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Organophosphates esters (OPEs) have become a preferred alternative in nail polish as plasticizers due to health concerns over previously used additives like dibutyl phthalate. However, the true extent of nail technicians' exposure to OPEs is largely unknown. This study shows that nail salon workers are significant exposed to OPEs, with varied concentrations found in air, dust, masks, and urine. The total concentrations of 11 OPEs in ultrasonic personal air samplers (UPAS) ranged from 251 to 1007 ng/m³, and in air conditioner filter dust from 371 to 14473 ng/g. Triphenyl phosphate (TPHP) was the most abundant compound found in the nail polishes used in these salons. On average, the concentrations of TPHP and diphenyl phosphate (DPHP) in workers' urine after work were 5.2 and 1.8 times higher than those before work, respectively. Two nail salons that had the highest nail polish usage also had very high concentrations of TPHP in surgical masks, dust, and UPAS. TPHP concentrations in workers' urine after work were 19 and 13 times those before work, respectively, in these two salons. Human internal exposure assessment showed that the average exposure dose of TPHP after work was 1.8 times higher than that before work. On average, use of masks reduced OPEs in urine by 77%. In conclusion, frequent mask replacement is highly recommended, especially in long working circumstances. Without regular replacement, masks may accumulate OPEs from the air, potentially becoming another source of human exposure to OPEs. Therefore, more attention should be paid to the occupational exposure of nail salon workers to OPEs, particularly considering that most practitioners in this industry are young women of reproductive age.

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In recent years, organophosphate esters (OPEs), widely used in industrial and consumer products, have become ubiquitous environmental contaminants, raising concerns about their potential effects on human health, particularly fetal neurodevelopment. While published studies have suggested that prenatal exposure to OPEs may negatively impact fetal neurodevelopment, the mechanisms remain unclear. Placental neurotransmitters play a crucial role in fetal neurodevelopment during critical periods, with their synthesis, release, transport, and expression dynamically regulated by various factors, including environmental influences. This review, based on potential mediating role of placental neurotransmitters in fetal neurodevelopment, systematically reviewed studies examining the associations between prenatal OPEs exposure, alterations in maternal placental neurotransmitters, and neurodevelopmental abnormalities in offspring. The majority of studies suggested that OPEs may impact fetal neurodevelopment by interfering with placental neurotransmitter homeostasis. This review provided the first systematic overview of research demonstrating the long-term impact of OPEs on offspring neurodevelopment via placental neurotransmitters, revealing novel mechanisms of OPEs neurotoxicity, and offering a new understanding of the potential mechanisms of OPEs action on neurodevelopment.

BackgroundAnimal studies have shown that exposure to organophosphate esters (OPEs) disturbs the composition of gut microbiome in rodents and zebrafish. However, current associated evidence in humans is limited. Considering the importance of gut microbiome in neonatal development, we need to investigate the impact of OPEs exposure on the early development stage of neonatal microbiome. ObjectiveTo investigate the associations between umbilical OPEs exposure and the diversity and composition of gut microbiome in newborns. MethodsBased on the Shanghai Maternal-Child Pairs Cohort (MCPC), 391 mother-infant pairs with comprehensive follow-up information and bio-samples were enrolled in this study. Concentrations of OPEs in neonatal cord blood were quantified using ultra performance liquid chromatography-tandem mass spectrometry. Meconium samples were collected after delivery and measured through 16S rRNA sequencing on the Illumina Miseq platform. Multiple linear regression models were used to assess the effects of OPEs exposure on the alpha diversity of meconium microbiome. Principal coordinate analysis and permutational multivariate analysis of variance based on unweighted UniFrac distance were used to compare the beta diversity differences between high and low exposure groups of OPEs. Linear discriminant analysis effect size (LEfSe) was utilized to analyze the differential gut microbiome taxa between high and low OPEs exposure groups. The functional pathways involved in the meconium microbiome were predicted based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and multivariate analysis by linear models (MaAsLin2) were conducted to explore the effects of OPEs exposure on gut microbiome pathways. ResultsSeven OPEs were detectable in the neonatal cord blood samples, of which four were detected higher than 50% including tributyl phosphate (TBP), tris (2-butoxyethyl) phosphate (TBEP), 2-ethylhexyl diphenyl phosphate (EHDPP), and tris (2-chloro-1 (chloromethyl) ethyl) phosphate (TDCPP), and the median concentrations of these four congeners were as follows: 0.52 μg·L−1 for TBP, 2.41 μg·L−1 for TBEP, 0.13 μg·L−1 for EHDPP, and 2.23 μg·L−1 for TDCPP. A significant association was observed between umbilical TBEP and TDCPP exposure and alpha diversity indices in neonatal meconium microbiome. Beta diversity significantly differed across varied high and low OPEs exposure groups. The results of LEfSe analysis indicated a significant correlation between umbilical OPEs exposure and 27 genera, including Streptococcus, Corynebacterium, Neisseria, Haemophilus, and Parabacteroides. The MaAsLin2 analysis identified associations between OPEs exposure and upregulation of pathways related to linoleic acid metabolism, steroid biosynthesis, Toll and Imd signaling pathway, retinol metabolism, NOD like receptor signaling pathway, and fatty acid biosynthesis . ConclusionUmbilical OPEs exposure is associated increased alpha diversity indices, increased relative abundances of Neisseria, Streptococcus, Parabacteroides, and Corynebacterium in the gut microbiome, as well as predicted metabolic pathway alterations in linoleic acid metabolism, fatty acid biosynthesis, etc. These findings indicate that umbilical OPEs exposure may disrupt meconium microbiome equilibrium.

Aryl-phosphate flame retardants (APFRs), a subcategory of organophosphate flame retardants (OPFRs), are present in a diverse range of materials including plastic, and foam products, furniture, and electronic waste. Despite their widespread use, research on the toxicity of APFRs remains limited. In order to clarify more clearly the environmental and health risks caused by APFRs, this review provides a comprehensive overview of the occurrence and toxicity of four environmental APFRs: triphenyl phosphate (TPHP), 2-ethylhexyl diphenyl phosphate (EHDPP), isobutyl diphenyl phosphate (IDPP), and diphenyl phosphate (DPHP). Regarding the toxicity of APFRs, it seems that EHDPP and TPHP act in different ways in the intestine, but both cause disorders of lipid metabolism in the liver. On the contrary, the toxic effects of EHDPP and IDPP in the liver may be similar, but the specific mechanisms require further study. At the same time, DPHP, as the main biotransformation of APFRs, should receive more attention for its toxicity. Prioritizing the investigation of in vivo transformation products, particularly DPHP and enhancing the study of APFRs' biodegradation are crucial to comprehensively assess the toxicity of APFRs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Attention-deficit/hyperactivity-disorder (ADHD) is a leading neurodevelopmental disorder in children worldwide; however, few modifiable risk factors have been identified. Organophosphate esters (OPEs) are ubiquitous chemical compounds that are increasingly prevalent as a replacement for other regulated chemicals. Current research has linked OPEs to neurodevelopmental deficits. The purpose of this study was to assess gestational OPE exposure on clinically-assessed ADHD in children at age 3 years. METHODS: In this nested case-control study within the Norwegian Mother, Father, and Child Cohort study, we evaluated the impact of OPE exposure at 17 weeks gestation on preschool-age ADHD. Between 2007 and 2011, 260 ADHD cases were identified using the Preschool Age Psychiatric Assessment and compared to a birth-year-stratified control group of 549 children. We categorized bis(2-butoxyethyl) phosphate (BBOEP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) as values

