Occurrence, distribution and risk assessment of organophosphate esters (OPEs) in water sources from Northeast to Southeast China

Chemical profiling of organic contaminants in rural surface waters combining target and non-target LC-HRMS/MS analysis

The pollution of natural waters by contaminants of emerging concern (CECs) is one of the pressing problems due to their global distribution and potential negative effects on the environment and human health. In rural areas with lower population density and limited industrial development, less contamination is expected. However, the lack of wastewater treatment plants (WWTPs) or their poor removal efficiency can lead to significant input of pollutants. In this context, 11 streams of rural areas in the Guadalquivir River basin, southeast of Spain, were studied over two years to obtain an overview of the origin and distribution of contaminants. A target method using solid-phase extraction and liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS) was developed for the analysis of 316 compounds in surface waters. A total of 78 target analytes were detected, comprising pesticides, pharmaceuticals, personal care products (PCPs), transformation products (TPs), and industrial chemicals. The flame retardant tributyl phosphate (16-3572 ng L-1) was detected in all samples, followed by caffeine (30-8090 ng L-1) and the analgesic tramadol (3-1493 ng L-1). The target approach was combined with a non-target analysis (NTA) strategy to obtain an overall perspective of the chemical profile of unexpected or unknown compounds in the samples. Up to 79 contaminants were tentatively identified, and 12 of them were finally confirmed with standards. Most of the contaminants determined by NTA were pharmaceuticals and their TPs. The results indicated that most of CECs have an urban origin despite traditional agriculture is the main economic activity in this region. Moreover, the absence of WWTPs in small towns is significant, as contamination levels at these sites were comparable to or higher than those in larger populations with sewage treatments.

Exposure to resorcinol bis (diphenyl phosphate) induces colonization of alien microorganisms with potential impacts on the gut microbiota and metabolic disruption in male zebrafish

Organophosphate esters (OPEs) have been demonstrated to induce various forms of toxicity in aquatic organisms. However, a scarcity of evidence impedes the conclusive determination of whether OPEs manifest sex-dependent toxic effects. Here, we investigated the effects of tris (1-chloro-2-propyl) phosphate (TCPP) and resorcinol bis (diphenyl phosphate) (RDP) on the intestines of both female and male zebrafish. The results indicated that, in comparison to TCPP, RDP induced more pronounced intestinal microstructural damage and oxidative stress, particularly in male zebrafish. 16S rRNA sequencing and metabolomics revealed significant alterations in the species richness and oxidative stress-related metabolites in the intestinal microbiota of zebrafish under exposure to both TCPP and RDP, manifesting gender-specific effects. Based on differential species analysis, we defined invasive species and applied invasion theory to analyze the reasons for changes in the male fish intestinal community. Correlation analysis demonstrated that alien species may have potential effects on metabolism. Overall, this study reveals a pronounced gender-dependent impact on both the intestinal microbiota and metabolic disruptions of zebrafish due to OPEs exposure and offers a novel perspective on the influence of pollutants on intestinal microbial communities and metabolism.

Potential adverse outcome pathway of neurodevelopmental toxicity, inflammatory response, and oxidative stress induction mediated by three alkyl organophosphate flame retardants in zebrafish larvae

Following restrictions on polybrominated flame retardants, trimethyl phosphate (TMP), triethyl phosphate (TEP), and tris(2-butoxyethyl) phosphate (TBEP) have been frequently used as plasticizers for fire-resistant plastics. This study investigated the neurodevelopmental effects, inflammatory response, and oxidative stress induction of three alkyl organophosphate flame retardants using a zebrafish embryo/larvae model. After exposure of zebrafish embryos to TMP, TEP, and TBEP (0, 0.02, 0.2, 2, 20, and 200 μg L-1) for 96 h, survival, development, swimming behavior, changes in acetylcholinesterase (AChE) activity, dopamine, tumor necrosis factor-alpha (TNF-α), interleukin (IL), reactive oxygen species (ROS), and antioxidant enzyme activities were observed. Concentrations of TMP, TEP, and TBEP were also measured in the whole body of exposed larvae. Our results showed that exposure to 200 μg L-1 TEP and ≥20 μg L-1 TBEP significantly reduced larval body length; however, TMP had no significant effects on developmental parameters up to 200 μg L-1. After 96 h of exposure to TBEP, total distance moved, mean velocity, AChE, and dopamine concentrations were significantly decreased. Exposure to TEP and TBEP decreased the expression of genes that regulate central nervous system development (e.g. gap43 and mbpa), whereas ROS, antioxidant enzymes, TNF-α, and IL-1β concentrations were significantly increased. Notably, pretreatment with an antioxidant N-acetylcysteine reduced neurotoxicity and oxidative stress caused by TEP and TBEP. The results of this study demonstrated that exposure to TEP and TBEP causes oxidative stress and has adverse effects on the neurobehavioral and immune system of zebrafish, leading to hypoactivity and ultimately impairing development.

