Toxic effects of triclosan in aquatic organisms: A review focusing on single and combined exposure of environmental conditions and pollutants.

Triclosan (TCS) is an antibacterial agent commonly used in personal care products. Due to its widespread use and improper disposal, it is also a pervasive contaminant, particularly in aquatic environments. When released into water bodies, TCS can induce deleterious effects on developmental and physiological aspects of aquatic organisms and also interact with environmental stressors such as weather, metals, pharmaceuticals, and microplastics. Multiple studies have described the adverse effects of TCS on aquatic organisms, but few have reported on the interactions between TCS and other environmental conditions and pollutants. Because aquatic environments include a mix of contaminants and natural factors can correlate with contaminants, it is important to understand the toxicological outcomes of combinations of substances. Due to its lipophilic characteristics, TCS can interact with a wide range of substances and environmental stressors in aquatic environments. Here, we identify a need for caution when using TCS by describing not only the effects of exposure to TCS alone on aquatic organisms but also how toxicity changes when it acts in combination with multiple environmental stressors.

Multiresidue determination and predicted risk assessment of emerging contaminants in sediments from Kongsfjorden, Svalbard.

The present work provides the first data on the occurrence of different classes of pharmaceuticals and personal care products (PPCPs) in surface marine sediments from an Arctic fjord (Kongsfjorden, Svalbard Islands, Norway). The target compounds included: ciprofloxacin; enrofloxacin; amoxicillin; erythromycin; sulfamethoxazole; carbamazepine; diclofenac; ibuprofen; acetylsalicylic acid; paracetamol; caffeine; triclosan; N,N-diethyl-meta-toluamide; 17ß-estradiol; 17α-ethinyl estradiol and estrone. Sampling was performed in the late summer, when high sedimentation rates occur, and over 5 years (2018-2022). Based on the environmental concentrations (MECs) found of emerging contaminants and the relative predicted no-effect concentrations (PNECs), an environmental risk assessment (ERA) for sediments was performed, including the estimation of the Risk Quotients (RQs) of selection and propagation of antimicrobial resistance (AMR) in this Arctic marine ecosystem. Sediments were extracted by Pressurized Liquid Extraction (PLE) and the extracts were purified by Solid Phase Extraction (SPE). Analytical determination was conducted with liquid chromatography-high-resolution mass spectrometry (HPLC-HRMS). PPCPs were detected in the sediments along the fjord in all the years investigated, with overall concentrations similar in most cases to those reported in urbanized areas of the planet and ranging from a minimum of 6.85 ng/g for triclosan to a maximum of 684.5 ng/g for ciprofloxacin. This latter was the only antibiotic detected but was the most abundant compound (32 %) followed by antipyretics (16 %), hormones (14 %), anti-inflammatories (13 %), insect repellents (11 %), stimulants (9 %), and disinfectants (5 %). Highest concentrations of all PPCPs detected were found close to the Ny-Ålesund research village, where human activities and the lack of appropriate wastewater treatment technologies were recognized as primary causes of local contamination. Finally, due to the presence in the sediments of the PPCPs investigated, the ERA highlights a medium (0.1 < RQ < 1) to high risk (RQ > 1) for organisms living in this Arctic marine ecosystem, including high risk of the spread of AMR.

[Determination of triclocarban and triclosan in urine by QuEChERS extraction and ultra-performance liquid chromatography-tandem mass spectrometry].

Objective: To establish a method for the determination of triclocarban (TCC) and triclosan (TCS) in urine by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) after purification by QuEChERS. Methods: In May 2022, urine samples were extracted by acetonitrile, purified by QuEChERS, separated by Waters Acquity UPLC BEH C18 column (100 mm×2.1 mm, 1.7 µm), and eluated with water-acetonitrile as mobile phase gradient at a flow rate of 0.3 ml/min. The detection was conducted in negative ion mode (ESI(-)) and multiple reaction monitoring (MRM) scanning, it was quantified with a internal standard method, and the methodology was verified. Results: The linear ranges of TCC and TCS were 0.5-100.0 µg/L and 1.0-100.0 µg/L, and the correlation coefficients were 0.9997 and 0.9991, respectively. The limits of detection and quantitation of TCC and TCS were 0.17 and 0.33 µg/L, and 0.5 and 1.0 µg/L, respectively. The recoveries of TCC and TCS were 100.1%-102.8% and 96.7%-108.6%, and the relative standard deviations were 4.9%-6.7% and 4.1%-8.3%, respectively, at 2.0, 10.0 and 80.0 µg/L. Conclusion: QuEChERS-UPLC-MS/MS method is simple, rapid, sensitive and reproducible, and can be used for rapid and accurate simultaneous detection of TCC and TCS exposure levels in occupational population.

