Concentrations Of Triclosan Research Articles

Impact of Triclosan on Bacterial Biodiversity and Sediment Enzymes - A Microcosm Study.

Triclosan (TCS), a widely used antimicrobial biocide, has raised serious concern among the scientific community in recent years owing to its ubiquitous presence around the globe and toxicity to aquatic organisms. The current study investigated the alterations in bacterial diversity, nutrients, and sediment enzyme activity in TCS-exposed sediment. TCS concentrations of 3mg/L (T1) and 6mg/L (T2) were applied in a microcosm setup for 28 days to sediment collected from Versova Creek, Mumbai. Among sediment enzymes, dehydrogenase activity exhibited the greatest degree of variability in 3mg/L exposed sediment. Nitrite, total nitrogen and urease exhibited higher concentrations in 6mg/L TCS exposed sediment. The concentration of ammonia was observed to be decreasing in treatments exposed to 6mg/L TCS. Total heterotrophic bacteria exhibited an increase in count in T1 and a decrease in T2. Metagenomics data showed a higher relative abundance of bacteria in T1 compared to T2 on the 28th day of sampling. Proteobacteria was found to be the most abundant phylum in all samples, and their relative abundance was reduced by 0.14% in T1 and 5.48% in T2. The results confirm the alterations in the composition of sediment bacterial communities and their enzymatic activities due to TCS exposure.

Physiological characteristics of microbial transformation during chronic exposure to triclosan as a hydrophobic antibacterial agent and post-antibacterial cessation

ABSTRACT The use of triclosan (TCS) in hygiene products and other materials raises concerns about increased antimicrobial resistance. Research has shown that bacteria can develop resistance to TCS, but there is limited understanding of how bacterial behavior changes after TCS is removed. This study focuses on how bacteria adapt to prolonged TCS exposure and recover after its removal. It aims to improve practices for using antimicrobial agents in sanitation products and emphasize the importance of understanding exposure and recovery times to prevent resistance development. The study evaluated the bacterial behavior, determining the minimum inhibition concentration of TCS that 90% of Escherichia coli was inhibited (MIC90), predicting bacterial growth kinetics using the Modified Gompertz model and membrane permeability recovery. Bacteria showed a significant increase in resistance levels during exposure, with the MIC90 steadily increasing over 30 days and peaking at 16 mg/L. Upon removal, there was a notable 2-fold decrease in resistance after 10 days of reculturing in a non-chemical medium, likely due to restructuring changes in cell membranes. Therefore, in addition to reducing the occurrence of antibacterial agents in the environment, advanced treatments for eliminating antibacterial resistance should be performed on wastewater before being discharged into the environment.

Integrative transcriptomic analysis reveals a broad range of toxic effects of triclosan on coral Porites lutea

Triclosan (TCS) is an antimicrobial agent commonly used in personal care products. However, little is known about its toxicity to corals. Here, we examined the acute toxic effects (96 h) of TCS at different levels to the coral Porites lutea. Results showed that the bioaccumulation factors (BAFs) of TCS in Porites lutea decreased with increasing TCS exposure levels. Exposure to TCS at the level up to 100 μg/L did not induce bleaching of Porites lutea. However, by the end of the experiment, both the density and chlorophyll a content of the symbiotic zooxanthellae were 19–52 % and 19.9–45.6 % lower in the TCS treatment groups than in the control, respectively. For the coral host, its total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT) activities were all significantly lower in the TCS treatment groups than the control. Transcriptome analysis showed that 942 and 1077 differentially expressed genes (DEGs) were identified in the coral host in the 0.5 and 100 μg/L TCS treatment groups, respectively. Meanwhile, TCS can interfere with pathways related to immune system and reproductive system in coral host. Overall, our results suggest that environmentally relevant concentrations of TCS can impact both the coral host and the symbiotic zooxanthellae.

