Influence of microplastic contamination on the dissipation of endocrine disrupting chemicals in soil environment

Microplastic (MP) contamination is in the spotlight today, yet knowledge of their interaction with other organic contaminants in the soil environment is limited. Concerns extend to endocrine disrupting chemicals (EDCs), known for their potential to interfere with the hormonal systems of organisms and for their persistence and widespread presence in the environment. In this study, the most frequently occurring EDCs were monitored both in alluvial soil and in soil contaminated with different MPs commonly found in soil media, polyethylene, polyamide, and polystyrene. Bisphenol A and parabens were the most rapidly dissipating compounds, followed by triclosan and triclocarban, with the latter showing poor degradation. Per- and polyfluoroalkyl substances (PFAS) showed high persistence as concentrations remained nearly constant throughout the experiment. Although they fitted well with first-order dissipation kinetics, most showed biphasic behavior. The co-occurrence of MPs in the soil influenced the kinetic behavior in most cases although the differences were not very marked. MPs could impact sorption-desorption processes, affecting contaminant mobility and bioavailability to organisms in soil. These findings strengthen evidence for the influence of MPs on the behavior of soil contaminants such as EDCs, not only as vectors or sources of contaminants but by affecting dissipation kinetics.

Fate, toxicity and effect of triclocarban on the microbial community in wastewater treatment systems

Triclocarban (TCC), one of the typical antimicrobial agents, is a contaminant of emerging concern commonly found in high concentration in water environments. However, the fate and toxicity of TCC in wastewater treatment systems remain poorly understood. Here, we investigated how TCC impacts chemical oxygen demand and inorganic nitrogen transformation in a hydrolytic anaerobic-anoxic/oxic process. In the anaerobic section, the transformation of TCC was dominated by reductive dechlorination and supplemented by two amid bonds hydrolysis. In the anoxic and oxic sections, the hydrolysis of amid bonds dominated. The toxicity was reduced after the treatment (IC₅₀ from 0.09 to 0.54). TCC inhibited NH₄⁺-N removal in the anaerobic section and led to the NO₃^--N accumulation (2.84-4.13 mg/L) after treatment, with the abundance of N-removal bacteria decreased by 6%. Furthermore, the original ecological niche was gradually replaced by TCC-resistant/degradative bacteria, formating new microbial modules to resist the TCC stress. Importantly, fourteen genera including Methanosaeta, Longilinea, Dokdonella and Mycobacterium as potential bioindicators warning TCC and its intermediates were proposed. Overall, this study provides new insights into the fate of TCC in biological wastewater treatment systems and suggests a great importance for TCC control to ensure the health and resilience of ecosystems.

Association of urinary triclosan, methyl triclosan, triclocarban, and 2,4-dichlorophenol levels with anthropometric and demographic parameters in children and adolescents in 2020 (case study: Kerman, Iran)

Endocrine-disrupting chemicals (EDCs) can be a major risk factor for noncommunicable illnesses, especially when children are exposed to them. The purpose of this study was to assess the urine concentrations of triclosan (TCS), methyl triclosan (MTCS), triclocarban (TCC), and 2,4-dichlorophenol (2,4-DCP) and its association with anthropometric and demographic parameters in children and adolescents aged 6-18 living in Kerman, Iran, in 2020. A GC/MS instrument was used to measure the concentrations of the analytes. TCS, MTCS, TCC, and 2,4-DCP geometric mean concentrations (µg/L) were 4.32 ± 2.08, 1.73 ± 0.88, 4.66 ± 10.25, and 0.19 ± 0.14, respectively. TCS, MTCS, TCC, and 2,4-DCP were shown to have a positive and significant association with BMI z-score and BMI (p-value < 0.01). TCS and MTCS have a positive, strong, and substantial association (p-value < 0.01, r = 0.74). There was no significant association between the waist circumference (WC) and the analytes studied. In addition, there was a close association between analyte concentration and demographic parameters (smoking, education, income, etc.) overall. In Kerman, Iran, the current study was the first to look into the association between TCS, MTCS, TCC, and 2,4-DCP analytes and anthropometric and demographic data. The levels of urinary TCS, MTCS, TCC, 2,4-DCP, and anthropometric parameters in children and adolescents are shown to have a significant association in this study. However, because the current study is cross-sectional and it is uncertain if a single experiment accurately reflects long-term exposure to these analytes, more research is needed to determine the impact of these analyses on the health of children and adolescents.

Occurrence and partitioning of bisphenol analogues, triclocarban, and triclosan in seawater and sediment from East China Sea

Bisphenol analogues (BPs), triclocarban (TCC), and triclosan (TCS) are well-known environmental endocrine disrupters. Many studies have characterized their occurrence in the freshwater environment. However, their environmental behaviors in the coastal marine environment remain poorly understood. Here, matched seawater and sediment samples were collected from East China Sea, and analyzed for 13 BPs (including halogenated derivatives of bisphenol A), TCC, and TCS. Bisphenol A (BPA; mean 23 ng/L) was the predominant BP in seawaters, followed by tetrabromobisphenol A (TBBPA; 2.3 ng/L) and bisphenol S (BPS; 2.2 ng/L). Seawater concentrations of TCS (<LOD-8.7 ng/L) were much higher (p < 0.01) than that of TCC (<LOD-0.33 ng/L). In sediments BPA was still the major BP (mean 13 ng/g dw, dry weight), followed by bisphenol F (1.6 ng/g dw) and BPS (0.69 ng/g dw). All sediment samples contained measurable TCC (0.12-6.6 ng/g dw), while TCS was occasionally detected. For the first time, this study reports the environmental occurrence of bisphenol M and 4,4'-sulfonylbis (2-aminophenol) (a first discovered BPS analogue) in seawaters and sediments. Spatially, inshore seawater and sediment samples contained higher (p < 0.01) BPA and BPS concentrations, compared with offshore samples. The mean log-transformed sediment-seawater partitioning coefficients (log K_oc) ranged from 2.3 (TBBPA) to 4.0 (TCC). The log K_oc values of BPA, BPS, and BPAF were lower than those previously reported in the freshwater environment. Overall, this study provides first data on the spatial distribution patterns and partitioning behaviors of BPs, TCC, and TCS in marine environment.