Takeaway food has become a prominent component of the diet in urban areas of China, especially for young people. Although dietary intake is a major pathway to contaminants for human exposure, studies on emerging organophosphite antioxidants (OPAs) and organophosphate esters (OPEs) in food are scarce. Here, we investigated four OPAs and 19 OPEs in takeaway foods (n = 99) and paired takeaway food packaging (n = 50) in China. AO168=O (mean: 14.9 ng/g ww), TPPO (mean: 1.05 ng/g ww), and TCIPP (mean: 0.579 ng/g ww) were dominant in the takeaway food. Some OPEs had significant correlations in takeaway food. Emerging OPAs and OPEs in takeaway food varied significantly depending on the packaging materials and food types. AO168 and AO168=O were widespread in the paired takeaway food packaging. The migration efficiencies of emerging OPAs and OPEs were low in takeaway food packaged in aluminum foil. Although the actual contamination of emerging OPAs and OPEs in takeaway food significantly differed from those of in food simulants migrated from paired takeaway food packaging, the results imply that food itself and takeaway food packaging are potential contamination sources of emerging OPAs and OPEs in takeaway food. The average estimated dietary intakes of emerging OPAs and OPEs were 465 ng/kg body weight (bw)/day and 91.9 ng/kg bw/day, respectively. The exposure risk of emerging OPAs and OPEs through takeaway food intake is low in China. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are one of the emerging environmental threats, causing the hazard to ecosystem safety and human health. Yet, the toxic effects and metabolic response mechanism after Escherichia coli (E.coli) exposed to TDCIPP and TEHP is inconclusive. Herein, the levels of SOD and CAT were elevated in a concentration-dependent manner, accompanied with the increase of MDA contents, signifying the activation of antioxidant response and occurrence of lipid peroxidation. Oxidative damage mediated by excessive accumulation of ROS decreased membrane potential and inhibited membrane protein synthesis, causing membrane protein dysfunction. Integrative analyses of GC-MS and LC-MS based metabolomics evinced that significant perturbation to the carbohydrate metabolism, nucleotide metabolism, lipids metabolism, amino acid metabolism, organic acids metabolism were induced following exposure to TDCIPP and TEHP in E.coli, resulting in metabolic reprogramming. Additionally, metabolites including PE(16:1(5Z)/15:0), PA(17:0/15:1(9Z)), PC(20:2(11Z,14Z)/12:0), LysoPC(18:3(6Z,9Z,12Z)/0:0) were significantly upregulated, manifesting that cell membrane protective molecule was afforded by these differential metabolites to improve permeability and fluidity. Overall, current findings generate new insights into the molecular toxicity mechanism by which E.coli respond to TDCIPP and TEHP stress and supply valuable information for potential ecological risks of OPEs on aquatic ecosystems.

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate ester that can adversely affect animal or human health. The intestinal microbiota is critical to human health. High-dose exposure to TDCIPP can markedly affect the intestinal ecosystem of mice, but the effects of long-term exposure to lower concentrations of TDCIPP on the intestinal flora and body metabolism remain unclear. In this study, TDCIPP was administered to Sprague–Dawley rats by gavage at a dose of 13.3 mg/kg bw/day for 90 days. TDCIPP increased the relative weight of the kidneys (P = 0.017), but had no effect on the relative weight of the heart, liver, spleen, lungs, testes, and ovaries (P > 0.05). 16 S rRNA gene sequencing revealed that long-term TDCIPP exposure affected the diversity, relative abundance, and functions of rat gut microbes. The serum metabolomics of the rats showed that TDCIPP can disrupt the serum metabolic profiles, result in the up-regulation of 26 metabolites and down-regulation of 3 metabolites, and affect multiple metabolic pathways in rat sera. In addition, the disturbed genera and metabolites were correlated. The functions of some disturbed gut microbes were consistent with the affected metabolic pathways in the sera, and these metabolic pathways were all associated with kidney disease, suggesting that TDCIPP may cause kidney injury in rats by affecting the intestinal flora and serum metabolism.

Copyright of Journal of Dalian Ocean University is the property of Journal of Dalian Ocean University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Herein, the trapping effectiveness of N95, filter KN95, medical surgical masks (MSMs), and disposable medical masks (DMMs) against 19 airborne traditional and novel organophosphate esters (OPEs) was evaluated. Laboratory simulations (n = 24 for each type of mask) showed that time-dependent accumulation of ∑19OPEs on the four types of masks ranged between 30.1 and 86.6 ng in 24 h, with the highest and lowest median amounts trapped by the N95 masks (53.3 ng) and DMMs (43.2 ng), respectively. The trapping efficiency of the four types of masks for ∑19OPEs decreased over time from 84 % to 39 % in 24 h, with N95 masks showing the highest median efficiency (70 %). Further, field investigations were conducted in five types of microenvironments (train, hospital, bus, supermarket, and canteen), and an analysis of 200 samples showed that ∑19OPEs were accumulated in the masks with a variable amount from 3.7 to 117 ng/mask. Consistent with the laboratory simulations, the N95 masks (29.0 ng/mask) exhibited the highest hourly median amount of trapped OPEs, followed by the KN95 masks (24.5 ng/mask), MSMSs (17.4 ng/mask), and DMMs (15.8 ng/mask). Triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), and cresyl diphenyl phosphate (CDP) as well as 4-isopropylphenyl diphenyl phosphate (4IPPDPP) and 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP) were the most commonly detected traditional and novel OPEs. Based on the amount of OPEs trapped on the masks, we estimated the concentration of ∑19OPEs in the train microenvironment to be the highest (222 ng/m3), which is approximately 2–5 times higher than that in the other microenvironments. The results of this study prove that masks can effectively protect humans from exposure to OPEs and act as low-cost indicators of indoor contamination.

Background: Organophosphate esters (OPEs), used as flame retardants and plasticizers, are chemicals of concern for maternal and infant health. Prior studies examining temporal trends and predictors of OPE exposure are primarily limited by small sample sizes. Objectives: Characterize temporal trends and predictors of OPE exposure biomarkers. Methods: We determined urinary concentrations of eight biomarkers of OPE exposure at three timepoints during pregnancy for participants in the LIFECODES Fetal Growth Study (n = 900), a nested case-cohort recruited between 2007 and 2018. We examined biomarker concentrations, their variability during pregnancy, and temporal trends over the study period. In addition, we identified sociodemographic and pregnancy characteristics associated with biomarker concentrations. Analyses were conducted using both the within-subject pregnancy geometric means and biomarker concentrations measured at individual study visits. Results: Five OPE biomarkers were detected in at least 60% of the study participants. Biomarkers were not strongly correlated with one another and intraclass correlation coefficients, measuring within-subject variability during pregnancy, ranged from 0.27 to 0.51. Biomarkers exhibited varying temporal trends across study years. For example, bis(1-chloro-2-propyl) phosphate (BCIPP) increased monotonically, whereas bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), displayed non-monotonic trends with concentrations that peaked between 2011 and 2014. We observed associations between sociodemographic characteristics and OPE biomarkers. In general, concentrations of most OPE biomarkers were higher among participants from racial and ethnic minority populations, participants who were younger, had higher pre-pregnancy body mass index (BMI), and less than a college degree. We observed consistent results using either averaged or visit-specific biomarker concentrations. Significance: We observed widespread exposure to several OPEs and OPE biomarkers displayed varying temporal trends in pregnant people from 2007 to 2018. Concentrations of most OPE biomarkers varied according to sociodemographic factors, suggesting higher burdens of exposure among participants with higher pre-pregnancy BMI, those belonging to racial and ethnic minority populations, and lower educational attainment.

Organophosphate esters (OPEs) are emerging contaminants that serve as alternatives to regulated substances in aquatic environments. A nationwide large-scale assessment for OPEs, including point sources, remains insufficient. To address this issue, we aimed to investigate OPEs occurrence and novel OPEs via comprehensive target, suspect and non-target analysis. Among the 11 target OPEs, 10 were detected at sampling sites distributed evenly nationwide. The highest mean concentrations were measured for tris-(2-butoxyethyl) phosphate (TBOEP) and tris(2-chloroisopropyl) phosphate (TCIPP). The multivariate statistical analysis revealed that TBOEP and TCIPP are essential components for assessing total OPEs pollution. The systematic risk assessment results evaluated the overall risk contribution of TBOEP and the significant risk impact of 2-ethylhexyl diphenyl phosphate. Promising suspect and non-target analysis enabled frequent detection and identification of 6 antioxidant transformation products (TPs), as well as the tentative identification of 14 OPEs and TPs, including 3 di-OPEs. Based on sampling site classification, we confirmed that major OPEs are significantly discharged near point sources. We believe that this is the first attempt to assess the nationwide risk and potential sources of OPEs in Korean surface waters, providing insights that could support further prioritization and regulation efforts. [Display omitted] • Nationwide monitoring showed OPEs, especially TBOEP, as predominant in Korean surface waters. • Multivariate analysis identified TBOEP and TCIPP as essential components for OPEs assessment. • TBOEP had overall risk contribution, with EHDPP showing significant risk impact. • Suspect and non-target analysis identified 20 novel OPEs and antioxidant TPs. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are commonly used in commercial products as flame retardants. In the present study, a simple method was established for the simultaneous determination of 10 OPEs in aquacultural water and sediments. The targets were extracted using dichloromethane or ethyl acetate, cleaned up by solid-phase extraction, and determined by gas chromatography – tandem mass spectrometry. The matrix effects were lower than 20% for all OPEs except for tris(2-chloroethyl) phosphate in sediments (matrix effect: 29.4%). In spiked water samples, the recoveries of the OPEs were from 72.3% to 108% with relative standard deviations ≤10.2% and the limits of detection from 0.17 to 1.13 ng·L−1. In spiked sediments, the recoveries of the OPEs were from 101% to 121% with relative standard deviations ≤11.2% with limits of detection from 0.02 to 0.32 ng·g−1, dry weight (dw). The developed method was applied to the analysis of aquaculture samples from Kaozhouyang Bay, China. The total concentration ranges of the 10 OPEs in the water and sediments were from 121 to 159 ng·L−1 and 7.54 to 13.3 ng·g−1, dw, respectively. [ABSTRACT FROM AUTHOR]

