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Articles de revues sur le sujet « OPES »

Auteur : Grafiati

Publié le 10 mars 2023

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Hu, Zhihui, Lingshi Yin, Xiaofeng Wen, et al. "Organophosphate Esters in China: Fate, Occurrence, and Human Exposure." Toxics 9, no. 11 (2021): 310. http://dx.doi.org/10.3390/toxics9110310.

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Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers. OPEs have been released into various environments (e.g., water, sediments, dust and air, and soil). To investigate the occurrence and distribution of OPEs in various environments in China, this review collects and discusses the published scientific studies in this field. Chlorinated OPEs, as flame retardants, are the predominant OPEs found in the environment. The analysis of data revealed large concentration variations among microenvironments, including inflowing river water (range: 0.69–10.62 µgL−1), sediments (range: 0.0197–0.234 µg/g), dust (range: 8.706–34.872 µg/g), and open recycling sites’ soil (range: 0.122–2.1 µg/g). Moreover, OPEs can be detected in the air and biota. We highlight the overall view regarding environmental levels of OPEs in different matrices as a starting point to monitor trends for China. The levels of OPEs in the water, sediment, dust, and air of China are still low. However, dust samples from electronic waste workshop sites were more contaminated. Human activities, pesticides, electronics, furniture, paint, plastics and textiles, and wastewater plants are the dominant sources of OPEs. Human exposure routes to OPEs mainly include dermal contact, dust ingestion, inhalation, and dietary intake. The low level of ecological risk and risk to human health indicated a limited threat from OPEs. Furthermore, current challenges and perspectives for future studies are prospected. A criteria inventory of OPEs reflecting the levels of OPEs contamination association among different microenvironments, emerging OPEs, and potential impact of OPEs on human health, particularly for children are needed in China for better investigation.

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Gong, Cheng, and Hong Liao. "A typical weather pattern for ozone pollution events in North China." Atmospheric Chemistry and Physics 19, no. 22 (2019): 13725–40. http://dx.doi.org/10.5194/acp-19-13725-2019.

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Abstract. Ground-level observations, reanalyzed meteorological fields and a 3-D global chemical and transport model (GEOS-Chem) were applied in this study to investigate ozone (O3) pollution events (OPEs) in North China (36.5–40.5∘ N, 114.5–119.5∘ E) during 2014–2017. Ozone pollution days (OPDs) were defined as days with maximum daily averaged 8 h (MDA8) concentrations over North China larger than 160 µg m−3, and OPEs were defined as periods with 3 or more consecutive OPDs. Observations showed that there were 167 OPDs and 27 OPEs in North China during 2014–2017, in which 123 OPDs and 21 OPEs occurred from May to July. We found that OPEs in North China occurred under a typical weather pattern with high daily maximum temperature (Tmax), low relative humidity (RH), anomalous southerlies and divergence in the lower troposphere, an anomalous high-pressure system at 500 hPa, and an anomalous downward air flow from 500 hPa to the surface. Under such a weather pattern, chemical production of O3 was high between 800 and 900 hPa, which was then transported downward to enhance O3 pollution at the surface. A standardized index I_OPE was defined by applying four key meteorological parameters, including Tmax, RH, meridional winds at 850 hPa (V850) and zonal winds at 500 hPa (U500). I_OPE can capture approximately 80 % of the observed OPDs and OPEs, which has implications for forecasting OPEs in North China.

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Zhou, Qi, Zihao Wei, Yanan Xu, and Changhu Xue. "Fibrous and Spherical Aggregates of Ovotransferrin as Stabilizers for Oleogel-Based Pickering Emulsions: Preparation, Characteristics and Curcumin Delivery." Gels 8, no. 8 (2022): 517. http://dx.doi.org/10.3390/gels8080517.

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This study aimed to explore the effects and mechanisms of differently shaped aggregates of ovotransferrin (OVT) particles on oleogel-based Pickering emulsions (OPEs). Medium-chain triglyceride oil-based oleogels were constructed using beeswax, and their gel-sol melting temperatures were investigated. Atomic force microscopy confirmed that both OVT fibrils and OVT spheres were successfully prepared, and the three-phase contact angle measurements indicated that fibrous and spherical aggregates of OVT particles possessed great potential to stabilize the OPEs. Afterward, the oil-in-water OPEs were fabricated using oleogel as the oil phase and OVT fibrils/spheres as the emulsifiers. The results revealed that OPEs stabilized with OVT fibrils (FIB-OPEs) presented a higher degree of emulsification, smaller droplet size, better physical stability and stronger apparent viscosity compared with OPEs stabilized with OVT spheres (SPH-OPEs). The freeze–thaw stability test showed that the FIB-OPEs remained stable after three freeze–thaw cycles, while the SPH-OPEs could barely withstand one freeze–thaw cycle. An in vitro digestion study suggested that OVT fibrils conferred distinctly higher lipolysis (46.0%) and bioaccessibility (62.8%) of curcumin to OPEs.

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Yin, Hongling, Jinfeng Liang, Di Wu, Shiping Li, Yi Luo, and Xu Deng. "Measurement report: Seasonality, distribution and sources of organophosphate esters in PM<sub>2.5</sub> from an inland urban city in Southwest China." Atmospheric Chemistry and Physics 20, no. 23 (2020): 14933–45. http://dx.doi.org/10.5194/acp-20-14933-2020.

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Abstract. Organophosphate esters (OPEs) are contaminants of emerging concern, and studies have concluded that urban areas are a significant source of OPEs. Samples were collected from six ground-based sites located in Chengdu, a typical rapidly developing metropolitan area in Southwest China, and were analyzed for seven OPEs in atmospheric PM2.5 (Σ7 OPEs). The concentrations of Σ7 OPEs in PM2.5 ranged from 5.83 to 6.91 ng m−3, with a mean of 6.6 ± 3.3 ng m−3, and the primary pollutants were tris-(2-butoxyethyl) phosphate (TBEP), tri-n-butyl phosphate (TnBP), tris-(2-chloroethyl) phosphate (TCEP) and tris-(2-chloroisopropyl) phosphate (TCPP), which together made up more than 80 % of the Σ7 OPEs. The concentrations of Σ7 OPEs were higher in autumn and winter than in summer. Nonparametric tests showed that there was no significant difference in Σ7 OPE concentrations among the six sampling sites, but the occurrence of unexpectedly high levels of individual OPEs at different sites in autumn might indicate noteworthy emissions. A very strong correlation (R2 = 0.98, p < 0.01) between the OPEs in soil and in PM2.5 was observed. Backward trajectory analysis indicated that the OPEs in PM2.5 were mainly affected by local sources. Principal component analysis (PCA) revealed that the OPEs in PM2.5 were largely sourced from the plastics industry, interior decoration and traffic emission (34.5 %) and the chemical, mechanical and electrical industries (27.8 %), while the positive matrix factorization (PMF) model revealed that the main sources were the plastics industry and indoor source emissions, the food and cosmetics industry and industrial emissions. In contrast to coastal cities, sustained and stable high local emissions in the studied inland city were identified, which is particularly noteworthy. Chlorinated phosphates, especially TCPP and TCEP, had a high content, and their usage and source emissions should be controlled.