Determination of the binding affinities of OPEs to integrin αvβ3 and elucidation of the underlying mechanisms via a competitive binding assay, pharmacophore modeling, molecular docking and QSAR modeling

Organophosphate esters (OPEs) can cause adverse biological effects through binding to integrin αvβ3. However, few studies have focused on the binding activity and mechanism of OPEs to integrin αvβ3. Herein, a comprehensive investigation of the mechanisms by which OPEs bind to integrin αvβ3 and determination of the binding affinity were conducted by in vitro and in silico approaches: competitive binding assay as well as pharmacophore, molecular docking and QSAR modeling. The results showed that all 18 OPEs exhibited binding activities to integrin αvβ3; moreover, hydrogen bonds were identified as crucial intermolecular interactions. In addition, essential factors, including the -P = O structure of OPEs, key amino acid residues and suitable cavity volume of integrin αvβ3, were identified to contribute to the formation of hydrogen bonds. Moreover, aryl-OPEs exhibited a lower binding activity with integrin αvβ3 than halogenated- and alkyl-OPEs. Ultimately, the QSAR model constructed in this study was effectively used to predict the binding affinity of OPEs to integrin αvβ3, and the results suggest that some OPEs might pose potential risks in aquatic environments. The results of this study comprehensively elucidated the binding mechanism of OPEs to integrin αvβ3, and supported the environmental risk management of these emerging pollutants.

Insights into the occurrence, spatial distribution, and ecological implications of organophosphate triesters in surface sediments from polluted urban rivers across China

Organophosphate triesters (tri-OPEs) are a kind of widespread contaminants in the world, particularly in China, which is a major producer and user of tri-OPEs. However, tri-OPE pollution in urban river sediments in China remains unclear. In current work, we carried out the first nationwide investigation to comprehensively monitor 10 conventional and five emerging tri-OPEs in sediments of 173 black-odorous urban rivers throughout China. Concentrations of 10 conventional and five emerging tri-OPEs were 3.8-1240 ng/g dw (mean: 253 ng/g dw) and 0.21-1107 ng/g dw (68 ng/g dw), respectively, and significantly differed among the cities sampled but generally decreased from Northeast and East China to Central and West China. These spatial patterns suggest that tri-OPE pollution was mainly from local sources and was controlled by the industrial and economic development levels in these four areas, as indicated by the significant correlations between tri-OPE concentrations and gross domestic production, gross industrial output, and daily wastewater treatment capacity. Although the tri-OPE composition varied spatially at different sites, which indicated different tri-OPE input patterns, it was commonly dominated by tris(2-chloroethyl) phosphate, tris(2-ethylhexyl) phosphate, and tris(1-chloro-2-propyl) phosphate (conventional tri-OPEs) and bisphenol A-bis(diphenyl phosphate) and isodecyl diphenyl phosphate (emerging tri-OPEs). A risk assessment indicated that tri-OPEs in most sampling sediments had a low to moderate risk to aquatic organisms.

