 (Wu et al., 2019). While based on comparison with relatively few data from North America; our data suggest more recent BFR use in childcare articles in Ireland than in the USA. ...
... Based on this definition, 50%, 14%, and 29% of car seats, child mattresses, and other childcare articles respectively contained TDCIPP, with corresponding figures for TCIPP being: 27%, 8.3%, and 22%. Meanwhile, detection frequencies of TCEP, TCIPP, and TDCIPP in 36 samples of fabric and foam collected from 18 child car seats purchased in 2018 in the USA were 25%, 8%, and 19%; with maximum concentrations of TCEP, TCIPP, and TDCIPP being: 0.16, 0.68, and 0.94 mg/kg (Wu et al., 2019). The most recent study measured TCIPP and TDCIPP in 10 foam samples from childcare articles on the US market (Gloekler et al., 2021). ...
Article
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Concentrations of legacy and alternative halogenated flame retardants (HFRs) including chlorinated organophosphate esters (Cl-OPEs), were measured in waste childcare articles (n = 274 for Cl-OPEs, n = 187 for other HFRs) from the Republic of Ireland between 2019 and 2020. Articles studied comprised foams and fabrics from: child car seats, cot mattresses, changing mats, pushchairs, prams, and related items. Fifteen articles (7.7%) exceeded the European Union limit value of 1000 mg/kg for polybrominated diphenyl ethers (PBDEs) (all due to BDE-209), an additional 15 exceeded the limit for hexabromocyclododecane (HBCDD), with 6 articles exceeding the limit for both PBDEs and HBCDD. An even greater proportion of articles contained concentrations exceeding 1000 mg/kg for: tris(1-chloro-2-propyl) phosphate (TCIPP) (n = 75, 27%) and tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) (n = 58, 21%), with concentrations greater than 1000 mg/kg also observed for: tris(2-chloroethyl) phosphate (TCEP) (n = 14, 5.0% articles), 2-ethylhexyl tetrabromobenzoate (EH-TBB) (n = 7, 3.7%), decabromodiphenyl ethane (DBDPE), and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) (both n = 5, 2.7%). Overall, 115 samples contained at least one HFR at a concentration exceeding 1000 mg/kg. In addition to the waste management implications of our findings, our data raise concerns about child exposure to HFRs during the use phase of these everyday items.
... Fourthly, we surprisingly found that some novel OPEs, that were newly identified in environmental samples, were not included in the list of OPFR of factory manufacturing. For instance, we and other colleagues recently identified numerous novel OPFRs, i.e. bis-(2-ethylhexyl)-phenyl phosphate (BEHPP), and tri(2,4-di-t-butylphenyl) phosphate (TDTBPP), at relatively great concentrations and with detection frequencies in indoor dust samples (Meng et al. 2020;Zhang et al. 2019;Venier et al. 2018;Wu et al. 2019;Ye et al. 2021). However, all of these emerging OPFRs are not on the list of production of OPFR industries. ...
... However, all of these emerging OPFRs are not on the list of production of OPFR industries. The possible reasons could be multiple, and four key reasons could be following as: (1) this survey might not cover all the OPFR factories due to its limitation; (2) largely unknown information on components of OPFR mixtures; (3) the diverse and ever-changing structures of OPFRs in industry; and (4) OPEs could also be generated from other compounds under natural environment (Wu et al. 2019;Liu and Mabury 2019). All these reasons would enhance the uncertainty for environmental monitoring of OPFRs, and raise a great challenge for comprehensive identification of all known and unknown OPFRs in Fig. 3 Distribution of logarithmic transformed n-octanol/ water partition coefficient (Log K OW ) and annual production volume (APV) of n = 50 organophosphate flame retardant (OPFR) monomers. ...
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Since the phase-out of traditional halogenated flame retardants (HFRs), interests of research are gradually being shifted to organophosphate flame retardants (OPFRs), and this can be reflected by the increasing number of publications on OPFRs year by year. Here, an extensive survey is conducted in an attempt to generate a list of OPFRs that are being produced in factories, and to investigate the annual production volume (APV). This survey suggests that at least n = 56 OPFR monomers and n = 62 OPFR mixtures are being currently produced in 367 factories around the world, and 201 out of them are in Mainland China. APV of OPFRs was estimated as 598,422 metric tons, and this number could be underestimated due to the limitation of available information. We also notice that current researches are confined to a limited number of OPFRs, especially for OP esters (OPEs), and other OPFRs with different structures from OPEs has been rarely studied. Based on all the collected datasets, we provide five recommendations for how to proceed with future research to more comprehensively understand the currently-produced OPFRs in the environment.
... PFAS-treated products are of high concern because of their proximity to the child's breathing zone, direct contact with their skin, as well as their potential to release PFAS to their surroundings, from which they may subsequently enter children via various pathways (e.g., dust ingestion). These products could also undergo enhanced photolysis due to sunlight exposure when used outdoors (Wu et al., 2019a). ...
... In addition to the exterior fabric, for some seats, samples were also taken from other fabrics or foams that had detectable levels of bromine, chlorine, or phosphorus -suggestive of flame retardant chemicals-as measured by X-ray fluorescence. Flame retardant measurements in these samples were published previously (Wu et al., 2019a). Thirty-one fabric samples (15 standalone fabrics and 16 laminated composites of foam and fabric) and five foam samples (one polyethylene foam and four polyurethane foam) were cut from 18 seats, placed in resealable Ziploc bags, and shipped to Indiana University for XPS and MS analyses. ...
Article
Fabric and foam samples from popular children’s car seats marketed in the United States during 2018 were tested for fluorine content by particle-included gamma ray emission spectroscopy (PIGE, n = 93) and X-ray photoelectron spectroscopy (XPS, n = 36), as well as for per- and polyfluoroalkyl substances (PFAS) by liquid and gas chromatography mass spectrometry (LC/MS and GC/MS, n = 36). PFAS were detected in 97% of the car seat samples analyzed with MS, with total concentrations of 43 PFAS (∑PFAS) up to 268 ng/g. Fabric samples generally had greater ∑PFAS levels than foam and laminated composites of foam and fabric. The three fabric samples with the highest total fluorine content as represented by the highest PIGE signal were also subjected to ultraviolet (UV) irradiation and the total oxidizable precursor (TOP) assay. Results from these treatments, as well as the much higher organofluorine levels measured by PIGE compared to LC/MS and GC/MS, suggested the presence of side-chain fluorotelomer-based polymers (FTPs), which have the potential to readily degrade into perfluoroalkyl acids (PFAAs) under UV light. Furthermore, fluorotelomer (meth)acrylates were found to be indicators for the presence of (meth)acrylate-linked FTPs in consumer products, and thus confirmed that at least half of the tested car seats had FTP-treated fabrics. Finally, extraction of selected samples with synthetic sweat showed that ionic PFAS, particularly those with fluorinated carbons ≤ 8, can migrate from fabric to sweat, suggesting a potential dermal route of exposure.
... Because furniture foam padding is almost always covered by fabrics, direct dermal contact with Cl-PFRs in foam occurs only rarely (e.g. in old/damaged furniture where fabric wear exposes the foam). Nevertheless, high concentrations of Cl-PFRs have been reported in furniture fabrics, which was attributed to migration from the underlying flame-retarded foam and/or the need to meet the strict UK/Ireland furniture flammability test for the fabric (Kjølholt et al., 2015;Stubbings et al., 2016;Wu et al., 2019). Thus a realistic exposure and risk assessment of Cl-PFRs dermal uptake should mainly consider contact with the covering fabric outer surface with which human contact occurs. ...
Article
The chlorinated organophosphate flame retardants (Cl-PFRs): tris-(2-chloroethyl)-phosphate (TCEP), tris-(1-chloro-2-propyl)-phosphate (TCIPP) and tris-(1,3-dichloropropyl)-phosphate (TDCIPP), have been widely used in upholstered furniture despite their carcinogenic potential. Although Cl-PFRs are mainly added to furniture foam, they are present in the fabrics likely due to migration from the foam. While several studies have assessed human exposure to Cl-PFRs via different pathways, no information exists on dermal uptake of these chemicals through contact with fabrics. In the current study, dermal absorption of TCEP, TCIPP and TDCIPP from 3 UK domestic furniture fabrics was experimentally assessed for the first time using in vitro 3D-human skin equivalents (EpiSkin™) under different real-life exposure scenarios. Results revealed all 3 target Cl-PFRs were dermally bioavailable to varying degrees (3.5%–25.9% of exposure dose) following 24 h contact with the studied fabrics. Estimated permeability coefficients (KP, cm h⁻¹) showed TCEP had the highest percutaneous penetration potential followed by TCIPP, then TDCIPP. Further investigation revealed human dermal uptake of Cl-PFRs can be influenced by several factors including: the specific physicochemical properties of the compound, the type of exposure matrix, the exposure dose and the degree of skin hydration at the point of contact. Exposure assessment revealed UK adults and toddlers can be exposed to 20.4 and 14.1 ng TCIPP/kg bw/day via contact with furniture fabrics in summer, which is higher than international average exposures via inhalation and dust ingestion for adults and dietary exposure for toddlers. Therefore, risk assessment studies for Cl-PFRs and future replacements should consider dermal contact with consumer products (e.g. furniture fabrics) as a potential significant human exposure pathway.
... Letter commonly used in floor polishes, and is used in paints, coatings, vinyl resins, and plastics. 47,48 It has been reported in children's car seats at levels higher than the other OPEs presented here, 49 although we did not measure concentrations of OPEs in products to confirm sources. We hypothesized that higher concentrations of OPEs in our study compared to most other studies could be due to the use of OPEs as flame retardants and/or plasticizers in products and materials in the sleeping microenvironment 50 because we vacuumed directly on this surface where dust could have achieved high levels of these OPEs. ...
Article
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We investigated the association between exposure to 29 organophosphate esters (OPEs) and the onset of childhood asthma and recurrent wheeze. Using a case-cohort design nested in the Canadian CHILD Cohort Study, we included a random sample of children (n = 429), all children with asthma at 5 years (n = 128), and all children with recurrent wheeze between 2 and 5 years (n = 331). The association between 14 highly detected OPEs measured in house dust vacuumed when children were 3–4 months of age, including the child’s sleeping environment, and asthma at 5 years and recurrent wheeze between 2 and 5 years was assessed using logistic regression. The most abundant OPEs were TBOEP (median: 45730 ng/g) ≫ TCiPP (6065 ng/g) > TCEP (5260 ng/g) > TPhP (4440 ng/g) > EHDPP (1750 ng/g). Concentrations were higher than those in most other studies worldwide, potentially due to the inclusion of dust from the child’s sleeping area. A 2–4-fold increased odds of asthma was observed across all quartiles of exposure to TBOEP compared to the lowest quartile, including a positive dose–response relationship. Inverse relationships (p < 0.05) were observed with the odds of asthma and recurrent wheeze for 24DiPPDPP, B4tBPPP, tri-m-cresyl phosphate (TmCP), and EHDPP, and between 4tBPDPP and odds of asthma.
... Some SPAs have also been detected in human serum (Du et al., 2019;Liu and Mabury, 2018b), urine (Liu and Mabury, 2019f;Wang and Kannan, 2019), breast milk (Zhang et al., 2020), and fingernails (Li et al., 2019a) from different countries, suggesting ubiquitous human exposure to these organic contaminants globally. As for OPAs, tris(2,4-di-tert-butylphenyl) phosphite (AO168) is the most frequently used OPA congener, and it has been detected in plastics and foams at high concentrations (Simoneit et al., 2005;Wu et al., 2019a). Although AO168 is not commonly detected in the environment, its oxidation product, tris(2,4-di-tert-butylphenyl) phosphate (AO168O), has been detected in indoor dust Mabury, 2018c, 2019b) and outdoor atmospheric particulate matter (Maceira et al., 2019;Shi et al., 2020;Venier et al., 2018). ...