Human exposure and health risk assessment of an increasingly used antibacterial alternative in personal care products: Chloroxylenol

The ban of some antibacterial ingredients, such as triclosan (TCS) and triclocarban (TCC), in personal care products (PCPs) in some countries (but not in China) has resulted in the increasing use of antibacterial alternatives, such as chloroxylenol (PCMX). However, the underlying human health risks and environmental impacts of PCMX exposure are largely unknown. Thus, the distribution characteristics of PCMX in PCPs and susceptible populations and the major routes and health risks of human exposure to PCMX were investigated. The PCMX, TCS, and TCC concentrations in PCPs, urine, drinking water, and surface water were determined using high-performance liquid chromatograph system equipped with diode array detector or triple quadrupole mass spectrometer. Results showed that PCMX is widely used in antibacterial hand sanitizers and household disinfectants in China. The addition of PCMX as an antibacterial ingredient in PCPs showed an increasing trend. The geomean concentrations of urinary PCMX in children and pregnant women were 21.6 and 31.9 μg·L^-1, respectively, which were much higher than TCS and TCC. A considerable concentration of PCMX ranging from 1.62 to 9.57 μg·L^-1 was observed in the aquatic environment, suggesting a potential massive-use of PCMX by humans. Human PCMX exposure via drinking was negligible because the PCMX concentrations in drinking water were less than 2.00 ng·L^-1. During human simulation experiment, we found that dermal contact was the dominant route of human PCMX exposure, accounting for 92.1% of the urinary PCMX concentration. The estimated daily intake of PCMX in 9.68% of children and 5.66% of pregnant women was higher than the reference dose. However, the urinary 8-hydroxy-2'-deoxyguanosine concentrations remained stable despite the elevated PCMX concentrations, thereby suggesting that daily PCMX exposure may not cause oxidative DNA damage in humans. Nevertheless, the potential ecotoxicity and health risks induced by chronic PCMX exposure cannot be ignored because of its increasing use.

Fate processes of Parabens, Triclocarban and Triclosan during wastewater treatment: assessment via field measurements and model simulations

The high levels of parabens (including methyl-, ethyl- and propyl congeners), triclocarban (TCC) and triclosan (TCS) used every year in China might be a problem to the typical wastewater treatment plant (WWTP). This study addresses measurements of parabens, TCC and TCS Northern China WWTP and a modelling assessment on the occurrence, fate and removal pathways in WWTP. Per-capita emissions of the three parabens, TCC and TCS to the WWTP were estimated as 0.41, 0.11 and 0.07 mg/d. After the wastewater treatment processes, 94, 92 and 87% of parabens, TCC and TCS were removed. The major removal pathway of parabens was biodegradation while that of TCC and TCS were sorption to sludge. Computer simulations on the fate processes of parabens, TCC and TCS in the WWTP using the SimpleTreat 4.0 model suggested the model could generally reproduce the measurements with root mean squared errors (RMSEs) of less than 10 ng/L. However, the model underestimated the removal of TCC and TCS from water to sludge in the primary tank. These discrepancies were attributed to the uncertainty of the predicted organic carbon-water partition coefficients (K_oc) to which the modelling results are highly sensitive. The model predictions using updated K_oc became more accurate and RMSEs of TCC and TCS were reduced by 40 and 80%, respectively. The modelling assessment suggests that the SimpleTreat, as a generic model to simulate chemical fate processes in WWTPs, has the potential to be applied to other similar WWTPs in China for estimating environmental releases of parabens, TCC and TCS at a larger spatial scale.

Age, gender, and racial/ethnic differences in the association of triclocarban with adulthood obesity using NHANES 2013-2016

This study examined the association between triclocarban and obesity among US adults and compared the pattern of this association across age, gender, and racial/ethnic groups. Study found triclocarban to be associated with obesity (OR: OR:1.123 95% CI: 1.046, 1.205) and this association remained among women (OR:1.14 95% CI: 1.031, 1.261). Study participants aged 60 years and older were more likely to be overweight (OR:1.131 95% CI: 1.022 1.251) and obese (OR:1.192 95% CI: 1.079, 1.317) when compared to other age groups. Likewise, non-Hispanic whites (OR:1.126 95% CI: 1.003, 1.263) and "other race including multi-racial" (OR:1.431 95% CI: 1.219, 1.679) were more likely to be obese when compared to other racial/ethnic groups. In conclusion, triclocarban is associated with obesity among US adults and there is evidence of gender, age, and racial/ethnicity differences in the association.

Triclosan and triclocarbon in maternal-fetal serum, urine, and amniotic fluid samples and their implication for prenatal exposure

Triclosan (TCS) and Triclocarbon (TCC) are chlorinated synthetic antimicrobial agents formaternal urinelated in quantities of consumer products. However, the biomonitoring of direct exposure reflection for fetuses are rare. In this study, we determine the concentrations of TCS and TCC in paired maternal serum, cord serum, maternal urine, and amniotic fluid samples collected from a cohort of 95 expecting mother-fetal pairs in Southern China. TCS and TCC are detected widely (detection rates: >76.9%) in maternal serum, cord serum, maternal urine, and amniotic fluid samples. TCS is found to be the predominant antimicrobial agent with median concentrations in maternal serum (1.5 ng/mL) and cord serum (1.8 ng/mL) that are one order of magnitude higher than those of tcc in maternal serum (0.085 ng/mL) and cord serum (0.052 ng/mL), respectively. Cord serum concentrations of tcs and tcc correlated well with the concentrations in maternal serum, which reflect the mothers' contribution to fetal exposure. The higher median ratio of cord serum/maternal serum_TCS (0.95) compared to that of cord serum/maternal serum_TCC (0.53) indicates high placental transmission ability of TCS. Moreover, the facility to penetrate the placental barrier and hard to depurate characteristics lead to the long residence of TCS in the fetal environment, causing great concern over the prenatal exposure risks during the critical window of fetal development. This study provides a novel contribution by increasing existing knowledge on the exposure assessment of TCS and TCC during pregnancy through the exploration of matched maternal-fetal samples.