Association of serum bisphenols, parabens, and triclosan concentrations with Sjögren Syndrome in the Hangzhou, China population.

Exposure to endocrine-disrupting chemicals (EDCs) has been linked to various immune deficiency disorders, including autoimmune diseases like Sjögren Syndrome (SjS). However, the detrimental effects of exposure to EDCs, including bisphenols, parabens, and triclosan (TCS), on SjS have been inadequately documented. Thus, we conducted a cross-sectional study that included both healthy individuals (controls) and patients with SjS (cases). We assessed serum concentrations of bisphenol A (BPA), bisphenol S (BPS), methyl parabens (MeP), ethyl parabens (EtP), and TCS. The relationship between the five EDCs levels and the risk of SjS was also explored. Additionally, we conducted an in-depth analysis of the collective influence of these EDCs mixtures on SjS, employing a weighted quantile sum regression model. Out of the five EDCs analyzed, EtP displayed the highest mean concentration (2.80 ng/mL), followed by BPA (2.66 ng/mL) and MeP (1.99 ng/mL), with TCS registering the lowest level (0.36 ng/mL). Notably, BPS exposure was significantly positively associated with the risk of being diagnosed with SjS (with an odds ratio [OR] of 1.17, p = 0.042). No statistically significant associations with SjS were observed for BPA, MeP, EtP, and TCS (p > 0.05). And we did not observe any significant effects of the EDCs mixture on SjS. To the best of our knowledge, this study is the first to suggest that BPS may potentially increase the risk of SjS. Although no significant effects were observed between other EDCs and SjS risk, we cannot disregard the potential harm of EDCs due to their non-monotonic dose response.

Ecotoxicological and human health risk assessment of triclosan antibacterial agent from municipal wastewater treatment plants.

In this study, the occurrence and environmental risks related to triclosan (TCS) in the two wastewater treatment plants (WWTPs) were investigated in Isfahan, Iran. Influent and effluent samples were collected and analyzed by dispersive liquid-liquid microextraction (DLLME)-GC-MS method with derivatization. Moreover, the risk of TCS exposure was conducted for aquatic organisms (algae, crustaceans, and fishes) and humans (males and females). TCS mean concentrations in influent and effluent of WWTPs were in the range of 3.70-52.99 and 0.83-1.09 µg/L, respectively. There were also no differences in the quantity of TCS and physicochemical parameters among the two WWTPs. The mean risk quotient (RQ) for TCS was higher than 1 (in algae) with dilution factors (DFs) equal to 1 in WWTP1. Moreover, the RQ value was higher than 1 for humans based on the reference dose of MDH (RFDMDH) in WWTP1. Furthermore, TCS concentration in wastewater effluent was the influential factor in varying the risk of TCS exposure. The results of the present study showed the risk of TCS exposure from the discharge of effluent of WWTP1 was higher than WWTP2. Moreover, the results of this study may be suitable for promoting WWTP processes to completely remove micropollutants.

Urinary concentrations and elimination half-lives of parabens, benzophenones, bisphenol and triclosan in Japanese young adults.