Article
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Although synthetic antioxidants (AOs) and photoinitiators (PIs) are known to be used in printing inks, there are little data on residual concentrations in printing paper products. In the present study, twenty-five PIs, ten AOs, and six transformation products were analyzed in two types of printing paper products, magazines and paperboard food packaging materials, both of which are unavoidable everyday products in our life. Nine AOs and six transformation products can be detected in food packaging materials with total concentrations (geometric mean, GM) of 1.16 × 10⁴ ng/dm². Twenty-two PIs were detected in food packaging materials with total concentrations (GM) of 1.76 × 10⁴ ng/dm². These chemicals were also detected in magazines, albeit at low concentrations (GM of AOs: 466 ng/dm², GM of PIs: 1.17 × 10³ ng/dm²). Magazine front covers were found to have much higher concentrations of the target compounds than magazine inside pages. Tris(2,4-di-tert-butylphenyl) phosphate (AO168O), 2,6-di-tert-butyl-4-methylphenol (BHT), bisphenol A (BPA), and benzophenone (BP) were among the predominant chemicals in those printing paper products. Preliminary calculations suggest that dermal exposure to AOs (GM: 6.25 ng/day) and PIs (GM: 17.0 ng/day) via contact with printing paper products is a minor exposure pathway compared to food intake/dust ingestion and is exceedingly unlikely to cause adverse health effects.
... It was reasonable to hypothesize that TDTBPP detected in the samples originated from the TDTBPPO since most information on TDTBPP was related to the degradation of TDTBPPO, or from migration from plastic materials (Venier et al., 2018). TDTBPPO was also known to oxidize into TDTBPP without the presence of fire (Liu and Mabury, 2019;Yang et al., 2016) and have been found in child car seats (Wu et al., 2018), which suggested that the formation of TDTBPP could even have occurred before the fire. Results showed that TDTBPP was released during the extinguishing phase regardless of the type of firefighting technique, but the highest intensities were found in soot from T3 and T4a. ...
Article
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During a fire event, potentially hazardous chemicals are formed from the combustion of burning materials and are released to the surrounding environment, both via gas and soot particles. The aim of this investigation was to study if firefighting techniques influence the emission of chemicals in gas phase and soot particles. Five full-scale fire tests were extinguished using four different firefighting techniques. A nontarget chemical analysis approach showed that important contaminants in gas and soot separating the different tests were brominated flame retardants (BFRs), organophosphate flame retardants (OPFR), polycyclic aromatic hydrocarbons (PAHs) and linear hydrocarbons. Reproducibility was evaluated by a field replicate test and it was determined that the temperature curve during the event had a bigger impact on the released chemicals than the firefighting technique used. However, despite fire intensity being a confounding factor, multivariate statistics concluded that water mist with additive resulted in less BFR emissions compared to foam extinguishing. The analysis also showed that the conventional spray nozzle method released more PAHs compared with the water mist method. The comprehensive chemical analysis of gas and soot released during fire events was able to show that different firefighting techniques influenced the release of chemicals.
... In addition, OPEs have also been detected in the human placenta (Ding et al., 2016), human breast milk (Kim et al., 2014), and human blood (Ya et al., 2019). Moreover, several unrecognized flame retardants have been identified, such as tri(2,4-di-tbutylphenyl) phosphate (TDTBPP) , resorcinol bis (diphenyl phosphate) (RDP) (Wu et al., 2018), 4-biphenylyl diphenyl phosphate (4-BPDP), and tris(2-biphenylyl) phosphate (TBPP) (Zhao et al., 2020). ...
Article
Organophosphate esters (OPEs) are extensively used as flame retardants and plasticizers in China; however, their potential carcinogenicity causes great concern. To date, their environmental distribution in water samples from the lower Yangtze River Basin still remains uncharacterized. This study systematically investigated the occurrence and spatial distribution of 13 OPEs, as well as their associated potential risks, in water samples from the lower Yangtze River and its 88 major inflowing rivers. The total OPE (ΣOPE) concentrations ranged from 55.6 to 5071 ng/L, with a median of 144 ng/L. Among them, halogenated OPEs were the dominant group with an average of 61.6%, and tris(1-chloro-2-propyl) phosphate (12.6–450 ng/L, median: 53.38 ng/L) and tris(2-choroethyl) phosphate (11.0–1202 ng/L, median: 36.4 ng/L) were the most abundant OPEs. Significantly different concentrations were found with spatial variations (p < 0.01), and were higher in southern cities than in northern cities of the lower Yangtze River Basin. Principal component analysis with multiple linear regression and Spearman correlations showed that the main sources were likely emission of vehicular and marine traffic. Ecological risk analysis showed that the risk quotient (RQ) values of samples remained below 1, but the percentage of 0.1 < RQ ≤ 1 was 26.9%, indicating a medium risk of OPEs in water samples. Moreover, ethylhexyl diphenyl phosphate predominantly contributed to the ecological risk, accounting for >89.2% of the total ecological risk of ΣOPEs. However, the total non-carcinogenic and carcinogenic risks of ΣOPEs were negligible at the detected concentrations, even in a high exposure scenario. The risks from major inflowing rivers of the lower Yangtze River were almost one order of magnitude higher than those of the mainstream lower Yangtze River.
... The MRM details were published previously. 28 Quality Control and Quality Assurance. The detailed quality control and assurance procedures were described in the IADN Quality Assurance Project Plan. ...
Article
Organophosphate esters (OPEs) were measured in atmospheric vapor and particle samples collected at six sites in the Laurentian Great Lakes basin every 12 days from January to December 2017 (inclusive). Median total OPE concentrations (∑OPEs) ranged from 41.2 pg/m3 at Eagle Harbor, Michigan to 1320 pg/m3 at Cleveland, Ohio. The most abundant OPEs measured in these samples were tris(1-chloro-2-propyl) phosphate (TCIPP), triphenyl phosphate (TPHP), triethyl phosphate (TEP), 2-isopropylphenyl diphenyl phosphate (2IPPDPP), tri-n-butyl phosphate (TNBP), and tris(2-butoxyethyl) phosphate (TBOEP). The spatial distribution of OPEs among the sites suggests that OPEs with longer atmospheric half-lives and relatively high octanol - air partitioning coefficients (KOA) are likely to have a greater potential to undergo long-range atmospheric transport. OPE particle-phase partitioning fraction (Φ) significantly and positively correlated with KOA, but declined with increasing relative humidity. Φ values varied seasonally and were lower in the summer for volatile OPEs. In addition, samples collected in the summer had significantly higher levels of ∑OPEs than samples collected in the winter. The estimated dry deposition flow of ∑OPEs to the Great Lakes was 1.22 tons/year, exceeding the corresponding flows reported for polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine pesticides.
... Sediments and soils may require sulfur removal, whereas biota require lipid removal, which can be done with sulfuric acid treatment, gel permeation chromatography (GPC), or column adsorption chromatography on sorbents like silica, alumina, or Florisil Giulivo et al. 2017;Novak et al. 2017;Persson et al. 2019). Instrumental analysis is based on gas-chromatographic (GC) separation on nonpolar or semi-polar capillary columns with mass spectrometric (MS) detection (Vecchiato et al. 2015;Newton et al. 2015;Martellini et al. 2016;Mcgrath et al. 2016;Pozo et al. 2016;Kademoglou et al. 2017;Liu et al. 2018;Pei et al. 2018;Ohajinwa et al. 2019;Wu et al. 2019). ...
Article
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Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants (BFRs), present in the environment, animals, and humans. Their levels, distribution, and human exposure have been studied extensively, and over the last decade, various legal measures have been taken to prohibit or minimize their production and use due to the increasing amount of evidence of their harmful effects on human and animal health.Our aim here was to make a comprehensive and up-to-date review of the levels and distribution of PBDEs in the aquatic environment, air, and soil, in indoor dust, and in humans. To fulfill this, we searched through Web of Science for literature data reported in the last five years (2015–2019) on levels of at least six key PBDE congeners in abovementioned matrices. According to our summarized data, significant PBDE mass concentrations/fractions are still being detected in various sample types across the world, which implies that PBDE contamination is an ongoing problem. Secondary sources of PBDEs like contaminated soils and landfills, especially those with electronic and electrical waste (e-waste), represent a particular risk to the future and therefore require a special attention of scientists.
... In addition, MEL is widely used in the synthesis of water-soluble resin for the production of wrinklefree textiles (Lacasse and Baumann, 2004;Zhang et al., 2008;Mecker et al., 2012;Rovina and Siddiquee, 2015), and in vinyl production as part of textile coatings to increase the stability of coatings (Salaun et al., 2009). The levels of MEL-based compounds in cover samples were higher than those of brominated flame retardants in car seat fabric (median 310 ng/g) (Wu et al., 2019), and those of bisphenols in infant clothing (median 12 ng/g) (Xue et al., 2017), suggesting nap mats can be a potential source of MEL-based contaminants in childcares. This is of concern given the extended time infants and young children spend sleeping (10e14 h per day) on nap mats, crib mattresses, and other bedding products (Boor et al., 2014). ...
Article
Melamine (MEL) and its derivatives are widely used in many consumer products, including furniture, kitchenware, and plastics. However, very limited knowledge exists on human exposure to MEL and its derivatives, especially in the indoor environment. Here, we determined the occurrence and distribution of 11 MEL derivatives in childcare facilities and estimated children's exposure through dust ingestion and dermal absorption. We analyzed dust and samples of nap mats, a commonly used item in many childcares, from eight facilities located in the United States. Eight MEL-based compounds were detected in dust, and total MEL concentrations ranged from 429 to 117,000 ng/g. The most abundant compounds found in the dust samples were MEL, cyanuric acid (CYA), ammeline (AMN), and ammelide (AMD), with median concentrations of 1620, 585, 1060, and 299 ng/g, respectively. MEL, CYA, AMN and 2,4,6-tris[bis(methoxymethyl)amino]-1,3,5-triazine (TBMMAT) were also detected in nap mats with median concentrations of 45.6, 19.8, 1510 and 2.5 ng/g, respectively. ΣMEL concentrations in mat covers (median 709 ng/g) were significantly higher than those in mat foam (median 15.1 ng/g). Estimated daily intakes (EDIs) of MEL and its derivatives via dust ingestion were two orders of magnitude higher than the EDIs through dermal absorption, but both were below the established tolerable daily intake levels. This is the first report on exposure to MEL and its derivatives in the childcare environment.
... Wu et al. [88] analysed Cl-PFRs in fabrics and foams from 18 children's car seats (n ¼ 36) and found TCEP, TCIPP and TDCIPP to be present in 25%, 8% and 19% of samples, respectively. Each of the compounds was detected in fabric samples, while only TCIPP was detected in the foam. ...
... During the analysis of flame retardants in children's car seats, 12 we noticed the presence of a few relatively abundant compounds, which we could not identify as flame retardants. We suspected that they were antioxidants, and we set out to determine their identities, verify their oxidation to a common product, and measure the concentrations of these compounds in the car seat samples, in e-waste dust from Ontario, in indoor dust from Bloomington, Indiana, and Toronto, Ontario, and in ambient atmospheric samples from Chicago, Illinois. ...
Article
Oil shale development is of great significance because oil and gas resources are scarce. Research on the prevention of oil shale dust explosion is particularly important for guaranteeing the safe development and utilization of oil shale resources. In this work, the flame morphology and velocity of oil shale dust with and without MCM-41 or FR-245 were compared. Furthermore, the novel green FR-245/MCM-41 inhibitor was prepared by jet mill method and used in oil shale dust explosion for the first time. The best ratio of FR-245/MCM-41 for flame inhibition was obtained, which was 9: 1. The pyrolysis oxidation behavior of oil shale before and after adding FR-245/MCM-41 was analyzed and compared by FWO and KAS methods. The results showed that the activation energy calculated by FWO and KAS methods greatly increased after adding FR-245/MCM-41, which increased by 95.36% and 115.15% than that before adding inhibitor, respectively. Significantly, the activation energy is particularly high for two methods when α between 0.2 and 0.6, due to that MCM-41 and FR-245 coexisted to limit the oxidation of oil shale. For α between 0.7 and 0.9, the activation energy is still high because of the existence of MCM-41. Combining the oil dust flame propagation behavior with the characterization results before and after explosion, the physical-chemical synergy mechanism of oil dust flame propagation inhibition was revealed.