Organophosphate esters in the urban atmosphere of Thessaloniki city, Greece

The occurrence of organophosphate esters (OPEs) in the atmosphere of the urban area of Thessaloniki city, Greece was studied. OPEs were determined in particulate matter (PM2.5) and precipitation during the period 2020-2021. ∑OPEs in rainwater ranged from 520 to 4719 ng L-11 (mean: 1662 ng L-1) with tris (2-butoxyethyl) phosphate (TBOEP) and tris (1-chloro-2-propyl) phosphate (TClPP) being the most abundant compounds. TBOEP and TClPP as well as triphenylphosphine oxide (TPPO) and tris (chloroethyl) phosphate (TCEP) were the dominant OPEs in PM2.5. Concentrations of ∑OPEs in PM2.5ranged from 2.82 to 13.3 ng m-3 (mean: 5.93 ng m-3). Wet deposition fluxes of OPEs were estimated and air mass back trajectories were used to elucidate possible source profiles. An overall low health risk for local population via inhalation of OPEs was revealed.

A critical review on organophosphate esters in drinking water: Analysis, occurrence, sources, and human health risk assessment

Organophosphate esters (OPEs) are ubiquitous in the environment. Copious studies assessed OPEs in various environmental media. However, there is limited summative information about OPEs in drinking water. This review provides comprehensive data for the analytical methods, occurrence, sources, and risk assessment of OPEs in drinking water. In general, liquid-liquid extraction and solid-phase extraction are the most common methods in the extraction of OPEs from drinking water, while gas chromatography and liquid chromatography are the most commonly used instrumental methods for detecting OPEs in drinking water. On the basis of these techniques, a variety of methods on OPEs pretreatment and determination have been developed to know the pollution situation of OPEs. Studies on the occurrence of OPEs in drinking water show that the total concentrations of OPEs vary seasonally and regionally, with tris(1-chloro-2-isopropyl) phosphate and tris(2-chloroethyl) phosphate dominant among different kinds of drinking water. Source identification studies show that there are three main sources of OPEs in drinking water: 1) source water contamination; 2) residual in drinking water treatment process; 3) leakage from device or pipeline. Besides, risk assessments indicate that individual and total OPEs pose no or negligible health risk to human, but this result may be significantly underestimated. Finally, the current knowledge gaps on the research of OPEs in drinking water are discussed and some suggestions are provided for future environmental research.

Pollution characteristics and health risk of sixty-five organics in one drinking water system: PAEs should be prioritized for control

Currently, a large number of emerging organic contaminants have been detected in domestic and international drinking water systems. However, there are differences among the research methods, which lead to system errors in directly comparing the hazards of different contaminants, so it is difficult to analyze the priority control pollutants and the risk control target in drinking water from previous studies. Therefore, we selected a drinking water treatment plant (DWTP) in the east of China, and detected trihalomethanes (THMs), antibiotics, phthalate esters (PAEs), organophosphate esters (OPEs), per and polyfluoroalkyl substances (PFASs), a total of sixty-five organic contaminants in one batch water sample of four seasons, and carried out the whole process monitoring of "Source water-DWTP-Network-Users", and calculated the health risks of contaminants in tap water. The results showed that DWTP could effectively remove antibiotics and PAEs; the removal rate of coagulation for antibiotics can be up to 47%; the release of PAEs in the plastic water supply pipe leads to a significant increase of the concentrations in the water transportation system, which can reach 2.92 times of that in finished water; compared with other contaminants, THMs and PAEs in tap water have higher health risks. This study reveals that THMs and PAEs are priority control organic pollutants, and the water supply network is the key risk control target in the drinking water system, providing a theoretical basis for how to ensure the safety of drinking water.

Interannual variation and machine learning simulation of organophosphate esters in Taihu Lake

Organophosphate esters (OPEs) are widespread in water bodies and have attracted public attention due to their hazards. This study investigated the presence of OPEs in surface water of Taihu Lake from 2012 and 2021-2022. The OPEs concentration was compared ten years ago and ten years later. Water and meteorological parameters were ranked using the random forest (RF) model, and OPEs concentration in lakes was simulated using selected parameters as inputs. The concentration of Σ7OPEs was higher ten years ago compared to ten years later. There was no significant seasonal difference in Σ7OPEs from 2021-2022, while the concentration of Σ7OPEs in 2012 was lower in summer than in other seasons. The spatial distribution of the two interannual Σ7OPEs exhibited a decreasing trend from the northwest region. The results of RF importance ranking and redundancy analysis showed that NH3-N, TN, TP, water temperature and relative humidity were the most influential factors affecting OPEs concentrations. RF models performed better for TnBP, as indicated by training R and test R values are excellent and relatively low errors. Our results demonstrated that machine learning models were useful in facilitating efficient monitoring and assessment of OPEs contamination in lakes.