Associations of prenatal maternal urinary concentrations of triclosan and benzophenone-3 with cognition in 7.5-month-old infants

BackgroundEndocrine-disrupting chemicals (EDCs) have been linked to adverse health outcomes and prenatal exposure is known to impact infant and child development. However, few studies have assessed early developmental consequences of prenatal exposure to two common phenolic compounds, benzophenone-3 (BP-3) and triclosan (TCS). ObjectiveWe evaluated the relationship of prenatal exposure to BP-3 and TCS with infant cognition at 7.5 months via performance on a visual recognition memory (VRM) task. MethodsDrawing from the Illinois Kids Development Study (IKIDS) cohort, prenatal exposure to BP-3 and TCS was assessed in pools of five urine samples collected from each woman across pregnancy. Cognition was measured in 310 infants using a VRM task assessing information processing speed, attention, and recognition memory through infrared eye-tracking. Generalized linear regression estimated exposure-outcome associations, followed by stratification to investigate modification of associations by infant sex and stimulus set. ResultsSampled mothers were more likely to be white, college educated, and middle or high income relative to the US population. Mean chemical exposures were significantly higher than those of adult women in the NHANES cohort. In models adjusted for income, gestational age at birth, and testing age, prenatal BP-3 exposure was associated with an increase in run duration (average time spent looking at the stimuli before looking away) (β = 0.0011, CI -0.0001:0.0022), indicating slower information processing speed, while TCS was associated with significantly longer time to familiarization (time to accrue a total of 20 s of looking time to the stimuli) (β = 0.0686, CI 0.0203:0.1168, p < 0.01), indicating poorer attention. Stratum-specific analyses isolated both effects to male infants who viewed the second of two stimulus sets. ConclusionHigher prenatal exposure to triclosan was associated with poorer attention in infancy, while benzophenone-3 may be associated with slower information processing speed, particularly among males.

Ratiometric fluorescence sensing of triclosan by Lanthanide-Functionalized Metal–Organic frameworks

As a widely used antibacterial and antifungal agent in numerous personal care and consumer products, triclosan (TCS) is frequently detected in natural water bodies and has caused serious harm on human health and ecosystems. The quantitative and fast analysis of TCS is thus of paramount significance, however still remains challenging. In recent years, ratiometric fluorescence sensing has attracted vast interests in analyte detection due to the dual emission, which can effectively eliminate interference from environmental factors and improve the detection accuracy. Benefiting from the strong encapsulation capability and structural adjustability, metal organic frameworks (MOFs) are demonstrated to be a perfect platform to construct ratiometric fluorescence sensors. In the present study, we modify a zirconium MOF, UiO-67-bpy, to be a ratiometric fluorescence sensor by introducing Eu3+ and carbon dots sequentially via the post-synthetic method. The obtained hybrid system, CDs@Eu/UiO-67-bpy, shows two well separated emission peaks. With the addition of TCS, the red fluorescence from Eu3+ at 611 nm decreases while the blue fluorescence from carbon dots at 412 nm remains unchanged, resulting an excellent ratiometric response. Linear relationships of the fluorescence ratio (F412/F611) against the concentration of TCS are acquired in both low and high concentration range with detection of limit as low as 0.53 and 2.3 μM, respectively. Moreover, satisfactory recoveries of TCS levels from CDs@Eu/UiO-67-bpy are achieved in various water samples and personal care products. The composite of CDs@Eu/UiO-67-bpy also displays a fluorescence color changing from red to blue responsive to different concentration of TCS, demonstrating great potential in practical application of CDs@Eu/UiO-67-bpy for visualized monitoring TCS.

Ecotoxicological effects of triclosan on Lemna minor: bioconcentration, growth inhibition and oxidative stress.

Triclosan (TCS), an emerging pollutant, is a notable contributor to adverse impacts on aquatic organisms due to its widespread use during COVID-19 and hydrophobic properties. There is extensive documented literature on TCS toxicity in commercially important fish species; however, studies on aquatic plants remain limited. In this prelude, the present study aims to evaluate the effect of TCS on Lemna minor, a commercially important aquatic plant species for 7days. The results showed dose-dependent significant alterations in growth, pigments and stress enzymes of L. minor at varied concentrations of TCS (1 to 8mg L-1). Median inhibitory concentration (IC50) was found to be 4.813mg L-1. Total chlorophyll and carotenoid levels decreased 73.11 and 81.83%, respectively after 7days of TCS exposure. A significant increase in catalase and superoxide dismutase activity was observed in TCS exposed groups as compared to the control. Bioconcentration factor was found to be in the range of 5.855 to 37.129 signifying TCS ability to accumulate and transfer through the food chain. Scanning electron microscopy (SEM) analysis showed deformation in the cell surface and alteration of stroma morphology of TCS exposed groups. Furthermore, the Fourier transform infrared spectroscopy (FTIR) study also revealed that higher concentrations of TCS could cause alteration in the functional groups in the plant. This study demonstrates that TCS negatively impacts the growth and metabolism of primary producers, offering crucial insights into its interactions with aquatic plants and establishing baseline information essential for crafting effective mitigation strategies for TCS contamination in aquatic environments.