Article
Forty-seven compounds among synthetic phenolic and amino antioxidants and ultraviolet filters, three suites of widely used chemical additives, were measured in eighteen popular children's car seats (fabric, foam, and laminated composites of both layers) marketed in the United States in 2018. Significantly higher levels of target compounds were found in foam and composite samples than in fabric samples. Median total concentrations of phenolic antioxidants and their transformation products ranged from 8.11 μg/g in fabric to 213 μg/g in foam In general, isooctyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AO-1135) and 2,4-di-tert-butylphenol (24-DBP) were the most abundant among all target compounds with maximum levels of526 μg/g in composite and 13.7 μg/g, respectively. The total concentrations of amino antioxidants and their transformation products and of ultraviolet filters were at least one order of magnitude lower than those of phenolic antioxidants, with medians of 0.15–37.1 μg/g and 0.29–1.81 μg/g, respectively, in which the predominant congeners were 4-tert-butyl diphenylamine (BDPA), 4,4′-di-tert-butyl diphenylamine (DBDPA), 4-tert-octyl diphenylamine (ODPA), 2,4-dihydroxybenzophenone (BP-1), 2-hydroxy-4-methoxybenzophenone (BP-3), and 2-(2-benzotriazol-2-yl)-4-methylphenol (UV-P). Large variabilities in usage of these chemicals resulted in different compositional patterns among the car seats. These results suggest that these compounds are major polymeric additives in children's car seats as they are present at greater levels than previously measured groups of chemicals like brominated flame retardants and per- and polyfluoroalkyl substances. Given the documented toxic potentials of synthetic antioxidants and ultraviolet filters, their abundances in children products are a cause for concern.
Article
The percutaneous penetration and exposure risk of organophosphate esters (OPEs) from children’s toys remains largely unknown. Percutaneous penetration of OPEs was evaluated by EPISkinTM model. Chlorinated OPEs (Cl-OPEs) and alkyl OPEs, except tris(2-ethylhexyl) phosphate, exhibited a fast absorption rate and good dermal penetration ability with cumulative absorptions of 57.6−127% of dosed OPEs. Cumulative absorptions of OPEs through skin cells were inversely associated with their molecular weight and log octanol-water partition coefficient. Additionally, a quantitative structure-activity relationship model indicated that topological charge and steric features of OPEs were closely related to the transdermal permeability of these chemicals. With the clarification of the factors affecting the transdermal penetration of OPEs, the level and exposure risk of OPEs in actual toys were studied. The summation of 18 OPE concentrations in 199 toy samples collected from China ranged from 6.82 to 228,254 ng/g, of which Cl-OPEs presented the highest concentration. Concentrations of OPEs in toys exhibited clear type differences. Daily exposure to OPEs via dermal, hand-to-mouth contact, and mouthing was evaluated, and dermal contact was a significant route for children’s exposure to OPEs. Hazard quotients for noncarcinogenic risk assessment were below 1, indicating that the health risk of OPEs via toys was relatively low.
Thesis
D’après la littérature scientifique, les plastiques présents en mer libèrent des micro et nano-plastiques ainsi des substances chimiques, potentiellement transférées ou bioaccumulées dans les organismes marins, ce qui constitue une source potentielle de préoccupation. Par ailleurs, l’aquaculture marine utilise de nombreux équipements en plastique, devant être recyclés en fin de vie (cf. Directive (UE) 2019/904). Dans ce contexte, tout nouvel équipement en plastique conçu pour l’aquaculture doit être éco-conçu et s’inscrire dans une économie circulaire. Le présent travail propose une méthodologie d’éco-conception, systémique et pilotée par l’usage, développée pour maîtriser l’innocuité, la durabilité et la recyclabilité des matériaux polymères utilisés en aquaculture, et comprenant 4 étapes : 1- une évaluation scientifique des risques liés à l’usage du matériau, 2- l’identification des points de contrôle de ces risques, 3- le développement d’actions préventives, 4- la définition de procédures de vérification de leur maîtrise, incluant la réalisation d’analyses biométriques et chimiques dans le cadre d’une expérimentation in situ.
Thesis
Ces travaux s’inscrivent dans le cadre du développement d’une nouvelle pièce ostréicole en plastique. Leur objectif est de proposer une méthodologie, spécifiquement développée pour l’écoconception des matériaux plastiques utilisés en ostréiculture, en vue de garantir : 1 – Leur innocuité vis-à-vis des huîtres, des consommateurs d’huîtres et des écosystèmes marins, 2 - Leur durabilité, ou maintien de leur intégrité physique dans le temps, afin d’optimiser leur durée d’utilisation et ralentir leur dégradation dans le milieu, 3 - Leur recyclabilité post utilisation, en vue d’assurer leur intégration dans une économie circulaire. Le développement de cette méthodologie s’est organisée autour d’un cadre général de gestion des risques, comprenant 5 étapes au niveau desquelles les données scientifiques, toxicologiques et écotoxicologiques, ainsi que les méthodes et outils d’aide à la décision identifiés comme étant les plus pertinents ont été utilisés, adaptés ou développés, pour identifier, évaluer et maîtriser les dangers potentiels. Pour faciliter son intégration dans une démarche d’écoconception, les attentes technico-économiques et le rôle de chaque acteur de la chaîne de valeur du matériau ont été pris en compte. La mise en œuvre de cette méthodologie a permis la sélection de 2 matrices polymères et de 2 formulations. Les 3 matériaux expérimentaux obtenus ont été testés in situ, dans le cadre d’un cycle de culture expérimentant le prototype du système de production en développement. Les premiers résultats obtenus suggèrent que la recyclabilité, la durabilité et les niveaux d’émission de substances dans le milieu peuvent être maîtrisés. Développé pour l’ostréiculture, cette méthodologie reposant sur l’établissement de scénarios de devenir, d’exposition et d’effets des composants des polymères, devrait être adaptable à d’autres usages
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Organic contaminants of emerging concern (OCECs) originating from assorted sources have attracted increasing attention latterly as most of them are not under routine surveillance or effective regulation but possess persistent, bioaccumulative, and toxic potential. Massive terrestrial inputs and proximity to intense human activities have elevated OCEC contamination in many estuaries. The present review outlines the current knowledge on the environmental occurrence and fate, as well as bioavailability of nine classes of OCECs, i.e., per- and polyfluoroalkyl substances, alternative halogenated flame retardants, organophosphate esters, chlorinated paraffins, ionic surfactants, phthalate alternatives, polyhalogenated carbazoles, synthetic antioxidants, and bisphenol A alternatives in global estuaries. Available data have documented prevalence of studied OCECs in estuarine compartments from around the world, particularly in North America, Europe, and Asia. Their spatiotemporal trends, vertical distributions in the water column, and multi-media partitioning are mainly dependent on anthropogenic impacts (e.g., production and consumption patterns, urbanization, industrialization, and waste treatment), hydrodynamics, meteorological conditions, characteristics of environmental media and the interactions with OCECs, and physiochemical properties of OCECs. Bioaccumulation and biomagnification have also been reported for many estuarine OCECs, which favor those with moderate hydrophobicity, considerable proteophilicity, and satisfactory resistance to environmental degradation and biological transformation. To comprehensively elucidate OCEC exposure for estuarine ecosystems from the big picture, future research is warranted in various fields, including environmental chemistry and (eco-)toxicology, and may involve more interdisciplinary collaborations.
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This study reviews current knowledge about the presence of brominated and chlorinated organophosphate flame retardants (BFRs and Cl-OPFRs) in plastic consumer articles, with particular reference to the potential as a result of recycling, for such chemicals to unintentionally contaminate articles in which flame retardants are not required. To minimize such unintentional contamination, jurisdictions such as the EU (European Union) have introduced limits on concentrations of some BFRs in waste plastics, with articles exceeding such limits prevented from being recycled. Substantial technical and economic constraints associated with the conventional methods for determining compliance with such limit values exist, leading to less specific, but simpler, more rapid, and less expensive methods such as portable X-ray fluorescence (XRF) spectrometry being identified as possible alternatives. This paper thus examines the evidence that XRF offers a viable method for checking compliance with existing and possible future limits on BFRs and Cl-OPFRs in waste plastics and identifies future research priorities.
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To investigate the level of polybrominated diphenyl ether (PBDE) contamination in the automobile microenvironment, air and dust samples were collected from 15 family automobiles in Hangzhou City, China. The PBDE concentrations, distribution of congeners, and human exposure were determined; and the content and distribution of PBDEs in automotive interior materials were analyzed. The results revealed that the average and median concentrations of ∑14PBDEs in the air in automobiles were 732 and 695 pg/m³, respectively, whereas those in automotive dust were 4913 and 5094 ng/g, respectively. Decabromodiphenyl ether (BDE-209) had the highest proportion, accounting for 61.3% and 88.8% of the ∑14PBDEs in the air and dust, respectively. The potential primary sources of PBDEs in automobile air and dust were volatile polyurethanes in seat covers and foot pads, respectively. Human exposure calculations revealed that infants and toddlers in cars were most exposed to air and dust, respectively. BDE-47 and -99 were the primary sources of health risks related to air and dust in cars.
Article
Several haloalkyl organophosphate triester (OPTE) flame retardants have been restricted in some countries due to their potential health risks, but the usage of alternative haloalkyl OPTEs is of concern. In this study, we comprehensively screened for haloalkyl OPTEs in house dust using high-resolution mass spectrometry. Through halogenation-guided nontarget screening, a rare chloroalkyl OPTE, diethylene glycol bis(bis(2-chloroisopropyl)phosphate) (DEGBBCPP), was unequivocally identified (Level 1) in house dust of Beijing, North China. In addition, by screening a suspect list of 61 haloalkyl OPTEs from the EPA's CompTox Chemicals Dashboard, we tentatively identified diethylene glycol bis(bis(2-chloroethyl)phosphate) (DEGBBCEP) and ethylene bis[bis(2-chloroethyl)phosphate] (EBBCEP) (Level 2). DEGBBCPP was detected in all 45 house dust samples, and the median concentration was 98.4 ng/g (13.6-6217 ng/g), that is, approximately one-half that of tris(1,3-dichloro-2-propyl) phosphate, a traditional high-production chloroalkyl OPTE. The detection frequencies of DEGBBCEP and EBBCEP were 96% and 98%, respectively, but at relatively low median concentrations of 10.6 ng/g (from not detected to 152 ng/g) and 3.79 ng/g (from not detected to 130 ng/g), respectively. In standard house dust SRM2585, DEGBBCEP and EBBCEP were detected at 160 ± 15.7 and 1897 ± 38.8 ng/g, respectively, but DEGBBCPP was not detected. Future studies should evaluate the potential adverse health effects of these emerging flame retardants.
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Common plasticizers and their alternatives are environmentally ubiquitous and have become a global problem. In this study, common plasticizers (phthalates and metabolites) and new alternatives [bisphenol analogs, t-butylphenyl diphenyl phosphate (BPDP), and bisphenol A bis(diphenyl phosphate) (BDP)] were quantified in urine and hair samples from children in Hong Kong, drinking water (tap water/bottled water) samples, and airborne particle samples from 17 kindergartens in Hong Kong. The results suggested that locally, children were exposed to various plasticizers and their alternatives. High concentrations of BPDP and BDP were present in urine, hair, tap water, bottled water, and air particulate samples. The geometric mean (GM) concentrations of phthalate metabolites in urine samples (126–2140 ng/L, detection frequencies < 81%) were lower than those detected in Japanese and German children in previous studies. However, a comparison of the estimated daily intake values for phthalates in tap water [median: 10.7–115 ng/kg body weight bw/day] and air particles (median: 1.23–7.39 ng/kg bw/day) with the corresponding reference doses indicated no risk. Bisphenol analogs were detected in 15–64% of urine samples at GM concentrations of 5.26–98.1 ng/L, in 7–74% of hair samples at GM concentrations of 57.5–2390 pg/g, in 59–100% of kindergarten air samples at GM concentrations of 43.1–222 pg/m³, and in 33–100% of tap water samples at GM concentrations of 0.90–3.70 ng/L. A significant correlation was detected between the concentrations of bisphenol F in hair and urine samples (r = .489, p < .05). The estimated daily urinary excretion values of bisphenol analogs suggest that exposure among children via tap water intake and airborne particle inhalation in kindergartens cannot be ignored in Hong Kong.