Environmental phenols are widely distributed in the environment and human samples, suggesting potential exposure to these chemicals. We designed an intervention trial with 30 participants over 6 days to assess the urinary concentrations and half-lives of environmental phenols in Japanese young people. The target environmental phenols include three parabens (methyl paraben, ethyl paraben, and propyl paraben), two benzophenones (benzophenone 1 and 3), two bisphenols (bisphenol F and bisphenol S), and triclosan. Throughout the intervention, the participants consumed the same food and drinks and used personal care products provided by the project. The target phenols were measured in urine from the participants using a liquid chromatography-tandem mass spectrometer. We compared the measured concentrations between the study periods to better understand the exposure tendency. Some statistically significant differences were observed. All target analytes were detected in more than 50% of samples collected on Day 0 (the day before the intervention). Methyl paraben was the dominant phenol detected in urine (1640 µg/g-creatinine), followed by ethyl paraben (119 µg/g-creatinine). Downward trends in creatinine-corrected concentrations were observed for all target analytes in some instances. Non-compartment analysis was performed to estimate urinary excretion parameters. The estimated half-lives ranged from 7.69 to 20.3 h. Use of paraben-free products during the intervention period reduced the body burden.

New insights into vermiremediation of sewage sludge: The effect of earthworms on micropollutants and vice versa.

Vermicomposting represents an environmentally friendly method for the treatment of various types of biowastes, including sewage sludge (SS), as documented in numerous studies. However, there are few papers providing insights into the mechanisms and toxicity effects involved in SS vermicomposting to present a comprehensive overview of the process. In this work, the vermiremediation of SS containing various micropollutants, including pharmaceuticals, personal care products, endocrine disruptors, and per/polyfluoroalkyl substances, was studied. Two SSs originating from different wastewater treatment plants (WWTP1 and WWTP2) were mixed with a bulking agent, moistened straw, at ratios of 0, 25, 50, and 75% SS. Eisenia andrei earthworms were introduced into the mixtures, and after six weeks, the resulting materials were subjected to various types of chemical and toxicological analyses, including conventional assays (mortality, weight) as well as tissue- and cell-level assays, such as malondialdehyde production, cytotoxicity tests and gene expression assays. Through the vermiremediation process significant removal of diclofenac (90%), metoprolol (88%), telmisartan (62%), and triclosan (81%) was achieved. Although the concentrations of micropollutants were substantially different in the original SS samples, the micropollutants vermiaccumulated to a similar extent over the incubation period. The earthworms substantially eliminated the present bacterial populations, especially in the 75% SS treatments, in which the average declines were 90 and 79% for WWTP1 and WWTP2, respectively. To the best of our knowledge, this is the first study to investigate the vermiremediation of such a large group of micropollutants in real SS samples and provide a thorough evaluation of the effect of SS on earthworms at tissue and cellular level.

Revealing mechanisms of triclosan on the removal and distribution of nitrogen and phosphorus in microalgal-bacterial symbiosis system.

Microalgal-bacterial symbiosis (MABS) system performs synergistic effect on the reduction of nutrients and carbon emissions in the water treatment process. However, antimicrobial agents are frequently detected in water, which influence the performance of MABS system. In this study, triclosan (TCS) was selected to reveal the effects and mechanisms of antimicrobial agents on MABS system. Results showed that the removal efficiencies of chemical oxygen demand, NH4+-N and total phosphorus decreased by 3.0%, 24.0% and 14.3% under TCS stress. In contrast, there were no significant decrease on the removal effect of total nitrogen. Mechanism analysis showed that both the growth rate of microorganisms and the nutrients retention capacity of extracellular polymeric substances were decreased. The intracellular accumulation for nitrogen and phosphorus was promoted due to the increased cytomembrane permeability caused by lipid peroxidation. Moreover, microalgae were dominant in MABS system with ratio between microalgae and bacteria of more than 5.49. The main genus was Parachlorella, with abundance of more than 90%. Parachlorella was highly tolerant to TCS, which might be conductive to maintain its survival. This study revealed the nutrients pathways of MABS system under TCS stress, and helped to optimize the operation of MABS system.

Uncovering the metabolic pathway of novel Burkholderia sp. for efficient triclosan degradation and implication: Insight from exogenous bioaugmentation and toxicity pressure.