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Liu, Wenxin, Hong Zhang, Jiaqi Ding, Wanyu He, Lin Zhu, and Jianfeng Feng. "Waterborne and Dietary Bioaccumulation of Organophosphate Esters in Zooplankton Daphnia magna." International Journal of Environmental Research and Public Health 19, no. 15 (2022): 9382. http://dx.doi.org/10.3390/ijerph19159382.

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Organophosphate esters (OPEs) are widely used as an additive in flame retardants, plasticizers, lubricants, consumer chemicals, and foaming agents. They can accumulate in aquatic organisms from water (waterborne exposure) and food (dietary exposure). However, the bioaccumulation characteristics and relative importance of different exposure routes to the bioaccumulation of OPEs are relatively poorly understood. In this study, Daphnia magna were exposed to fo typical OPEs (tris(2-chloroethyl) phosphate (TCEP), tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), tris(2-butoxyethyl) phosphate (TBOEP), and triphenyl phosphate (TPHP)), and their toxicokinetics under waterborne and dietary exposure routes were analyzed. For the waterborne exposure route, the bioconcentration factors (BCFs) increased in the order of TBOEP, TCEP, TDCPP, and TPHP, which were consistent with their uptake rate constants. TPHP might have the most substantial accumulation potential while TBOEP may have the smallest potential. In dietary exposure, the depuration rate constants of four OPEs were different from those in the waterborne experiment, which may indicate other depuration mechanisms in two exposure routes. The biomagnification factors (BMFs) of fur OPEs were all below 1, suggesting trophic dilution in the transfer of four OPEs from Scenedesmus obliquus to D. magna. Except for TBOEP, the contributions of dietary exposure were generally lower than waterborne exposure in D. magna under two exposure concentrations. This study provides information on the bioaccumulation and contribution of OPEs in D. magna via different exposure routes and highlights the importance of considering different exposure routes in assessing the risk of OPEs.

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Luo, Haiying, Yanping Xian, Xindong Guo, et al. "Dispersive Liquid-Liquid Microextraction Combined with Ultrahigh Performance Liquid Chromatography/Tandem Mass Spectrometry for Determination of Organophosphate Esters in Aqueous Samples." Scientific World Journal 2014 (2014): 1–9. http://dx.doi.org/10.1155/2014/162465.

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A new technique was established to identify eight organophosphate esters (OPEs) in this work. It utilised dispersive liquid-liquid microextraction in combination with ultrahigh performance liquid chromatography/tandem mass spectrometry. The type and volume of extraction solvents, dispersion agent, and amount of NaCl were optimized. The target analytes were detected in the range of 1.0–200 µg/L with correlation coefficients ranging from 0.9982 to 0.9998, and the detection limits of the analytes were ranged from 0.02 to 0.07 µg/L(S/N=3). The feasibility of this method was demonstrated by identifying OPEs in aqueous samples that exhibited spiked recoveries, which ranged between 48.7% and 58.3% for triethyl phosphate (TEP) as well as between 85.9% and 113% for the other OPEs. The precision was ranged from 3.2% to 9.3% (n=6), and the interprecision was ranged from 2.6% to 12.3% (n=5). Only 2 of the 12 selected samples were tested to be positive for OPEs, and the total concentrations of OPEs in them were 1.1 and 1.6 µg/L, respectively. This method was confirmed to be simple, fast, and accurate for identifying OPEs in aqueous samples.

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Waterstone, Marv. "T(r)Opes: Geographicus Interruptus." Environment and Planning A: Economy and Space 36, no. 3 (2004): 481–89. http://dx.doi.org/10.1068/a3658.

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Viott, R. C., T. A. Menezes, A. P. G. Mellagi, M. L. Bernardi, I. Wentz, and F. P. Bortolozzo. "Performance of low birth-weight piglets upon protein-energy and/or colostrum supplementation." Arquivo Brasileiro de Medicina Veterinária e Zootecnia 70, no. 4 (2018): 1293–300. http://dx.doi.org/10.1590/1678-4162-9798.

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ABSTRACT The study aimed to investigate the effect of oral protein-energy supplement (OPES) and/or extra colostrum within the first few hours of life on the survival and growth performance of low birth-weight piglets during the suckling period. Based upon nutritional strategy, low-birth-weight piglets (804−1309g) were randomly allocated into four groups: C0S0 (control group, n= 300) - no supplementation; C1S0 (n= 299) - supplementation with 50mL of a colostrum pool through an orogastric tube; C0S1 (n= 298) - oral supplementation with 8mL oral OPES; C1S1 (n= 297) - supplementation with both 50mL of colostrum and 8mL of OPES. The piglets’ body weight was monitored at birth, 24h after birth, on day 7, day 14 and day 20 post-partum. Both colostrum and protein-energy supplementations did not affect (P>0.05) colostrum intake (253.6g; 259.4g; 259.4g; 263.8g for C0S0, C1S0, C0S1, C1S1, respectively), weight gain during the first 24h (62.6g; 68.3g; 67.1g and 69.8g for C0S0, C1S0, C0S1, C1S1, respectively) and pre-weaning mortality (11.3%, 11.4%, 12.4% and 9.4% for C0S0, C1S0, C0S1, C1S1, respectively). Administration of OPES increased (P= 0.032) the average daily weight gain from birth till weaning (189.1 vs. 182.3g) and tended to increase the weight of the piglets (P= 0.060) at weaning (4893.1 vs. 4746.4g for OPES and no OPES, respectively). In conclusion, nutritional manipulation does not affect colostrum intake and pre-weaning mortality of low birth-weight piglets. However, body weight gain during the suckling period and the weight at weaning were observed to be marginally improved by administration of OPES.

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Wang, Xiaotong, Trang Luu, Marc A. Beal, Tara S. Barton-Maclaren, Bernard Robaire, and Barbara F. Hales. "The Effects of Organophosphate Esters Used as Flame Retardants and Plasticizers on Granulosa, Leydig, and Spermatogonial Cells Analyzed Using High-Content Imaging." Toxicological Sciences 186, no. 2 (2022): 269–87. http://dx.doi.org/10.1093/toxsci/kfac012.