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This critical review summarizes the occurrence of 63 novel brominated flame retardants (NBFRs) in indoor air, dust, consumer goods and food. It includes their EU registration and (potential) risks. The increasing application of NBFRs calls for more research on their occurrence, environmental fate and toxicity. This review reports which NBFRs are actually being studied, which are detected and which are of most concern. It also connects data from the European Chemical Association on NBFRs with other scientific information. Large knowledge gaps emerged for 28 (out of 63) NBFRs, which were not included in any monitoring programs or other studies. This also indicates the need for optimized analytical methods including all NBFRs. Further research on indoor environments, emission sources and potential leaching is also necessary. High concentrations of 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP), decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) were often reported. The detection of hexabromobenzene (HBB), pentabromotoluene (PBT), 1,4-dimethyltetrabromobenzene (TBX), 4-(1,2-dibromoethyl)-1,2-dibromocyclohexane (DBE-DBCH) and tetrabromobisphenol A bis(2,3-dibromopropyl) ether (TBBPA-BDBPE) also raises concern.
Article
Triphenyl phosphate (TPHP) was frequently detected in various environment, which has caused wide attention out of its adverse effects on organisms. Hence, an effective and reasonable method is in urgent demand for removing TPHP. In this study, microbial consortium GYY with efficient capacity to degrade TPHP has been isolated, which could degrade 92.2% of TPHP within 4 h under the optimal conditions (pH 7, inoculum size 1 g/L wet weight, 30 °C, TPHP initial concentration 3 μmol/L). Some intermediate products such as diphenyl phosphate (DPHP), phenyl phosphate (PHP), OH-TPHP, and methoxylation products were identified, suggesting that TPHP was metabolized by hydrolysis, methoxylation after hydrolysis, and methoxylation after hydroxylation pathways. The sequencing analysis demonstrated that Pseudarthrobacter and Sphingopyxis were the dominant genera in consortium GYY during the process of TPHP biodegradation. Also, Sphingopyxis (GY-1) that degraded 98.9% of TPHP (3 μmol/L) within 7 days was further isolated and identified. Overall, this study provides a new insight on TPHP metabolic transformation by consortium and theoretical basis of developing bioremediation technology for TPHP contamination.
Article
Here, fifteen OPEs were investigated in n = 50 floor dust samples collected from six types of indoor spaces in Nanjing, eastern China, in the year 2018. Ten OPEs, including tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), tris(1,3-dichloro-isopropyl) phosphate (TDCIPP), tris(2-ethylhexyl) phosphate (TEHP), tris(2-butoxyethyl) phosphate (TBOEP), 2-ethylhexyl-diphenyl phosphate (EHDPP), triphenyl phosphate (TPHP), tris(methyl-phenyl) phosphate (TMPP), 4-biphenylyl diphenyl phosphate (4-BPDP) and tris(2-biphenylyl) phosphate (TBPP), were detected in at least one of the analyzed samples (>method limits of quantification). Regardless of indoor spaces, EHDPP (34% of Σ8OPEs, mean: 1.43 μg/g) and TDCIPP (19%, 0.81 μg/g) were the ascendant OPEs in indoor floor dust. 4-BPDP and TBPP were detectable in indoor floor dust samples, but at relatively low detection frequencies with 2% and 10%, respectively. Various indoor microenvironments exhibited different pollution characteristics of OPEs. Floor dust collected from electronic product maintenance centers contained the richest OPE contaminants with highest mean Σ8OPEs concentration of 7.92 μg/g. On the basis of measured Σ10OPEs concentrations in dust sample, we estimated daily intake via floor dust ingestion to be 1.37, 0.75 and 1.24 ng/kg BW/day for electronic engineers, undergraduates, and graduate students under mean-exposure scenario, respectively. Overall, our study reported the occurrence of 4-BPDP and TBPP in environmental samples for the first time, and demonstrated that indoor floor dust ingestion exposure does values were far less than reference dosage values of oral toxicity proposed by United States Environmental Protection Agency (USEPA) Integrated Risk Information System.
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A total of 41 play mats made from different raw materials, such as polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), chemical crosslinked polyethylene (XPE), and polyvinyl chloride (PVC), were obtained from Chinese markets and analyzed for flame retardants. Polybrominated diphenyl ethers (PBDEs) and their replacements, organophosphate esters (OPEs), were measured and the associated exposure risks for children were evaluated. The levels (range; median) of OPEs (6.6-7400; 200 ng g-1) were generally 1-2 orders of magnitude higher than those of PBDEs (0.13-72; 13 ng g-1), consistent with the production and usage trends of flame retardants. The concentrations of both PBDEs and OPEs were the lowest in XPE mats (0.13-5.6; 3.3 ng g-1 for PBDEs and 6.6-320; 47 ng g-1 for OPEs) compared to the other three types. Concentration comparison and compositional analysis suggested that PBDEs and OPEs in play mats were most probably from leaching of raw materials, during production, storage, and/or transport. Children's exposure to PBDEs and OPEs from play mats was estimated for three pathways, i.e., dermal contact, inhalation, and hand-to-mouth ingestion. The combined exposure was 5-6 orders of magnitude lower than the established reference dose values, suggesting no obvious health concern regarding the occurrence of PBDEs and OPEs in play mats. Nevertheless, selection of less contaminated, i.e., XPE mats among those under investigation, by consumers is strongly recommended to minimize any potential exposure risk.
Article
Smartphones have become an integral tool of society; in the year 2017, approximately 30% of the global population used smartphones. After their life cycle of use, most smartphones are not recycled and are instead discarded as e-waste, which increases the probability that chemicals they contain will eventually be released into the natural environment. In this study, the concentration and distribution of 52 major flame retardant (FR) chemicals were measured in eight components of seven models of largely produced smartphones. The results demonstrated that organophosphate esters (OPEs) were the principal FRs in these smartphone devices, while a suite of halogenated flame retardants (HFRs), including 25 polybrominated diphenyl ethers (PBDEs), were not detected. Triphenyl phosphate (TPHP) was the primary FR in the smartphones, followed by tris(2-butoxyethyl) phosphate (TBOEP), 2-ethylhexyl diphenyl phosphate (EHDPP), triethyl phosphate (TEP), tris(2-chloroethyl) phosphate (TCEP), and tris(2-chloroisopropyl) phosphate (TCIPP), respectively. The average smartphone contained 3.37 × 107 ng TPHP/unit, which was concentrated in the phone screen. We estimated the annual amount of ΣOPEs and TPHP in smartphones used globally to be 53.5 and 51.8 tons, respectively. Extracts of phone screens were further analyzed by use of an untargeted screening strategy, and other 10 organic chemicals were identified. Interestingly, 3 out of them shared similar backbone structure of TPHP, and these 3 chemicals were tri(2,4-di-t-butylphenyl) phosphate (TDTBPP; CAS No. 95906–11–9), 2-biphenylol diphenyl phosphate (BPDPP; 132–29-6), and tris (2-biphenyl) phosphate (TBPHP; 132–28-5). Collectively, this study provided the first information on distribution of major FRs in different components of smartphones, and also identified other 10 current-use organic chemicals including three novel aryl OPEs which should be considered in further environmental studies including in toxicological and monitoring programs.
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Short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) in commercial rubber track products and raw materials (rubber granules and adhesives) were investigated by two-dimensional gas chromatography with electron-capture negative-ionization mass spectrometry (GC × GC-ECNI-MS). The mean SCCP and MCCP concentrations in the rubber track products were 3.64 × 103 and 4.14 × 104 μg/g, respectively. The mean SCCP concentration in the products was significantly higher than those in the rubber granules (2.78 μg/g), but in the same order of magnitude as those in the adhesives (3.34 × 103 μg/g). The SCCP concentrations in almost half of the rubber track products and four fifths of the adhesives exceeded the limit (1.5 g/kg) set in Chinese standard GB 36246-2018. The dominant SCCP and MCCP congeners in the rubber track products were similar to those in the relevant adhesives but different from those in the paired granules. Principal component analysis and contribution calculations indicated that chlorinated paraffins (CPs) in adhesives could be the main sources of CPs in rubber track products. The high CP concentrations found in rubber track products are of special concern because of the relatively high exposures for children and negative effect on human health and environment.
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Background: Human health risk assessment methods have advanced in recent years to more accurately estimate risks associated with exposure during childhood. However, predicting risks related to infant exposures to environmental chemicals in breast milk and formula remains challenging. Objectives: Our goal was to compile available information on infant exposures to environmental chemicals in breast milk and formula, describe methods to characterize infant exposure and potential for health risk in the context of a risk assessment, and identify research needed to improve risk analyses based on this type of exposure and health risk information. Methods: We reviewed recent literature on levels of environmental chemicals in breast milk and formula, with a focus on data from the United States. We then selected three example publications that quantified infant exposure using breast milk or formula chemical concentrations and estimated breast milk or formula intake. The potential for health risk from these dietary exposures was then characterized by comparison with available health risk benchmarks. We identified areas of this approach in need of improvement to better characterize the potential for infant health risk from this critical exposure pathway. Discussion: Measurements of chemicals in breast milk and formula are integral to the evaluation of risk from early life dietary exposures to environmental chemicals. Risk assessments may also be informed by research investigating the impact of chemical exposure on developmental processes known to be active, and subject to disruption, during infancy, and by analysis of exposure-response data specific to the infant life stage. Critical data gaps exist in all of these areas. Conclusions: Better-designed studies are needed to characterize infant exposures to environmental chemicals in breast milk and infant formula as well as to improve risk assessments of chemicals found in both foods. https://doi.org/10.1289/EHP1953.
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Coaches spend long hours training gymnasts of all ages aided by polyurethane foam used in loose blocks, mats, and other padded equipment. Polyurethane foam can contain flame retardant additives such as polybrominated diphenyl ethers (PBDEs), to delay the spread of fires. However, flame retardants have been associated with endocrine disruption and carcinogenicity. The National Institute for Occupational Safety and Health (NIOSH) evaluated employee exposure to flame retardants in four gymnastics studios utilized by recreational and competitive gymnasts. We evaluated flame retardant exposure at the gymnastics studios before, during, and after the replacement of foam blocks used in safety pits with foam blocks certified not to contain several flame retardants, including PBDEs. We collected hand wipes on coaches to measure levels of flame retardants on skin before and after their work shift. We measured flame retardant levels in the dust on window glass in the gymnastics areas and office areas, and in the old and new foam blocks used throughout the gymnastics studios. We found statistically higher levels of 9 out of 13 flame retardants on employees' hands after work than before, and this difference was reduced after the foam replacement. Windows in the gymnastics areas had higher levels of 3 of the 13 flame retardants than windows outside the gymnastics areas, suggesting that dust and vapor containing flame retardants became airborne. Mats and other padded equipment contained levels of bromine consistent with the amount of brominated flame retardants in foam samples analyzed in the laboratory. New blocks did not contain PBDEs, but did contain the flame retardants 2-ethylhexyl 2,3,4,5-tetrabromobenzoate and 2-ethylhexyl 2,3,4,5-tetrabromophthalate. We conclude that replacing the pit foam blocks eliminated a source of PBDEs, but not 2-ethylhexyl 2,3,4,5-tetrabromobenzoate and 2-ethylhexyl 2,3,4,5-tetrabromophthalate. We recommend ways to further minimize employee exposure to flame retardants at work and acknowledge the challenges consumers have identifying chemical contents of new products.
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Background: A reduction in the use of polybrominated diphenyl ethers (PBDEs) because of human health concerns may result in an increased use of and human exposure to organophosphate flame retardants (OPFRs). Human exposure and health studies of OPFRs are lacking. Objectives: We sought to define the degree of temporal variability in urinary OPFR metabolites in order to inform epidemiologic study design, and to explore a potential primary source of exposure by examining the relationship between OPFRs in house dust and their metabolites in urine. Methods: Nine repeated urine samples were collected from 7 men over the course of 3 months and analyzed for bis(1,3-dichloro-2-propyl) phosphate (BDCPP) and diphenyl phosphate (DPP), metabolites of the OPFRs tris(1,3-dichloro-2-propyl) phosphate (TDCPP) and triphenyl phosphate (TPP), respectively. Intraclass correlation coefficients (ICCs) were calculated to characterize temporal reliability. Paired house dust and urine samples were collected from 45 men. Results: BDCPP was detected in 91% of urine samples, and DPP in 96%. Urinary BDCPP showed moderate-to-strong temporal reliability (ICC range, 0.55–0.72). ICCs for DPP were lower, but moderately reliable (range, 0.35–0.51). There was a weak [Spearman r (rS) = 0.31] but significant (p = 0.03) correlation between urinary BDCPP and TDCPP concentrations in house dust that strengthened when nondetects (rS = 0.47) were excluded. There was no correlation between uncorrected DPP and TPP measured in house dust (rS < 0.1). Conclusions: Household dust may be an important source of exposure to TDCPP but not TPP. Urinary concentrations of BDCPP and DPP were moderately to highly reliable within individuals over 3 months.
