Atmospheric deposition and co-occurrence patterns of organophosphate flame retardants (OPFRs) and perfluorooctanoic acid (PFOA) in urban snow.

In Japan, organophosphate and polybrominated flame retardants are used in building materials and electric appliances to protect them from fire hazards. In this study, to identify the emission sources of these flame retardants to indoor air, the migration rates (flux) of organophosphate and polybrominated flame retardants from building materials and electrical appliances to solid extraction disks that were placed in contact with the interior surfaces were measured. In addition to the migration test, indoor air and outdoor air concentrations of these flame retardants were investigated. With regard to building materials in a newly built house, triethylphosphate (TEP) and tributylphosphate (TBP) were detected in the wall and ceiling coverings, and tris(2-butoxyethyl)phosphate (TBEP) was detected in the wooden flooring cleaned with a floor polish agent. With regard to electrical appliances, triphenylphosphate (TPHP) was predominantly detected in computer monitors and tris(2-chloroethyl) phosphate (TCEP) in television (TV) sets, with the highest median levels. Among the polybrominated compounds, only 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was detected from a few old TV sets manufactured before 1995. In an indoor and outdoor air survey, nine organophosphates and nine polybrominated flame retardants were detected from indoor air. In outdoor air, only four organophosphate flame retardants were detected. The maximum level of indoor organophosphate compounds was 1260 ng/m(3) with tris(2-chloro-1-methylethyl) phosphate (TCPP), and that of polybrominated compounds was 29.5 ng/m(3) with hexabromocyclododecane (HBCD). Tetrabromobisphenol A (TBBPA) was not detected in this study, although it has the largest demand among flame retardants in Japan. The results of the migration test and the indoor air survey revealed that in indoor air, organophosphate compounds were more predominant than polybrominated compounds in Tokyo. Polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE) are commonly used as flame retardants in plastics. The use of these two compounds in electric appliances will be banned in 2007 by the EU Directives on waste electrical and electronic equipment (WEEE) and on the restriction of the use of certain hazardous substances (RoHS) in electrical and electronic equipment. In Japan, the use of PBB was banned and that of PBDE diminished in the early 1990s by the self-imposed controls of the Japanese Flame Retardants Conference (Akutu and Hori, 2004). In Japan, the predominantly used organic flame retardants were tetrabromobisphenol A and organophosphate compounds. Tetrabromobisphenol A has been reported to disrupt endocrine systems (Kitamura et al., 2005), and some organophosphate flame retardants were recently reported to have neurochemical hazardous effects. Furthermore, organophosphate compounds were suspected to cause endocrine-disrupting effects (Fang et al., 2003; Ohyama et al., 2005) or attention deficit hyperactivity disorder (ADHD) (Winrow et al., 2003). In this study, organophosphate and polybrominated flame retardants were surveyed in indoor environments in Tokyo.

Evaluation of the current contamination status of PFASs and OPFRs in South Korean tap water associated with its origin

Pre- and post-natal exposure of children to organophosphate flame retardants: A nationwide survey in France.

OPFRs and BFRs induced A549 cell apoptosis by caspase-dependent mitochondrial pathway

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs) are chemicals that may contribute to placenta-mediated complications and adverse maternal-fetal health risks. Few studies have investigated these chemicals in relation to biomarkers of effect during pregnancy. We measured 12 PFASs and four urinary OPFR metabolites in 132 healthy pregnant women during mid-gestation and examined a subset with biomarkers of placental development and disease (n = 62). Molecular biomarkers included integrin alpha-1 (ITGA1), vascular endothelial-cadherin (CDH5), and matrix metalloproteinase-1 (MMP1). Morphological endpoints included potential indicators of placental stress and the extent of cytotrophoblast (CTB)-mediated uterine artery remodeling. Serum PFASs and urinary OPFR metabolites were detected in ∼50%-100% of samples. The most prevalent PFASs were perfluorononanoic acid (PFNA), perfluorooctanoic acid (PFOA), and perfluorooctane sulfonic acid (PFOS), with geometric mean (GM) levels of ∼1.3-2.8 (95% confidence limits from 1.2-3.1) ng/ml compared to ≤0.5 ng/ml for other PFASs. Diphenyl phosphate (DPhP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) were the most prevalent OPFR metabolites, with GMs of 2.9 (95% CI: 2.5-3.4) and 3.6 (95% CI: 2.2-3.1) ng/ml, respectively, compared to <1 ng/ml for bis(2-chloroethyl) phosphate (BCEP) and bis(1-chloro-2-propyl) phosphate (BCIPP). We found inverse associations of PFASs or OPFRs with ITGA1 or CDH5 immunoreactivity and positive associations with indicators of placental stress in multiple basal plate regions, indicating these chemicals may contribute to abnormal placentation and future health risks. Associations with blood pressure and lipid concentrations warrant further examination. This is the first study of these chemicals with placental biomarkers measured directly in human tissues and suggests specific biomarkers are sensitive indicators of exposure during a vulnerable developmental period.