Occurrence and Safety Evaluation of Antimicrobial Compounds Triclosan and Triclocarban in Water and Fishes of the Multitrophic Niche of River Torsa, India

Personal care product (PCP) chemicals have a greater chance of accumulation in the aquatic environments because of their volume of use. PCPs are biologically active substances that can exert an adverse effect on the ecology and food safety. Information on the status of these substances in Indian open water ecosystems is scarce. In this paper, we report the incidence of two synthetic antimicrobials, triclosan (TCS), including its metabolite methyl-triclosan (Me-TCS) and triclocarban (TCC) in Torsa, a transboundary river flowing through India. In water TCS and TCC were detected at levels exceeding their respective PNEC (Predictive No Effect Concentration). Both the compounds were found to be bioaccumulative in fish. TCS concentration (91.1-589 µg/kg) in fish was higher than that of TCC (29.1-285.5 µg/kg). The accumulation of residues of the biocides varied widely among fishes of different species, ecological niche, and feeding habits. Me-TCS could be detected in fishes and not in water. The environmental hazard quotient of both TCS and TCC in water indicated a moderate risk. However, the health risk analysis revealed that fishes of the river would not pose any direct hazard to human when consumed. This is the first report of the occurrence of these PCP chemicals in a torrential river system of the eastern Himalayan region.

Concentration and distribution of parabens, triclosan, and triclocarban in pregnant woman serum in China

Despite mass production and widespread use of parabens, triclosan (TCS), and triclocarban (TCC) in a range of personal care products, little is known about their concentrations and distribution in pregnant woman serum in China. In this study, 5 parabens (methyl- (MeP), ethyl- (EtP), butyl- (BuP), heptyl- (HeP) and benzyl-parabens (BzP)) and 4 their metabolites (methyl protocatechuate (OH-MeP), ethyl protocatechuate (OH-EtP), 3,4-dihydroxybenzoic acid (3,4-DHB) and 4-hydroxybenzoic acid (4-HB)), TCS, and TCC were measured, by using solid-phase extraction (SPE) and ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) techniques, in pregnant woman serum samples collected from 13 provinces in China. Total concentrations of parabens (∑PBs), their metabolites (∑MBs), and TCC and TCS (∑AAs) in serum ranged from 0.221-18.6 (geometric mean (GM): 2.47), 47.4-598 (212), and 0.101-5.84 (1.01) ng/mL, respectively. MeP, EtP, 4-HB and TCS were the dominant compounds, and their GM concentrations were 1.86, 0.239, 211 and 1.00 ng/mL, respectively. Geographical distribution of target chemicals in serum was determined. Concentrations of MeP (5.49 ng/mL) and EtP (0.895 ng/mL) in sera from the Northeast China were higher than those from other regions (MeP: 0.987-3.54, EtP: 0.07-0.254 ng/mL; p < 0.05). The highest 4-HB concentrations were found in sera from the Southwest China (GM: 286 ng/mL), whereas the TCS concentrations in sera from the North China (1.18 ng/mL) were higher than those found for other regions (p < 0.05). The estimated daily intakes (EDIs; range: 49.5-126 μg/kg body weight (bw)/day) showed that the Chinese women were in a low health risk from exposure to such chemicals. This is the first study to report concentration profiles of parabens, TCS and TCC in pregnant woman serum in China.

Correlates of exposure to phenols, parabens, and triclocarban in the Study of Environment, Lifestyle and Fibroids

We performed a cross-sectional analysis to identify correlates of urinary concentrations of seven phenols (bisphenols A, F, and S; 2,4-dichlorophenol; 2,5-dichlorophenol; benzophenone-3; triclosan), triclocarban, and four parabens (butyl, ethyl, methyl, and propyl). We analyzed baseline data from 766 participants in the Study of Environment, Lifestyle, and Fibroids, a prospective cohort study of 1693 Black women aged 23-34 years residing in Detroit, Michigan (2010-2012). We collected data on demographic, behavioral, and anthropometric factors via telephone interviews, clinic visits, and self-administered questionnaires. For each biomarker, we used linear regression models to estimate mean differences in log-transformed, creatinine-corrected concentrations across factors of interest. Each biomarker was detected in >50% of participants. Median creatinine-corrected concentrations were the highest for methyl paraben (116.8 μg/g creatinine), propyl paraben (16.8 μg/g creatinine), and benzophenone-3 (13.4 μg/g creatinine). Variables most strongly associated with biomarker concentrations included season of urine collection, education, and body mass index (BMI). BMI was positively associated with bisphenol A and S and triclocarban concentrations and inversely associated with butyl and methyl paraben concentrations. In this cohort of Black women, exposure to phenols, parabens, and triclocarban was prevalent and several factors were associated with biomarker concentrations.

Occurrence, fate and risk assessment of biocides in wastewater treatment plants and aquatic environments in Thailand

This study investigated the occurrence and fate of 19 biocides in 8 wastewater treatment plants and receiving aquatic environments (both freshwater and estuarine systems) in Thailand. The predominant compound in wastewater and surface water was methylparaben with the maximum concentration of 15.2 μg/L detected in the receiving river, while in sludge and sediment was triclocarban with the maximum concentration of 8.47 μg/g in sludge. Triclosan was the main contaminants in the fish samples with the maximum concentration of 1.20 μg/g. Similar results of biocides were found in the estuarine system in Pattaya city, with the maximum concentration of 185 ng/L in sea water for methylparaben, and 242 ng/g in estuarine sediment for triclocarban. The aqueous removal rates for the biocides ranged from 15% to 95% in average. The back estimated-usage and total estimated emission of Ʃ19 biocides in Thailand was 279 and 202 tons/year, respectively. Preliminary ecological risk assessment showed that clotrimazole and triclosan could pose high risks to aquatic organisms in the receiving aquatic environments.