Triclosan (TCS), a synthetic and broad-spectrum antimicrobial agent, is frequently detected in various environmental matrices. A novel TCS degrading bacterial strain, Burkholderia sp. L303, was isolated from local activated sludge. The strain could metabolically degrade TCS up to 8 mg/L, and optimal conditions for TCS degradation were at temperature of 35 °C, pH 7, and an increased inoculum size. During TCS degradation, several intermediates were identified, with the initial degradation occurring mainly through hydroxylation of aromatic ring, followed by dechlorination. Further intermediates such as 2-chlorohydroquinone, 4-chlorocatechol, and 4-chlorophenol were produced via ether bond fission and C-C bond cleavage, which could be further transformed into unchlorinated compounds, ultimately resulting in the complete stoichiometric free chloride release. Bioaugmentation of strain L303 in non-sterile river water demonstrated better degradation than in sterile water. Further exploration of the microbial communities provided insights into the composition and succession of the microbial communities under the TCS stress as well as during the TCS biodegradation process in real water samples, the key microorganisms involved in TCS biodegradation or showing resistance to the TCS toxicity, and the changes in microbial diversity related to exogenous bioaugmentation, TCS input, and TCS elimination. These findings shed light on the metabolic degradation pathway of TCS and highlight the significance of microbial communities in the bioremediation of TCS-contaminated environments.

Biological treatment of triclosan using a novel strain of Enterobacter cloacae and introducing naphthalene dioxygenase as an effective enzyme.

In recent years, triclosan (TCS) has been widely used as an antibacterial agent in personal care products due to the spread of the Coronavirus. TSC is an emerging contaminant, and due to its stability and toxicity, it cannot be completely degraded through traditional wastewater treatment methods. In this study, a novel strain of Enterobacter cloacae was isolated and identified that can grow in high TCS concentrations. Also, we introduced naphthalene dioxygenase as an effective enzyme in TCS biodegradation, and its role during the removal process was investigated along with the laccase enzyme. The change of cell surface hydrophobicity during TCS removal revealed that a glycolipid biosurfactant called rhamnolipid was involved in TCS removal, leading to enhanced biodegradation of TCS. The independent variables, such as initial TCS concentration, pH, removal duration, and temperature, were optimized using the response surface method (RSM). As a result, the maximum TCS removal (97%) was detected at a pH value of 7 and a temperature of 32 °C after 9 days and 12 h of treatment. Gas chromatography-mass spectrometry (GC/MS) analysis showed five intermediate products and a newly proposed pathway for TCS degradation. Finally, the phytotoxicity experiment conducted on Cucumis sativus and Lens culinaris seeds demonstrated an increase in germination power and growth of stems and roots in comparison to untreated water. These results indicate that the final treated water was less toxic.

Derivatized versus non-derivatized LC-MS/MS techniques for the analysis of estrogens and estrogen-like endocrine disruptors in human plasma.

Bisphenols, parabens, alkylphenols and triclosan are anthropogenic substances with a phenolic group that have been introduced to the environment in recent decades. As they possess hormone-like effects, they have been termed endocrine disruptors (EDs), and can interfere with steroid pathways in organisms. To evaluate the potential impact of EDs on steroid biosynthesis and metabolism, sensitive and robust methods enabling the concurrent measurement of EDs and steroids in plasma are needed. Of crucial importance is the analysis of unconjugated EDs, which possess biological activity. The aim of the study was to develop and validate LC-MS/MS methods with and without a derivatization step for the analysis of unconjugated steroids (estrone-E1, estradiol-E2, estriol-E3, aldosterone-ALDO) and different groups of EDs (bisphenols, parabens, nonylphenol-NP and triclosan-TCS), and compare these methods on a set of 24 human plasma samples using Passing-Bablok regression analysis. Both methods were validated according to FDA and EMA guidelines. The method with dansyl chloride derivatization allowed 17 compounds to be measured: estrogens (E1, E2, E3), bisphenols (bisphenol A-BPA, BPS, BPF, BPAF, BPAP, BPZ, BPP), parabens (methylparaben-MP, ethylparaben-EP, propylparaben-PP, butylparaben-BP, benzylparaben-BenzylP), TCS and NP, with lower limits of quantification (LLOQs) between 4 and 125 pg/mL. The method without derivatization enabled 15 compounds to be analyzed: estrogens (E1, E2, E3), ALDO, bisphenols (BPA, BPS, BPF, BPAF, BPAP, BPZ), parabens (MP, EP, PP, BP, BenzylP) with LLOQs between 2 and 63 pg/mL, and NP and BPP in semiquantitative mode. Adding 6 mM ammonium fluoride post column into mobile phases in the method without derivatization achieved similar or even better LLOQs than the method with the derivatization step. The uniqueness of the methods lies in the simultaneous determination of different classes of unconjugated (bioactive) fraction of EDs together with selected steroids (estrogens + ALDO in the method without derivatization), which provides a useful tool for evaluating the relationships between EDs and steroid metabolism.