Organophosphates esters (OPEs) have become a preferred alternative in nail polish as plasticizers due to health concerns over previously used additives like dibutyl phthalate. However, the true extent of nail technicians' exposure to OPEs is largely unknown. This study shows that nail salon workers are significant exposed to OPEs, with varied concentrations found in air, dust, masks, and urine. The total concentrations of 11 OPEs in ultrasonic personal air samplers (UPAS) ranged from 251 to 1007 ng/m³, and in air conditioner filter dust from 371 to 14473 ng/g. Triphenyl phosphate (TPHP) was the most abundant compound found in the nail polishes used in these salons. On average, the concentrations of TPHP and diphenyl phosphate (DPHP) in workers' urine after work were 5.2 and 1.8 times higher than those before work, respectively. Two nail salons that had the highest nail polish usage also had very high concentrations of TPHP in surgical masks, dust, and UPAS. TPHP concentrations in workers' urine after work were 19 and 13 times those before work, respectively, in these two salons. Human internal exposure assessment showed that the average exposure dose of TPHP after work was 1.8 times higher than that before work. On average, use of masks reduced OPEs in urine by 77%. In conclusion, frequent mask replacement is highly recommended, especially in long working circumstances. Without regular replacement, masks may accumulate OPEs from the air, potentially becoming another source of human exposure to OPEs. Therefore, more attention should be paid to the occupational exposure of nail salon workers to OPEs, particularly considering that most practitioners in this industry are young women of reproductive age., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

A total of 102 urban soil and surface dust samples were collected from Lanzhou of China to clarify the occurrences, sources, affecting factors, and health risks of 13 organophosphate esters (OPEs). The total concentration of 13 OPEs (Ʃ 13 OPEs) in urban soil and surface dust ranged from 80.1 to 749 and 244 to 4905 ng/g, dominated by chlorinated OPEs (39.9 % and 65.1 %). The Ʃ 13 OPEs in the two media was higher in the central and eastern of Lanzhou due to local topography and wind direction. OPEs in the two media originated from industrial, traffic and commercial activities (37-53.4 %), atmospheric depositions (24.3-31.3 %), and OPEs-containing material emissions (14.5-31.7 %). Transport station number, residential/commercial area distribution, and road length were positively correlated with Ʃ 13 OPEs in the two media, suggesting that traffic activities are the main factors influencing the distribution of OPEs. Probabilistic non-cancer (< 1) and cancer (< 1 × 10 -6 ) risks of human exposed to OPEs were low, mainly attributed to OPEs-containing material emissions (47.5-62.0 %) in urban soil and industrial/traffic activities (57.8-92.2 %) in surface dust. Reducing the frequency of human exposed to the two media and controlling the release of OPEs from pollution sources may mitigate population exposure risks., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tris (2-chloroethyl) phosphate (TCEP), an emerging environmental pollutant, has been frequently detected in natural waters. The objective of this study was to investigate possible parental transfer of TCEP and transgenerational effects on the early development and thyroid hormone homeostasis in F1 larvae following parental whole life-cycle exposure to TCEP. To this end, zebrafish (Danio rerio) embryos were exposed to environmentally relevant concentrations (0.8, 4, 20 and 100 μg/L) of TCEP for 120 days until sexual maturation. Parental exposure to TCEP resulted in significant levels of TCEP, developmental toxicity including decreased survival and final hatching rates, accelerated heart rate and elevated malformation rate, as well as induction of oxidative stress and cell apoptosis in F1 offspring. In F1 eggs, declined thyroxin (T4) levels were observed, consistent with those in plasma of F0 adult females, indicating the maternal transfer of thyroid endocrine disruption to the offspring. In addition, mRNA levels of several genes along the hypothalamic-pituitary-thyroid (HPT) axis were significantly modified in F1 larvae, which could be linked to transgenerational developmental toxicity and thyroid hormone disruption. For the first time, we revealed that the parental exposure to environmentally relevant levels of TCEP could cause developmental toxicity and thyroid endocrine disruption in subsequent unexposed generation.

Organophosphate esters (OPEs) are widespread in various environmental media, and can disrupt thyroid endocrine signaling pathways. Mechanisms by which OPEs disrupt thyroid hormone (TH) signal transduction are not fully understood. Here, we present in vivo-in vitro-in silico evidence establishing OPEs as environmental THs competitively entering the brain to inhibit growth of zebrafish via multiple signaling pathways. OPEs can bind to transthyretin (TTR) and thyroxine-binding globulin, thereby affecting the transport of TH in the blood, and to the brain by TTR through the blood–brain barrier. When GH3 cells were exposed to OPEs, cell proliferation was significantly inhibited given that OPEs are competitive inhibitors of TH. Cresyl diphenyl phosphate was shown to be an effective antagonist of TH. Chronic exposure to OPEs significantly inhibited the growth of zebrafish by interfering with thyroperoxidase and thyroglobulin to inhibit TH synthesis. Based on comparisons of modulations of gene expression with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases, signaling pathways related to thyroid endocrine functions, such as receptor–ligand binding and regulation of hormone levels, were identified as being affected by exposure to OPEs. Effects were also associated with the biosynthesis and metabolism of lipids, and neuroactive ligand–receptor interactions. These findings provide a comprehensive understanding of the mechanisms by which OPEs disrupt thyroid pathways in zebrafish.

Organophosphate (OP) and organophosphate ester (OPE) adducts of albumin are valuable biomarkers for retrospective verification of exposure. In the present study, our goal was to determine whether OPE flame retardants (OPE FRs) and OPE plasticizers can covalently bind to human serum albumin (HSA), which would allow the resulting adducts to be used to evaluate exposure. Eleven OPE FRs and plasticizers were examined in a HSA-adduct in vitro assay. Pure HSA was incubated with the target OPEs, as well as with an OP insecticide (profenofos) positive control. After enzymatic cleavage with pepsin or Glu-C, the digested albumin was analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-ToF-MS). Under optimized HSA assay conditions, tyrosine adducts were formed at Y411 and Y148/Y150 with a characteristic mass shift for phosphorylation (Δm/z 166) for the profenofos positive control. However, no such phosphorylated peptides were detected for the 11 target OPEs. This negative result suggests that these OPEs have very different affinities from the OP insecticide. They are less reactive or they may specifically interact with other proteins.

As a flame retardant, triphenyl phosphate (TPHP) is commonly added to various daily products. Due to its easy diffusion, TPHP pollution has become a global concern. Despite the wide focus on environmental risk, the sub-chronic ecotoxicity of TPHP in soil organisms remains unclear. In this study, the artificial soil exposure method was used to analyze the oxidative stress and DNA damage in earthworms with 0, 20, 40, 60 and 80 mg/kg TPHP treatments through the response of reactive oxygen species (ROS), antioxidant and detoxifying enzymes, malondialdehyde (MDA) and olive tail moment (OTM) at 7, 14, 21 and 28 days. Throughout the experimental period, the results showed that the ROS content in earthworms treated with 20, 40, 60 and 80 mg/kg TPHP treatments increased by 9.43–18.37 %, 6.07–25.73 %, 7.71–42.61 % and 8.22–46.70 %, respectively, compared to the control treatment. Meanwhile, the activities of antioxidant and detoxification enzymes in earthworms with all TPHP treatments were significantly activated after exposure for 7 and 14 days, and then inhibited at 21 and 28 days. Despite the protection of antioxidant enzymes and detoxification enzymes, MDA content in earthworms with the 20 mg/kg treatment still significantly increased at 7 and 14 days of exposure, as well as in the other three treatments. Compared to the control treatment, the obviously higher OTM values in earthworms with TPHP treatments possibly indicated a genotoxicity of TPHP in earthworms. Furthermore, the integrated biomarker response index (IBRv2) revealed that earthworms showed an obvious biochemical response TPHP-contaminated soil, which was strongly correlated with TPHP concentrations and exposure time. This study provides insights into the TPHP hazard in the soil environment and offers a reference to assess its environmental risk to soil ecosystems.