Contamination and spatial distribution of parabens, their metabolites and antimicrobials in sediment from Korean coastal waters

Synthetic antimicrobials known as parabens, triclosan (TCS), and triclocarban (TCC) are emerging environmental contaminants. Limited studies on these contaminants have been conducted in coastal environments. In our study, parabens, their metabolites, TCS, and TCC were measured in sediment collected along the Korean coast, to investigate contamination status, spatial distribution, and potential health risks to coastal environments. Methyl paraben and 4-hydroxybenzoic acid were detected in all sediment samples, suggesting widespread contamination. Total concentrations of parent parabens, their metabolites, TCS, and TCC ranged from 0.19 to 11.2 (mean: 2.40) ng/g dry weight, 9.65 to 480 (mean: 120) ng/g dry weight, and < limit of quantification (LOQ)-6.10 (mean: 0.41) ng/g dry weight, and from < LOQ-41.0 (mean: 2.78) ng/g dry weight, respectively. The overall contamination of parabens and antimicrobials in sediment was different from that reported for persistent organic pollutants due to different contamination sources among chemical groups. Significant correlation was found among target contaminants in sediment, suggesting the existence of a common source. Total organic carbon (TOC) was significantly correlated with the concentrations of target contaminants, implying a major factor for coastal distribution of parabens and antimicrobials. The concentrations of parabens and TCS measured in sediment did not exceed a hazard quotient (HQ), implying low potential health risks associated with exposure to these contaminants. This is the first study to report the nationwide distribution of parabens, their metabolites, and antimicrobials in the coastal environments of Korea.

Fate of Triclocarban (TCC) in aquatic and terrestrial systems and human exposure

Triclocarban (TCC) is considered as contaminant of emerging concern (CEC), and ranked in the top 10 CEC occurrence. TCC is a high production volume synthetic chemical used extensively in various personal care products. This chemical will be released into the environment via incomplete wastewater treatment and untreated wastewater discharge. TCC and its transformation products (4,4'-dichlorocarbilide (DCC),1-(3-chlorophenyl)-3-phenylurea (MCC) and carbanilide (NCC),2'OH-TCC, 3'OH-TCC) were detected in the environmental matrices. Sediment organic carbon will influence TCC concentrations in suspended and bed sediments. TCC is an antimicrobial agent and also emerging endocrine disruptor that can cause immune dysfunction and affect human reproductive outcomes. Furthermore, TCC alters the expression of proteins related to binding and metabolism, skeletal muscle development and function, nervous system development and immune response. TCC has potential health risks in wildlife and humans. Several animal studies illustrate that it can cause various adverse effects, which can be monitored by antioxidant biomarkers (CAT, GST and LPO). Accumulation of TCC in organisms depends on the lipophilicity and bioavailability of TCC in sediment and water. TCC was continuously detected in aquatic system. TCC is a lipophilic compound, which can efficiently bind with lipid content. Women are more vulnerable to TCC due to substantially higher frequency and extended exposure to TCC. This review provides basic information of occurrence of TCC and the exposure levels in aquatic organisms. Several literature have shown the higher usage and human exposure levels of TCC, which provides useful information for the chemical management approaches.

Spatial distribution of parabens, triclocarban, triclosan, bisphenols, and tetrabromobisphenol A and its alternatives in municipal sewage sludges in China

Parabens, triclocarban (TCC), triclosan (TCS), bisphenols (BPs), and tetrabromobisphenol A and its alternatives (TBBPAs) are used in a broad range of daily consumer products and industrial productions. Concerns have been raised over exposure of humans to these chemicals, because of their adverse health effects. However, information on the spatial distribution of parabens, TCC, TCS, BPs and TBBPAs in sludge from waste water treatment plants (WWTPs) in China is still limited. In this study, 19 endocrine disrupting chemicals, including six parabens, two antimicrobials (TCC and TCS), eight BPs and three TBBPAs, were determined in sludges from 46 WWTPs across China. Concentrations of target chemicals were found in a decreased order as: ∑(TCC+TCS) (mean: 3930, range: 1340-11,100ng/g dw)>∑₈BPs (201, 23.1-1240ng/g dw)>∑₆parabens (67.9, 10.4-272ng/g dw)>∑₃TBBPAs (18.4, 1.36-195ng/g dw). Methyl paraben (MeP), TCC, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) were the major compounds found in sludge, accounting for 89.0%, 57.7%, 85.8% and 93.3% of ∑₆parabens, ∑(TCC+TCS), ∑₈BPs and ∑₃TBBPAs, respectively. Elevated concentrations of BPs and TBBPAs were found in sludges from the Northeast China and Central South China (p<0.05), respectively, whereas there were no significant spatial difference in concentrations of parabens or antimicrobials among different geographical regions (p>0.05). Calculation of mass loading showed that sludge from East China (1340kg/yr) and South Central China (1060kg/yr) released relatively more such chemicals. This nationwide study provided baseline concentrations of these chemicals in sludges and estimated their environmental release through sludge in China.

An Immunoaffinity Purification Method for the Simultaneous Analysis of Triclocarban and Triclosan in Foodstuffs by Liquid Chromatography Tandem Mass Spectrometry

Triclocarban (TCC) and triclosan (TCS) have been simultaneously detected in five kinds of foodstuffs using an immunoaffinity purification method coupled with ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) for the first time. Two highly specific monoclonal antibodies against TCC and TCS were produced and coupled to N-hydroxysuccinimide-activated Sepharose 6B gel to prepare the immunosorbent. Under the optimal conditions, mean recoveries from spiked samples by the IAC-UHPLC-MS/MS method were 70.1-92.8% for TCC and 76.6-102.5% for TCS. Intraday relative standard deviations were below 14.5%. The limits of quantification (LOQs) of TCC were 1 ng/L for beverage samples and 0.01-0.02 μg/kg for food samples. The LOQs of TCS were 0.03 μg/L for beverage samples and 0.2-0.3 μg/kg for food samples. The applicability of the method has been proven by analyzing TCC and TCS in different samples from supermarkets in Beijing. The proposed method is sufficiently sensitive and reliable for monitoring trace concentrations of TCC and TCS in food samples.