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Abstract The replacement of regulated brominated flame retardants and plasticizers with organophosphate esters (OPEs) has led to their pervasive presence in the environment and in biological matrices. Further, there is evidence that exposure to some of these chemicals is associated with reproductive toxicity. Using a high-content imaging approach, we assessed the effects of exposure to 9 OPEs on cells related to reproductive function: KGN human granulosa cells, MA-10 mouse Leydig cells, and C18-4 mouse spermatogonial cells. The effects of OPEs were compared with those of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), a legacy brominated flame retardant. Alterations in several important cell features, including cell survival, mitochondrial dynamics, oxidative stress, lysosomes, and lipid droplets, were analyzed. Most of the OPEs tested displayed higher cytotoxicity than BDE-47 in all 3 cell lines. Effects on phenotypic parameters were specific for each cell type. Several OPEs increased total mitochondria, decreased lysosomes, increased the total area of lipid droplets, and induced oxidative stress in KGN cells; these endpoints were differentially affected in MA-10 and C18-4 cells. Alterations in cell phenotypes were highly correlated in the 2 steroidogenic cell lines for a few triaryl OPEs. Potency ranking using 2 complementary approaches, Toxicological Prioritization Index analyses and the lowest benchmark concentration/administered equivalent dose method, revealed that while most of the OPEs tested were more potent than BDE-47, others showed little to no effect. We propose that these approaches serve as lines of evidence in a screening strategy to identify the potential for reproductive and endocrine effects of emerging chemicals and assist in regulatory decision-making.

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Fattori, B., P. Giusti, V. Mancini, et al. "ACTA OTORHINOLARYNGOLOGICA ITALICA." Acta Otorhinolaryngologica Italica 36, no. 5 (2016): 395–402. http://dx.doi.org/10.14639/0392-100x-829.

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L’obiettivo di questo studio era quello di confrontare la Videofluoroscopia (VFS), la valutazione endoscopica a fibre ottiche della deglutizione (FEES) e la scintigrafia oro-faringo-esofagea (OPES) per quanto riguarda la caduta pre-deglutitoria, il ristagno post-deglutitorio e l’aspirazione, al fine di valutare l’attendibilità di questi test nel rilevare la disfagia orofaringea. Sessanta pazienti, affetti da disfagia di varia origine, sono stati arruolati nello studio e sottoposti a VFS, FEES e OPES utilizzando un bolo liquido e uno semi-solido. Abbiamo usato la VFS come esame di riferimento. La FEES e la OPES hanno entrambe mostrato una buona sensibilità, con valori complessivi elevati (rispettivamente ≥ 80% e ≥ 90%). Il confronto tra FEES e VFS relativamente alla caduta pre-deglutitoria ha evidenziato una buona specificità (84,4% per i semi-solidi e 86,7% per i liquidi). Nel caso di ristagni post-deglutitori, il confronto tra FEES e VFS ha rivelato una buona validità complessiva (75% per i semi-solidi), con specificità e sensibilità ben equilibrate per i semi-solidi. Il confronto tra OPES e VFS ha dimostrato buona sensibilità (88,6%) e validità complessiva (76,7%) per i liquidi. Il confronto dei dati ottenuti tra FEES e VFS, relativamente all’ aspirazione, ha evidenziato una bassa validità complessiva (≤ 65%). D’altra parte, la OPES ha mostrato una validità complessiva apprezzabile (71,7%). VFS, FEES e OPES sono in grado di rilevare la disfagia oro-faringea. La FEES ha fornito risultati significativi nella valutazione dei ristagni post-deglutitori.

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Li, Haihong, Mingli Ye, Fangfang Wu, et al. "Determination of Organophosphorus Esters in Fall Protection Equipment by Accelerated Solvent Extraction and Solid-Phase Extraction Coupled with LC-MS/MS Detection." Journal of Analytical Methods in Chemistry 2021 (January 5, 2021): 1–7. http://dx.doi.org/10.1155/2021/8878247.

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An analysis method was established to determine 14 organophosphorus ester (OPE) flame retardants in fall protection equipment by combining accelerated solvent extraction (ASE) and solid-phase extraction (SPE) with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The ASE parameters were optimized as follows: static extraction with acetonitrile at 80°C for 5 min for two cycles. The combined extract was purified with the ENVI-18 cartridge before further analysis. A HILIC column was used to separate the OPEs using an acetonitrile/water mixture as the mobile phase with the detection by the electrospray ionization mass spectrometry, which was operated under the positive mode. Under optimized conditions, the limit of detection for the target OPEs ranged in 0.015–1.33 ng/g, with a spike recovery of 71.6%–114% and a relative standard deviation of 0.8%–11.2%. The developed method was used to analyze OPEs in fall protection equipment (safety helmets and ropes), where OPEs were all detectable. Safety ropes displayed a higher concentration of OPEs than ones in safety helmets, with the pollutants being mainly triphenyl phosphate, 2-ethylhexyl diphenyl phosphate (EHDPP), tri(2-ethylhexyl) phosphate, and tri-n-butyl phosphate in the range of 11.07 ng/g‒815.53 ng/g. The EHDPP was the dominant compound in safety helmets with the concentration from 26.84 to 95.29 ng/g, while the other OPEs in safety helmets were lower than 5.136 ng/g. The potential health and environmental risks of these fall protection equipment during their use and disposal call for further attention.

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Li, Xiaomin, Nannan Zhao, Jie Fu, et al. "Organophosphate Diesters (Di-OPEs) Play a Critical Role in Understanding Global Organophosphate Esters (OPEs) in Fishmeal." Environmental Science & Technology 54, no. 19 (2020): 12130–41. http://dx.doi.org/10.1021/acs.est.0c03274.

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Wang, Yujie, Ming Yang, Fushun Wang, Xueping Chen, Minghong Wu, and Jing Ma. "Organophosphate Esters in Indoor Environment and Metabolites in Human Urine Collected from a Shanghai University." International Journal of Environmental Research and Public Health 18, no. 17 (2021): 9212. http://dx.doi.org/10.3390/ijerph18179212.