Influence of exposure time, physicochemical properties, and plant transpiration on the uptake dynamics and translocation of pharmaceutical and personal care products in the aquatic macrophyte Typha latifolia.

Typha latifolia is widely used as a phytoremediation model plant for organic compounds. However, the dynamic uptake and translocation of pharmaceutical and personal care products (PPCPs) and their relationship with physicochemical properties, such as lipophilicity (LogKow), ionization behavior (pKa), pH-dependent lipophilicity (LogDow), exposure time and transpiration, are scarcely studied. In the current study, hydroponically grown T. latifolia was exposed to carbamazepine, fluoxetine, gemfibrozil, and triclosan at environmentally relevant concentrations (20 µg/L each). Eighteen out of thirty-six plants were exposed to the PPCPs and the other eighteen were untreated. Plants were harvested at 7, 14, 21, 28, 35, and 42 days and separated into root, rhizome, sprouts, stem, and lower, middle, and upper leaf sections. Dry tissue biomass was determined. PPCP tissue concentrations were analyzed by LC-MS/MS. PPCP mass per tissue type was calculated for each individual compound and for the sum of all compounds during each exposure time. Carbamazepine, fluoxetine, and triclosan were detected in all tissues, while gemfibrozil was detected only in roots and rhizomes. In roots, triclosan and gemfibrozil mass surpassed 80% of the PPCP mass, while in leaf carbamazepine and fluoxetine mass represented 90%. Fluoxetine accumulated mainly in the stem and the lower and middle leaf, while carbamazepine accumulated in the upper leaf. The PPCP mass in roots and rhizome was strongly positively correlated with LogDow, while in leaf it was correlated with water transpired and pKa. PPCP uptake and translocation in T. latifolia is a dynamic process determined by the properties of contaminants and plants.

Co-exposure to parabens and triclosan and associations with cognitive impairment in an elderly population from Shenzhen, China.

Parabens and triclosan (TCS) have been extensively applied in personal care products (PCPs) as preservatives and antibacterial agents. However, their potentiality to disrupt the neurological system has induced increasing concern. The elderly population is at a higher risk of neurodegenerative disorder, although research on its association with PCP exposure remains scarce. Here, we measured the urinary levels of four parabens, TCS, and an oxidative stress marker among 540 participants from the Shenzhen aging-related disorder cohort during 2017-2018. The Mini-Mental State Examination (MMSE) was used to assess the cognitive status of participants. Their demographic, dietary, and behavioral factors were collected via questionnaire survey. Among the four paraben analogs, the median concentration of methyl parabens (MeP) was the highest (Low-risk group: 1.21 ng/mL, High-risk group: 1.64 ng/mL). TCS and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were detected in more than 90% of the samples. Weighted quantile sum regression and quantile-based g-computation showed that the combined effect of all analytes was positively associated with the level of 8-OHdG. BtP, EtP and MeP were identified as the major contributors to the joint effect. After stratification by gender, females exhibited more pronounced changes in urinary 8-OHdG level than males. However, the positive correlation between co-exposure to parabens and TCS and cognitive impairment was not significant (p > 0.05) in both models, which warrants investigation with the larger sample size.

A thin biofilm of chitosan as a sorptive phase in the rotating disk sorptive extraction of triclosan and methyl triclosan from water samples.