A reduction in triclosan and triclocarban in water resource recovery facilities' influent, effluent, and biosolids following the U.S. Food and Drug Administration's 2013 proposed rulemaking on antibacterial products

Pharmaceutical and personal care product compounds (PPCPs) comprise a large and diverse group of chemical compounds, including prescription and over-the-counter drugs and cleaning agents. Although PPCPs in the effluent and biosolids of water resource recovery facilities (WRRFs) are currently not regulated, public interest has led the Metropolitan Water Reclamation District of Greater Chicago to monitor for 11 PPCPs in the influent, effluent, and biosolids at its seven WRRFs. In 2016, the U.S. Food and Drug Administration (FDA) issued a final rule establishing that 19 specific ingredients, including triclosan and triclocarban, were no longer generally recognized as safe and effective, which prohibits companies from marketing soaps as antibacterial if they contain one or more of these ingredients. It was presumed that since the proposed rulemaking in 2013, manufacturers began to remove these active ingredients from their products. Annual monitoring of 11 PPCPs from 2012 to 2017 demonstrated a 71% decrease in triclosan and 72% decrease in triclocarban in per capita influent loading into seven WRRFs. There was a 70% decrease in triclosan and 80% decrease in triclocarban concentrations in biosolids. These declines suggest the FDA rule for the reduction in use of these compounds was effective and resulted in manufacturers removing these ingredients from their products. PRACTITIONER POINTS: Reduction in triclosan and triclocarban per capita influent loading observed from 2012 to 2017. Reduction in triclosan and triclocarban biosolids loading observed from 2012 to 2017. 2016 FDA rulemaking on antimicrobial soaps was effective in removing triclosan and triclocarban from these products. Positive impact on quality of biosolids land applied to farmland.

Triclocarban at environmentally relevant concentrations induces the endoplasmic reticulum stress in zebrafish

Triclocarban (TCC) is an antibacterial agent commonly found in environmental, wildlife, and human samples. However, with in-depth study of TCC, its negative effects are increasingly presented. Toxicological studies of TCC at environmentally relevant concentrations have been conducted in zebrafish embryos and indicated that TCC leads to deformity of development causes developmental deformities. However, the molecular mechanisms underlying the toxicity of TCC in zebrafish embryos have not been entirely elucidated. We investigated whether exposure to TCC at environmentally relevant concentrations induces endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in zebrafish. Zebrafish embryos were grown to 32 hours post fertilization and exposed to 2.5, 5, and 10 μg/L TCC and used in whole-mount in situ hybridization to visualize the expression of ER chaperone hspa5 and ER stress-related apoptosis factor chop. Zebrafish livers were exposed to different concentrations of TCC to elaborate the relationships between fatty degeneration and ER stress. Then, a human hepatic cell line (HL-7702) was used to test whether TCC induced ER stress in human livers similar to those of zebrafish. In zebrafish embryos, TCC induced high hspa5 expression, which could defend against external stimulations. Furthermore, hapa5, hsp90b1, and chop exhibited ectopic expressions in the neuromast, intestinal tract, and tail tip of zebrafish embryos. On the one hand, significant differences were observed in the mRNA and protein expressions of the ER stress molecular chaperone pPERK-pEIF2a-ATF4 and ATF6 pathways in HL-7702 cells exposed to TCC. On the other hand, lipid droplet accumulation slightly increased in zebrafish livers exposed to 10 μg/L TCC in vitro. These results demonstrate that TCC not only damages the development of zebrafish embryos and structure of zebrafish liver but also influences human hepatic cells by activating ER stress and the UPR signaling pathway.

Diclofenac, carbamazepine and triclocarban biodegradation in agricultural soils and the microorganisms and metabolic pathways affected

The incomplete elimination of pharmaceuticals and personal care products (PPCPs) during wastewater treatment has resulted in their detection in the environment. PPCP biodegradation is a potential removal mechanism; however, the microorganisms and pathways involved in soils are generally unknown. Here, the biodegradation of diclofenac (DCF), carbamazepine (CBZ) and triclocarban (TCC) in four agricultural soils at concentrations typically detected in soils and biosolids (50 ng g^-1) was examined. Rapid DCF removal (<7 days) was observed under aerobic conditions, but only limited biodegradation was noted under other redox conditions. CBZ and TCC degradation under aerobic conditions was slow (half-lives of 128-241 days and 165-190 days for CBZ and TCC). Phylotypes in the Proteobacteria, Gemmatimonadales and Actinobacteria were significantly more abundant during DCF biodegradation compared to the controls (no DCF). For CBZ, those in the Bacteroidetes, Actinobacteria, Proteobacteria and Verrucomicrobia were enriched compared to the controls. Actinobacteria and Proteobacteria were also enriched during TCC biodegradation. Such differences could indicate these microorganisms are associated with the biodegradation of these compounds, as they appear to be benefiting from their removal. The impact of these PPCPs on the KEGG pathways associated with metabolism was also examined. Four pathways were positively impacted during DCF biodegradation (propanoate, lysine, fatty acid & benzoate metabolism). These pathways are likely common in soils, explaining the rapid removal of DCF. There was limited impact of CBZ on the metabolic pathways. TCC removal was linked to genes associated with the degradation of simple and complex substrates. The results indicate even low concentrations of PPCPs significantly affect soil communities. The recalcitrant nature of TCC and CBZ suggests soils receiving biosolids could accumulate these chemicals, representing risks concerning crop uptake.

Assessment of human exposure to triclocarban, triclosan and five parabens in U.S. indoor dust using dispersive solid phase extraction followed by liquid chromatography tandem mass spectrometry

Antimicrobials in indoor dust pose concerns due to their endocrine disrupting activities and potential promotion of antibiotic resistance. We adopted dispersive solid phase extraction (d-SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify antimicrobials in dust. The method showed favorable linearity (R² >0.99), recovery (83-115%), and method detection limits (1.2-5.6 ng/g, dry weight). All seven analytes were found at median concentrations in ng/g in each of the 80 U.S. dust samples collected from athletic facilities and residential homes: methyl paraben (1920) > propyl paraben (965) > triclosan (390) > triclocarban (270) > ethyl paraben (195) > butyl paraben (80) > benzyl paraben (6). Triclosan levels in dust from athletic facilities were significantly higher than those in private homes (p < 0.05). Median estimated daily intake (EDI) of antimicrobials in ng/kg-body weight/d from dust ingestion was lowest for adults (1.9) and higher for more sensitive subpopulations, including infants (19.8), toddlers (23.6), children (11.8) and teenagers (4.6). This first application of d-SPE to the analysis of dust produced U.S. baseline data for triclosan and triclocarban levels in indoor dust just prior to the 2017 Federal ban on use of these trichlorinated aromatics in antiseptic soaps and related personal care products.