Organophosphate esters (OPEs) are one of the emerging environmental threats, causing the hazard to ecosystem safety and human health. Yet, the toxic effects and metabolic response mechanism after Escherichia coli (E.coli) exposed to TDCIPP and TEHP is inconclusive. Herein, the levels of SOD and CAT were elevated in a concentration-dependent manner, accompanied with the increase of MDA contents, signifying the activation of antioxidant response and occurrence of lipid peroxidation. Oxidative damage mediated by excessive accumulation of ROS decreased membrane potential and inhibited membrane protein synthesis, causing membrane protein dysfunction. Integrative analyses of GC-MS and LC-MS based metabolomics evinced that significant perturbation to the carbohydrate metabolism, nucleotide metabolism, lipids metabolism, amino acid metabolism, organic acids metabolism were induced following exposure to TDCIPP and TEHP in E.coli , resulting in metabolic reprogramming. Additionally, metabolites including PE(16:1(5Z)/15:0), PA(17:0/15:1(9Z)), PC(20:2(11Z,14Z)/12:0), LysoPC(18:3(6Z,9Z,12Z)/0:0) were significantly upregulated, manifesting that cell membrane protective molecule was afforded by these differential metabolites to improve permeability and fluidity. Overall, current findings generate new insights into the molecular toxicity mechanism by which E.coli respond to TDCIPP and TEHP stress and supply valuable information for potential ecological risks of OPEs on aquatic ecosystems. [Display omitted] • Excessive accumulation of ROS triggered activation of antioxidant system. • Obvious lipid peroxidation and ATPase inactivation were induced by TDCIPP exposure. • Differential metabolites were identified by coupling GC-MS and LC-MS platform. • Dysregulation of lipid metabolism affected membrane function and stability. • TDCIPP and TEHP had negative impacts at metabolic network and phylogenetic level. [ABSTRACT FROM AUTHOR]

Tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is a widely used organophosphate ester that can adversely affect animal or human health. The intestinal microbiota is critical to human health. High-dose exposure to TDCIPP can markedly affect the intestinal ecosystem of mice, but the effects of long-term exposure to lower concentrations of TDCIPP on the intestinal flora and body metabolism remain unclear. In this study, TDCIPP was administered to Sprague–Dawley rats by gavage at a dose of 13.3 mg/kg bw/day for 90 days. TDCIPP increased the relative weight of the kidneys (P = 0.017), but had no effect on the relative weight of the heart, liver, spleen, lungs, testes, and ovaries (P > 0.05). 16 S rRNA gene sequencing revealed that long-term TDCIPP exposure affected the diversity, relative abundance, and functions of rat gut microbes. The serum metabolomics of the rats showed that TDCIPP can disrupt the serum metabolic profiles, result in the up-regulation of 26 metabolites and down-regulation of 3 metabolites, and affect multiple metabolic pathways in rat sera. In addition, the disturbed genera and metabolites were correlated. The functions of some disturbed gut microbes were consistent with the affected metabolic pathways in the sera, and these metabolic pathways were all associated with kidney disease, suggesting that TDCIPP may cause kidney injury in rats by affecting the intestinal flora and serum metabolism. [Display omitted] • Chronic exposure to TDCIPP disrupted the rat intestinal flora. • Chronic exposure to TDCIPP altered serum metabolism in rats. • A correlation was found between the perturbed genera and serum metabolites. • TDCIPP might damage rat kidneys by disrupting the intestinal flora or metabolism. [ABSTRACT FROM AUTHOR]

The phasing out of brominated flame retardants from markets has prompted an increased focus on organophosphate ester (OPE) flame retardants because of their wide usage and toxicity. The high usage of OPEs inevitably leads to widespread occurrence in the environment and thus human internal exposure. Accordingly, extensive internal exposure to OPEs and their metabolites (mOPEs) has been reported in recent years. Here, we review literature findings relating to sample pretreatment protocols and instrumental analysis procedures for OPE determination; the occurrence and composition profiles of OPEs and mOPEs in human matrices including urine, blood, milk, nails, hair, and placenta; the health risks associated with OPE exposure; and notable challenges in OPE analysis. Measured urinary concentrations of dialkyl and diaryl mOPEs were relatively high in the USA but comparatively low in Europe and Asia. There have been few studies on OPEs and their hydroxylated metabolites (HO-OPEs) in human matrices. The main OPEs originating from daily necessity products are tris(2-chloroisopropyl) phosphate, tris(1,3-dichloro-2-propyl) phosphate, and triphenyl phosphate, although there are regional differences. Human exposure to OPEs occurs mainly through oral ingestion. Because of the relatively short biological half-lives of OPEs, urinary mOPE concentrations reflect short-term human OPE exposure, while OPE levels in hair and nails better reflect long-term exposure because of the low metabolic activities of OPEs in these matrices. There is a need to develop effective and flexible pretreatment methods and sensitive instrumental analysis protocols for OPEs/mOPEs and to increase the availability of commercial HO-OPE standards. [ABSTRACT FROM AUTHOR]

Abstract Background Organophosphate esters (OPEs) are synthetic chemicals used as flame retardants and plasticizers in a variety of goods. Despite ubiquitous human exposures and laboratory evidence that prenatal OPE exposures may disrupt offspring metabolism, perinatal studies of OPE health effects are limited. The objectives of this study were to: 1) Determine predictors and reproducibility of urinary OPE biomarker concentrations during pregnancy, and 2) Estimate the relation of prenatal OPE exposures with birth outcomes and cord blood adipokine and insulin concentrations. Methods We analyzed five OPE metabolites in urine samples collected at up to three visits during pregnancy from 90 women enrolled in the ORigins of Child Health And Resilience in Development (ORCHARD) pregnancy cohort in Baltimore, MD from 2017 to 2019. To quantify the variability of metabolite concentrations during pregnancy, we calculated intraclass correlation coefficients (ICCs) for each metabolite using mixed effects regression models. Using self-reported questionnaire data collected during gestation, we assessed possible sociodemographic and environmental/behavioral predictors of each OPE metabolite using generalized estimating equations to account for repeated exposure measures. We ascertained birth outcomes of 76 offspring from medical records, including weight-for-gestational age, length, ponderal index, and gestational age. In a subset of 37 infants, we measured cord blood concentrations of leptin, adiponectin, and insulin. To account for repeated exposure measures, we used linear structural equation models to assess the relations of standard deviation (SD) increases in prenatal OPE metabolite factor scores with continuous birth outcomes and cord blood biomarker concentrations. Results ICCs ranged from 0.09 for isopropylphenyl-phenyl phosphate (ip-PPP) to 0.59 for bis(1,3-dichloro-2-propyl) phosphate (BDCIPP). We observed little consistency in environmental or behavioral predictors of OPE exposures, although concentrations were generally lower for samples collected in the afternoon compared to morning and winter compared to other seasons. In adjusted analyses, a SD increase in BDCIPP concentration was associated with a 0.06 g/cm3 (95% CI: 0.00, 0.12) greater ponderal index. A SD increase in BDCIPP was associated with a 0.37 (95% CI: − 0.62, − 0.13) SD lower insulin concentration and 0.24 (95% CI: − 0.39, − 0.08) SD lower leptin concentration. Other OPEs were not associated with infant outcomes. Conclusions These findings suggest some OPEs may be metabolic disruptors warranting investigation in larger studies.

[Display omitted] • Development of magnetic β-ketoenamine COF (Tp-DHBD M−COF). • Room-temperature mechanochemical method simplified the synthesis of M−COF. • A COF-MSPE method was developed to detect residue-prone OPEs in water environment. • The method showed good extraction efficiency (>60 %) for 12 OPEs at 1–10 ng/mL. In this work, Fe 3 O 4 /Tp-BHBD β-ketoenamine covalent organic framework (COF) was rapidly prepared. Then, it was used as magnetic solid phase microextraction (MSPE) adsorbents for the adsorption and determination of organophosphate ester (OPE) residues in surface water coupling with liquid chromatography-tandem mass spectrometry. The results of material characterization tests confirmed the generation of magnetized COF. The adsorption process was optimized by Box-Behnken Design and one-factor optimization experiments. After five use cycles, Fe 3 O 4 /Tp-DHBD still achieved good adsorption and high recovery. Under the optimal conditions, the developed Fe 3 O 4 /Tp-DHBD COF-MSPE-HPLC-MS/MS method obtained good linearity for 12 OPEs within 0.25–50.0 ng mL−1 and the limit of detection of 0.02–0.18 ng mL−1. The relative standard deviations were less than 8.6 %. Rapid detection and analysis of three samples from wastewater treatment plant showed that the recoveries of most of target OPEs at different spiked concentrations ranged from 62.0 % to 116.9 %, 60.9 %-115.1 %, and 60.4 %-112.9 %, respectively. In general, the established COF-MSPE method can provide convenient and satisfactory purification for OPEs compounds in surface water by adsorption and desorption, which is promising for specific applications. [ABSTRACT FROM AUTHOR]