The features and nature of the sorptive phase may be the stage that determines the scope of microextraction techniques. In search of new alternatives, materials of natural origin have recently been explored to establish greener analytical strategies. Based on that search, this research proposes the use of chitosan as a sorptive phase, which was assessed in the rotating disk sorptive extraction of emerging contaminants from aqueous systems. Chitosan is a biopolymer of animal origin that is usually found in the shells of crustaceans. The main characteristic of this material is the presence of a high number of nitrogenous groups, which gives it high reactivity, but its main disadvantage is associated with its high swelling capacity. In this research, chitosan was crosslinked with a low concentration of glutaraldehyde to form thin films that were easily immobilized on the surface of the rotating disk. The main advantage of this modification is the considerable decrease in the swelling capacity, which prevents loss and rupture of the sorbent during high rotation of the disk. In addition, it not only improved the physical characteristics of chitosan but also increased its extraction capacity. With regard to its use as a sorptive phase, all the variables associated with the microextraction of the analytes were studied, and optimal variables were found to be: pH 4, 20% NaCl (salting out effect), 30-45 min as equilibrium time and elution of analytes with a mixture of methanol:ethyl acetate (1:1). Validation of the methodology for the determination of methyl triclosan and triclosan was carried out, and relative recoveries between 89 and 96% and relative standard deviations less than 14% were found. The detection limits were 0.11 and 0.20 µg L-1, respectively. Through its application in real samples (natural and residual waters), triclosan was quantified between 0.7 and 1.3 µg L-1. Finally, the "green" properties of the phase were evaluated, demonstrating that it is reusable for at least three cycles and biodegradable. Compared to its efficiency with a commercial phase (in this case, the styrene divinyl benzene phase), the proposed biosorbent provided a similar and even higher sorptive capacity (depending on the analyte).

Triclosan and related compounds in the environment: Recent updates on sources, fates, distribution, analytical extraction, analysis, and removal techniques.

Triclosan (TCS) has been widely used in daily life because of its broad-spectrum antibacterial activities. The residue of TCS and related compounds in the environment is one of the critical environmental safety problems, and the pandemic of COVID-19 aggravates the accumulation of TCS and related compounds in the environment. Therefore, detecting TCS and related compound residues in the environment is of great significance to human health and environmental safety. The distribution of TCS and related compounds are slightly different worldwide, and the removal methods also have advantages and disadvantages. This paper summarized the research progress on the source, distribution, degradation, analytical extraction, detection, and removal techniques of TCS and related compounds in different environmental samples. The commonly used analytical extraction methods for TCS and related compounds include solid-phase extraction, liquid-liquid extraction, solid-phase microextraction, liquid-phase microextraction, and so on. The determination methods include liquid chromatography coupled with different detectors, gas chromatography and related methods, sensors, electrochemical method, capillary electrophoresis. The removal techniques in various environmental samples mainly include biodegradation, advanced oxidation, and adsorption methods. Besides, both the pros and cons of different techniques have been compared and summarized, and the development and prospect of each technique have been given.

Innovative electrochemical biosensor with nitrifying biofilm and nitrite oxidation signal for comprehensive toxicity detection in Tuojiang River.

Water toxicity detection, as a valuable supplement to conventional water quality measurement, is an important method for evaluating water environmental quality standards. However, the toxicity of composite pollutants is more complicated due to their mixture effects. This study developed a novel, rapid and interference-resistant detection method for water toxicity based on an electrochemical biosensor using peak current from nitrite oxidation as a signal. Toxicants could weaken the characteristic peak current of nitrite to indicate the magnitude of toxicity. The proof-of-concept study was first conducted using a synthetic water sample containing trichloroacetic acid (TCAA), and then the results were compared with those of the traditional toxicity colorimetric method (CCK-8 kit) and laser confocal microscopy (CLSM). The accuracy of the biosensor was further verified with water samples containing individual pollutants such as Cd2+ (50-150 µg/L), Cr6+ (20-80 µg/L) mixture, triclosan (TCS; 0.1-1.0 µg/L) and TCAA (10-80 µg/L), or a mixture of the above. The viability of the sensor was further validated with the actual water sample from the Tuojiang River. The results demonstrated that although the concentration of a single conventional pollutant in water did not exceed the discharge standard for surface water, the comprehensive toxicity of natural water should not be ignored. This method could be a beneficial supplement to conventional water quality detection to understand the characteristics of the water, and thus contribute to the next stage of water treatment.