Contamination and risk profiles of triclosan and triclocarban in sediments from a less urbanized region in China

Triclosan and triclocarban are priority environmental contaminants of increasing concern to environmental health. After application, the chemicals enter the aquatic environment and easily distribute in bed sediment due to their hydrophobicity, and thus pose potential ecological risks. This study investigated the distribution and risks of triclosan and triclocarban in the sediment environment of a less urbanized region in South China. The sampling sites with high levels of triclosan and triclocarban were found to locate in the tributaries. When compared to other monitoring results obtained from more densely populated regions, the residues of triclosan and triclocarban in the investigated region were low, suggesting that these two chemicals conservation in sediment is related to anthropic activities. The results of risk quotients showed that high risks to aquatic organisms were posed by triclosan residues in sediment, while the risks to benthic organisms were quite low. Triclocarban residues in sediment posed minimal to medium risks to aquatic and benthic organisms. In summary, using either of the calculation methods of risk quotients, medium risks posed by the antimicrobials can be found in certain sampling sites with low population densities. The results may be useful in the development of evidence-based policies for the government.

Degradation of 4,4'-Dinitrocarbanilide in Chicken Breast by Thermal Processing

Nicarbazin is one of the major anticoccidials used in broiler feeds. The compound 4,4'-dinitrocarbanilide (DNC) is the marker residue of concern left from nicarbazin in chicken meat. The effect of thermal processing on DNC content accumulated in chicken breast was assessed, and samples were analyzed by liquid chromatography-tandem mass spectrometry. Five conventional cooking methods were evaluated: boiling, grilling, microwaving, frying, and roasting. To ensure DNC in meat, broilers were fed nicarbazin without withdrawal period. All heating methods surpassed the 70 °C end point core temperature in chicken breast. Maximum DNC degradation was reached at 10 min for boiling, at 30 min for grilling, and at 2 min for microwaving, and no further reduction was observed for longer thermal processing time. Boiling was more efficient in reducing DNC (69%). Grilling, microwaving, and frying achieved on average 55% of degradation. The outcomes reported herein may be considered in decision-making regarding further review of maximum residue limits.

Transformation, Conjugation, and Sequestration Following the Uptake of Triclocarban by Jalapeno Pepper Plants

Plant uptake and metabolism of emerging organic contaminants, such as personal-care products, pose potential risks to human health. In this study, jalapeno pepper ( Capsicum annuum) plants cultured in hydroponic media were exposed to both ¹⁴C-labeled and unlabeled triclocarban (TCC) to investigate the accumulation, distribution, and metabolism of TCC following plant uptake. The results revealed that TCC was detected in all plant tissues; after 12 weeks, the TCC concentrations in root, stem, leaf, and fruit tissues were 19.74 ± 2.26, 0.26 ± 0.04, 0.11 ± 0.01, and 0.03 ± 0.01 mg/kg dry weight, respectively. More importantly, a substantial portion of the TCC taken up by plants was metabolized, especially in the stems, leaves, and fruits. Hydroxylated TCC (e.g., 2'-OH TCC and 6-OH TCC) and glycosylated OH-TCC were the main phase I and phase II metabolites in plant tissues, respectively. Bound (or nonextractable) residues of TCC accounted for approximately 44.6, 85.6, 69.0, and 47.5% of all TCC species that accumulated in roots, stems, leaves, and fruits, respectively. The concentrations of TCC metabolites were more than 20 times greater than the concentrations of TCC in the above-ground tissues of the jalapeno pepper plants after 12 weeks; crucially, approximately 95.6% of the TCC was present as metabolites in the fruits. Consequently, human exposure to TCC through the consumption of pepper fruits is expected to be substantially higher when phytometabolism is considered.

Activated carbon as a means of limiting bioaccumulation of organochlorine pesticides, triclosan, triclocarban, and fipronil from sediments rich in organic matter

Addition of activated carbon to contaminated sediment is an established means of remediation but its applicability to sediments high in organic carbon is presently unknown. We evaluated the effects of adding either granular activated carbon (GAC) or pelletized fine-grained activated carbon (PfAC, containing ∼ 50% AC) to contaminated sediments from Lake Apopka featuring a very high total organic carbon content (∼39% w/w dry). Sediments showing background levels of legacy pesticides were spiked with a mixture of 5 chemicals (p,p'-DDE, dieldrin, triclosan, triclocarban, and fipronil) to a nominal concentration of 2 μg/g sediment for each chemical. Following incubation of spiked sediments with the addition of activated carbon for 30 days, we assessed the success on limiting bioaccumulation using Lumbriculus variegatus (blackworm). In contaminant-spiked sediments amended with PfAC, blackworm body burdens of triclosan, triclocarban, and fipronil decreased by >50% and those of p,p'-DDE and dieldrin decreased by <30%. GAC addition to spiked sediments was less impactful, and yielded notable benefits in worm body burden reduction only for fipronil (40%). Fipronil achieved high treatment efficiency within the 30 day amendment with both GAC and PfAC. This is the first study to examine AC treatment in artificially contaminated sediments intrinsically very rich in organic matter content. PfAC exhibited superior performance over GAC for mitigating the uptake of certain organochlorines by aquatic organisms. These results indicate that further studies focusing on additional types of sediments and a broader spectrum of hydrophobic pollutants are warranted.