Tris(2-chloroethyl) Phosphate Exerts Hepatotoxic Impacts on Zebrafish by Disrupting Hypothalamic-Pituitary-Thyroid and Gut-Liver Axes

The ubiquitous environmental presence of tris(2-chloroethyl) phosphate (TCEP) poses a potential threat to animals; however, little is known about its hepatotoxicity. In this study, the effects of TCEP exposure (0.5 and 5.0 μg/L for 28 days) on liver health and the potential underlying toxification mechanisms were investigated in zebrafish. Our results demonstrated that TCEP exposure led to hepatic tissue lesions and resulted in significant alterations in liver-injury-specific markers. Moreover, TCEP-exposed fish had significantly lower levels of thyrotropin-releasing hormone and thyroid-stimulating hormone in the brain, evidently less triiodothyronine whereas more thyroxine in plasma, and markedly altered expressions of genes from the hypothalamic-pituitary-thyroid (HPT) axis in the brain or liver. In addition, a significantly higher proportion of Bacteroidetes in the gut microbiota, an elevated bacterial source endotoxin lipopolysaccharide (LPS) in the plasma, upregulated expression of LPS-binding protein and Toll-like receptor 4 in the liver, and higher levels of proinflammatory cytokines in the liver were detected in TCEP-exposed zebrafish. Furthermore, TCEP-exposed fish also suffered severe oxidative damage, possibly due to disruption of the antioxidant system. These findings suggest that TCEP may exert hepatotoxic effects on zebrafish by disrupting the HPT and gut-liver axes and thereafter inducing hepatic inflammation and oxidative stress.

Occurrences and migration of organophosphite and organophosphate esters into food simulants from single-use food packaging in China

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.

Efficient removal of Tris(2-chloroethyl) phosphate by biochar derived from shrimp shell: Adsorption performance and mechanism study

Tris(2-chloroethyl) phosphate (TCEP) has been detected all over the world as a typical refractory organic phosphate, especially in groundwater. This work applied a calcium-rich biochar derived from shrimp shell as a low-cost adsorbent for TCEP removal. Based on the kinetics and isotherm studies, the adsorption of TCEP on biochar was monolayer adsorbed on a uniform surface, with SS1000 (the biochar was prepared at the carbonization temperature of 1000 °C) achieving the maximum adsorption capacity of 264.11 mg·g^-1. The prepared biochar demonstrated stable TCEP removal ability throughout a wide pH range, in the presence of co-existing anions, and in diverse water bodies. A rapid removal rate of TCEP was observed during the adsorption process. When the dosage of SS1000 was 0.2 g·L^-1, 95% of TCEP could be removed within the first 30 min. The mechanism analysis indicated that the calcium species and basic functional groups on the SS1000 surface were highly involved in the TCEP adsorption process.

Organophosphate Esters (OPEs) Flame Retardants in Water: A Review of Photocatalysis, Adsorption, and Biological Degradation

As a substitute for banned brominated flame retardants (BFRs), the use of organophosphate esters (OPEs) increased year by year with the increase in industrial production and living demand. It was inevitable that OPEs would be discharged into wastewater in excess, which posed a great threat to the health of human beings and aquatic organisms. In the past few decades, people used various methods to remove refractory OPEs. This paper reviewed the photocatalysis method, the adsorption method with wide applicability, and the biological method mainly relying on enzymolysis and hydrolysis to degrade OPEs in water. All three of these methods had the advantages of high removal efficiency and environmental protection for various organic pollutants. The degradation efficiency of OPEs, degradation mechanisms, and conversion products of OPEs by three methods were discussed and summarized. Finally, the development prospects and challenges of OPEs’ degradation technology were discussed.