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Background: There is increasing interest in the potential effects of polybrominated diphenyl ethers (PBDEs) on children’s neuropsychological development, but only a few small studies have evaluated such effects. Objectives: Our goal was to examine the association between PBDE concentrations in colostrum and infant neuropsychological development and to assess the influence of other persistent organic pollutants (POPs) on such association. Methods: We measured concentrations of PBDEs and other POPs in colostrum samples of 290 women recruited in a Spanish birth cohort. We tested children for mental and psychomotor development with the Bayley Scales of Infant Development at 12–18 months of age. We analyzed the sum of the seven most common PBDE congeners (BDEs 47, 99, 100, 153, 154, 183, 209) and each congener separately. Results: Increasing Σ7PBDEs concentrations showed an association of borderline statistical significance with decreasing mental development scores (β per log ng/g lipid = –2.25; 95% CI: –4.75, 0.26). BDE-209, the congener present in highest concentrations, appeared to be the main congener responsible for this association (β = –2.40, 95% CI: –4.79, –0.01). There was little evidence for an association with psychomotor development. After adjustment for other POPs, the BDE-209 association with mental development score became slightly weaker (β = –2.10, 95% CI: –4.66, 0.46). Conclusions: Our findings suggest an association between increasing PBDE concentrations in colostrum and a worse infant mental development, particularly for BDE-209, but require confirmation in larger studies. The association, if causal, may be due to unmeasured BDE-209 metabolites, including OH-PBDEs (hydroxylated PBDEs), which are more toxic, more stable, and more likely to cross the placenta and to easily reach the brain than BDE-209.
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Polybrominated diphenyl ethers (PBDEs) are persistent, bioaccumulative, and endocrine-disrupting chemicals. We used handwipes to estimate exposure to PBDEs in house dust among toddlers and examined sex, age, breast-feeding, race, and parents' education as predictors of serum PBDEs. Eighty-three children from 12 to 36 months of age were enrolled in North Carolina between May 2009 and November 2010. Blood, handwipe, and house dust samples were collected and analyzed for PBDEs. A questionnaire was administered to collect demographic data. PBDEs were detected in all serum samples (geometric mean for ΣpentaBDE in serum was 43.3 ng/g lipid), 98% of the handwipe samples, and 100% of the dust samples. Serum ΣpentaBDEs were significantly correlated with both handwipe and house dust ΣpentaBDE levels, but were more strongly associated with handwipe levels (r = 0.57; p < 0.001 vs. r = 0.35; p < 0.01). Multivariate model estimates revealed that handwipe levels, child's sex, child's age, and father's education accounted for 39% of the variation in serum ΣBDE3 levels (sum of BDEs 47, 99, and 100). In contrast, age, handwipe levels, and breast-feeding duration explained 39% of the variation in serum BDE 153. Our study suggests that hand-to-mouth activity may be a significant source of exposure to PBDEs. Furthermore, age, socioeconomic status, and breast-feeding were significant predictors of exposure, but associations varied by congener. Specifically, serum ΣBDE3 was inversely associated with socioeconomic status, whereas serum BDE-153 was positively associated with duration of breast-feeding and mother's education.
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The results of a study on the analytical identification and quantification of migration of chemicals from plastics baby bottles found in the European Union market made of materials that are now present as substitutes for polycarbonate (PC) are reported. A total of 449 baby bottles with a focus on first age or sets of bottles were purchased from 26 European Union countries, Canada, Switzerland and the USA. From this collection, which contained several duplicates, a total of 277 baby bottles were analysed. The materials included different types of plastic such as PC, polyamide (PA), polyethersulphone (PES), polypropylene (PP), but also silicone, and from the United States a co-polyester marketed under the trade name Tritan™. The bottles were subjected to the conventional migration test for hot fill conditions, i.e. 2 h at 70°C. The simulant used was that specified in European Union legislation (2007/19/EC) for milk, i.e. 50% ethanol. In a first phase 1, migration was conducted since the scope of this investigation was a screening rather than a true compliance testing check. Second and third migrations were performed on selected articles when migrated substances exceeded limits specified in the legislation. In order to verify some materials, a portion of the bottle was cut to run an FT-IR fingerprint to confirm the nature of the polymer. The migration solutions in general showed a low release of substances. Results showed that bottles made of PP and silicones showed a greater number of substances in the migration solutions and in greater quantity. Chemicals from PP included alkanes, which could be found in >65% of the bottles at levels up to 3500 µg kg⁻¹; and benzene derivatives in 17% of the baby bottles and found at levels up to 113 µg kg⁻¹. Some substances were found on a regular basis such as plasticisers, esters and antioxidants (e.g. tris(2,4-di-tert-butylphenyl)phosphate, known as Irgafos 168. Some substances found were not included in the Community positive list, which means that those should not be found even in the first migration. Such substances included 2,6-di-isopropylnaphthalene (DIPN), found in 4% of the bottles at levels up to 25 µg kg⁻¹, 2,4-di-tert-butyl phenol (in 90% of the bottles at levels up 400 µg kg⁻¹). Moreover, bisphenol A (BPA) was detected and quantified in baby bottles made of PA, but limited to one brand and model specific (but labelled BPA free). Results for baby bottles made of silicone also indicated the presence of components, e.g. potentially coming from inks (benzophenone, diisopropyl naphtahalene - DIPN, which could come for example from the presence of instruction leaflets in the bottles). In the case of silicone, phthalates were also found in relevant concentrations, with levels for DiBP and DBP from the first migration test of 50-150 µg kg⁻¹ and DEHP at levels 25-50 µg kg⁻¹.
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Polybrominated diphenyl ethers (PBDEs) are a class of persistent compounds that have been used as flame retardants in vehicles, household furnishings, and consumer electronics. This study examined whether concentrations of PBDEs in maternal serum during pregnancy were associated with infant birth weight, length, head circumference, and length of gestation. Participants were pregnant women (n = 286) enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) Study, a longitudinal cohort study of low-income, predominantly Mexican families living in the Salinas Valley, California. Blood samples were collected near the 26th week of pregnancy in 1999-2000, and concentrations of 10 PBDE congeners (BDE-17, -28, -47, -66, -85, -99, -100, -153, -154, and -183) were measured. Multiple linear regression models were used to investigate the association of lipid-adjusted, log(10)-transformed PBDE concentrations and birth outcome. In adjusted analyses, negative associations with birth weight were seen with BDE-47 (β = -115 g, 95% confidence interval (CI): -229, -2), BDE-99 (β = -114 g, 95% CI: -225, -4), and BDE-100 (β = -122 g, 95% CI: -235, -9). These findings were diminished slightly and were no longer statistically significant when maternal weight gain was included in the models. PBDE congeners were not associated with birth length, head circumference, or gestational duration.
Article
Using high-resolution mass spectrometry, we identified tri(2,4-di-t-butylphenyl) phosphate (TDTBPP) in e-waste dust. This is a previously unsuspected pollutant that had not been reported before in the environment. To assess its abundance in the environment, we measured its concentration in e-waste dust, house dust, sediment from the Chicago Ship and Sanitary Canal, Indiana Harbor water filters, and filters from high-volume air samplers deployed in Chicago, IL. To provide a context for interpreting these quantitative results, we also measured the concentrations of triphenyl phosphate (TPhP), a structurally similar compound, in these samples. Median concentrations of TDTBPP and TPhP were 14 400 and 41 500 ng/g, respectively, in e-waste dust and 4900 and 2100 ng/g, respectively, in house dust. TDTBPP was detected in sediment, water, and air with median concentrations of 527 ng/g, 3700 pg/L, and 149 pg/m³, respectively. TDTBPP concentrations were generally higher or comparable to those of TPhP in all media analyzed, except for the e-waste dust. Exposure from dust ingestion and dermal absorption in the e-waste recycling facility and in homes was calculated. TDTBPP exposure was 571 ng/kg bw/day in the e-waste recycling facility (pro-rated for an 8-h shift), and 536 ng/kg bw and 7550 ng/kg bw/day for adults and toddlers, respectively, in residential environments.
Article
An analytical method was developed for screening and identifying novel flame retardants in curtains purchased in Japan in 2014 by use of a liquid chromatograph interfaced with a hybrid quadrupole Orbitrap mass spectrometer (LC–Orbitrap-MS; Q Exactive Plus). To enable complete extraction of flame retardants in curtains, we used an extraction method developed earlier, in which a solvent mixture of 1,1,1,3,3,3-hexafluoro-2-propanol/chloroform (1:4, v/v) was used to completely dissolve the curtain matrix. An initial gas chromatography–MS scan analysis confirmed the presence of several unidentified flame retardants in curtains. We then determined the precise masses of the detected compounds by use of a LC–Orbitrap-MS and used that information to construct chemical formula of the detected compounds. The MAGMa online spectral data annotation was then used to generate a list of candidate compounds. For the determination and confirmation of the chemical structures of the candidate compounds, we reviewed the literature and acquired standards and compared mass fragment patterns of the most probable candidate compounds with those of standards. We unequivocally identified the compounds in curtain samples as (5-ethyl-2-methyl-2-oxido-1,3,2-dioxaphosphorinan-5-yl)methyl-methyl-methylphosphonate (PMMMP), naphthalen-2-yl diphenyl phosphate (NDPhP), and 6-benzyl benzo[c][2,1]benzoxaphosphinine 6-oxide (BzlDOPO). This study elucidates the occurrence of three novel phosphorus-based flame retardants in curtains, and the technique we proposed here can be applied for the detection of environmental chemicals in other products.
Article
Despite extensive application in consumer products and concerns over their adverse health effects, how external exposure to brominated flame retardants (BFRs) contributes to their human body burdens is not yet fully understood. While recent studies focused on inadvertent indoor dust ingestion and diet as potential major pathways of exposure, dermal uptake has been largely overlooked. We provide the first experimentally-based assessment of dermal uptake of BFRs via contact with indoor dust and flame-retarded furniture fabrics. Results reveal substantial uptake from furniture fabrics (e.g. 8.1 ng pentaBDE/kg bw/day for adults in summer), exceeding the overall adult intake of pentaBDE estimated previously via other exposure pathways. For HBCDs, despite the low absorption fraction (<2.5%) from the studied fabrics, the estimated dermal uptake of UK adults and toddlers (101 and 76.9 ng/kg bw/day) exceed the reported average daily intakes of 7.9 and 43.0 ng/kg bw/day for these UK age groups. Conversely, uptake from dust was low (0.05 and 0.19 ng pentaBDE/kg bw/day for adults and toddlers, respectively), indicating previous pharmacokinetic approaches may have overestimated the significance of this route. Future exposure and risk assessment studies should consider dermal contact with treated products as a significant pathway of human exposure to BFRs and related chemicals.
Article
Background: Following the phase-out of polybrominated diphenyl ethers (PBDEs), organophosphate esters (OPEs) have been increasingly used in consumer products and building materials for their flame retardant and plasticizing properties. As a result, human exposure to these chemicals is widespread as evidenced by common detection of their metabolites in urine. However, little is known about the major exposure pathways, or factors that influence children's exposure to OPEs. Furthermore, little data is available on exposure to the novel aryl OPEs. Objectives: To examine predictors of children's internal exposure, we assessed relationships between OPEs in house dust and on hand wipes and levels of their corresponding metabolites in paired urine samples (n = 181). We also examined associations between urinary metabolites and potential covariates, including child's age and sex, mother's educational attainment and race, and average outdoor air temperature. Methods: Children aged 3 to 6 years provided urine and hand wipe samples. Mothers or legal guardians completed questionnaires, and a house dust sample was taken from the main living area during home visits. Alkyl chlorinated and aryl OPEs were measured in dust and hand wipes, and composite urine samples were analyzed for several metabolites. Results: Tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCIPP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), 2-ethylhexyl diphenyl phosphate (EHDPHP), triphenyl phosphate (TPHP), and 2-isopropylphenyl diphenyl phosphate (2IPPDPP) were detected frequently in hand wipes and dust (>80%), indicating that these compounds were near-ubiquitous in indoor environments. Additionally, bis(1-chloro-2-propyl) 1-hydroxy-2-propyl phosphate (BCIPHIPP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), diphenyl phosphate (DPHP), mono-isopropyl phenyl phenyl phosphate (ip-PPP), and mono-tert-butyl phenyl phenyl phosphate (tb-PPP) were detected in >94% of tested urine samples, signifying that TESIE participants were widely exposed to OPEs. Contrary to PBDEs, house dust OPE concentrations were generally not correlated with urinary OPE metabolite levels; however, hand wipe levels of OPEs were associated with internal dose. For example, children with the highest mass of TDCIPP on hand wipes had BDCIPP levels that were 2.73 times those of participants with the lowest levels (95% CI: 1.67, 4.48, p < 0.0001). Of the variables examined, hand wipe level was the most consistent and strongest predictor of OPE urinary metabolite concentrations. Outdoor air temperature was also a significant predictor of urinary BDCIPP concentrations, with a 1 °C increase in temperature corresponding to a 4% increase in urinary BDCIPP (p < 0.0001). Conclusions: OPE exposures are highly prevalent, and data provided herein further substantiate hand-to-mouth contact and dermal absorption as important pathways of OPE exposure, especially for young children.