Fate of triclocarban in agricultural soils after biosolid applications

Triclocarban [N-(4-chlorophenyl)-N-(3,4-dichlorophenyl) urea] (TCC) is an antimicrobial agent utilized in a variety of consumer products. It is commonly released into domestic wastewaters and upon treatment, it is known to accumulate in biosolids. This study examines the occurrence of TCC in biosolids and its long-term fate in biosolid-treated soils. TCC levels in the biosolids from a large waste water treatment plant (WWTP) over 2 years showed little variability at 18,800 ± 700 ng g^-1 dry wt. (mean ± SEM). Surface soil samples (top 10 cm) were collected from 26 commercial farms located in northern VA, US that had received biosolid applications from the WWTP. Samples were grouped as farms receiving no biosolids, farms with a single biosolid application, and those receiving multiple biosolid applications from 1992 to 2006. Our results illustrate that TCC soil residues remained years after biosolid application. The two most important parameters controlling TCC topsoil concentrations were the biosolid application rate and the period since the last application. No TCC removal was observed in farms where the time since biosolid application was between 7 and 9 months. TCC concentration analyzed 7 and 8 years after biosolid applications were 45.8 ± 6.1 and 72.4 ± 15.3 ng g^-1 dry wt., respectively, showing its persistence in soils and build-up upon multiple biosolid applications. A soil TCC half-life of 287.5 ± 45.5 days was estimated.

Occurrence of and human exposure to parabens, benzophenones, benzotriazoles, triclosan and triclocarban in outdoor swimming pool water in Changsha, China

The entry of personal care products (PCPs) into the environment has, in turn, caused negative influences to human health. Public swimming pools are places that have attracted increasing concerns. In this article, 35 outdoor swimming pools in Changsha City (China) were examined in view of the occurrence of 22 target PCPs contaminants, which fall into four categories: preservatives, UV filters, anticorrosion agents, and antimicrobials. Out of them, 16 compounds were detected in the collected samples. The preservatives was the most dominant category, with methyl paraben being the top compound (a.v. 0.85μg/L) followed by p-hydroxybenzoic acid (a.v. 0.13μg/L) and 1H-benzotriazole (a.v. 0.14μg/L). The correlations among 22 PCPs and their four categories were evaluated using the nonparametric Spearman correlations analysis. In the source tracing investigation, the level of PCPs in swimming pools was determined to be primarily associated with the consumption of these products while weakly related to the filling waters. The quantitative risk assessment revealed that the PCPs concentrations were at a safe level.

Antimicrobial compounds (triclosan and triclocarban) in sewage sludges, and their presence in runoff following land application

The reuse of treated municipal sewage ('biosolids') on land is an effective method to divert waste away from landfill and to use an alternative, low cost method of fertilisation. While legislation has mainly focused on the control of nutrient and metal application rates to land, other potentially harmful emerging contaminants (ECs) may be present in biosolids. Up to 80% of municipal sewage sludge is reused in agriculture in Ireland, which is currently the highest rate of reuse in Europe. However, unlike other countries, no study has been conducted on the presence of ECs across a range of wastewater treatment plants (WWTPs) in this country. This study evaluated the concentrations of two ECs in sewage sludge, the antimicrobials triclosan (TCS) and triclocarban (TCC), and their presence in surface runoff following land application in controlled rainfall simulation studies. In 16 WWTPs, concentrations of TCS and TCC were 0.61 and 0.08µgg^-1, which is at the lower end of concentrations measured in other countries. The concentrations in runoff post land application were also mainly below the limits of detection (90ngL^-1 for TCS, 6ngL^-1 for TCC), indicating that runoff is not a significant pathway of entry into the environment.

The Florence Statement on Triclosan and Triclocarban

The Florence Statement on Triclosan and Triclocarban documents a consensus of more than 200 scientists and medical professionals on the hazards of and lack of demonstrated benefit from common uses of triclosan and triclocarban. These chemicals may be used in thousands of personal care and consumer products as well as in building materials. Based on extensive peer-reviewed research, this statement concludes that triclosan and triclocarban are environmentally persistent endocrine disruptors that bioaccumulate in and are toxic to aquatic and other organisms. Evidence of other hazards to humans and ecosystems from triclosan and triclocarban is presented along with recommendations intended to prevent future harm from triclosan, triclocarban, and antimicrobial substances with similar properties and effects. Because antimicrobials can have unintended adverse health and environmental impacts, they should only be used when they provide an evidence-based health benefit. Greater transparency is needed in product formulations, and before an antimicrobial is incorporated into a product, the long-term health and ecological impacts should be evaluated. https://doi.org/10.1289/EHP1788.

Influence of thermal hydrolysis-anaerobic digestion treatment of wastewater solids on concentrations of triclosan, triclocarban, and their transformation products in biosolids

The growing concern worldwide regarding the presence of emerging contaminants in biosolids calls for a better understanding of how different treatment technologies at water resource recovery facilities (WRRFs) can influence concentrations prior to biosolids land application. This study focuses on the influence of solids treatment via the Cambi Thermal Hydrolysis Process™ in conjunction with anaerobic digestion (TH-AD) on concentrations of triclosan (TCS), triclocarban (TCC), and their transformation products in biosolids and sludges. Concentrations of the target analytes in biosolids from the TH-AD process (Class A), sludges from the individual TH-AD treatment steps, and limed biosolids (Class B) from the same WRRF were compared. TCC concentrations were significantly lower in Class A biosolids than those in the Class B product - a removal that occurred during thermal hydrolysis. Concentrations of TCS, methyl triclosan, and 2,4-dichlorophenol, conversely, increased during anaerobic digestion, leading to significantly higher concentrations of these compounds in Class A biosolids when compared to Class B biosolids. Implementation of the TH-AD process had mixed effect on contaminant concentrations.

Effects of the antimicrobial contaminant triclocarban, and co-exposure with the androgen 17β-trenbolone, on reproductive function and ovarian transcriptome of the fathead minnow (Pimephales promelas)

Triclocarban (TCC) is an antimicrobial agent routinely detected in surface waters that has been hypothesized to interact with the vertebrate endocrine system. The present study examined the effects of TCC alone and in combination with the model endocrine disruptor 17β-trenbolone (TRB) on fish reproductive function. Adult Pimephales promelas were continuously exposed to either 1 µg TCC/L or 5 µg TCC/L, to 0.5 µg TRB/L, or to a mixture (MIX) of 5 µg TCC/L and 0.5 µg TRB/L for 22 d, and a variety of reproductive and endocrine-related endpoints were examined. Cumulative fecundity was significantly reduced in fathead minnows exposed to TRB, MIX, or 5 µg TCC/L. Exposure to 1 µg TCC/L had no effect on reproduction. In general, both TRB and MIX treatments caused similar physiological effects, evoking significant reductions in female plasma vitellogenin, estradiol, and testosterone, and significant increases in male plasma estradiol. Based on analysis of the ovarian transcriptome, there were potential pathway impacts that were common to both TRB- and TCC-containing treatment groups. In most cases, however, those pathways were more plausibly linked to differences in reproductive status than to androgen-specific functions. Overall, TCC was reproductively toxic to fish at concentrations at or near those that have been measured in surface water. There was little evidence that TCC elicits reproductive toxicity through a specific mode of endocrine or reproductive action, nor that it could augment the androgenic effects of TRB. Nonetheless, the relatively small margin of safety between some measured environmental concentrations and effect concentrations suggests that concern is warranted. Environ Toxicol Chem 2017;36:231-242. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Chinese population exposure to triclosan and triclocarban as measured via human urine and nails