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In China, organophosphate esters (OPEs) are widely used in indoor environments. However, there is little information regarding the internal and external exposure of university students to OPEs. Therefore, in this study, nine OPEs and eight OPE metabolites (mOPEs) were measured in indoor dust and atmospheric PM2.5 samples from a university campus in Shanghai, as well as in urine samples collected from the university students. The total concentration of OPEs in the indoor dust in female dormitories (1420 ng/g) was approximately twice that in male dormitories (645 ng/g). In terms of indoor PM2.5, the highest OPE concentration was found in meeting rooms (105 ng/m3, on average), followed by chemical laboratories (51.2 ng/m3), dormitories (44.9 ng/m3), and offices (34.9 ng/m3). The total concentrations of the eight mOPEs ranged from 279 pg/mL to 14,000 pg/mL, with a geometric mean value of 1590 pg/mL. The estimated daily intake values based on the indoor dust and PM2.5 OPE samples (external exposure) were 1–2 orders of magnitude lower than that deduced from the concentration of urinary mOPEs (internal exposure), indicating that dermal contact, dust ingestion, and inhalation do not contribute significantly to OPE exposure in the general population. Moreover, additional exposure routes lead to the accumulation of OPEs in the human body.

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Harino, Hiroya, Emi Yatsuzuka, Chiaki Yamao, Masaaki Ueno, and Madoka Ohji. "Current status of organophosphorus compounds contamination in Maizuru Bay, Japan." Journal of the Marine Biological Association of the United Kingdom 94, no. 1 (2013): 43–49. http://dx.doi.org/10.1017/s002531541300129x.

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The concentrations of organophosphoric acid triesters (OPEs) in water samples from Maizuru Bay were in the range of 3.0–62 ng/l. In general, the concentrations of OPEs were found in the order of TBXP > TDCPP > TCEP > TBP > TCP > TPP > TEP. The organophosphorous pesticides (OPPs) diazinon, fenitrothion, iprobenfos and chlorpyrifos were detected in water samples. The concentrations of OPEs in sediment from Maizuru Bay were in the range of <0.5–56 µg kg−1 dry weight (dw). Among OPPs, diazinon in sediment samples were in the range of 1.8–71 µg kg−1 dw. However, the detection frequencies of fenitrothion and chlorpyrifos in sediment were low. The concentrations of OPEs in mussels from Maizuru Bay were in the range of <1–34 µg kg−1 wet weight (ww). The concentrations of OPEs were found in the order of TBP > TDCPP > TCP > TBXP = TPP = TCEP. Pesticides were detected in mussels, but these concentrations were lower than the acceptable daily intake (ADI) values. The partition coefficients between water and sediment (Kws) of diazinon and fenitrothion were 200–1300 and 200–300, respectively and the partition coefficients between water and biological samples (Kwb) of diazinon and fenitrothion were 700–3300 and 450–700, respectively, suggesting that these pesticides accumulate in biological samples at higher rates than in sediment.

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Rajappan, Sinu C., Olav Vestrheim, Mona Sharafi, Jianing Li, and Severin T. Schneebeli. "Carbonyl-to-Alkyne Electron Donation Effects in up to 10-nm-Long, Unimolecular Oligo(p-phenylene ethynylenes)." Organic Materials 03, no. 02 (2021): 337–45. http://dx.doi.org/10.1055/s-0041-1730899.

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We synthesized some of the longest unimolecular oligo(p-phenylene ethynylenes) (OPEs), which are fully substituted with electron-withdrawing ester groups. An iterative convergent/divergent (a.k.a. iterative exponential growth – IEG) strategy based on Sonogashira couplings was utilized to access these sequence-defined macromolecules with up to 16 repeating units and 32 ester substituents. The carbonyl groups of the ester substituents interact with the triple bonds of the OPEs, leading to (i) unusual, angled triple bonds with increased rotational barrier, (ii) enhanced conformational disorder, and (iii) associated broadening of the UV/Vis absorption spectrum. Our results demonstrate that fully air-stable, unimolecular OPEs with ester groups can readily be accessed with IEG chemistry, providing new macromolecular backbones with unique geometrical, conformational, and photophysical properties.

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Liu, Yunlang, Tingting Zhu, Zuoming Xie, et al. "Human Exposure to Chlorinated Organophosphate Ester Flame Retardants and Plasticizers in an Industrial Area of Shenzhen, China." International Journal of Environmental Research and Public Health 19, no. 5 (2022): 3126. http://dx.doi.org/10.3390/ijerph19053126.

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Human exposure to organophosphate esters (OPEs) is more pervasive in industrial areas manufacturing OPE-related products. OPE exposure is of great concern due to its associations with adverse health effects, while studies on OPE exposure in industrial districts are scarce. This study aimed to assess human exposure to OPEs in a typical industrial area producing large amounts of OPE-related products in Shenzhen, China. Tris (2-chloroethyl)-phosphate (TCEP), tris (2-chloroisopropyl) phosphate (TCPP) and other common OPEs were analyzed in urine (n = 30) and plasma (n = 21) samples. Moreover, we measured five OPE metabolites (mOPEs) in plasma samples (n = 21). The results show that TCPP and TCEP are dominant compounds, with moderate to high levels compared with those reported in urine and plasma samples from other regions. In addition, di-n-butyl phosphate (DnBP) and diethyl phosphite (DEP) were frequently detected in plasma samples and could be considered as biomarkers. Risk assessment revealed a moderate to high potential health risk from TCEP exposure. Our results provide basic data for human exposure to OPEs in industrial areas and call for the prevention and mitigation of industrial chlorinated OPE pollution.

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Shimazu, Haruki. "Characteristics of Organophosphate Ester Formation during Smoking." Environment and Pollution 7, no. 2 (2018): 32. http://dx.doi.org/10.5539/ep.v7n2p32.

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This study examines the occurrence of organophosphate esters (OPEs) in cigarettes and sidestream cigarette smoke and to see the OPE formation characteristics during smoking. All seven OPEs in both gas and particulate phases were measured in sidestream cigarette smoke for four brands of cigarettes. Tributyl phosphate (TBP), tris(2-butoxyethyl) phosphate (TBEP), tris(2-chloroethyl) phosphate (TCEP), and triphenyl phosphate (TPP) were found frequently. Median total OPE increases in the air samples during smoking were 56.2 ng per cigarette for gas-phase OPEs and 2360 ng per cigarette for particulate-phase OPEs. TBP and TCEP could be absorbed to particles in air more readily than alkans as seen from the correlation line between gas&ndash;particle partition coefficients (Kp) and the subcooled liquid vapor pressures (PL&ordm;) for alkans. Furthermore, TBP was determined in the cigarettes. Median total OPE decreases in the cigarette samples during smoking were 1200 ng per cigarette. The combustion reaction increased TBP and TBEP levels in cigarettes, and particulate-phase TBEP in air appeared to influence the production of TBP, TCEP, and TPP. TBP and TBEP in cigarettes likely affect the production of TBP, TBEP, TCEP, and TPP in air during smoking.