In this study, the concentrations of organophosphate flame retardants (OPFR) and perfluoroalkyl substances (PFAS) were investigated in raw water and treated water samples obtained from 18 drinking water treatment plants (DWTPs). The ∑13OPFR concentrations in the treated water samples (29.5–122 ng/L; median 47.5 ng/L) were lower than those in the raw water (37.7–231 ng/L; median 98.1 ng/L), which indicated the positive removal rates (0–80%) of ∑13OPFR in the DWTPs. The removal efficiencies of ∑27PFAS in the DWTPs ranged from −200% to 50%, with the ∑27PFAS concentrations in the raw water (4.15–154 ng/L; median 32.0 ng/L) being similar to or lower than those in the treated water (4.74–116 ng/L; median 42.2 ng/L). Among OPFR, tris(chloroisopropyl) phosphate (TCIPP) and tris(2-chloroethyl) phosphate (TCEP) were dominant in both raw water and treated water samples obtained from the DWTPs. The dominant PFAS (perfluorooctanoic acid (PFOA) and perfluorohexanoic acid (PFHxA)) in the raw water samples were slightly different from those in the treated water samples (PFOA, L-perfluorohexane sulfonate (L-PFHxS), and PFHxA). The 95-percentile daily intakes of ∑13OPFR and ∑27PFAS via drinking water consumption were estimated to be up to 4.9 ng/kg/d and 0.22 ng/kg/d, respectively. The hazard index values of OPFR and PFAS were lower than 1, suggesting the risks less than known hazardous levels.

Endocrine disruption potentials of organophosphate flame retardants and related mechanisms in H295R and MVLN cell lines and in zebrafish

Estimation of Serum PFOA Concentrations from Drinking and Non-Drinking Water Exposures.

Spatiotemporal distribution and mass loading of organophosphate flame retardants (OPFRs) in the Yellow River of China (Henan segment)

Investigating the associations between organophosphate flame retardants (OPFRs) and fine particles in paired indoor and outdoor air: A probabilistic prediction model for deriving OPFRs in indoor environments

Background/aim Organophosphate flame retardants (OPFRs) are increasingly used in consumer products and are widely detected in adults. Carcinogenicity and damage to immunologic, neurologic and developmental systems are observed in human cell lines along with reproductive changes in adult males. Young children are vulnerable to OPFR exposure, but little is known about children’s exposure levels or risk factors. Methods We examined parent-reported demographic and dietary survey data in relation to urinary metabolite concentrations of three OPFRs [Tris (1,3-dichloro-isopropyl) phosphate (TDCPP), triphenyl phosphate (TPP), and isopropylated triphenyl phosphate (ITP)] in 15- to 18 month old toddlers (n=41) residing in Seattle, Washington State, USA. Urinary metabolite concentrations were log 10 -transformed and adjusted for urinary specific gravity. Multiple linear regression, adjusting for lab, annual maternal income, and child sex, was used to evaluate associations between metabolite concentrations and demographic and dietary predictors. Results OPFR metabolites were detected in 100% of subjects. The metabolite of TPP, diphenyl phosphate (DPP) was detected most commonly (100%), with TDCPP metabolite, bis (1,3-dichloro-2-propyl) phosphate (BDCPP), detected in 85%–95% of samples, and ITP metabolite, monoisopropylphenyl phenyl phosphate (ip-DPP), detected in 81% of samples (n=21). Toddlers of mothers earning $10,000/year (7.8 ng/mL, 95% CI: 5.03 to 12.11 and 4.69 ng/mL, 95% CI: 3.65 to 6.04, respectively). Conclusion Our study confirmed ubiquity of OPFR exposure in toddlers. Very low maternal income was a significant predictor of OPFR metabolite concentrations. While no dietary factors were significantly associated with exposure levels, results suggested meat and fish consumption may be associated with higher OPFR levels while increased dairy and fresh food consumption may be associated with lower OPFR levels.