Fluorescence turn-off sensing strategy based on Al-based MOF for selective detection of tricresyl phosphate

Tricresyl phosphate (TCP), a notable emerging pollutant with a high bioconcentration factor and biotoxicity, is a typical representative of aryl-organophosphorus flame retardants. The electrochemical and chromatographic technologies used in conventional TCP detection have a variety of drawbacks. Hence, it is crucial to suggest an easy, accurate, and selective method for detecting TCP. In this study, we presented a brand-new method based on NH₂-MIL-53(Al) nanoprobe for the direct luminescence assay of TCP. NH₂-MIL-53(Al) possessed an excellent crystal structure and superior optical qualities. Notably, the introduction of TCP caused a considerable dampening of the photoluminescence signal of the nanoprobe. The fluorescence response based on static quenching was verified by fluorescence lifetime decay curves. The thermodynamic analysis further concluded that TCP and nanoprobe spontaneously produced non-fluorescent complexes due to hydrophobic interaction. The quenching efficiency (F₀-F)/F₀ of the nanoprobe and the TCP concentration displayed good linearity in the scope of 0.3-3.0 μM (R² = 0.996), and the LOD was 0.058 μM under the ideal detection conditions. More significantly, the technique was effectively used to identify TCP in lake and tap water (RSD ≤5.79%), which provided a fresh perspective on how to recognize OPFRs in environmental water.

Translocation and metabolism of tricresyl phosphate in rice and microbiome system: Isomer-specific processes and overlooked metabolites

Tricresyl phosphate (TCP) is extensively used organophosphorus flame retardants and plasticizers that posed risks to organisms and human beings. In this study, the translocation and biotransformation behavior of isomers tri-p-cresyl phosphate (TpCP), tri-m-cresyl phosphate (TmCP), and tri-o-cresyl phosphate (ToCP) in rice and rhizosphere microbiome was explored by hydroponic exposure. TpCP and TmCP were found more liable to be translocated acropetally, compared with ToCP, although they have same molecular weight and similar K_ow. Rhizosphere microbiome named microbial consortium GY could reduce the uptake of TpCP, TmCP, and ToCP in rice tissues, and promote rice growth. New metabolites were successfully identified in rice and microbiome, including hydrolysis, hydroxylated, methylated, demethylated, methoxylated, and glucuronide- products. The methylation, demethylation, methoxylation, and glycosylation pathways of TCP isomers were observed for the first time in organisms. What is more important is that the demethylation of TCPs could be an important and overlooked source of triphenyl phosphate (TPHP), which broke the traditional understanding of the only manmade source of toxic TPHP in the environment. Active members of the microbial consortium GY during degradation were revealed and metagenomic analysis indicated that most of active populations contained TCP-degrading genes. It is noteworthy that the strains and function genes in microbial consortium GY that responsible for TCP isomers' transformation were different. These results can improve our understanding of the translocation and transformation of organic pollutant isomers in plants and rhizosphere microbiome.

A scalable field study using leaves as a novel passive air sampler to evaluate the potential source of organophosphate esters in street dust

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers in industrial and commercial products. It is generally believed that OPEs in street dust mainly originate from road traffic and anthropogenic activities. The influence of atmospheric deposition is still unknown. In this study, leaves were employed as a novel passive air sampler to collect particle matters (PM) in 12 cities in the central province of Henan, China. Similar compositional profiles of OPEs were found in street dust and PM samples. The concentrations of individual OPEs in PM were 1-4 times higher than in street dust. Chlorinated OPEs concentration in PM shows a moderate correlation (r² = 0.538, p < 0.01) with that in street dust. The concentration of alkyl OPEs in PM has a high correlation (r² = 0.843, p < 0.01) with that in street dust. No significant correlation (r² = 0.133, p = 0.132) was found on the aryl OPEs concentrations between street dust and PM. Spearman correlation reveals that the emission sources of tricresyl phosphate (TCrP) and triethyl phosphate (TEP) may be different from other OPEs in dust and PM samples. Principle component analysis (PCA) provides an appropriate explanation that tris (2-chloroethyl) phosphate (TCEP), triphenyl phosphate (TPhP), tris (chloropropyl) phosphate (TCPP), tributyl phosphate (TnBP), and TEP in street dust and PM may be emitted from the same sources, suggesting that PM has a significant influence on the occurrence of OPEs in street dust. The estimated dry deposition fluxes of particle-bound OPEs show a significant correlation (R² = 0.969, p < 0.01) with OPEs concentrations in street dust, revealing that the input of atmospheric deposition could be a major source of OPEs in street dust.