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Fukushima, M., S. Kawai, and Y. Yamaguchi. "Behavior of Organophosphoric Acid Triesters in Japanese Riverine and Coastal Environment." Water Science and Technology 25, no. 11 (1992): 278. http://dx.doi.org/10.2166/wst.1992.0302.

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The long-term monitoring of organophosphoric acid triesters started in 1976 in the Yodo River basin; Lake Biwa, Yodo River and the rivers in Osaka City. An extensive survey was also conducted in the Yamato River and Osaka Bay, Japan. This report presents the current levels and distributions of OPEs as well as the historical trend of TDCPP. Some or all of OPEs studied here have been detected in the entire water samples over the monitoring period. It was clear that OPEs were ubiquitous pollutants in the river and coastal waters. Total OPE levels ranged from 0.4 to 2.4 µgl−1 in the Yodo River basin, 2.4 to 12 µgl−1 in the rivers in Osaka City, 18 to 28 µgl−1 in the Yamato River basin and 0.1 to 1.3 µgl−1 in Osaka Bay. An apparent difference was found in the individual OPE level among the different water areas surveyed. In the Lake Biwa and the Yodo River, the predominant compound was TBXP followed by TCEP and TDCPP. The higher levels were observed for TBXP, TEP, TCPP and TCEP in the rivers in Osaka City. The highest TCPP level, which occupied more than 70% of OPEs' composition, was observed and the mean level reached to 13.1µgl−1 in the Yamato River. In Osaka Bay, 6 kinds of OPEs, except for TPP, TEHP and TCP, were found and the most prevalent compounds were TCEP and TBP. TDCPP had gradually increased in concentration in the Yodo River basin until 1987 from 1976 year by year. However, the reverse trend of TDCPP has been noticed during the last several years.

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Chen, Charlise Xinyi, Han Yan, and Barbara Hales. "Gestational and early postnatal exposure to a mixture of organophosphate ester flame retardants found in Canadian house dust on hindlimb skeletal development in postnatal day 4 rats." McGill Science Undergraduate Research Journal 15, no. 1 (2020): 18–23. http://dx.doi.org/10.26443/msurj.v15i1.5.

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Background: Ever since organophosphate esters (OPEs) became the mainstream replacement for organobromine compounds in fire retardants (FRs), numerous studies have explored their potential as endocrine disruptors and developmental toxicants. The purpose of this study is to investigate the impact of gestational and early postnatal exposure of OPE mixtures on the ossification of hindlimb phalangeal in postnatal day 4 (PND4) rat pups, as the amount of OPEs within the diet mixture is relative to its composition in Canadian household dust.Methods: Male and female adult Charles River Sprague-Dawley rats were exposed to OPE mixtures for 70 and 21 days, respectively. The OPE doses were determined to be 10x, 1,000x, and 30,000x the relative human exposure. The progenies were exposed to OPEs both gestationally (~21 days) and lactationally (4 days). At least 2 of each sex from each litter were sacrificed and processed at PND4 for skeletal staining using Alizarin red and Alcian blue. The samples were analyzed and compared against a reference sample to examine any abnormalities in ossification.Results: At PND4, there is no significant effect of OPEs on the number of pups with abnormal ossification between the control and treatment groups. High doses of OPEs, at concentrations 30,000x of relative human exposures, showed a significant increase in the severity of delay of ossification at the middle phalanx of PND4 pups.Limitations: Due to the limitation of small sample sizes (litter n=6-7) and a wide variance in data, there is no clear evidence on whether OPE exposure induces greater incidences of abnormal ossification in the digits of PND4 pups.Conclusion: There is a delay in ossification from OPE exposure at the high dose (30,000x).

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Monge, Florencia A., Adeline M. Fanni, Patrick L. Donabedian, et al. "Selective In Vitro and Ex Vivo Staining of Brain Neurofibrillary Tangles and Amyloid Plaques by Novel Ethylene Ethynylene-Based Optical Sensors." Biosensors 13, no. 2 (2023): 151. http://dx.doi.org/10.3390/bios13020151.

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The identification of protein aggregates as biomarkers for neurodegeneration is an area of interest for disease diagnosis and treatment development. In this work, we present novel super luminescent conjugated polyelectrolyte molecules as ex vivo sensors for tau-paired helical filaments (PHFs) and amyloid-β (Aβ) plaques. We evaluated the use of two oligo-p-phenylene ethynylenes (OPEs), anionic OPE12- and cationic OPE24+, as stains for fibrillar protein pathology in brain sections of transgenic mouse (rTg4510) and rat (TgF344-AD) models of Alzheimer’s disease (AD) tauopathy, and post-mortem brain sections from human frontotemporal dementia (FTD). OPE12- displayed selectivity for PHFs in fluorimetry assays and strong staining of neurofibrillary tangles (NFTs) in mouse and human brain tissue sections, while OPE24+ stained both NFTs and Aβ plaques. Both OPEs stained the brain sections with limited background or non-specific staining. This novel family of sensors outperformed the gold-standard dye Thioflavin T in sensing capacities and co-stained with conventional phosphorylated tau (AT180) and Aβ (4G8) antibodies. As the OPEs readily bind protein amyloids in vitro and ex vivo, they are selective and rapid tools for identifying proteopathic inclusions relevant to AD. Such OPEs can be useful in understanding pathogenesis and in creating in vivo diagnostically relevant detection tools for neurodegenerative diseases.

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THIELEMANS, K. "A MATHEMATICA™ PACKAGE FOR COMPUTING OPERATOR PRODUCT EXPANSIONS." International Journal of Modern Physics C 02, no. 03 (1991): 787–98. http://dx.doi.org/10.1142/s0129183191001001.

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A general purpose Mathematica™ package for computing Operator Product Expansions of composite operators in meromorphic conformal field theory is described. Given the OPEs for a set of “basic” fields, OPEs of arbitrarily complicated composites can be computed automatically. Normal ordered products are always reduced to a standard form. Two explicit examples are presented: the conformal anomaly for superstrings and a free field realization for the [Formula: see text] Kač-Moody-algebra.

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Gangemi, Chiara Maria Antonietta, Anna Barattucci, and Paola Maria Bonaccorsi. "A Portrait of the OPE as a Biological Agent." Molecules 26, no. 11 (2021): 3088. http://dx.doi.org/10.3390/molecules26113088.