[Simultaneous determination of triclosan，triclocarban and p-chloro-m-xylenol in disinfectant，personal care products and oiltment by nonaqueous capillary electrophoresis].

Triclosan （TCS）， triclocarban （TCC）， and p-chloro-m-xylenol （PCMX） are some of the most widely used antibiotics because of their broad-spectrum and highly-efficient bactericidal effects. In the context of disinfection， the National Standard GB 38598-2020 stipulates that the contents of the effective ingredients present in a disinfectant must be specified， wherein their range must fall within 90%-110% of the specified central value. To ensure a suitable product quality， analysis by high performance liquid chromatography （HPLC） is recommended by both the GB/T 27947-2020 and GB/T 34856-2017. However， the results analyzed according to the National Standard method often exceed the declared contents， thereby indicating the necessity to establish a new method based on a completely different principle （e. g.， capillary electrophoresis）， especially since it was not possible to analyze TCS， TCC， and PCMX in a single injection using the National Standard method. Moreover， using this method， large amounts of methanol were consumed， which could be potentially harmful to both operators and the environment. In terms of their water solubilities， this decreases in the order of PCMX>TCS>TCC， wherein TCC is insoluble in water. As such， the use of nonaqueous capillary electrophoresis （NACE） based on running buffer solutions prepared in pure organic solvents （e. g.， methanol or acetonitrile） is necessary. In this paper， a new NACE approach combined with an ultraviolet detection method was developed for the simultaneous analysis of TCS， TCC， and PCMX in disinfectants， personal care products， and ointments. For this purpose， an uncoated fused silica capillary （20 cm×50 µm， total length=30.2 cm） was used as the separation column with a separation buffer composed of 14 mmol/L sodium borate， 2 g/L polyethylene glycol （PEG） 20000， and 0.5 mmol/L dodecyltrimethylammonium bromide （DTAB） in methanol. Following optimization of the separation parameters， the complete and simultaneous separation of TCS， TCC， and PCMX was achieved when the sample solution was prepared using 5 g/L PEG 20000 in methanol-acetonitrile （50∶50， v/v）. It was possible to directly inject the sample into the analysis system after a simple dilution with the sample medium， and no interference was observed in any of the sample electropherograms when a separation voltage and detection wavelength of -12 kV and 214 nm were employed， respectively. Furthermore， TCS， TCC， and PCMX showed good linear relationships with their corrected peak areas within a mass concentration range of 1-100 mg/L， and the correlation coefficients （r） were all greater than 0.99. Moreover， the limits of detection （LODs， S/N=3） and limits of quantification （LOQs， S/N=10） were determined to be 0.2 and 1 mg/L， respectively. The spiked recoveries ranged from 94.5% to 104.4% with relative standard deviations of ≤4.8% in all cases. Subsequently， the established method was used to analyze 31 commercial samples， including hand sanitizer， disinfectant， baby powder， and antibacterial cream. A comparative analysis of HPLC， the developed NACE method， and our previously reported micellar electrokinetic chromatographic （MEKC） method was also carried out for the quantitative determination of TCS， TCC， and PCMX. Although no statistically significant differences were observed among the three methods， the results determined for 16 out of the 31 samples did not match the claimed contents. These results therefore indicate the necessity to further control the compositions of disinfectant products. Our results indicate that the newly established NACE method can be an important alternative to HPLC for routine laboratory analyses， especially considering that it minimizes waste generation， requires only a simple sample pretreatment process， and exhibits a good selectivity to the target compounds. It is therefore hoped that the NACE method will be incorporated into the National Standard method in the near future.

Are human exposure assessment the same for non-persistent organic chemicals? -from the lens of urinary variability and predictability.