Flame retardants (FRs) are added to vehicles to meet flammability standards, such as US Federal Motor Vehicle Safety Standard FMVSS 302. However, an understanding of which FRs are being used, sources in the vehicle, and implications for human exposure is lacking. US participants ( n = 101) owning a vehicle of model year 2015 or newer hung a silicone passive sampler on their rearview mirror for 7 days. Fifty-one of 101 participants collected a foam sample from a vehicle seat. Organophosphate esters (OPEs) were the most frequently detected FR class in the passive samplers. Among these, tris(1-chloro-isopropyl) phosphate (TCIPP) had a 99% detection frequency and was measured at levels ranging from 0.2 to 11,600 ng/g of sampler. TCIPP was also the dominant FR detected in the vehicle seat foam. Sampler FR concentrations were significantly correlated with average ambient temperature and were 2-5 times higher in the summer compared to winter. The presence of TCIPP in foam resulted in ∼4 times higher median air sampler concentrations in winter and ∼9 times higher in summer. These results suggest that FRs used in vehicle interiors, such as in seat foam, are a source of OPE exposure, which is increased in warmer temperatures.

This study aimed to investigate the occurrences of a suite of thirty-one organophosphate tri-esters (tri-OPEs) and six di-esters (di-OPEs) in house dust collected from Adelaide, South Australia. The results demonstrate ubiquitous presence of most OPEs in Adelaide house dust, with median concentration of 40,200 and 5260 ng/g dry weight for ∑tri-OPEs and ∑di-OPEs, respectively. A number of emerging OPEs with chemical structures resembling that of triphenyl phosphate (TPHP), including bisphenol A bis(diphenyl phosphate) (BPA-BDPP), cresyl diphenyl phosphate (CDP), isodecyl diphenyl phosphate (IDDPP), resorcinol-bis(diphenyl)- phosphate (RDP), as well as a suite of isopropylated or tert-butylated triarylphosphate ester isomers (ITPs or TBPPs), were frequently detected with combined levels surpassing that of TPHP. The investigated di-OPEs, predominated by DPHP, consisted of approximately 13% of the ∑tri-OPEs concentrations. Median concentration ratios of diphenyl phosphate (DPHP) and bis(2-ethylhexyl) phosphate (BEHP) to their respective tri-OPEs [i.e., TPHP and tris(2-ethylhexyl) phosphate (TEHP)] were determined to be 1.8 and 2.0, respectively, indicating possible commercial applications for these two di-OPEs. The estimated human intakes of dust-associated OPEs via dust ingestion and dermal contact were much lower than the reference doses. However, the risks of human exposure to OEPs may be complicated by quickly expanding family of OPEs containing various analogues and isomers as well as additional exposure pathways. Therefore, elucidation of human exposure to OPEs and associated risks requires extensive efforts in analytical, environmental, toxicological, and epidemiological investigations.

The widespread use of hazardous organophosphate ester (OPE) flame retardants has led to the contamination of groundwater and drinking water sources. Given the negative impact of OPEs on environmental and human health, there is a critical need to identify effective remediation processes. This study reports that ultrasonic irradiation at 640 kHz leads to effective degradation of tris(2-chloroethyl) phosphate (TCEP), a model organophosphate flame retardant. The concentration of TCEP in an irradiated aqueous solution was monitored by a gas chromatography- nitrogen phosphorus detector (GC-NPD) technique. TCEP has a half-life of less than 1 h under the used experimental conditions. The degradation follows pseudo-first-order kinetics with rate constants varying from 0.09 to 0.02 min−1 depending on initial concentrations ranging from 3.1 to 84 μM. The observed rate constant decreases with the increase in initial TCEP concentration, implying the process likely involves a heterogeneous process controlled by partitioning at the gas–liquid interface during ultrasonic cavitation. The degradation fits the heterogeneous Langmuir-Hinshelwood model, further suggesting the degradation occurs at the gas–liquid interface. Detailed product studies using liquid chromatography orbitrap high-resolution mass spectrometry confirm the primary degradation products are the mono and diester adducts of TCEP, specifically 2-chloroethyl dihydrogen phosphate and bis(2-chloroethyl) hydrogen phosphate. Mineralization of TCEP to chloride and phosphate was monitored by ion chromatography, yielding mass balances of 48% and 32% for chloride and phosphate, respectively, after 6 h of treatment. The results demonstrate that ultrasonic irradiation is effective for the degradation of the halogenated flame retardant TCEP. The results suggest ultrasonic treatment can be used alone or in combination with other methods for the remediation of problematic organophosphorus flame retardants. [ABSTRACT FROM AUTHOR]

Background: Organophosphate esters (OPEs) are synthetic chemicals used as flame retardants and plasticizers in a variety of goods. Despite ubiquitous human exposures and laboratory evidence that prenatal OPE exposures may disrupt offspring metabolism, perinatal studies of OPE health effects are limited. The objectives of this study were to: 1) Determine predictors and reproducibility of urinary OPE biomarker concentrations during pregnancy, and 2) Estimate the relation of prenatal OPE exposures with birth outcomes and cord blood adipokine and insulin concentrations.Methods: We analyzed five OPE metabolites in urine samples collected at up to three visits during pregnancy from 90 women enrolled in the ORigins of Child Health And Resilience in Development (ORCHARD) pregnancy cohort in Baltimore, MD from 2017 to 2019. To quantify the variability of metabolite concentrations during pregnancy, we calculated intraclass correlation coefficients (ICCs) for each metabolite using mixed effects regression models. Using self-reported questionnaire data collected during gestation, we assessed possible sociodemographic and environmental/behavioral predictors of each OPE metabolite using generalized estimating equations to account for repeated exposure measures. We ascertained birth outcomes of 76 offspring from medical records, including weight-for-gestational age, length, ponderal index, and gestational age. In a subset of 37 infants, we measured cord blood concentrations of leptin, adiponectin, and insulin. To account for repeated exposure measures, we used linear structural equation models to assess the relations of standard deviation (SD) increases in prenatal OPE metabolite factor scores with continuous birth outcomes and cord blood biomarker concentrations.Results: ICCs ranged from 0.09 for isopropylphenyl-phenyl phosphate (ip-PPP) to 0.59 for bis(1,3-dichloro-2-propyl) phosphate (BDCIPP). We observed little consistency in environmental or behavioral predictors of OPE exposures, although concentrations were generally lower for samples collected in the afternoon compared to morning and winter compared to other seasons. In adjusted analyses, a SD increase in BDCIPP concentration was associated with a 0.06 g/cm3 (95% CI: 0.00, 0.12) greater ponderal index. A SD increase in BDCIPP was associated with a 0.37 (95% CI: - 0.62, - 0.13) SD lower insulin concentration and 0.24 (95% CI: - 0.39, - 0.08) SD lower leptin concentration. Other OPEs were not associated with infant outcomes.Conclusions: These findings suggest some OPEs may be metabolic disruptors warranting investigation in larger studies. [ABSTRACT FROM AUTHOR]

Since the production of brominated flame retardants has been gradually phased out, organophosphate esters (OPEs) are increasingly used as the substitutes. Given their toxicity and water solubility, OPEs may jeopardize the aquatic environment and organisms. Here, we examined the concentration, composition, and biological risk of OPEs in the water collected from the eight major waterways in the Pearl River Delta, a highly industrialized region in China. We found a widespread occurrence of OPEs in this region (∑9OPEs: 134 to 442 ng L−1), dominated by TCPP, TCEP, and TnBP. Halogenated OPEs were dominant over alkyl and aromatic OPEs. The biological risk of OPEs, mainly contributed by TPhP and TnBP, was low (RQ < 0.1). The contamination level of OPEs in the Pearl River Delta was likely associated with the degree of industrial activities. Although OPEs posed low risk to aquatic organisms, more attention should be paid to some OPEs in the future, such as TnBP, due to the high usage and toxicity. Considering the concentrations of OPEs worldwide and their usage, OPEs may become the emerging pollutants of global concern in the next decade. [ABSTRACT FROM AUTHOR]