Occupational exposure of nail technicians to industrial chemicals: A pilot study

Previous studies have observed the use of complex industrial chemicals in beauty products. However, occupational exposure of beauty practitioners to various chemicals has not been sufficiently assessed. Our study recruited 37 female nail technicians from 28 nail salons in South China and investigated the abundances and profiles of more than 60 industrial chemicals or their metabolites in indoor dust, hand wipes, and urine of nail technicians. Thirty female college students were also recruited for comparison. The results revealed broad exposure of nail technicians to 42 target chemicals or their metabolites, with mono-phthalate esters (mono-PAEs) exhibiting the highest concentrations (median 284 ng/mL), followed by parabens (median 57.9 ng/mL) and antioxidants (median 19.6 ng/mL) in urine. The urinary concentrations of mono-PAEs, parabens, triclosan (TCS) and triclocarban of nail technicians were significantly higher than those of college students. Pre-shift and post-shift urine did not exhibit significant differences for most chemicals, likely reflecting continuous and long-term exposure. Hand wipe levels of TCS and 2,6-di-tert-butyl-4-methylpheno were significantly associated with urinary levels of these chemicals or their metabolites, while such a pattern was not observed between dust and urinary levels. This highlights the influence of dermal contact or hand-to-mouth transfer on the intake of these chemicals. Collectively, our pilot study demonstrates the occupational exposure of nail technicians to industrial chemicals in beauty products and calls for vigilant self-protection measures to mitigate exposure risks in beauty practitioners.

Changes in prenatal urinary concentrations of triclocarban and triclosan following the US FDA ban in 2016: the ECHO cohorts

Changes in prenatal urinary concentrations of triclocarban and triclosan following the US FDA ban in 2016: the ECHO cohorts

Parabens, bisphenols, and triclosan in coral polyps, algae, and sediments from sanya, China: Occurrence, profiles, and environmental implications

Parabens, bisphenols (BPs), and triclosan (TCS) are common environmental phenols widely applied in industrial products, pharmaceuticals, and personal care products. They are endocrine disruptors and pervade the natural environment, causing significant detrimental impacts on ecosystems, including marine habitats. Therefore, in this study, 40 samples comprising coral polyps, algae, and sediments were collected from Sanya, Hainan Province, China, in which the presence and compositional profiles of parabens, BPs, and TCS were examined to identify their fate in the oceans. The results unveiled the ubiquitous occurrence of at least one paraben or bisphenol in all samples, with TCS detected in over 80% of cases. Notably, coral samples contained the most contaminants (median concentration: 9.42 ng/g dry weight-dw), followed by sediment samples (5.95 ng/g dw) and algal samples (3.58 ng/g dw). Attributed to their broadest application, methylparaben (MeP) and propylparaben (PrP) emerged as the primary paraben constituents. MeP displayed the highest median concentration in coral samples (4.42 ng/g dw), probably related to its high-water solubility and the filtration mechanism employed by the coral polyps during seawater intake. Intriguingly, bisphenol P (BPP) superseded bisphenol A (BPA) as the dominant bisphenol, especially in the algal samples, probably owing to the lipophilic character of BPP and the enhanced biodegradability of BPA within aquatic environments. The highest concentration of TCS (3.44 ng/g dw) was found in the sediment samples, associated with its long half-life in the sediments. Furthermore, the correlation between multiple parabens and TCS implies their co-use to augment antimicrobial efficacy. Future research should prioritize the examination of these phenols in diverse marine environmental media. Corresponding toxicological experiments should be conducted to visualize their transport dynamics, degradation byproducts, and toxicity to marine biota to gain insights into the risks they pose to the marine ecosystem.