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Oligophenylene ethynylenes, known as OPEs, are a sequence of aromatic rings linked by triple bonds, the properties of which can be modulated by varying the length of the rigid main chain or/and the nature and position of the substituents on the aromatic units. They are luminescent molecules with high quantum yields and can be designed to enter a cell and act as antimicrobial and antiviral compounds, as biocompatible fluorescent probes directed towards target organelles in living cells, as labelling agents, as selective sensors for the detection of fibrillar and prefibrillar amyloid in the proteic field and in a fluorescence turn-on system for the detection of saccharides, as photosensitizers in photodynamic therapy (due to their capacity to highly induce toxicity after light activation), and as drug delivery systems. The antibacterial properties of OPEs have been the most studied against very popular and resistant pathogens, and in this paper the achievements of these studies are reviewed, together with almost all the other roles held by such oligomers. In the recent decade, their antifungal and antiviral effects have attracted the attention of researchers who believe OPEs to be possible biocides of the future. The review describes, for instance, the preliminary results obtained with OPEs against severe acute respiratory syndrome coronavirus 2, the virus responsible for the COVID-19 pandemic.

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Reine, Pablo, Araceli G. Campaña, Luis Alvarez de Cienfuegos, et al. "Chiral double stapled o-OPEs with intense circularly polarized luminescence." Chemical Communications 55, no. 72 (2019): 10685–88. http://dx.doi.org/10.1039/c9cc04885e.

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Matarranz, Beatriz, Goutam Ghosh, Ramesh Kandanelli, Angel Sampedro, Kalathil K. Kartha, and Gustavo Fernández. "Understanding the role of conjugation length on the self-assembly behaviour of oligophenyleneethynylenes." Chemical Communications 57, no. 40 (2021): 4890–93. http://dx.doi.org/10.1039/d1cc01054a.

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Radić, Kristina, Bisera Jurišić Dukovski, and Dubravka Vitali Čepo. "Influence of Pomace Matrix and Cyclodextrin Encapsulation on Olive Pomace Polyphenols’ Bioaccessibility and Intestinal Permeability." Nutrients 12, no. 3 (2020): 669. http://dx.doi.org/10.3390/nu12030669.

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Olive pomace is a rich source of biologically active compounds, mainly polyphenols. Recently, an efficient and sustainable cyclodextrin (CD)-enhanced extraction was developed. It enabled a relatively simple formulation of high-quality olive pomace extracts (OPEs) that can be used as alternative sources of olive-derived polyphenols in the nutrition and pharma industries. However, biological effects and nutraceutical potential of OPEs are primarily limited by generally low oral bioavailability of major polyphenols (hydroxytyrosol and its derivatives) that can be significantly influenced by OPE matrix and the presence of CDs in formulation. The major goal of this research was to investigate the impact of complex matrix and different types of CDs on gastrointestinal stability and intestinal permeability of major OPE polyphenols, and provide additional data about mechanisms of absorption and antioxidant activity in gut lumen. Obtained results showed high bioaccessibility but relatively low permeability of OPE polyphenols, which was negatively affected by OPE matrix. CDs improved antioxidant efficiency of tested OPEs and tyrosol gastrointestinal stability. Effects of CDs on permeability and the metabolism of particular OPE polyphenols were CD- and polyphenol-specific.

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Resa, Sandra, Pablo Reiné, Luis Álvarez de Cienfuegos, et al. "Optically active Ag(i): o-OPE helicates using a single homochiral sulfoxide as chiral inducer." Organic & Biomolecular Chemistry 17, no. 36 (2019): 8425–34. http://dx.doi.org/10.1039/c9ob01573f.

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Ruan, Xinchao, Qian Lu, and Zeyu Yang. "Analytical method development for determining polycyclic aromatic hydrocarbons and organophosphate esters in indoor dust based on solid phase extraction and gas chromatography/mass spectrometry." Analytical Methods 8, no. 7 (2016): 1690–98. http://dx.doi.org/10.1039/c5ay02789f.

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Wu, Zhijiang, Jinping Liu, and Ying Peng. "QuEChERS purification prior to stable isotope dilution-ultra-high performance liquid chromatography tandem mass spectrometry to determine organophosphate esters of trace amounts in dairy products." Analytical Methods 9, no. 15 (2017): 2290–98. http://dx.doi.org/10.1039/c6ay03162e.

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Si, Hua-Yan, Le-Jia Wang, Wen-Jie Feng, et al. "Facilely controlling the Förster energy transfer efficiency of dendron encapsulated conjugated organic molecular wire–CdSe quantum dot nanostructures." New Journal of Chemistry 39, no. 3 (2015): 1916–21. http://dx.doi.org/10.1039/c4nj01888e.

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Wang, Yiping, Zhenxia Du, Yun Zhang, Lili Zhou, and Wenlian Yu. "Development of a rapid detection method for eight organophosphate esters in plastic samples from automobile interiors using ultra-performance liquid chromatography tandem mass spectrometry with microwave assisted extraction." Analytical Methods 7, no. 23 (2015): 9861–66. http://dx.doi.org/10.1039/c5ay02077h.

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Herzog, Christopher P. "OPEs and 4-point functions in AdS/CFT correspondence." Journal of High Energy Physics 2001, no. 02 (2001): 038. http://dx.doi.org/10.1088/1126-6708/2001/02/038.

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Deni, Elisa, Alicia Zamarrón, Paola Bonaccorsi, et al. "Glucose-functionalized amino-OPEs as biocompatible photosensitizers in PDT." European Journal of Medicinal Chemistry 111 (March 2016): 58–71. http://dx.doi.org/10.1016/j.ejmech.2016.01.041.

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Yin, Yuhan, Nannan Zhao, Liu Yifei, et al. "Deposition, bioaccumulation and depletion of organophosphate triesters (tri-OPEs) and their organophosphate diester metabolites (di-OPEs) from feed to laying hens’ eggs." Journal of Hazardous Materials 440 (October 2022): 129858. http://dx.doi.org/10.1016/j.jhazmat.2022.129858.

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Percy, Zana, Ann M. Vuong, Yingying Xu, et al. "Maternal Urinary Organophosphate Esters and Alterations in Maternal and Neonatal Thyroid Hormones." American Journal of Epidemiology 190, no. 9 (2021): 1793–802. http://dx.doi.org/10.1093/aje/kwab086.