BackgroundEnvironmental chemical exposures can affect telomere length, which in turn has been associated with adverse health outcomes including cancer. Firefighters are occupationally exposed to many hazardous chemicals and have higher rates of certain cancers. As a potential biomarker of effect, we assessed associations between chemical exposures and telomere length in women firefighters and office workers from San Francisco, CA.MethodsWe measured serum concentrations of polyfluoroalkyl substances (PFAS), urinary metabolites of flame retardants, including organophosphate flame retardants (OPFRs), and telomere length in peripheral blood leukocytes in women firefighters (N = 84) and office workers (N = 79) who participated in the 2014–15 Women Workers Biomonitoring Collaborative. Multiple linear regression models were used to assess associations between chemical exposures and telomere length.ResultsRegression results revealed significant positive associations between perfluorooctanoic acid (PFOA) and telomere length and perfluorooctanesulfonic acid (PFOS) and telomere length among the whole cohort. Models stratified by occupation showed stronger and more significant associations among firefighters as compared to office workers. Among firefighters in models adjusted for age, we found positive associations between telomere length and log-transformed PFOA (β (95%CI) = 0.57(0.12, 1.02)), PFOS (0.44 (0.05, 0.83)), and perfluorodecanoic acid (PFDA) (0.43 (0.02, 0.84)). Modeling PFAS as categories of exposure showed significant associations between perfluorononanoic acid (PFNA) and telomere length among firefighters. Significant associations between OPFR metabolites and telomere length were seen for bis (1,3-dichloro-2-propyl) phosphate (BDCPP) and telomere length among office workers (0.21(0.03, 0.40)) and bis (2-chloroethyl) phosphate (BCEP) and telomere length among firefighters (− 0.14(− 0.28, − 0.01)). For OPFRs, the difference in the direction of effect by occupational group may be due to the disparate detection frequencies and concentrations of exposure between the two groups and/or potential unmeasured confounding.ConclusionOur findings suggest positive associations between PFAS and telomere length in women workers, with larger effects seen among firefighters as compared to office workers. The OPFR metabolites BDCPP and BCEP are also associated with telomere length in firefighters and office workers. Associations between chemical exposures and telomere length reported here and by others suggest mechanisms by which these chemicals may affect carcinogenesis and other adverse health outcomes.

Organophosphate flame retardants (OPFRs) are common replacements for the phased-out polybrominated diphenyl ethers (PBDEs) and have been detected at high concentrations in environmental samples. OPFRs are structurally similar to organophosphate pesticides and may adversely affect the developing nervous system. This study evaluated the overt toxicity, uptake, and neurobehavioral effects of tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tris (2-chloroethyl) phosphate (TCEP), tris (1-chloro-2-propyl) phosphate (TCPP), and tris (2,3-dibromopropyl) phosphate (TDBPP) in early life stage zebrafish. Chlorpyrifos was used as a positive control. For overt toxicity and neurobehavioral assessments, zebrafish were exposed from 0 to 5 days postfertilization (dpf). Hatching, death, or malformations were evaluated daily. Teratogenic effects were scored by visual examination on 6 dpf. To evaluate uptake and metabolism, zebrafish were exposed to 1 µM of each organophosphate (OP) flame retardant and collected on 1 and 5 dpf to monitor accumulation. Larval swimming activity was measured in 6 dpf larvae to evaluate neurobehavioral effects of exposures below the acute toxicity threshold. TDBPP elicited the greatest toxicity at >1 µM. TDCPP and chlorpyrifos were overtly toxic at concentrations ≥10 µM, TCEP, and TCPP were not overtly toxic at the doses tested. Tissue concentrations increased with increasing hydrophobicity of the parent chemical after 24 h exposures. TDCPP and TDBPP and their respective metabolites were detected in embryos on 5 dpf. For all chemicals tested, developmental exposures that were not overtly toxic significantly altered larval swimming activity. These data indicate that OPFRs adversely affect development of early life stage zebrafish.