In this work, an analytical method has been developed and validated for the determination of organophosphate esters (OPEs) in urban ornamental tree leaves. OPEs are flame retardants and plasticizers which are classified as health and environmental hazards substances. Their presence in urban air has been previously described. The method proposed in this work would allow the use of urban tree leaves as simple, cheap, and widely distributed in urban areas alternative to the existing active and passive sampler for sample collection. The method was based on sample treatment by selective pressurized liquid extraction (SPLE) and determination by gas chromatography with triple quadrupole mass spectrometry detector. After the optimization of the extraction solvent, the key parameters applied to SPLE (clean sorbent and sorbent amount applied for the sample clean-up, temperature, extraction cycles, and time) were optimized using a Box-Behnken response surface design. The method achieves high recoveries (higher than 60% for most of the target compounds), accuracies between 70 and 109%, and method detection and quantification limits ranged 0.05–4.96 ng/g dw (dry weight) and 0.15–14.4 ng/g dw, respectively. The method allowed the proper biomonitoring of OPE in tree leaves. Concentrations measured in analyzed samples were from 47.5 to 5477 ng/g dw (TEP). The most frequently detected compounds were triethyl phosphate tri-n-butyl phosphate, triphenyl phosphate, and tris(1-chloro-2-propyl)phosphate, while tris(2-ethylhexyl)phosphate was not detected in the analyzed samples. The proposed analytical method constitutes a starting point for the use of ornamental urban trees as passive sampler for the evaluation of OPE as air pollutants. [ABSTRACT FROM AUTHOR]

As a new class of organophosphate ester, cresyl diphenyl phosphate (CDP) has been widely monitored in environmental matrices and human samples, nonetheless, its toxicity is not fully understood. Here we described an in-depth analysis of the disruptions in lipid homeostasis of zebrafish following exposure to CDP concentrations ranging from 2.0 to 313.0 μg/L. Nile red staining revealed significant alterations in lipid contents in 72 hpf zebrafish embryos at CDP concentrations of 5.3 μg/L and above. Lipidomic analysis unveiled substantial disruptions in lipid homeostasis. Notably, disruptive effects were detected in various lipid classes, including phospholipids (i.e. cardiolipin, lysophosphatidylcholine, and phosphatidylethanolamine), glycerolipids (triglycerides), and fatty acids (fatty acids (FA) and wax esters (WE)). These alterations were further supported by transcriptional changes, with remarkable shifts observed in genes associated with lipid synthesis, transport, and metabolism, encompassing phospholipids, glycerolipids, fatty acids, and sphingolipids. Furthermore, CDP exposure elicited a significant elevation in ATP content and swimming activity in embryos, signifying perturbed energy homeostasis. Taken together, the present findings underscore the disruptive effects of CDP on lipid homeostasis, thereby providing novel insights essential for advancing the health risk assessment of organophosphate flame retardants. [Display omitted] • CDP exposure led to a significant alteration in lipid content in zebrafish embryos. • Lipidomic analysis unveiled substantial disruptions in lipid homeostasis. • Lipid homeostasis alteration was further supported at the transcriptional level. • CDP exposure further perturbed ATP content and swimming activity of zebrafish embryos. [ABSTRACT FROM AUTHOR]

[Display omitted] • Time-dependent efficacy of four types of masks in trapping airborne OPEs was assessed. • N95 masks presented the highest trapping capacity for OPEs. • OPEs contamination in the train was the heaviest among the five types of microenvironments. • Non-carcinogenic risk of OPEs can decrease by an order of magnitude via wearing masks. Herein, the trapping effectiveness of N95, filter KN95, medical surgical masks (MSMs), and disposable medical masks (DMMs) against 19 airborne traditional and novel organophosphate esters (OPEs) was evaluated. Laboratory simulations (n = 24 for each type of mask) showed that time-dependent accumulation of ∑ 19 OPEs on the four types of masks ranged between 30.1 and 86.6 ng in 24 h, with the highest and lowest median amounts trapped by the N95 masks (53.3 ng) and DMMs (43.2 ng), respectively. The trapping efficiency of the four types of masks for ∑ 19 OPEs decreased over time from 84 % to 39 % in 24 h, with N95 masks showing the highest median efficiency (70 %). Further, field investigations were conducted in five types of microenvironments (train, hospital, bus, supermarket, and canteen), and an analysis of 200 samples showed that ∑ 19 OPEs were accumulated in the masks with a variable amount from 3.7 to 117 ng/mask. Consistent with the laboratory simulations, the N95 masks (29.0 ng/mask) exhibited the highest hourly median amount of trapped OPEs, followed by the KN95 masks (24.5 ng/mask), MSMSs (17.4 ng/mask), and DMMs (15.8 ng/mask). Triethyl phosphate (TEP), tris(1-chloro-2-propyl) phosphate (TCIPP), tri-n-butyl phosphate (TNBP), and cresyl diphenyl phosphate (CDP) as well as 4-isopropylphenyl diphenyl phosphate (4IPPDPP) and 2,4-diisopropylphenyl diphenyl phosphate (24DIPPDPP) were the most commonly detected traditional and novel OPEs. Based on the amount of OPEs trapped on the masks, we estimated the concentration of ∑ 19 OPEs in the train microenvironment to be the highest (222 ng/m3), which is approximately 2–5 times higher than that in the other microenvironments. The results of this study prove that masks can effectively protect humans from exposure to OPEs and act as low-cost indicators of indoor contamination. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) as substitutes for PBDEs have been widely detected in the marine environment, while little is known about the pollution characteristics and variation of OPEs in estuarine environments with complex hydrodynamic conditions and land-based input. Yangtze River Estuary (YRE) is a typical highly urbanized and industrialized estuary, with a complex hydrological environment and geochemical behavior. This study found that the concentrations of OPEs in both seawater and sediments in the YRE were higher in spring than in summer. Alkyl OPEs were the first contributor, with TnBP and TiBP as the main components, where the contribution of alkyl OPEs had exceeded 75 % in both seawater and sediments in spring, and 60 % in summer seawater, and even 80 % in sediments. In spring, OPEs peaked in the central to southern region near the YRE. In summer, OPEs were mainly concentrated in the southern branch waterway and southern nearshore area of the YRE and showed a decreasing trend to the northeast. The OPEs in the sediments were mainly concentrated in the Yangtze River Mud Area (YREMA) and the Zhe-Min Coastal Mud Area (ZMCMA). Based on the fugacity model and principal component analysis, sediments could be released into the aquatic environment as an endogenous source, and exogenous sources were mainly municipal and industrial sewage discharge sources, urban and marine traffic discharge sources, and atmospheric deposition sources. The ecological risk analysis showed that the Σ14OPEs had exhibited a low to moderate ecological risk in the southern branch waterway and the south-central region offshore. • The OPEs in seawater peaked in the southern branch waterway and southern nearshore area. • The OPEs in sediment were concentrated in the YREMA and the ZMCMA. • The OPEs concentration was higher in spring than in summer. • OPEs had low to moderate ecological risks in the water environment of the YRE. [ABSTRACT FROM AUTHOR]

Organophosphate ester (OPE) flame retardants and plasticizers, consumer product additives with widespread human exposure, were evaluated for their effect on the activity of purified human liver carboxylesterase (hCE1). Four of the 15 OPEs tested had IC50 values lower than 100 nM, including triphenyl phosphate (TPHP), 2-ethylhexyl diphenyl phosphate (EHDPHP), 4-isopropylphenyl diphenyl phosphate (4IPPDPP), and 4- tert -butylphenyl diphenyl phosphate (4tBPDPP), as did 4 of the commercial flame retardant mixtures tested. Because hCE1 is critical for the activation of imidapril, an angiotensin-converting enzyme-inhibitor prodrug prescribed to treat hypertension, the most potent inhibitors, TPHP and 4tBPDPP, and an environmentally relevant mixture (house dust) were further evaluated for their effect on imidapril bioactivation in vitro. TPHP and 4tBPDPP were potent inhibitors of hCE1-mediated imidapril activation (K i = 49.0 and 17.9 nM, respectively). House dust extracts (100 µg/ml) also caused significant reductions (up to 33%) in imidapril activation. Combined, these data suggest that exposure to OPEs may affect pharmacotherapy. [ABSTRACT FROM AUTHOR]