Article
We assessed exposure to 39 brominated and 16 organophosphate ester flame retardants (FRs) from both dust and indoor air at seven childcare centres in Seattle, USA, and investigated the importance of nap mats as a source of these chemicals. Many childcare centres serving young children use polyurethane foam mats for the children's naptime. Until recently, the vast majority of these mats sold in the United States contained flame-retarded polyurethane foam to meet California Technical Bulletin 117 (TB117) requirements. With the 2013 update of TB117, allowing manufacturers to meet flammability standards without adding FRs to filling materials, FR-free nap mats have become widely available. We conducted an intervention study by actively switching out FR-treated nap mats with FR-free nap mats and measuring FR levels in indoor air and dust before and after the switch-out. The predominant FRs found in dust and indoor air were 2-ethylhexyl tetrabromobenzoate (EHTBB) and tris(1-chloro-2-propyl) phosphate (TCIPP), respectively. Nap mat samples analysed from four of the six centres contained a Firemaster® mixture, while one mat was predominantly treated with tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and the other contained no detectable target FRs. After replacement, there was a significant decrease (p = 0.03-0.09) in median dust concentrations for bis(2-ethylhexyl) tetrabromophthalate (BEHTBP), EHTBB, tris(4-butylphenyl) phosphate (TBPP), and TDCIPP with reductions of 90%, 79%, 65%, and 42%, respectively. These findings suggest that the nap mats were an important source of these FRs to dust in the investigated childcare environments and that a campaign of swapping out flame-retarded mats for FR-free ones would reduce exposure to these chemicals. While calculated exposure estimates to the investigated FRs via inhalation, dust ingestion, and dermal absorption were below established reference dose values, they are likely underestimated when considering the toddlers' direct contact to the mats and personal cloud effects.
Article
Polyurethane foam (PUF) in upholstered furniture frequently is treated with flame retardant chemicals (FRs) to reduce its flammability and adhere to rigorous flammability standards. For decades, a commercial mixture of polybrominated diphenyl ethers (PBDEs) called PentaBDE was commonly applied to foam to fulfill these regulations; however, concerns over toxicity, bioaccumulation, and persistence led to a global phase-out in the mid-2000s. Although PentaBDE is still detected in older furniture, other FR compounds such as tris(1,3-dichloroisopropyl) phosphate (TDCIPP) and Firemaster® 550 (FM550) have been increasingly used as replacements. While biomonitoring studies suggest exposure is widespread, the primary sources of exposure are not clearly known. Here, we investigated the relationships between specific FR applications in furniture foam and human exposure. Paired samples of furniture foam, house dust and serum samples were collected from a cohort in North Carolina, USA and analyzed for FRs typically used in PUF. In general, the presence of a specific FR in the sofa of a home was associated with an increase in the concentration of that FR in house dust. For example, the presence of PentaBDE in sofas was associated with significantly higher levels of BDE-47, a major component of PentaBDE, in house dust (10β=6.4, p
Article
Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) has been widely used as a flame retardant and is commonly detected in environmental samples. Biomonitoring studies relying on urinary metabolite levels [i.e., bis(1,3-dichloro-2-propyl) phosphate (BDCIPP)] demonstrate widespread exposure, but TDCIPP intake is unknown. Intake data are critical components of meaningful risk assessments and are needed to elucidate the potential health impacts of TDCIPP exposure. Using biomonitoring data, we estimated TDCIPP intake for infants aged 2−18 months. Children were recruited from central North Carolina (n = 43, recruited in 2014 and 2015), and spot urine samples were analyzed for BDCIPP. TDCIPP intake rates were estimated using daily urine excretion and the fraction of TDCIPP excreted as BDCIPP in urine. Daily TDCIPP intake estimates ranged from 0.01 to 15.03 μg kg–1 day–1 for children included in our assessment, with some variation depending on model assumptions. The U.S. Consumer Products Safety Commission previously established an acceptable daily intake of 5 μg kg–1 day–1 for non-cancer health risks. Depending on modeling assumptions, we found that 2–9% percent of infants had TDCIPP intake estimates above this threshold. Our results indicate that current TDCIPP exposure levels could pose health risks for highly exposed infants.
Article
This is the first study on organophosphate esters (OPEs) flame retardants and plasticizers in the sediment of the Great Lakes. Concentrations of 14 OPEs were measured in three sediment cores and 88 Ponar surface grabs collected from Lakes Ontario, Michigan, and Superior of North America. The sum of these OPEs (Σ14OPEs) in Ponar grabs averaged 2.2 ng g-1 dw, 4.7 ng g-1 dw, and 16.6 ng g-1 dw in Lakes Superior, Michigan, and Ontario, respectively. Multiple linear regression analyses demonstrated statistically significant associations between logarithm concentrations of Σ14OPEs as well as selected congeners in surface grab samples and sediment organic carbon content as well as a newly developed urban distance factor. Temporal trends observed in dated sediment cores from Lake Michigan demonstrated that the recent increase in depositional flux to sediment is dominated by chlorinated OPEs, particularly tris(2-chloroisopropyl) phosphate (TCPP), which has a doubling time of about 20 years. Downward diffusion within sediment may have caused vertical fractionation of OPEs over time. Two relatively hydrophilic OPEs including TCPP had much higher concentrations in sediment than estimated based on equilibria between water and sediment organic carbon. Approximately a quarter (17 tonnes) of the estimated total OPE burden (63 tonnes) in Lake Michigan resides in sediment, which may act as a secondary source releasing OPEs to the water column for years to come.
Article
Flame retardant (FR) chemicals have often been added to polyurethane foam to meet required state and federal flammability standards. However, some FRs (e.g. PBDEs and TDCIPP) are associated with health hazards and are now restricted from use in some regions. In addition, California's residential furniture flammability standard (TB-117) has undergone significant amendments over the last few years, and TDCIPP has been added to California's Proposition 65 list. These events have likely led to shifts in the types of FRs used, and the products to which they are applied. To provide more information on the use of FRs in products containing polyurethane foam (PUF), we established a screening service for the general public. Participants residing in the US were allowed to submit up to 5 samples from their household for analysis, free of charge, and supplied information on the product category, labeling, and year and state of purchase. Between February 2014 and June 2016, we received 1,141 PUF samples for analysis from various products including sofas, chairs, mattresses, car seats and pillows. Of these samples tested, 52% contained a FR at levels greater than 1% by weight. Tris (1,3-dichloroisopropyl) phosphate (TDCIPP) was the most common FR detected in PUF samples, and was the most common FR detected in all product categories. Analysis of the data by purchasing date suggests that the use of TDCIPP decreased in recent years, paralleled with an increase in the use of TCIPP and a non-halogenated aryl phosphate mixture we call "TBPP." In addition, we observed significant decreases in FR applications in furniture products and child car seats, suggesting the use of additive FRs in PUF may be declining, perhaps as a reflection of recent changes to TB-117 and Proposition 65. More studies are needed to determine how these changes in FR use in products relate to changes in exposure among the general population.
Article
Mixtures of polybrominated diphenyl ethers (PBDEs) are present in indoor environments. Studies of the developmental effects of exposure to these chemicals in large prospective mother-child cohorts are required, with data on prenatal exposure and long-term follow-up of the children. We aimed to investigate the relationship between prenatal and childhood exposure to PBDEs and neurodevelopment at the age of six years. We determined the levels of PBDEs and other neurotoxicants in cord blood and dust collected from the homes of children for 246 families included in the PELAGIE mother-child cohort in France. We assessed two cognitive domains of the six-year-old children using the Wechsler Intelligence Scale for Children-IV. Verbal comprehension scores were lower in children from homes with higher concentrations of BDE99 (βDetects<median_vs_NonDetects=-1.6; 95% CI: -6.1, 2.9; βDetects≥median_vs_NonDetects=-5.4; -9.9, -1.0; ptrend=0.02) and of BDE209 (β2nd_vs_1st_tertile=-1.8; 95% CI: -6.1, 2.5; β3rd_vs_1st_tertile=-3.2; -7.5, 1.2; ptrend=0.15) in dust, particularly for boys (ptrend=0.02 and 0.04, respectively). Working memory scores seemed to be lower in children with higher BDE99 concentrations in dust (ptrend=0.10). No association was observed with cord blood levels of BDE209. Our findings are in agreement with those of four previous studies suggesting adverse cognitive outcomes among children associated with early-life exposure to penta-BDE mixtures, and provide new evidence for the potential neurotoxicity of BDE209. Several countries are in the process of banning the use of PBDE mixtures as flame-retardants. However, these compounds are likely to remain present in the environment for a long time to come.
Article
Organophosphate esters (OPEs) have been widely used in various products as alternatives to brominated flame retardants. Although widespread OPE exposure is expected in humans, the accumulation of OPEs has seldom been studied in the human body. In this study, 12 OPE analogs were analyzed in 50 human placentas collected in Eastern China. The concentrations of the 9 most frequently detected OPEs (Σ9OPEs) ranged from 34.4 to 862ng/g lipid weight (lw), with a median of 301ng/g lw. Tri(2-chloroethyl) phosphate (TCEP) was identified as the most abundant analog, with a median concentration of 142ng/g lw, followed by tributoxyethyl phosphate (TBEP) and triphenyl phosphate (TPhP). Statistical analysis showed no analog of OPEs or Σ9OPEs was positively correlated with the lipid content of the placentas. There were no correlations observed between the OPE concentrations and maternal characteristics. Food consumption habits exhibited weak effects on OPE levels in the placentas. Further investigation is required to determine the effects of OPEs on fetuses due to the expected increase in maternal exposure to these esters.
Article
Despite extensive literature on their potential adverse health effects, there is a lack of information on human dermal exposure to organic flame retardant chemicals (FRs). This study applies an in vitro physiologically based extraction test to provide new insights into the dermal bioaccessibility of various FRs from indoor dust to synthetic sweat/sebum mixture (SSSM). The bioaccessible fractions of α-, β- and γ-hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) to 1:1 (sweat/sebum) mixture were 41%, 47%, 50% and 40%, respectively. For Tris-2-chloroethyl phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCIPP) and tris-1,3-dichloropropyl phosphate (TDCIPP), bioaccessible fractions were 10%, 17% and 19%. Composition of the SSSM and compound-specific physicochemical properties were the major factors influencing the bioaccessibility of target FRs. Except for TBBPA, the presence of cosmetics (moisturising cream, sunscreen lotion, body spray and shower gel) had a significant effect (P<0.05) on the bioaccessibility of the studied FRs. The presence of cosmetics decreased the bioaccessibility of HBCDs from indoor dust, whereas shower gel and sunscreen lotion enhanced the bioaccessibility of target PFRs. Our bioaccessibility data were applied to estimate the internal exposure of UK adults and toddlers to the target FRs via dermal contact with dust. Our worst-case scenario exposure estimates fell far below available health-based limit values for TCEP, TCIPP and TDCIPP. However, future research may erode the margin of safety for these chemicals.Journal of Exposure Science and Environmental Epidemiology advance online publication, 6 January 2016; doi:10.1038/jes.2015.84.