Physiological and transcriptome level responses of Microcystis aeruginosa and M. viridis to environmental concentrations of triclosan

The toxicity of triclosan (TCS) to various aquatic organisms has been demonstrated at environmental concentrations. However, the effects and mechanisms of TCS on toxic cyanobacteria remains largely unexplored. This study investigated the physiological and molecular variations in two representative toxic Microcystis species (M. aeruginosa and M. viridis) under exposure to TCS for 12 d. Our findings demonstrated that the median effective concentration (EC50) of TCS for both Microcystis species were close to the levels detected in the environment (M. aeruginosa: 9.62 μg L−1; M. viridis: 27.56 μg L−1). An increased level of reactive oxygen species (ROS) was observed in Microcystis, resulting in oxidative damage when exposed to TCS at concentrations ranging from 10 μg L−1 to 50 μg L−1. The photosynthetic activity of Microcystis had a certain degree of recovery capability at low concentrations of TCS. Compared to M. aeruginosa, the higher recovery capability of the photosynthetic system in M. viridis would be mainly attributed to the increased ability for PSII repair and phycobilisome synthesis. Additionally, the synthesis of microcystins in the two species and the release rate in M. viridis significantly increased under 10–50 μg L−1 TCS. At the molecular level, exposure to TCS at EC50 for 12 d induced the dysregulation of genes associated with photosynthesis and antioxidant system. The upregulation of genes associated with microcystin synthesis and nitrogen metabolism further increased the potential risk of microcystin release. Our results revealed the aquatic toxicity and secondary ecological risks of TCS at environmental concentrations, and provided theoretical data with practical reference value for TCS monitoring.

Ecotoxicological risk assessment of triclosan, an emerging pollutant in a riverine and estuarine ecosystems: A comparative study

Triclosan (TCS), an antibacterial biocide, pervades water and sediment matrices globally, posing a threat to aquatic life. In densely populated cities like Mumbai, rivers and coastal bodies demand baseline TCS data for ecotoxicological assessment due to the excessive use of personal care products comprising TCS. This pioneering study compares spatiotemporal TCS variations and risks in freshwater and marine ecosystems employing multivariate analysis of physicochemical parameters. Over five months (January to May 2022), Mithi River exhibited higher TCS concentrations (water: 1.68 μg/L, sediment: 3.19 μg/kg) than Versova Creek (water: 0.49 μg/L, sediment: 0.69 μg/kg). Principal component analysis revealed positive correlations between TCS and physicochemical parameters. High-risk quotients (>1) underscore TCS threats in both water bodies. This study furnishes crucial baseline data, emphasizing the need for effective treatment plans for TCS in effluent waters released into the adjacent aquatic systems.

Assessment of triclosan induced histopathological and biochemical alterations, and molecular docking simulation analysis of acetylcholinesterase enzyme in the gills of fish, Cyprinus carpio.

Triclosan (TCS), an antimicrobial additive in various personal and health care products, has been widely detected in aquatic environment around the world. The present study investigated the impacts of TCS in the gills of the fish, Cyprinus carpio employing histopathological, biochemical, molecular docking and simulation analysis. The 96h LC50 value of TCS in C. carpio was found to be 0.968mg/L. Fish were exposed to 1/1000th (1µg/L), 1/100th (10µg/L), and 1/10th (100µg/L) of 96h LC50 value for a period of 28days. The histopathological alterations observed in the gills were hypertrophy, hyperplasia, edematous swellings, and fusion of secondary lamellae in TCS exposed groups. The severity of these alterations increased with both the concentration as well as the duration of exposure. The present study revealed that the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase, glutathione peroxidase, and reduced glutathione content decreased significantly (p < 0.05) in both concentration and duration dependent manner. However, a significant (p < 0.05) increase in the activity of the metabolic enzymes such as acid phosphatase and alkaline phosphatase was observed in all three exposure concentrations of TCS from 7 to 28days. The activity of acetylcholinesterase declined significantly (p < 0.05) from 7 to 28days whereas the content of acetylcholine increased significantly at the end of 28day. The experimental results were further confirmed by molecular docking and simulation analysis that showed strong binding of TCS with acetylcholinesterase enzyme. The study revealed that long-term exposure to sublethal concentrations of TCS can lead to severe physiological and histopathological alterations in the fish.

Comparison of chemical contaminant measurements using CLAM, POCIS, and silicone band samplers in estuarine mesocosms.