Assessment of human exposure to mixtures of non-persistent chemicals from food matrices and consumer products requires accurate characterization and estimation of their preceding exposure levels, and assessment sampling approaches for these varying chemicals remain disputable. Here, we used high-throughput targeted method to quantify urinary concentrations of 59 most common non-persistent chemicals (6 parabens, 14 bisphenols, 1 triclosan, 7 benzophenones, 2 dichlorophenols, 13 phthalate metabolites and 16 antioxidants) in 158 consecutive spot samples from 11 participants over three consecutive days, 33 samples of which were first morning voids (FMVs). We found 49 chemicals with detection frequencies over 70 % in all urine samples. Principal component analyses showed greater inter-person variations than each person's inter-day variations. Intraclass correlation coefficient (ICC) to assess the reproducibility of targeted chemicals demonstrated that regardless of sampling approaches, dichlorophenols, most parabens, benzophenones and triclosan showed moderate to high reproducibility (0.445 < ICC < 0.969), with relatively high predictive power of FMVs for 24-h collections. Notably, most phthalates, bisphenols and antioxidants showed low ICC values. Together, our work demonstrates that FMV samples may be adequate for assessing human exposure to parabens, benzophenones, triclosan and dichlorophenols, whereas multiple consecutive urine collections may be advantageous for evaluating exposure to most phthalates, bisphenols and antioxidants.

Comprehensive insight into triclosan-from widespread occurrence to health outcomes.

Humans are exposed to the variety of emerging environmental pollutant in everyday life. The special concern is paid to endocrine disrupting chemicals especially to triclosan which could interfere with normal hormonal functions. Triclosan could be found in numerous commercial products such as mouthwashes, toothpastes and disinfectants due to its antibacterial and antifungal effects. Considering the excessive use and disposal, wastewaters are recognized as the main source of triclosan in the aquatic environment. As a result of the incomplete removal, triclosan residues reach surface water and even groundwater. Triclosan has potential to accumulate in sediment and aquatic organisms. Therefore, the detectable concentrations of triclosan in various environmental and biological matrices emerged concerns about the potential toxicity. Triclosan impairs thyroid homeostasis and could be associated with neurodevelopment impairment, metabolic disorders, cardiotoxicity and the increased cancer risk. The growing resistance of the vast groups of bacteria, the evidenced toxicity on different aquatic organisms, its adverse health effects observed in vitro, in vivo as well as the available epidemiological studies suggest that further efforts to monitor triclosan toxicity at environmental levels are necessary. The safety precaution measures and full commitment to proper legislation in compliance with the environmental protection are needed in order to obtain triclosan good ecological status. This paper is an overview of the possible negative triclosan effects on human health. Sources of exposure to triclosan, methods and levels of detection in aquatic environment are also discussed.

A comparative study on the sensitivity of selected freshwater fishes against triclosan exposure.

Triclosan, a broad-spectrum antimicrobial agent, which is widely used in several pharmaceutical and personal care products, has been known to pose adverse impacts on various groups of aquatic organisms, including fish. The present study aimed to compare the sensitivity of five selected freshwater fishes toward triclosan exposure. The acute toxicity or median lethal concentration (LC50-96 h) of triclosan determined using probit analysis was 1.76 mg L-1 in Anabas testudineus, 448 µg L-1 in Danio rerio, 700 µg L-1 in Gambusia affinis, 1.35 mg L-1 in Oreochromis mossambicus, and 750 µg L-1 in Pseudetroplus maculatus. Based on the length-weight relationship, the lowest condition factor, or K value, was recorded in Danio rerio (0.931) while the highest value was observed in Anabas testudineus (2.343) indicating negative allometric growth. Similarly, the weight of fishes and gill weight declined significantly (p < 0.05) in their respective LC50-96 h groups with concomitant alterations in the rate of oxygen consumption denoting respiratory distress. Triclosan exposure also resulted in the modification of fish behavior and histomorphological damage in gill tissues. The alterations in all parameters tested were more prominent in Danio rerio and thus considered the most sensitive species, while Anabas testudineus comparatively tolerated the toxicant to some extent. The study provides the baseline data that variation in the length-weight relationship is one of the major factors that influences the toxic effects of triclosan on the selected freshwater fishes.