• Effective degradation of a flame retardant TCEP by TiO 2 photocatalysis. • TOC study and Cl− & PO 4 3− mass balances indicated near complete mineralization. • Degradation by-products were identified by 1H- and 31P-NMR spectroscopy. • OH mediated oxidation of the alkyl chain of TCEP mechanism was proposed. The presence of halogenated organophosphate flame retardants in natural water systems is a widespread concern because of their potential threat to human health and the environment. TiO 2 photocatalysis at 350 nm leads to rapid degradation of tris (2-chloroethyl) phosphate (TCEP). The observed degradation follows pseudo-first-order kinetics at a specific concentration. The apparent rate constants varied from 0.28 to 0.03 min−1 depending on the initial concentrations over the range of 18–270 μM, indicating the heterogeneous degradation process is likely controlled by mass transfer (adsorption↔desorption) at the surface of TiO 2. The degradation kinetics also fit the Langmuir-Hinshelwood model with apparent kinetic parameters of 0.03 μM−1 and 13.1 μM min−1 for the apparent equilibrium constant (K LH) and the reactivity constant (k rxn-LH) respectively. 1H- and 31P-NMR studies indicate sequential oxidation of the alkyl ester chains (alkyl phosphate), initially leading to the diester product, followed by the formation of the monoester and ultimately producing phosphate. Under strongly alkaline conditions the degradation is enhanced, from pH 4 to 9 the degradation is relatively constant, while under highly acidic conditions the degradation is inhibited. Effective mineralization is achieved as demonstrated by excellent chloride (98%) and phosphate (94%) mass balances as well as the loss of total organic carbon (TOC) >95%. The addition of an equal molar amount of the hydroxyl radical scavenger, coumarin, leads to pronounced reduction in degradation indicating hydroxyl radicals mediate the degradation process. These results demonstrate TiO 2 photocatalytic oxidation has promise for the treatment of aqueous solutions contaminated with organophosphate flame retardants. [ABSTRACT FROM AUTHOR]

Abstract High volume air samples were collected from April 2016 to March 2017 at five locations across the Beijing-Tianjin-Hebei (BTH) region, to investigate the atmospheric occurrence of organophosphate esters (OPEs). The mean atmospheric concentrations of ∑ 8 OPEs (gas and particle phases) varied from 531 ± 393 pg/m3 to 2180 ± 1490 pg/m3 with the highest level observed at the urban sampling site in Tianjin City. ∑ 8 OPEs were predominated by the chlorinated OPEs (TCEP, TCPP, and TDCIPP), which accounted for 60% ± 16% of the OPE concentrations across the BTH region. Generally, higher levels of gaseous OPEs were found in summer, while higher levels of particle-bound OPEs were observed in winter. The concentrations of gaseous OPEs were positively and significantly correlated with local temperatures (p < 0.05) and relative humidity (p < 0.01), while significantly positive correlations were found between concentrations of particle-bound OPEs and total suspended particulates (TSP) (p < 0.01). These findings confirmed that temperatures, relative humidity and levels of TSP are the main drivers for OPE distributions in different seasons and areas. Gas/particle partitioning of OPEs was also investigated based on the absorption-partitioning model (octanol–air partitioning coefficient (K oa) -based model) and Junge–Pankow adsorption-partitioning model (J-P model). K oa -based model generally showed a better performance in comparison with the measured results. The assessment of inhalation exposure risks indicated that relatively higher exposure risks were found in the urban areas, in particular, in Tianjin City (a median value of the estimated daily intake (EDI) of 106 pg/kg body weight/day), suggesting that more attention should be drawn to OPE distributions in the heavily industrialized megacities. Graphical abstract Image 1 Highlights • Spatial and temporal distribution of OPEs was first investigated in the BTH region, China. • OPE levels in atmosphere of the urban areas were significantly higher than the rural area. • Environmental and meteorological factors were the main drivers for OPEs distribution in different seasons and areas. The spatio-temporal distribution of OPEs was first investigated in the BTH region, China and the influence of environmental and meteorological factors was discussed. [ABSTRACT FROM AUTHOR]

• Biomarkers of OPE exposure were highly detected, suggesting widespread OPE exposure. • OPE biomarkers displayed varying temporal trends from 2007 to 2018. • Demographic characteristics were associated with urinary OPE biomarker concentrations. Organophosphate esters (OPEs), used as flame retardants and plasticizers, are chemicals of concern for maternal and infant health. Prior studies examining temporal trends and predictors of OPE exposure are primarily limited by small sample sizes. Characterize temporal trends and predictors of OPE exposure biomarkers. We determined urinary concentrations of eight biomarkers of OPE exposure at three timepoints during pregnancy for participants in the LIFECODES Fetal Growth Study (n = 900), a nested case-cohort recruited between 2007 and 2018. We examined biomarker concentrations, their variability during pregnancy, and temporal trends over the study period. In addition, we identified sociodemographic and pregnancy characteristics associated with biomarker concentrations. Analyses were conducted using both the within-subject pregnancy geometric means and biomarker concentrations measured at individual study visits. Five OPE biomarkers were detected in at least 60% of the study participants. Biomarkers were not strongly correlated with one another and intraclass correlation coefficients, measuring within-subject variability during pregnancy, ranged from 0.27 to 0.51. Biomarkers exhibited varying temporal trends across study years. For example, bis(1-chloro-2-propyl) phosphate (BCIPP) increased monotonically, whereas bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) and diphenyl phosphate (DPHP), displayed non-monotonic trends with concentrations that peaked between 2011 and 2014. We observed associations between sociodemographic characteristics and OPE biomarkers. In general, concentrations of most OPE biomarkers were higher among participants from racial and ethnic minority populations, participants who were younger, had higher pre-pregnancy body mass index (BMI), and less than a college degree. We observed consistent results using either averaged or visit-specific biomarker concentrations. We observed widespread exposure to several OPEs and OPE biomarkers displayed varying temporal trends in pregnant people from 2007 to 2018. Concentrations of most OPE biomarkers varied according to sociodemographic factors, suggesting higher burdens of exposure among participants with higher pre-pregnancy BMI, those belonging to racial and ethnic minority populations, and lower educational attainment. [ABSTRACT FROM AUTHOR]

Despite a sustained effort in surveying flame retardants (FRs) in wildlife from industrialized regions, their occurrence in birds or any other wildlife species spanning the Arctic regions, particularly in North America, has received limited attention. This study investigated in the top predator glaucous gull ( Larus hyperboreus ) breeding in the Eastern Canadian Arctic (Cape Dorset, Nunavut) a comprehensive suite of FRs including unstudied halogenated and non-halogenated FRs of potential health concern, along with legacy organochlorines and mercury. The influence of diet acquired locally and in wintering areas on the tissue contaminant profiles was also investigated using δ 15 N and δ 13 C signatures in liver and feathers. The principal constituent in the Deca-brominated diphenyl ether (BDE) mixture, BDE-209, was remarkably the most concentrated PBDE congener determined in liver samples of Eastern Canadian Arctic glaucous gulls. This suggests dietary exposure from the local marine food web and perhaps also from nearby community landfills. Moreover, this study revealed for the first time the presence of 16 emerging halogenated and non-halogenated FRs in glaucous gulls from this Arctic region including HBB, DDC-CO ( anti and syn isomers), PBEB, EHTBB, BEHTBP as well as a series of organophosphate esters (OPEs) (TCEP, TCIPP, TPP, TDCIPP, TDBPP, TBNP, TBOEP, TBEP, TCrP, EHDPP, and TEHP). With the exception of BDE-209, concentrations of other halogenated FRs and organochlorines were found to be in the lower range in liver of Eastern Canadian Arctic glaucous gulls compared to individuals from other circumpolar populations (Svalbard and Greenland). Mercury and methylmercury concentrations, however, were greater than reported elsewhere for glaucous gull populations. [ABSTRACT FROM AUTHOR]

The Hun River is an important main tributary of the Liao River system. It is located in northeast China, and provides water resources for agriculture and industry. A man made reservoir (Dahuofang Reservoir, DHF) has been constructed mid-stream in the Hun River, supplying drinking water to surrounding cities. Pollution from organic contaminants is of great concern. In the present study, 40 sediment samples were collected and analyzed for the occurrence and distribution of two groups of emerging organic pollutants; namely, organophosphate esters (OPs) and synthetic musks (SMs). In all samples taken from upstream of the Hun River (UHR), downstream of the Hun River (DHR), and from DHF, the following concentrations were recorded: 0.141–4.39, 1.21–245, and 0.117–0.726 µg/kg galaxolide (HHCB), and 0.098–3.82, 2.79–213, 0.430–0.956 µg/kg tonalide (AHTN), respectively. For OPs, seven target analytes were detected in most of the sediment samples, with chlorinated OPs Tris-(2-chloroethyl) phosphate and Tris(2-chloro-isopropyl) phosphate being the dominant components, at levels varied in the range of LOD-0.810, ND-49.6, and 0.532–3.18 µg/kg, and LOD-0.786, ND-60.1, and 0.352–1.32 µg/kg from UHR, DHR and DHF, respectively. The elevated levels of these target compounds were detected in DHR, including its two main tributaries, Xi River and Pu River, which drain through cities with industrial development and dense populations. Our results indicate that domestic and industrial wastewater contributed to OPs and SMs sediment pollution, posing low to medium ecological risks to sediment dwelling organisms. [ABSTRACT FROM AUTHOR]