Discrete water samples represent a snapshot of conditions at a particular moment in time and may not represent a true chemical exposure caused by changes in chemical input, tide, flow, and precipitation. Sampling technologies have been engineered to better estimate time-weighted concentrations. In this study, we consider the utility of three integrative sampling platforms: polar organic chemical integrative sampler (POCIS), silicone bands (SBs), and continuous, low-level aquatic monitoring (CLAM). This experiment used simulated southeastern salt marsh mesocosm systems to evaluate the response of passive (POCIS, SBs) and active sampling (CLAM) devices along with discrete sampling methodologies. Three systems were assigned to each passive sampler technology. Initially, all tanks were dosed at nominal (low) bifenthrin, pyrene, and triclosan concentrations of 0.02, 2.2, and 100 µg/L, respectively. After 28 days, the same treatment systems were dosed a second time (high) with bifenthrin, pyrene, and triclosan at 0.08, 8.8, and 200 µg/L, respectively. For passive samplers, estimated water concentrations were calculated using published or laboratory-derived sampling rate constants. Chemical residues measured from SBs resulted in high/low ratios of approximately 2x, approximately 3x, and 1x for bifenthrin, pyrene, and triclosan. A similar pattern was calculated using data from POCIS samples (~4x, ~3x, ~1x). Results from this study will help users of CLAM, POCIS, and SB data to better evaluate water concentrations from sampling events that are integrated across time. Integr Environ Assess Manag 2024;20:1384-1395. © 2024 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Human exposure characteristics of pharmaceutical and personal care product chemicals and associations with dietary habits

Considering the widespread presence of pharmaceutical and personal care products (PPCPs) in the environment and their adverse health effects, human exposure to PPCPs has caused worldwide concern. However, there remains insufficient information on the exposure assessment of the Chinese population. Based on this, the exposure levels of 13 PPCPs in the urine samples of 986 Chinese adults were measured, aiming to provide information on the prevalence of PPCP occurrence and investigate potential correlations between PPCP exposure and obesity. Results showed that the detection rates of these compounds in urine ranged from 28.12 % to 98.58 %, with median concentrations ranging below the limit of detection to 10.58 ng mL−1. Methyl-paraben (MeP) was the most dominant paraben and had the highest urinary concentration (median = 10.12 ng mL−1), while 4-hydroxy-benzophenone (4-OH-BP) was the dominant benzophenone derivative (median = 0.22 ng mL−1). In antibacterials, the urinary concentration of triclosan (mean = 42.00 ng mL−1) was much higher than that of triclocarban (mean = 0.63 ng mL−1). PPCP concentrations were significantly associated with sex, age, body mass index, education level, and annual household income (p < 0.050). Regression analysis of dietary habits showed that seafood and tea consumption may be significant exposure sources of PPCP exposure (p < 0.050). Furthermore, individual exposure to MeP (odds ratio (OR) < 1, p = 0.002) and 4-OH-BP (OR < 1, p = 0.009) exhibited a significantly negative association with obesity in females. Also, analysis results from quantile g-computation and Bayesian kernel machine regression models demonstrated that an inverse correlation between PPCP mixture exposure and obesity was significant in females. This study reports the extensive prevalence of PPCP exposure among adults from China, and may provide crucial insights into PPCP exposure dynamics. More epidemiological studies are need in the future, with a thorough knowledge of PPCP exposure.

Environmental phenol exposures in 6- to 12-week-old infants: The Infant Feeding and Early Development (IFED) study

BackgroundExposure to phenols, endocrine-disrupting chemicals used in personal care and consumer products, is widespread. Data on infant exposures are limited despite heightened sensitivity to endocrine disruption during this developmental period. We aimed to describe distributions and predictors of urinary phenol concentrations among U.S. infants ages 6–12 weeks. MethodsThe Infant Feeding and Early Development (IFED) study is a prospective cohort study of healthy term infants enrolled during 2010–2013 in the Philadelphia region. We measured concentrations of seven phenols in 352 urine samples collected during the 6- or 8- and/or 12-week study visits from 199 infants. We used linear mixed models to estimate associations of maternal, sociodemographic, infant, and sample characteristics with natural-log transformed, creatinine-standardized phenol concentrations and present results as mean percent change from the reference level. ResultsMedian concentrations (μg/L) were 311 for methylparaben, 10.3 for propylparaben, 3.6 for benzophenone-3, 2.1 for triclosan, 1.0 for 2,5-dichlorophenol, 0.7 for BPA, and 0.3 for 2,4-dichlorophenol. Geometric mean methylparaben concentrations were approximately 10 times higher than published estimates for U.S. children ages 3–5 and 6–11 years, while propylparaben concentrations were 3–4 times higher. Infants of Black mothers had higher concentrations of BPA (83%), methylparaben (121%), propylparaben (218%), and 2,5-dichorophenol (287%) and lower concentrations of benzophenone-3 (−77%) and triclosan (−53%) than infants of White mothers. Triclosan concentrations were higher in breastfed infants (176%) and lower in infants whose mothers had a high school education or less (−62%). Phenol concentrations were generally higher in summer samples. ConclusionsWidespread exposure to select environmental phenols among this cohort of healthy U.S. infants, including much higher paraben concentrations compared to those reported for U.S. children, supports the importance of expanding population-based biomonitoring programs to infants and toddlers. Future investigation of exposure sources is warranted to identify opportunities to minimize exposures during these sensitive periods of development.