Article
Infant products containing polyurethane foam are commonly treated with organophosphate flame retardants (PFRs), including tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and triphenyl phosphate (TPHP). Infants may have greater exposure due to greater contact with these products, yet little is known about levels of exposure or the factors contributing to higher exposure. We recruited children age 2-18 months from North Carolina to investigate PFR exposure (n=43; recruited 2014-2015). Parents provided information on potential sources and modifiers of exposure, and reported whether they owned common infant products. We measured 5 PFR metabolites in urine samples collected from children. TDCIPP and TPHP metabolites [bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP)] were most commonly detected (>93% detect). Other metabolites were detected infrequently (<35% detect). Although we did not observe a clear age trend for infants, BDCIPP levels were substantially higher than those reported for adults (geometric mean=7.3 ng/mL). The number of infant products owned was strongly associated with BDCIPP; children with ≥17 products had BDCIPP levels that were 6.8 times those with <13 (p=0.02). Infants attending daycare centers also had higher BDCIPP levels (3.7 times those of others; p=0.07), suggesting time spent in this microenvironment contributes to higher exposure. In contrast, DPHP levels were not related to products owned, time in different microenvironments, or behavior.
Article
In the Laurentian Great Lakes basin of North America, an increasing number of chemicals of emerging concern (CECs) are being investigated, including legacy and replacement flame retardants (FRs). In the present study, 14 polybrominated diphenyl ethers (PBDEs), 23 non-PBDEs halogenated FRs (NPHFRs) and 16 organophosphate ester FRs (OPE-FRs) were analyzed in 100 individual eggs collected in 2012 and 2013 and in 15 egg pools of herring gulls collected in 2012 from 20 colonies across the entire Laurentian Great Lakes basin. For CEC-FRs in eggs from all colonies, 14 PBDEs, 12 NPHFRs and 9 OPE-FRs were quantifiable in at least one of the 115 analyzed samples. The mean sum PBDE (Σ14PBDE) concentrations ranged from 244 to 657ng/g wet weight (ww), and on average were 1-2 orders of magnitude greater than the Σ12NPHFR concentrations (13.8-35.6ng/gww), and 2-3 orders of magnitude greater than Σ9OPE-FR concentrations (0.31-2.14ng/gww). Mean Σ14PBDE and sum of syn- and anti-Dechlorane Plus isomer (Σ2DDC-CO) concentrations in eggs from colonies within Laurentian Great Lakes Areas of Concern (AOCs) were in most cases greater than in eggs from nearby colonies outside of AOCs. Comparing CEC-FR concentrations in eggs collected in 2012-2013 to those previously measured in eggs collected approximately 7 years earlier (2006 and 2008) showed that Σ7PBDE (BDE-28, -47, -100, -99, -154,-153 and -183) mean concentrations in eggs from 6 colonies were approximately 30% less than they were in eggs from the same colonies from the earlier time period, whereas 3 current-use FR (BDE-209, HBCDD and Σ2DDC-CO) concentrations were significantly greater (p<0.05) than previously measured. Between 2006 and 2013 there were significant changes in individual PBDE patterns for BDE-71, -138, -153, -203, -206 and -207. Among all of the examined CEC-FRs, concentrations of Σ4PBDE (BDE-47, -99, -100 and -153) and HBCDD in gull eggs from all colonies were greater than or comparable to their lowest observed effect concentrations (LOECs) based on in ovo egg injection studies. Overall, the current profiles of a broad suite of FRs in Laurentian Great Lakes herring gull eggs highlights the need to better understand e.g., exposure-effect implications and metabolism of FRs, i.e. OPE-FRs, and emphasizes the importance of continued monitoring of CEC-FRs whose concentrations appear to be increasing, including BDE-209, HBCDD and DDC-COs.
Article
We report for the first time either in vitro or in vivo the phase I hydroxylation and phase II conjugation metabolic pathways of an organophosphate flame retardant, triphenyl phosphate (TPHP), in addition to diphenyl phosphate (DPHP) metabolite formation. Using a chicken embryonic hepatocyte (CEH) assay, TPHP was phase I metabolized to p- and m-hydroxy-TPHP metabolites, which were largely present in the assay medium and cells as phase II conjugates with glucuronic acid. After treatment with β-glucuronidase, deconjugated p-OH-TPHP was present in both the medium and cells at increasing concentrations of 0.073 ± 0.003, 1.95 ± 0.03, and 2.10 ± 0.09 nmol/well at CEH incubation time points of 0, 12, and 36 h, respectively. Similarly, after β-glucuronidase treatment, there were increasing m-OH-TPHP concentrations of 0.0050 ± 0.0005, 0.18 ± 0.01, and 0.18 ± 0.01 nmol/well. p-OH-TPHP at 36 h accounted for 60% of the initial TPHP treatment concentration, which was 3.5- or 12-fold greater than that of the DPHP or m-OH-TPHP metabolites, respectively. Overall, in TPHP-exposed organisms, this study demonstrates the importance of phase I and II metabolic processes in the biological fate of TPHP.
Article
Resorcinol bis-(diphenylphosphate) (RDP) is widely used as flame retardant in electrical/electronic products and constitutes a suitable alternative to decabrominated diphenyl ether. Due to its toxicity and its recently reported ubiquity in electronics and house dust, there are increasing concerns about human exposure to this emerging contaminant. With the aim of identifying human-specific biomarkers, the in vitro metabolism of RDP and its oligomers was investigated using human liver microsomes and human liver cytosol. Mono- and di-hydroxy-metabolites, together with glucuronidated and sulfated metabolites were detected. Regarding RDP oligomers, only a hydroxy-metabolite of the dimer could be detected. RDP and its oligomers were also readily hydrolyzed at physiological pH, giving rise to a variety of compounds, such as diphenyl phosphate, para-hydroxy-triphenyl phosphate and para-hydroxy RDP, which were further metabolized. These degradation products are possibly of environmental importance in future studies.
Article
The time-dependent stock of PBDEs contained in in-use products (excluding building materials and large vehicles) was estimated for the U.S. and Canada from 1970 to 2020 based on product consumption patterns, PBDE contents and product lifespan. The stocks of penta- and octaBDE peaked in in-use products at 17,000 (95% confidence interval: 6,000-70,000) and 4,000 (1,000-50,000) tonnes in 2004, respectively, and for decaBDE at 140,000 (40,000-300,000) tonnes in 2008. Products dominating PBDE usage were polyurethane foam used in furniture (65% of pentaBDE), casings of electrical and electronic equipment or EEE (80% of octaBDE), and EEE and automotive seating (35% of decaBDE for each category). The largest flow of PBDEs in products, excluding automotive sector, to the waste phase occurred between 2005 and 2008 at ~10,000 tonnes per year. Total consumption of penta-, octa- and decaBDE from 1970 to 2020 in products considered was estimated at ~46,000, ~25,000 and ~380,000 tonnes, respectively. Per capita usage was estimated at 10-250, 10-150 and 200-2000 g•capita-1•y-1 for penta-, octa- and decaBDE, respectively, over the time span. Considering only the first use (no reuse and/or storage) of PBDE-containing products, approximately 60% of the stock of PBDEs in 2014 or ~70,000 tonnes, of which 95% is decaBDE, will remain in the use phase in 2020. Total emissions to air of all PBDEs from the in-use product stock was estimated at 70-700 tonnes between 1970 and 2020, with annual emissions of 0.4-4 tonnes•y-1 for each of penta- and octaBDE, and 0.35-3.5 tonnes•y-1 for decaBDE in 2014.
Article
Information regarding decabromodiphenyl ethane (DBDPE) effects on hepatotoxicity and metabolism is limited. In the present study, Wistar rats were given oral DBDPE at different doses. DBDPE induced oxidative stress, elevated blood glucose levels, increased CYP2B2 mRNA, CYP2B1/2 protein, 7-pentoxyresorufin O-depentylase (PROD) activity, and induced CYP3A2 mRNA, CYP3A2 protein, and luciferin benzylether debenzylase (LBD) activity. UDPGT activity increased with its increasing exposure levels, suggesting that oral DBDPE exposure induces drug-metabolizing enzymes in rats via the CAR/PXR signaling pathway. The induction of CYPs and co-regulated enzymes of phase II biotransformation may affect the homeostasis of endogenous substrates, including thyroid hormones, which may, in turn, alter glucose metabolism.
Article
Resorcinol bis (diphenylphosphate) (RBDPP) and bis phenol A bis (diphenylphosphate) (BPA-BDPP) are two halogen free organophosphorus flame retardant (PFRs) that are used as alternative for the decabromodiphenyl ether (DecaBDE) technical mixture in TV/flatscreen housing and other electronic consumer products. In this study, dust samples were collected from various microenvironments in the Netherlands (houses, cars), Greece (houses) and Sweden (apartments, cars, furniture stores, electronics stores) and analyzed for RBDPP and BPA-BDPP. Additionally, the dust samples from the Netherlands were analysed for decabromodiphenyl ether (BDE209) for comparison and for TPHP which is a by-product in the RBDPP and BPA-BDPP technical product. BPA-BDPP was detected in almost all dust samples from the Netherlands, Greece and Sweden. Highest concentrations were found in dust samples collected on electronic equipment from all three countries with BPA-BDPP levels ranging from <0.1-1300 µg/g and RBDPP levels from <0.04-520 µg/g. RBDPP and BPA-BDPP levels in dust collected further away from the electronics (source) were usually lower. BDE209 levels in the Netherlands dust samples collected on and around the electronics were similar and much lower than the BPA-BDPP/RBDPP levels, indicating that the electronics were not the source of BDE209. Strong positive correlations were found between TPHP concentrations and those of RBDPP (r=0.805) and BPA-BDPP (r=0.924), probably due to TPHP being a by-product in commercial RBDPP and BPA-BDPP mixtures in electronics. To our knowledge this is the first time that RBDPP and BPA-BDPP were detected in dust samples from Europe.
Article
With the phase-out of polybrominated diphenyl ether (PBDE) flame retardants, the use of new and alternate flame retardants has been increasing. 2,2-bis(chloromethyl)propane-1,3-diyltetrakis(2-chloroethyl) bisphosphate, known as V6, is a flame retardant applied to polyurethane foam commonly found in furniture and automobile foam. However, to the authors' knowledge, no research has been conducted on V6 levels in the environment. The intention of this study was to measure the concentration of V6 in foam collected from baby products where it was recently detected and measure levels in dust samples collected from homes and automobiles in the Boston, MA area. To accomplish this, a pure V6 commercial standard was purchased from a Chinese manufacturer and purified (>98%). An analytical method to measure V6 in dust samples using liquid chromatography tandem mass spectrometry (LC/MS-MS) was developed. Extraction was conducted using accelerated solvent extraction (ASE) and extracts were purified using an ENVI-Florisil SPE column (500 mg, 3 mL). V6 was measured in foam samples collected from baby products with a concentration ranging from 24 500 000 to 59 500 000 ng/g of foam (n = 12, average ± sd: 46 500 000 ± 12 000 000 ng/g; i.e., on average, 4.6% of the foam mass was V6). V6 was also detected in 19 of 20 car dust samples and 14 of 20 house dust samples analyzed. The concentration of V6 in the house dust ranged from <5 ng/g to 1110 ng/g with a median of 12.5 ng/g, and <5 ng/g to 6160 ng/g in the car dust with a median of 103.0 ng/g. Concentrations in car dust were significantly higher than in the house dust potentially indicating higher use of V6 in automobiles compared to products found in the home. Furthermore, tris (2-chloroethyl) phosphate (TCEP), a known carcinogen, was found in the V6 commercial mixture (14% by weight) as an impurity and was consistently detected with V6 in the foam samples analyzed. A significant correlation was also observed between V6 and TCEP in the dust samples suggesting that the use of V6 is a significant source of TCEP in the indoor environment.
