[Pollution Level and Risk Assessment of OPEs in Typical River Basins of China].

Organophosphate esters(OPEs), as a substitute for brominated flame retardants, are widely used in production and life, and their environmental pollution and toxic effects have attracted widespread attention. In this study, the concentrations and distribution characteristics of OPEs in seven major drainage basins of China were sorted out. The average daily dose of OPEs in Chinese adults, adolescents, and children was calculated to assess the health risks, and the reliability of the results was evaluated using Monte Carlo simulation. The toxic effect concentrations of 12 OPEs on aquatic organisms were investigated, and the species sensitivity distribution(SSD) curve was constructed to assess the ecological risk. The results showed that the 5th percentile concentration of ΣOPEs in the seven drainage basins was 52.61 ng·L-1 under the low exposure scenario. The median concentration of ΣOPEs in the seven basins was 499.74 ng·L-1, with trichloroethyl phosphate(TCEP), triethyl phosphate(TEP), and triethyl phosphate(1,3-dichloro-2-propyl) esters(TDCP) as the main contaminants. Under the high exposure scenario, the 95th percentile concentration of ΣOPEs in the seven basins was 1904.4 ng·L-1, 3.8 times that of the intermediate exposure scenario, and the Yangtze River Basin had the highest ΣOPEs concentration under the high exposure scenario. The health risk assessment showed that the non-carcinogenic risk of OPEs exposure through drinking water was within acceptable limits for different populations. Trimethyl phosphate(TMP), triisobutyl phosphate(TiBP), and TCEP were the main contributors to cancer risk. The results of ecological risk assessment showed that TCEP had medium ecological risk at the high exposure level, tributyl phosphate(TnBP) had medium ecological risk under the intermediate exposure scenario, and there was higher ecological risk under the high exposure scenario. Triphenyl phosphate(TPhP) had a risk quotient greater than 1 under the low, intermediate, and high exposure scenarios, and there was a high ecological risk, which requires special attention.

[Occurrence Distribution and Risk Assessment of Organophosphate Esters in A Typical Area of the Estuary in the Yellow River Basin].

As a type of emerging pollutant, organophosphate esters (OPEs) have the characteristics of toxicity, persistence, and bioaccumulation. Due to their wide use in production and life, OPEs pose potential risks to ecosystems when they enter the environment. In this study, the concentrations of 14 species of OPEs in surface water were determined using UPLC-MS/MS, and the spatial distribution of the OPEs in the surface water of the estuary of the Yellow River basin was further analyzed. The pollution sources were analyzed using correlation analysis and principal component analysis, and the ecological risk was evaluated. The results indicated that the concentration of Σ14OPEs in surface water ranged from 183.81 to 1674.52 ng·L-1, with an average concentration of 638.25 ng·L-1. Tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propanyl) phosphate (TCPP) were the main OPEs. The Xiaoqing River flowing through the urban area differed from the main stream of the Yellow River and other branches in terms of OPEs composition characteristics, which showed a greater impact from human activities. The distribution of Σ14OPEs showed an obvious regional pattern, with a trend of increasing and then decreasing along the direction of the Yellow River inlet. The results of source analysis revealed that human activities such as industrial wastewater discharge from different industries, transportation, and atmospheric deposition were the sources of OPEs in surface water. The ecological risk assessment results indicated that TCEP posed a high risk to aquatic organisms in the main stream of the Yellow River, Xiaoqing River, and Zhimai River, and tri-n-butyl phosphate (TnBP) and triphenyl phosphate (TPhP) posed a low risk at some sites.

[Pollution Characteristics and Risk Assessment of Organophosphate Esters in Rivers and Water Body Around Taihu Lake].

To explore the pollution characteristics, potential sources, and ecological and health risk of organophosphate eaters (OPEs) in the surface water of Taihu Lake, water samples from 18 surrounding rivers were collected, as well as 11 water samples from Taihu Lake. The concentrations of 13 OPEs in the water were determined using UPLC-MS/MS, and the spatial distribution of the OPEs in surface water of Taihu Lake basin was further analyzed. The results indicate that, in addition to tripropyl phosphate (TPrP), 2-ethylhexyl diphenyl phosphate (EHDPP), and tricresyl phosphate (TCrP), ten OPEs were detected in all the water samples, the total concentration (ΣOPEs) ranged from 152.5 ng·L-1 to 2524 ng·L-1, and the concentration median value was 519.2 ng·L-1. Tri(chloropropyl) phosphate (TCPP) and tri(2-chloroethyl) phosphate (TCEP) were the dominant OPEs, with the concentration ranges of 73.7-1753.9 ng·L-1 (medium value:204.6 ng·L-1) and 43.9-313.5 ng·L-1 (medium value:131.3 ng·L-1), respectively. The ΣOPEs decreased from the northwest region to the southeast, which corresponds to the economic and industrial development. The results of the source identification reveal that the wastewater discharge from electronics and textile enterprises, construction materials, and vehicular and marine traffic emissions may be the principal sources of the OPEs in Taihu Lake. The ecological risk assessment results indicate that only TCPP, tri(dichloropropyl) phosphate (TDCP), and triphenyl phosphate (TPhP) in some sites had a low risk. The health risk assessment reveals that there were no risks based on water intake, but the long-term risk of OPEs to the aquatic ecosystem and surrounding residents still need attention.

[Pollution Characteristics and Risk Assessment of Typical Organophosphate Esters in Beijing Municipal Wastewater Treatment Plant and the Receiving Water].

Organophosphate esters (OPEs) are ubiquitous in the environment and pose a potential threat to ecosystems and human health. A method for the determination of eight OPEs by ultra-performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) was established. The recovery rates of eight target compounds with different solid-phase extraction columns, different eluents, and different eluent volumes were compared. The results showed that using ENVI-18 column enrichment, OPEs were eluted with 8 mL acetonitrile containing 25% (volume fraction) dichloromethane, and the labeled recovery rate of the target compound was 92.5%-102.2%. The recoveries of different matrix samples were 88.5%-116.1% and relative standard deviation was 1.7%-9.9%. The concentration range of 8 different detectable organophosphate esters in the effluent of sewage treatment plant is 85.9-235.4 ng·L-1 during the six-day sampling process, permissive river downstream of the six-day ΣOPEs average total concentration was 130.3 ng·L-1, higher than the 119.4 ng·L-1 upstream water concentration, but lower than the sewage treatment plant effluent concentration of total 162.5ng·L-1. The study shows that the sewage treatment plant cannot completely remove OPEs; for triethyl phosphate (TEP) and 3 (2-ethyl hexyl) phosphate ester (TEHP) there exists a negative removal phenomenon, whereas for other OPEs the removal rate was between 14.1% and 84.9%, and the total ΣOPEs removal rate by the sewage plant was 50.0%. The TPhP in the effluent of the sewage treatment plant has medium environmental risk (RQ>0.1), and other organophosphates have low environmental risk (RQ<0.1); however, the long-term mixing effects of organophosphate esters on the ecosystem of the receiving river should not be ignored.