Organophosphite antioxidants (OPAs) and organophosphate esters (OPEs) are used as additives in food packaging. Because these chemicals have been found in various foods, they have caused increasing concern about potential health risks through food intake. Little information is available about the migration behaviors of OPAs and OPEs from single-use food packaging into food. In the present study, four OPAs and 23 OPEs were analyzed in paper and plastic single-use food packaging (n = 312), which are widely used for take-out food in China. The total concentrations of OPAs and OPEs in the packaging samples were 1966 and 189 ng/g, respectively. Tris (2,4-di- tert -butylphenyl) phosphite (AO168) was the dominant compound. OPAs and OPEs were present at higher concentrations in the plastic packaging than in the paper packaging. In a migration test, four OPAs and 15 OPEs were found in food simulants (4% acetic acid, 10% ethanol, and hexane). Higher levels of individual and total OPAs were found in hexane than the other food simulants, especially for AO168 migration from plastic packaging. The amounts of OPEs in the food simulants increased from the aqueous simulants (4% acetic acid and 10% ethanol) to the fatty food simulant (hexane). The migration efficiencies of the OPAs were higher than those of the OPEs. Preliminary calculations suggest that dietary exposure to OPAs and OPEs because of migration will be low for the population in China. [Display omitted] • OPAs and OPEs were existed in single-use food packaging and food simulants. • OPAs/OPEs had higher concentrations in plastic materials than paper materials. • OPAs had higher migration efficiencies than OPEs. • Dietary risk by migration of OPAs/OPEs from single-use food packaging was low. • Migration of OPAs/OPEs from single-use food packaging was firstly studied. [ABSTRACT FROM AUTHOR]

Tris(2-butoxyethyl) phosphate (TBOEP) is an organophosphate ester used as substitute following the phase-out of brominated flamed retardants. Because of its high production volume and its use in a broad range of applications, this chemical is now frequently detected in the environment and biota. However, limited information is available on the long-term effects of TBOEP in aquatic organisms. In this study, Daphnia magna were exposed over three 21d generations to an environmentally relevant concentration of TBOEP (10 μg/L) and effects were evaluated at the gene transcription, protein, and life-history (i.e., survival, reproduction and growth) levels. Chronic exposure to TBEOP did not impact survival or reproduction of D. magna but affected the growth output. The mean number of molts was also found to be lower in daphnids exposed to the chemical compared to control for a given generation, however there were no significant differences over the three generations. Molecular responses indicated significant differences in the transcription of genes related to growth, molting, ecdysteroid and juvenile hormone signaling, proteolysis, oxidative stress, and oxygen transport within generations. Levels of mRNA were also found to be significantly different for genes known to be involved in endocrine-mediated mechanisms such as reproduction and growth between generations F0, F1, and F2, indicating effects of parental exposure on offspring. Transcription results were supported by protein analyses with the significant decreased in catalase (CAT) activity in F1 generation, following the decreased transcription of cat in the parental generation. Taken together, these multi-biological level results suggest long-term potential endocrine disruption effects of TBOEP in D. magna exposed to an environmentally relevant concentration. This study highlights the importance of using chronic and multigenerational biological evaluation to assess risks of emerging chemicals. [ABSTRACT FROM AUTHOR]

67 soil samples from the road greenbelts, the paddy/vegetable fields, the parks, the commercial and residential areas in the subtropical city, Guangzhou, China, were collected and analyzed for 11 organophosphate esters (OPEs) and triphenylphosphine oxide (TPPO). OPEs were detected in all soil samples analyzed, which indicate that OPEs are ubiquitous environmental contaminants. The ∑ 11 OPEs concentrations ranged from 0.041 mg kg −1 -dry weight (dw) to 1.37 mg kg −1 -dw, with the mean and median concentrations of 0.25 mg kg −1 -dw and 0.24 mg kg −1 -dw, respectively. High concentrations of OPEs were observed in the roadside soils collected from the commercial areas with heavy traffic and extensive anthropogenic activities. Of 11 OPEs, tris(2-butoxyethyl) phosphate (TBOEP), tri-cresyl-phosphate (TMPP), tributyl phosphate (TNBP) and tris(2-chloroethyl) phosphate (TCEP) were the most abundant OPEs, contributing 42.8 ± 15.4%, 17.2 ± 11.9%, 10.9 ± 6.85% and 9.70 ± 9.56% of ∑ 11 OPEs, respectively. Principal component analysis (PCA) suggested that OPEs accumulation in the urban soils derived from different sources. As compared to the results for other studies, the urban soils of Guangzhou were moderately polluted by OPEs. [ABSTRACT FROM AUTHOR]

Organophosphate esters (OPEs) are chemical compounds incorporated intomaterials as flame-proof and/or plasticizing agents. In thiswork, 13 non-halogenated and 5 halogenated OPEs were studied. Their mass spectra were interpreted and compared in terms of fragmentation patterns and dominant ions via various ionization techniques [electron ionization (EI) and chemical ionization (CI) under vacuum and corona discharge atmospheric pressure chemical ionization (APCI)] on gas chromatography coupled to mass spectrometry (GC-MS). The novelty of this paper relies on the investigation of APCI technique for the analysis of OPEs via favored protonationmechanism, where the mass spectra weremostly dominated by the quasi-molecular ion [M+H]+. The EI mass spectra were dominated by ions such as [H4PO4]+, [M-R]+, [M-Cl]+, and [M-Br]+, and for some non-halogenated aryl OPEs, [M]+• was also observed. The CI mass spectra in positivemode were dominated by [M+H]+ and sometimes by [M-R]+, while in negative mode, [M-R]- and more particularly [X]- and [X2]-• were mainly observed for the halogenated OPEs. Both EI and APCI techniques showed promising results for further development of instrumental method operating in selective reaction monitoring mode. Instrumental detection limits by using APCI mode were 2.5 to 25 times lower than using EI mode for the non-brominated OPEs, while they were determined at 50-100 times lower by the APCI mode than by the EI mode, for the two brominated OPEs. The method was applied to fish samples, and monitored transitions by using APCI mode showed higher specificity but lower stability comparedwith EI mode. The sensitivity in terms of signal-to-noise ratio varying fromone compound to another. [ABSTRACT FROM AUTHOR]

Background: Attention-deficit/hyperactivity-disorder (ADHD) is a leading neurodevelopmental disorder in children worldwide; however, few modifiable risk factors have been identified. Organophosphate esters (OPEs) are ubiquitous chemical compounds that are increasingly prevalent as a replacement for other regulated chemicals. Current research has linked OPEs to neurodevelopmental deficits. The purpose of this study was to assess gestational OPE exposure on clinically-assessed ADHD in children at age 3 years.Methods: In this nested case-control study within the Norwegian Mother, Father, and Child Cohort study, we evaluated the impact of OPE exposure at 17 weeks' gestation on preschool-age ADHD. Between 2007 and 2011, 260 ADHD cases were identified using the Preschool Age Psychiatric Assessment and compared to a birth-year-stratified control group of 549 children. We categorized bis(2-butoxyethyl) phosphate (BBOEP) and bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) as values < limit of detection (LOD) (BBOEP N = 386, BDCIPP N = 632), ≥LOD but < limit of quantification (LOQ) (BBOEP N = 413; BDCIPP N = 75), or above LOQ (BBOEP N = 70; BDCIPP N = 102). Diphenyl phosphate (DPhP) and di-n-butyl phosphate (DnBP) were categorized as quartiles and also modeled with a log10 linear term. We estimated multivariable adjusted odds ratios (ORs) using logistic regression and examined modification by sex using an augmented product term approach.Results: Mothers in the 3rd DnBP quartile had 1.71 times the odds of having a child with ADHD compared to the 1st quartile (95%CI: 1.13, 2.58); a similar trend was observed for log10 DnBP and ADHD. Mothers with BDCIPP ≥ LOD but < LOQ had 1.39 times the odds of having a child with ADHD compared to those with BDCIPP < LOD (95%CI: 0.83, 2.31). Girls had lower odds of ADHD with increasing BBOEP exposure (log10 OR: 0.55 (95%CI: 0.37, 0.93), however boys had a weakly increased odds (log10 OR: 1.25 (95%CI: 0.74, 2.11) p-interaction = 0.01].Conclusions: We found modest increased odds of preschool ADHD with higher DnBP and BDCIPP exposure. [ABSTRACT FROM AUTHOR]