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Abstract Production of organophosphate esters (OPEs), which represent a major flame-retardant class present in consumer goods, has increased over the past 2 decades. Experimental studies suggest that OPEs may be associated with thyroid hormone disruption, but few human studies have examined this association. We quantified OPE metabolites in the urine of 298 pregnant women from Cincinnati, Ohio, in the Health Outcomes and Measures of the Environment Study (enrolled 2003–2006) at 3 time points (16 and 26 weeks’ gestation, and at delivery), and thyroid hormones in 16-week maternal and newborn cord sera. Urinary bis(1,3-dichloro-2-propyl)-phosphate concentrations were generally associated with decreased triiodothyronine and thyroxine levels and increased thyroid-stimulating hormone levels in maternal and newborn thyroid hormones in quartile dose–response analyses and multiple informant models. There was weaker evidence for thyroid hormone alterations in association with diphenyl-phosphate and di-n-butyl-phosphate. Bis-2-chloroethyl-phosphate was not associated with alterations in thyroid hormones in any analyses. We did not observe any evidence of effect modification by infant sex. These results suggest that gestational exposure to some OPEs may influence maternal and neonatal thyroid function, although replication in other cohorts is needed.

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Ding, Jiaqi, Wenxin Liu, Hong Zhang, Lingyan Zhu, Lin Zhu, and Jianfeng Feng. "Liver-Based Probabilistic Risk Assessment of Exposure to Organophosphate Esters via Dust Ingestion Using a Physiologically Based Toxicokinetic (PBTK) Model." International Journal of Environmental Research and Public Health 18, no. 23 (2021): 12469. http://dx.doi.org/10.3390/ijerph182312469.

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Organophosphate esters (OPEs) are widely used and harmful to organisms and human health. Dust ingestion is an important exposure route for OPEs to humans. In this study, by integrating ToxCast high-throughput in vitro assays with in vitro to in vivo extrapolation (IVIVE) via physiologically based Toxicokinetic (PBTK) modeling, we assessed the hepatocyte-based health risk for humans around the world due to exposure to two typical OPEs (TPHP and TDCPP) through the dust ingestion exposure route. Results showed that the health guidance value of TPHP and TCDPP obtained in this study was lower than the value obtained through animal experiments. In addition, probabilistic risk assessment results indicate that populations worldwide are at low risk of exposure to TPHP and TDCPP through dust ingestion due to low estimated daily intakes (EDIs) which are much lower than the reference dose (RfDs) published by the US EPA, except in some regional cases. Most margin of exposure (MOE) ranges of TDCPP for children are less than 100, which indicates a moderately high risk. Researchers should be concerned about exposure to TDCPP in this area. The method proposed in this study is expected to be applied to the health risk assessment of other chemicals.

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Morcillo, Sara P., Delia Miguel, Luis Álvarez de Cienfuegos, et al. "Stapled helical o-OPE foldamers as new circularly polarized luminescence emitters based on carbophilic interactions with Ag(i)-sensitivity." Chemical Science 7, no. 9 (2016): 5663–70. http://dx.doi.org/10.1039/c6sc01808d.

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Fernández, Zulema, Berta Fernández, Emilio Quiñoá, Ricardo Riguera, and Félix Freire. "Chiral information harvesting in helical poly(acetylene) derivatives using oligo(p-phenyleneethynylene)s as spacers." Chemical Science 11, no. 27 (2020): 7182–87. http://dx.doi.org/10.1039/d0sc02685a.

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Echigo, Shinya, Harumi Yamada, Saburo Matsui, Shosuke Kawanishi, and Kenichi Shishida. "Comparison between O3/VUV, O3/H2O2, VUV and O3 processes for the decomposition of organophosphoric acid triesters." Water Science and Technology 34, no. 9 (1996): 81–88. http://dx.doi.org/10.2166/wst.1996.0182.

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O3/vacuum ultraviolet (VUV, ultraviolet radiation by a low pressure mercury lamp at 185 and 254 nm), O3/H2O2 and VUV processes rapidly decomposed organophosphoric acid triesters (OPEs) dissolved in distilled water as compared to simple ozonation. The O3/VUV process was the fastest of the three advanced oxidation processes (AOPs) for the decomposition of 1 mg/l of OPEs in pH 7.5 phosphate buffer solution (0.5 mM). However the difference between the pseudo-first-order rate constants of the O3/VUV and O3/H2O2 processes decreased in the condition of increasing OPEsw concentration, and the efficiencies of the two processes were almost the same at an initial concentration of 20 mg/l. Contrary to results in distilled water, in an effluent from a solid waste landfill site, the O3/H2O2 process was the fastest. This is manily due to the absorption of VUV radiation by nitrate ion. WE confirmed that nitrate ion of more than a few mg/l strongly interfered with the generation of hydroxyl (OH) radicals from VUV radiation while the O3/H2O2 process was not affected. The use of an ESR-spin trapping technique revealed that AOPs generated more OH radicals than ozonation alone, and the detection of hydrogen atom confirmed that VUV radiation directly generated OH radicals from water.

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Awonaike, Boluwatife, Ying Duan Lei, and Frank Wania. "Precipitation-induced transport and phase partitioning of organophosphate esters (OPEs) in urban and rural watersheds." Environmental Science: Water Research & Technology 7, no. 11 (2021): 2106–15. http://dx.doi.org/10.1039/d1ew00329a.

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Particle-bound OPEs were observed at fractions higher than expected based on predicted partitioning behaviour, i.e. organic carbon–water partitioning ratios (log ) calculated from field data were generally higher than predicted values.

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Sühring, Roxana, Martin Scheringer, Timothy F. M. Rodgers, Liisa M. Jantunen, and Miriam L. Diamond. "Evaluation of the OECD POV and LRTP screening tool for estimating the long-range transport of organophosphate esters." Environmental Science: Processes & Impacts 22, no. 1 (2020): 207–16. http://dx.doi.org/10.1039/c9em00410f.

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OECD POV and LRT Screening Tool (the Tool) underestimates the long-range transport potential of OPEs. Adding optional settings for episodic air and river-based transport, and cold temperatures can significantly improve estimates.

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Roy, Syamantak, and Tapas Kumar Maji. "Self-assembled organic and hybrid materials derived from oligo-(p-phenyleneethynylenes)." Chemical Communications 58, no. 26 (2022): 4149–67. http://dx.doi.org/10.1039/d2cc00186a.

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Self-assembly of oligo-(p-phenyleneethynylenes) (OPEs), a class of π-conjugated systems, into versatile materials has widened the application horizon of this molecular system with properties ranging from opto-electronics and energy to biology.

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Petkou, Anastasios C. "Boundary multi-trace deformations and OPEs in AdS/CFT correspondence." Journal of High Energy Physics 2002, no. 06 (2002): 009. http://dx.doi.org/10.1088/1126-6708/2002/06/009.