Monitoring human exposure to four parabens and triclosan: comparing silicone wristbands with spot urine samples as predictors of internal dose

BackgroundPeople are exposed to a variety of chemicals each day as a result of their personal care product (PCP) use.ObjectiveThis study was designed to determine if silicone wristbands provide a quantitative estimate of internal dose for phenols commonly associated with PCPs, with a focus on triclosan and four parabens: methyl-, ethyl-, propyl-, and butylparaben. Uptake of these compounds into wristbands and correlations with internal dose were assessed.MethodsTen adults from central North Carolina wore five silicone wristbands, with one wristband removed each day for 5 days. Each participant provided a 24 h urine sample and a random spot urine sample each day, in which paraben and triclosan metabolites were evaluated.ResultsAll parabens and triclosan were detected frequently in wristbands and, except for butylparaben, in urine samples. Wristband and spot urine concentrations of parabens and triclosan were both compared to a measurement of internal dose (i.e., the total metabolite mass excreted over 5 days as a measurement of internal dose).Impact statementThe two most hydrophobic compounds investigated, butylparaben and triclosan, displayed significant linear uptake in wristbands over 5 days, whereas concentrations of methyl- and ethylparaben displayed a steady state concentration. In general, wristbands and spot urine samples were similarly correlated to internal dose for frequently detected parabens and triclosan. However, wristbands have additional advantages including higher detection rates and reduced participant burden that may make them more suitable tools for assessing exposure to PCPs.

Multidrug-resistant Stenotrophomonas maltophilia in residential aged care facilities: An emerging threat.

Stenotrophomonas maltophilia is a multidrug-resistant (MDR), Gram-negative bacterium intrinsically resistant to beta-lactams, including last-resort carbapenems. As an opportunistic pathogen, it can cause serious healthcare-related infections. This study assesses the prevalence, resistance profiles, and genetic diversity of S. maltophilia isolated from residential aged care facilities (RACFs). RACFs are known for their overuse and often inappropriate use of antibiotics, creating a strong selective environment that favors the development of bacterial resistance. The study was conducted on 73 S. maltophilia isolates recovered from wastewater and facility swab samples obtained from three RACFs and a retirement village. Phenotypic and genotypic assessments of the isolates revealed high carbapenem resistance, exemplifying their intrinsic beta-lactam resistance. Alarmingly, 49.3% (36/73) of the isolates were non-wild type for colistin, with minimum inhibitory concentration values of > 4 mg/L, and 11.0% (8/73) were resistant to trimethoprim-sulfamethoxazole. No resistance mechanisms were detected for either antimicrobial. Genotypic assessment of known lineages revealed isolates clustering with Sm17 and Sm18, lineages not previously reported in Australia, suggesting the potential ongoing spread of MDR S. maltophilia. Lastly, although only a few isolates were biocide tolerant (2.7%, 2/73), their ability to grow in high concentrations (64 mg/L) of triclosan is concerning, as it may be selecting for their survival and continued dissemination.

Pollution levels and ecological risks of PPCPs in water and sediment samples of Danjiangkou Reservoir.