The occurrence and fate of 14 triester organophosphate flame retardants (OPFRs) and plasticizers and their two diester metabolites were investigated in a wastewater treatment plant (WWTP) in the Albany area of New York State. All target OPFRs were found in wastewater, with average concentrations that ranged from 20.1 ng/L for tris(methylphenyl) phosphate (TMPP) to 30 100 ng/L for tris(2-butoxyethyl)phosphate (TBOEP) in influents and from 7.68 ng/L for TMPP to 12 600 ng/L for TBOEP in final effluents. TBOEP was the dominant compound in influents (max: 69 500 ng/L) followed in decreasing order by tris(1-chloro-2-propyl)phosphate (TCIPP; max: 14 500 ng/L), bis(1,3-dichloro-2-propyl)phosphate (BDCIPP; max: 4550 ng/L), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP; max: 3150 ng/L) and tris(2-chloroethyl)phosphate (TCEP; max: 8450 ng/L). The fraction of TMPP sorbed to suspended particulate matter (SPM) was 56.4% of the total mass in wastewater, which was the highest among the target chemicals analyzed. The average concentrations of OPFRs in sludge were between 4.14 ng/g dw for tripropyl phosphate (TPP) and 7290 ng/g dw for TBOEP; for ash, they were between 2.17 ng/g dw for TMPP and 427 ng/g dw for triphenyl phosphate (TPhP). The mass loadings of OPFRs into the WWTP ranged from 0.02 mg/day/person for TPP to 28.7 mg/day/person for TBOEP, whereas the emission from the WWTP ranged from 0.01 mg/day/person for 2-ethylhexyl diphenyl phosphate (EHDPP) to 5.12 mg/day/person for TCIPP. The removal efficiencies for OPFRs were slightly above 60% for TMPP, TBOEP, and tris(2-ethylhexyl)phosphate (TEHP) whereas those for other OPFRs were <40% (TPhP and BDCIPP) to negative values, suggesting incomplete removal in WWTPs.

Contaminants of Emerging Concern (CECs), including per- and polyfluoroalkyl substances (PFASs) and organophosphate flame retardants (OPFRs), have raised global concerns due to their persistence, bioaccumulation potential, and toxicity. This study presents a comprehensive investigation of the occurrence, spatiotemporal distribution, potential sources, and the ecological and human health risks associated with 18 PFASs and 9 OPFRs in the surface waters of the upper Yangtze River, China. The water samples were collected from the main stream and five major tributaries (Min, Jinsha, Tuo, Jialing, and Wu Rivers) in 2022 and 2023. The total concentration of PFASs and OPFRs ranged from 16.07 to 927.19 ng/L, and 17.36 to 190.42 ng/L, respectively, with a consistently higher concentration observed in the main stream compared to the tributaries. Ultra-short-chain PFASs (e.g., TFMS) and halogenated OPFRs (e.g., TCPP) were the predominant compounds, likely originating from industrial discharges, wastewater effluents, and other anthropogenic sources. Ecological risk assessments indicated low-to-moderate risks at most sampling sites, with higher risks near wastewater discharge points. Human health risk evaluations suggested negligible non-carcinogenic risks but identified potential carcinogenic risks from OPFR exposure for adults at specific locations, particularly in Leshan city. This study highlights the importance of understanding the fate and impacts of PFASs and OPFRs in the upper Yangtze River, and provides valuable insights for developing targeted pollution control strategies and risk management measures.