Association of organophosphate ester exposure with cardiovascular disease among US adults: Cross-sectional findings from the 2011-2018 National Health and Nutrition Examination Survey

Organophosphate esters (OPEs) are widely used as flame retardants and plasticizers worldwide. Therefore, the potentially deleterious effect of OPE on human beings deserves extensive attention. The primary objective of this present study was to untangle the relationship between OPE exposure and cardiovascular disease (CVD) among general population. Detailed information about participants' baseline characteristics, involving socioeconomic data, demographic data and key covariates was obtained from National Health and Nutrition Examination Survey (NHANES) 2011-2018. Multivariate logistic regression models with adjustment for prior-determined covariates were utilized to examine the relationship between various OPEs and CVD among US adults and calculate odd ratios (ORs) and corresponding confidence intervals (CIs). Two multi-pollutant statistical strategies (weighted quantile sum regression and Bayesian kernel machine regression) were employed to investigate the joint effect of OPE mixture on CVD. A total of 5067 participants were included in this study. In completely-adjusted logistic model, the highest tertiles of OPE metabolites were positively associated with CVD risk, while the relationships did not reach statistical significance. The weighted quantile sum (WQS) index was significantly correlated with increased prevalence of CVD (adjusted OR: 1.25; CI: 1.02, 1.53, p value = 0.032) and Diphenyl phosphate (DPHP) was the greatest contributor (31.38%). The BKMR also indicated that mixed OPE exposure associated with an increased risk of CVD. Taken together, the present study demonstrated that there were possible links between OPE exposures and increased risk of CVD, while the relationships did not reach statistical significance. Our study provided the suggestive evidence that cumulative effect of OPE mixtures on CVD. DPHP may be a major driver of this positive association. Given the limitation of cross-sectional design and relatively limited kinds of OPE metabolites, further studies are warranted to longitudinally evaluate the potential effect of a wider range of OPEs on CVD or cardiac metabolism.

Genotoxic and Toxic Effects of The Flame Retardant Tris(Chloropropyl) Phosphate (TCPP) in Human Lymphocytes, Microalgae and Bacteria

Tris(chloropropyl) phosphate (TCPP) is a characteristic and widely used organophosphorus flame retardant. TCPP is comprised of four isomers and the most abundant is tris(1-chloro-2-propyl) phosphate. TCPP can be released into the environment, with potential impacts on living organisms and humans due to its extensive industrial use. Aiming to assess the potential risks of TCPP on human health and the environment, its toxic and genotoxic effects-using organisms from different trophic levels, i.e., bacteria, green microalgae, and human cells-were investigated. TCPP exposure at nominal concentrations of 10, 20, 30 and 40 μg mL^-1 was studied to identify the potential risk of inducing genotoxic effects in cultured human lymphocytes. Treatment with 30 and 40 μg mL^-1 of TCPP induced marginally significant micronuclei (MN) frequencies as well as cytotoxic effects. Freshwater microalgae species treated with TCPP (0.5, 1, 10, 20 and 50 μg L^-1) showed different growth rates over time. All the tested microalgae species were adversely affected after exposure to TCPP during the first 24 h. However, differences among the microalgae species' sensitivities were observed. In the case of the freshwater species, the most sensitive was found to be Chlorococcum sp. The marine algal species Dunaliella tertiolecta and Tisochrysis lutea were significantly affected after exposure to TCPP. The effects of TCPP on Aliivibrio fischeri that were observed can classify this flame retardant as a "harmful" compound. Our results suggest a potential risk to aquatic organisms and humans from the wide utilization of TCPP and its consequent release into the environment. These results highlight that further research should be conducted to investigate the effects of TCPP individually and in combination with other organophosphorus flame retardants in various organisms. In addition, the concern induced by TCPP points out that measures to control the introduction of TCPP into the environment should be taken.