The concentrations and distribution patterns of three typical pharmaceuticals and personal care products (PPCPs) in water and sediment samples obtained from Danjiangkou Reservoir during two seasonal sampling periods were studied to determine their impact on water quality. The temporal and spatial variations in concentrations measured were analyzed and related to ecological risks with data obtained during the mean-flow period (in June) and the dry period (in November). We found a high detection rate of ketoprofen (KTP) in water samples from Danjiangkou Reservoir; the concentrations ranged from not detected (ND) to 46.80ng/L with the highest values measured in the Hanku tributary samples followed by the samples collected in the main body of Danjiangkou Reservoir. The KTP concentrations in the Danku tributary samples were the lowest measured in this study. In addition, the concentrations of KTP in the Shending River, Sihe River, Jianghe River, Guanshan River, and Jianhe River water samples were relatively high in the mean-flow period. The water sample detection rates and concentrations of triclosan (TCS) and triclocarban (TCC) were low in both the mean-flow period and the dry period. All three kinds of PPCPs were detected in the sediment samples with the concentrations of KTP, TCS, and TCC ranging from 0.76 to 7.89μg/kg, 0.01 to 0.59μg/kg, and 0.01 to 11.36μg/kg, respectively. Overall, the concentrations of the three measured PPCPs in the water and sediment samples were all relatively low compared to results reported in the recent literature. The dry period concentrations of PPCPs in the water samples were lower than the concentrations measured in the mean-flow period. However, dry period concentrations were higher in the sediment samples compared to those in the mean-flow period samples. Our interpretation of the spatial and temporal patterns of PPCPs in Danjiangkou Reservoir suggests that these compounds were likely mainly derived from wastewater discharge in the upper reaches of the reservoir. The risk quotient (RQ) method was used for an ecological risk assessment of the detected PPCPs in this study. We found that TCS in water and sediment posed medium ecological risks to algae at different times of the year. In view of the extreme importance of water safety in Danjiangkou Reservoir, the ecological risks of PPCPs require additional attention.

Time-varying associations of gestational and childhood triclosan with pubertal and adrenarchal outcomes in early adolescence.

Triclosan is an endocrine-disrupting chemical, but associations with pubertal outcomes remain unclear. We examined associations of gestational and childhood triclosan with adolescent hormone concentrations and pubertal stage. We quantified urinary triclosan concentrations twice during pregnancy and seven times between birth and 12 years in participants recruited from Cincinnati, OH (2003-2006). We averaged concentrations across pregnancy and childhood and separately considered individual exposure periods in multiple informant models. At 12 years, we measured serum hormone concentrations (males [n = 72] and females [n = 84]-dehydroepiandrosterone-sulfate, luteinizing hormone, follicle-stimulating hormone; males-testosterone; females-estradiol). Also at age 12 years, participants self-reported physical development and menarchal timing. We estimated associations (95% confidence interval) of triclosan with hormone concentrations, more advanced physical development, and age at menarche. For females, each doubling of childhood triclosan was associated with 16% lower estradiol concentrations (-29%, 0%), with stronger associations for measures closer to adolescence. We found suggestive evidence that higher triclosan at any age was associated with ~10% (for gestational triclosan: -18%, -2%) lower follicle-stimulating hormone concentrations among males and early postnatal (1-3 years) triclosan was associated with 63% (5%, 96%) lower odds of advanced pubic hair development in females. In multiple informant models, each doubling of gestational triclosan concentrations was associated with 5% (0%, 9%) earlier age at menarche, equivalent to 5.5 months. Gestational and childhood triclosan concentrations were related to some pubertal outcomes including hormone concentrations and age at menarche. Our findings highlight the relevance of elucidating potential sex-specific and time-dependent actions of triclosan.

Triclosan, an antimicrobial drug, induced reproductive impairment in the freshwater fish, Anabas testudineus (Bloch, 1792).

Triclosan (TCS), an antimicrobial drug, is known to occupy different compartments in aquatic ecosystems. The present study focused to evaluate the reproductive toxicity of triclosan, at environmentally relevant (0.009 and 9μg L-1) and sublethal (176.7μg L-1) concentrations for 90days in the pre-spawning phase of the fish, Anabas testudineus. The reproductive biomarkers, namely, gonadal steroidogenic enzymes, expression of aromatic genes, levels of serum gonadotropins, sex hormones, and histology of gonads were analyzed. The weight of the animal, brain weights along with gonadosomatic index decreased while mucus deposition increased significantly at all concentrations of triclosan as the primary defensive mechanism to prevent the entry of toxicants. Triclosan disrupted gonadal steroidogenesis as evidenced by a reduction in the activities of gonadal steroidogenic enzymes. The expressions of cyp19a1a and cyp19a1b genes were up-regulated in the brain of both sexes and testis, while down-regulated in the ovary indicating estrogenic effects of the compound. The endocrine-disrupting effects of triclosan were confirmed. The current results suggest that chronic exposure to triclosan altered reproductive endpoints thereby impairing normal reproductive functions in fish.