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Phillips, Allison L., and Heather M. Stapleton. "Inhibition of Human Liver Carboxylesterase (hCE1) by Organophosphate Ester Flame Retardants and Plasticizers: Implications for Pharmacotherapy." Toxicological Sciences 171, no. 2 (2019): 396–405. http://dx.doi.org/10.1093/toxsci/kfz149.

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Abstract 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 (Ki = 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.

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Schubert, Armin, John E. Tetzlaff, Ming Tan, Victor J. Ryckman, and Edward Mascha. "Consistency, Inter-rater Reliability, and Validity of 441 Consecutive Mock Oral Examinations in Anesthesiology." Anesthesiology 91, no. 1 (1999): 288–98. http://dx.doi.org/10.1097/00000542-199907000-00037.

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Background Oral practice examinations (OPEs) are used extensively in many anesthesiology programs for various reasons, including assessment of clinical judgment. Yet oral examinations have been criticized for their subjectivity. The authors studied the reliability, consistency, and validity of their OPE program to determine if it was a useful assessment tool. Methods From 1989 through 1993, we prospectively studied 441 OPEs given to 190 residents. The examination format closely approximated that used by the American Board of Anesthesiology. Pass-fail grade and an overall numerical score were the OPE results of interest. Internal consistency and inter-rater reliability were determined using agreement measures. To assess their validity in describing competence, OPE results were correlated with in-training examination results and faculty evaluations. Furthermore, we analyzed the relationship of OPE with implicit indicators of resident preparation such as length of training. Results The internal consistency coefficient for the overall numerical score was 0.82, indicating good correlation among component scores. The interexaminer agreement was 0.68, indicating moderate or good agreement beyond that expected by chance. The actual agreement among examiners on pass-fail was 84%. Correlation of overall numerical score with in-training examination scores and faculty evaluations was moderate (r = 0.47 and 0.41, respectively; P &lt; 0.01). OPE results were significantly (P &lt; 0.01) associated with training duration, previous OPE experience, trainee preparedness, and trainee anxiety. Conclusion Our results show the substantial internal consistency and reliability of OPE results at a single institution. The positive correlation of OPE scores with in-training examination scores, faculty evaluations, and other indicators of preparation suggest that OPEs are a reasonably valid tool for assessment of resident performance.

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Fournier-Delpech, S., Y. Guérin, M. Magistrini, Y. Combarnous, and JJ Roi. "Asthénospermie immuno-induite par une protéine épididymaire, la préalbumine ovine (oPES)." Reproduction Nutrition Development 35, no. 4 (1995): 427–36. http://dx.doi.org/10.1051/rnd:19950407.

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Bhattacharyya, Sohini, and Tapas Kumar Maji. "Dependence of optoelectronic and mesophasic properties on crystal packing in OPEs." Acta Crystallographica Section A Foundations and Advances 73, a2 (2017): C752. http://dx.doi.org/10.1107/s2053273317088222.

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Ye, Langjie, Weikun Meng, Jianan Huang, Jianhua Li, and Guanyong Su. "Establishment of a Target, Suspect, and Functional Group-Dependent Screening Strategy for Organophosphate Esters (OPEs): “Into the Unknown” of OPEs in the Sediment of Taihu Lake, China." Environmental Science & Technology 55, no. 9 (2021): 5836–47. http://dx.doi.org/10.1021/acs.est.0c07825.

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Heslop, P. J., and P. S. Howe. "OPEs and 3-point correlators of protected operators in N=4 SYM." Nuclear Physics B 626, no. 1-2 (2002): 265–86. http://dx.doi.org/10.1016/s0550-3213(02)00023-8.

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Wang, Shijie, Anming Liu, Meihong Li, et al. "Organophosphate esters in tree bark and human hair in Weifang and Yantai, Shandong Province, China: concentrations, profiles and sources." Journal of Environmental Exposure Assessment 1, no. 2 (2022): 12. http://dx.doi.org/10.20517/jeea.2022.01.

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Organophosphate ester (OPE) concentrations and distributions in 15 tree bark and 59 human hair samples from Weifang and Yantai (Shandong Province, China) were determined. The total OPE concentrations in tree bark samples from Weifang and Yantai were 16.5 ng/g-78.5 ng/g and 9.34 ng/g-98.6 ng/g dry weight (dw), respectively. The total OPE concentrations in hair samples from Weifang and Yantai were 54.2 ng/g dw-8450 ng/g dw and 7.26 ng/g dw -13,900 ng/g dw, respectively. Chlorinated OPEs were dominant in the tree bark samples from both Weifang and Yantai. Tris(2-chloroethyl)phosphate (TCEP) was the dominant OPE in the hair samples from residents of Weifang and Yantai. Attention should be paid to human exposure to TCEP, which is carcinogenic. The OPE concentrations in human hair were highest for the < 20 years age group. The OPE patterns between the two cities were similar for both tree bark and hair, but the OPE patterns in the tree bark and hair samples from the same place were significantly different. This indicates that the outdoor atmosphere may not be the main source of OPEs in human hair.

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Ali, Nadeem, Nabil A. Alhakamy, Iqbal M. I. Ismail, et al. "Exposure to Phthalate and Organophosphate Esters via Indoor Dust and PM10 Is a Cause of Concern for the Exposed Saudi Population." International Journal of Environmental Research and Public Health 18, no. 4 (2021): 2125. http://dx.doi.org/10.3390/ijerph18042125.

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In this study, we measured the occurrence of organophosphate esters (OPEs) and phthalates in the settled dust (floor and air conditioner filter dust) and in suspended particulate matter (PM10) from different microenvironments (households (n = 20), offices (n = 10) and hotels (n = 10)) of Jeddah, Saudi Arabia. Bis (2-Ethylhexyl) phthalate (DEHP) was the major pollutant (contributing >85% of total chemicals burden) in all types of indoor dust with a concentration up to 3,901,500 ng g−1. While dibutyl phthalate (DBP) and DEHP together contributed >70% in PM10 (1900 ng m−3), which indicate PM10 as a significant source of exposure for DBP and DEHP in different Saudi indoor settings. Tris (1-chloro-2-propyl) phosphate (TCPP) was the major OPE in PM10 with a concentration of up to 185 ng m−3 and the occurrence of OPEs in indoor dust varied in studied indoor settings. The estimated daily intake (EDI) of studied chemicals via dust ingestion and inhalation of PM10 was below the reference dose (RfD) of individual chemicals. However, estimated incremental lifetime cancer risk (ILCR) with moderate risk (1.5 × 10−5) for Saudi adults and calculated hazardous index (HI) of >1 for Saudi children from DEHP showed a cause of concern to the local public health.

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