Article
Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and polybrominated biphenyls (PBBs) were found in children’s toys purchased from South China. The median BFR concentrations in the hard plastic toys were 53 000, 5540 ng/g, 101.1 ng/g, and 27.9 ng/g, for total PBDEs, DBDPE, BTBPE, and PBBs, respectively, which were notably higher than values in other toys. The PBDE concentrations were below the threshold limit (1000 ppm) required by the European Commission’s Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives in all of the toys, except for one hard plastic toy with a total PBDE concentration of 5 344 000 ng/g. The BFR profiles in the toys were consistent with the patterns of their current production and consumption in China, where PBDEs, specifically decaBDE product, were the dominant BFR, followed by the emerging DBDPE. The relatively high concentrations of octa- and nonaBDEs in the foam toys and the results of principal component analysis (PCA) may suggest the decomposition of highly brominated BDEs during the manufacturing processes of the toys. Daily total PBDE exposures associated with toys via inhalation, mouthing, dermal contact, and oral ingestion ranged from 82.6 to 8992 pg/kg bw-day for children of 3 months to 14 years of age. Higher exposures, predominantly contributed through the mouthing pathway, were observed for infants and toddlers than for the other subgroups. In most cases, children’s BFR exposure via the toys likely accounts for a small proportion of their daily BFR exposure, and the hazard quotients for noncancer risk evaluation were far below 1. To the author’s knowledge, this is the first study to examine the concentrations of BFRs in toys, and the potential exposures to children.
Article
Since the ban on some brominated flame retardants (BFRs), phosphorus flame retardants (PFRs), which were responsible for 20% of the flame retardant (FR) consumption in 2006 in Europe, are often proposed as alternatives for BFRs. PFRs can be divided in three main groups, inorganic, organic and halogen containing PFRs. Most of the PFRs have a mechanism of action in the solid phase of burning materials (char formation), but some may also be active in the gas phase. Some PFRs are reactive FRs, which means they are chemically bound to a polymer, whereas others are additive and mixed into the polymer. The focus of this report is limited to the PFRs mentioned in the literature as potential substitutes for BFRs. The physico-chemical properties, applications and production volumes of PFRs are given. Non-halogenated PFRs are often used as plasticisers as well. Limited information is available on the occurrence of PFRs in the environment. For triphenyl phosphate (TPhP), tricresylphosphate (TCP), tris(2-chloroethyl)phosphate (TCEP), tris(chloropropyl)phosphate (TCPP), tris(1,3-dichloro-2-propyl)phosphate (TDCPP), and tetrekis(2-chlorethyl)dichloroisopentyldiphosphate (V6) a number of studies have been performed on their occurrence in air, water and sediment, but limited data were found on their occurrence in biota. Concentrations found for these PFRs in air were up to 47 μg m−3, in sediment levels up to 24 mg kg−1 were found, and in surface water concentrations up to 379 ng L−1. In all these matrices TCPP was dominant. Concentrations found in dust were up to 67 mg kg−1, with TDCPP being the dominant PFR. PFR concentrations reported were often higher than polybrominated diphenylether (PBDE) concentrations, and the human exposure due to PFR concentrations in indoor air appears to be higher than exposure due to PBDE concentrations in indoor air.
Article
The emissions of selected flame retardants were measured in 1- and 0.02-m3 emission test chambers and 0.001-m3 emission test cells. Four product groups were of interest: insulating materials, assembly foam, upholstery/mattresses, and electronics equipment. The experiments were performed under constant environmental conditions (23°C, 50% RH) using a fixed sample surface area and controlled air flow rates. Tris (2-chloro-isopropyl)phosphate (TCPP) was observed to be one of the most commonly emitted organophosphate flame retardants in polyurethane foam applications. Depending on the sample type, area-specific emission rates (SERa) of TCPP varied between 20 ng m−2 h−1 and 140 μg m−2 h−1.The emissions from electronic devices were measured at 60°C to simulate operating conditions. Under these conditions, unit specific emission rates (SERu) of organophosphates were determined to be 10–85 ng unit−1 h−1. Increasing the temperature increased the emission of several flame retardants by up to a factor of 500. The results presented in this paper indicate that emissions of several brominated and organophosphate flame retardants are measurable. Polybrominated diphenylethers exhibited an SERa of between 0.2 and 6.6 ng m−2 h−1 and an SERu of between 0.6 and 14.2 ng unit−1 h−1. Because of sink effects, i.e., sorption to chamber components, the emission test chambers and cells used in this study have limited utility for substances low vapour pressures, especially the highly brominated compounds; hexabromocyclododecane had an SERa of between 0.1 and 29 ng m−2 h−1 and decabromodiphenylether was not detectable at all.
Article
With the phase-out of PentaBDE in 2004, alternative flame retardants are being used in polyurethane foam to meet flammability standards. However, insufficient information is available on the identity of the flame retardants currently in use. Baby products containing polyurethane foam must meet California state furniture flammability standards, which likely affects the use of flame retardants in baby products throughout the U.S. However, it is unclear which products contain flame retardants and at what concentrations. In this study we surveyed baby products containing polyurethane foam to investigate how often flame retardants were used in these products. Information on when the products were purchased and whether they contained a label indicating that the product meets requirements for a California flammability standard were recorded. When possible, we identified the flame retardants being used and their concentrations in the foam. Foam samples collected from 101 commonly used baby products were analyzed. Eighty samples contained an identifiable flame retardant additive, and all but one of these was either chlorinated or brominated. The most common flame retardant detected was tris(1,3-dichloroisopropyl) phosphate (TDCPP; detection frequency 36%), followed by components typically found in the Firemaster550 commercial mixture (detection frequency 17%). Five samples contained PBDE congeners commonly associated with PentaBDE, suggesting products with PentaBDE are still in-use. Two chlorinated organophosphate flame retardants (OPFRs) not previously documented in the environment were also identified, one of which is commercially sold as V6 (detection frequency 15%) and contains tris(2-chloroethyl) phosphate (TCEP) as an impurity. As an addition to this study, we used a portable X-ray fluorescence (XRF) analyzer to estimate the bromine and chlorine content of the foam and investigate whether XRF is a useful method for predicting the presence of halogenated flame retardant additives in these products. A significant correlation was observed for bromine; however, there was no significant relationship observed for chlorine. To the authors knowledge, this is the first study to report on flame retardants in baby products. In addition, we have identified two chlorinated OPFRs not previously documented in the environment or in consumer products. Based on exposure estimates conducted by the Consumer Product Safety Commission (CPSC), we predict that infants may receive greater exposure to TDCPP from these products compared to the average child or adult from upholstered furniture, all of which are higher than acceptable daily intake levels of TDCPP set by the CPSC. Future studies are therefore warranted to specifically measure infants exposure to these flame retardants from intimate contact with these products and to determine if there are any associated health concerns.
Article
This review summarises current knowledge about production volumes, physico-chemical properties, analysis, environmental occurrence, fate and behaviour and human exposure to the "novel" brominated flame retardants (NBFRs). We define the term NBFRs as relating to BFRs which are new to the market or newly/recently observed in the environment. Restrictions and bans on the use of some polybrominated diphenyl ether (PBDE) formulations, in many jurisdictions, have created a market for the use of NBFRs. To date, most data on NBFRs have arisen as additional information generated by research designed principally to study more "traditional" BFRs, such as PBDEs. This has led to a wide variety of analytical approaches for sample extraction, extract purification and instrumental analysis of NBFRs. An overview of environmental occurrence in abiotic matrices, aquatic biota, terrestrial biota and birds is presented. Evidence concerning the metabolism and absorption of different NBFRs is reviewed. Human exposure to NBFRs via different exposure pathways is discussed, and research gaps related to analysis, environmental sources, fate, and behaviour and human exposure are identified.
Article
Brominated flame retardants (BFRs) released from e-waste related activities may affect the health of local people. Assessing the impact of e-waste exposure during recycling and dismantling activities on local people's thyroid hormone levels is an area of ongoing research. During November and December 2008, the process of e-waste recycling and dismantling was investigated, and 236 occupation-exposed people and 89 non-occupation-exposed people approximate to the e-waste recycling sites were surveyed; their thyroid hormone levels (THs), thyrotropins (TSH) and BFRs levels in serum were assayed. Multiple regression models were constructed to analyze the changes of serum THs and TSH in the people living in the exposure area (exposure group) and the people in the control group. Covariates known to be or likely to be associated with THs, TSH and BFRs levels were analyzed. Lower level of Triiodothyronine (T(3)) in both occupation-exposed and non-occupation-exposed group were observed (p<0.01), when compared with the control group, and the same trend was obtained for free triiodothyronine (fT(3)) and free thyroxine (fT4) (p<0.01). However, no significant difference in thyroxine (T(4)) was found between the two groups. The level of TSH in the e-waste recycling occupational-exposed group ranged from 0.00 to 5.00microIU/ml with a mean of 1.26microIU/ml, whereas the level of TSH in the control group was from 0.03 to 5.54microIU/ml with a mean of 1.57microIU/ml. This study revealed that people having worked on e-waste recycling and dismantling had significantly lower TSH compared with the control group (p<0.01). Moreover, the level of BDE-205 is positively associated with the level of T4, as confirmed by the linear regression model (unstandardized regression coefficient, beta=0.25, rho=0.001) and a weaker positive relation was also found between the levels of BDE-126 and T4. Meanwhile, a weak negative relation was found between the levels of PBB 103 and T3, and between the levels of fT3 and fT4. These results suggest that exposure to BFRs released from primitive e-waste handling may contribute to the changes of THs and TSH levels.
Article
Restrictions on the use of polybrominated diphenyl ethers (PBDEs) have resulted in the increased use of alternate flame retardant chemicals to meet flammability standards. However, it has been difficult to determine which chemical formulations are currently being used in high volumes to meet flammability standards since the use of flame retardant formulations in consumer products is not transparent (i.e., not provided to customers). To investigate chemicals being used as replacements for PentaBDE in polyurethane foam, we analyzed foam samples from 26 different pieces of furniture purchased in the United States primarily between 2003 and 2009. Samples included foam from couches, chairs, mattress pads, pillows, and, in one case, foam from a sound-proofing system of a laboratory-grade dust sieve, and were analyzed using gas chromatography mass spectrometry. Fifteen of the foam samples contained the flame retardanttris(1,3-dichloro-2-propyl) phosphate (TDCPP; 1-5% by weight), four samples contained tris(1-chloro-2-propyl) phosphate (TCPP; 0.5 -22% by weight), one sample contained brominated chemicals found in a new flame retardant mixture called Firemaster 550 (4.2% by weight), and one foam sample collected from a futon likely purchased prior to 2004 contained PentaBDE (0.5% by weight). Due to the high frequency of detection of the chlorinated phosphate compounds in furniture foam,we analyzed extracts from 50 house dust samples collected between 2002 and 2007 in the Boston, MA area for TDCPP, TCPP, and another high volume use organophosphate-based flame retardant used in foam, triphenylphosphate (TPP). Detection frequencies for TDCPP and TPP in the dust samples were > 96% and were log normally distributed, similar to observations for PBDEs. TCPP was positively detected in dust in only 24% of the samples, but detection was significantly limited by a coelution problem. The geometric mean concentrations for TCPP, TDCPP, and TPP in house dust were 570, 1890, and 7360 ng/g, respectively, and maximum values detected in dust were 5490, 56,080 and 1,798,000 ng/g, respectively. These data suggest that levels of these organophosphate flame retardants are comparable, or in some cases greater than, levels of PBDEs in house dust. The high prevalence of these chemicals in foam and the high concentrations measured in dust (as high as 1.8 mg/g) warrant further studies to evaluate potential health effects from dust exposure, particularly for children.
Article
Toxicity of a relative new flame retardant, namely decabromodiphenyl ethane (DBDPE), marketed as an alternative to decabromodiphenyl ether (BDE-209) was assessed both in vivo and in vitro using the freshly separated fish hepatocyte assay and standardized water flea and zebrafish egg-larvae tests. The fish hepatocyte assay, based on the synthesis and secretion of vitellogenin from isolated male liver cells produced a clear dose-response curve in the presence of DBDPE. DBDPE induced the induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity at low test concentrations, but started to inhibit the activity at higher concentrations. Also, the induction of the hepatocyte conjugation activity, uridinediphosphoglucuronosyltransferase (UDPGT), was induced with no signs of inhibition even at the highest test concentration. The reduced EROD activity resulted in a drop in the production of vitellogenin by the cells. In vivo tests showed that DBDPE was acutely toxic to water fleas, the 48 h EC-50 value being 19 microg/L. Moreover, DBDPE reduced the hatching rates of exposed zebra-fish eggs and raised significantly the mortality of hatched larvae. Because there is hardly any information available on the effects of DBDPE on the aquatic environments, it is crucial to obtain more data on the effects and effective concentrations of DBDPE along with its occurrence in the environment. Such data would enable reliable assessments of the risks posed by this flame retardant.
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