Triclosan (TCS) and triclocarban (TCC) exposures are highly concerned due to their suspected endocrine-disrupting effects. The present study investigated TCS and TCC exposure levels in the general Chinese population by biomonitoring human urine and nail samples. TCS (69-80 %) and TCC (99-100 %) were frequently detected, which demonstrates that the general Chinese population has extensive exposure to these chemicals. The geometric mean (GM) urinary concentrations were 0.40 μg/g creatinine (creat), 95 % confidence interval (CI) 0.30-0.56, for TCS and 0.40 μg/g creat, 95 % CI 0.29-0.56, for TCC. On the other hand, the GM levels of TCS and TCC were 13.57 (5.67 μg/kg) and 84.66 μg/kg (41.50 μg/kg) in fingernail (toenail) samples, respectively, indicating that the levels in fingernails were approximately twice as high as those in toenails. Pearson's correlation coefficients between the urine and fingernail (toenail) samples were 0.715 (0.614) for TCS and 0.829 (0.812) for TCC. These data suggest that nail samples can be applied to the biomonitoring for TCS and TCC in the general population. We observed that the levels of both chemicals were higher in females than in males for urine and fingernail samples, but no significant differences were found between different genders for either compound in toenails. Nineteen- to 29-year-olds had the highest TCS levels in their nail samples, whereas TCC levels did not differ with regard to age. Region of residence significantly influenced TCS and TCC concentrations in the three biological matrices measured.

Offline solid-phase extraction for preconcentration of pharmaceuticals and personal care products in environmental water and their simultaneous determination using the reversed phase high-performance liquid chromatography method

The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of five representative and commonly present pharmaceuticals and personal care products (PPCPs), a new class of emerging pollutants in the aquatic environment. The target list of analytes including ciprofloxacin, acetaminophen, caffeine benzophenone and irgasan were separated by a simple HPLC method. The column used was a reversed-phase C18 column, and the mobile phase was 1 % acetic acid and methanol (20:80 v/v) under isocratic conditions, at a flow rate of 1 mL min(-1). The analytes were separated and detected within 15 min using the photodiode array detector (PDA). The linearity of the calibration curves were obtained with correlation coefficients 0.98-0.99.The limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and ruggedness demonstrated the reproducibility, specificity and sensitivity of the developed method. Prior to the analysis, the SPE was performed using a C18 cartridge to preconcentrate the targeted analytes from the environmental water samples. The developed method was applied to evaluate and fingerprint PPCPs in sewage collected from a residential engineering college campus, polluted water bodies such as Nag river and Pili river and the influent and effluent samples from a sewage treatment plant (STP) situated at Nagpur city, in the peak summer season. This method is useful for estimation of pollutants present in microquantities in the surface water bodies and treated sewage as compared to nanolevel pollutants detected by mass spectrometry (MS) detectors.

Acute Depigmentation of Fertile Brown Eggs in a Commercial Layer Operation

Rapid depigmentation of brown eggs is an infrequent but startling event in the commercial egg industry that can result in significant economic losses. Loss of shell pigment in brown-shelled eggs is caused by various factors. In many cases, the exact cause of flock-wide pigment loss remains undetermined. A rapid decline in shell pigmentation was observed in 2 flocks of Hyline brown layers. The lack of evidence of an infectious disease process suggested a feed or management problem. On the basis of a small-scale, “in-house” feeding trial, the feed was identified as the cause of depigmentation. Feed analysis by liquid chromatography with mass spectrometry confirmed the presence of 4,4'-dinitrocarbanilide, a major component of nicarbazin (NCZ). There was no evidence of increased mortality, and only a slight but transient drop in the egg production was observed. Depigmentation effects were rapidly reversed after replacing the feed with NCZ-free feed.

Aerobic biodegradation potential of endocrine-disrupting chemicals in surface-water sediment at Rocky Mountain National Park, USA

Endocrine-disrupting chemicals (EDCs) in surface water and bed sediment threaten the structure and function of aquatic ecosystems. In natural, remote, and protected surface-water environments where contaminant releases are sporadic, contaminant biodegradation is a fundamental driver of exposure concentration, timing, duration, and, thus, EDC ecological risk. Anthropogenic contaminants, including known and suspected EDCs, were detected in surface water and sediment collected from 2 streams and 2 lakes in Rocky Mountain National Park (Colorado, USA). The potential for aerobic EDC biodegradation was assessed in collected sediments using 6 (14) C-radiolabeled model compounds. Aerobic microbial mineralization of natural (estrone and 17β-estradiol) and synthetic (17α-ethinylestradiol) estrogen was significant at all sites. Bed sediment microbial communities in Rocky Mountain National Park also effectively degraded the xenoestrogens bisphenol-A and 4-nonylphenol. The same sediment samples exhibited little potential for aerobic biodegradation of triclocarban, however, illustrating the need to assess a wider range of contaminant compounds. The present study's results support recent concerns over the widespread environmental occurrence of carbanalide antibacterials, like triclocarban and triclosan, and suggest that backcountry use of products containing these compounds should be discouraged.

Meta-analysis of biosolid effects on persistence of triclosan and triclocarban in soil

Biosolids are extensively used in agriculture as fertilizers while offering a practical solution for waste disposal. Many pharmaceutical and personal care products (PPCPs), such as triclosan and triclocarban, are enriched in biosolids. Biosolid amendment changes soil physicochemical properties, which may in turn alter the persistence of PPCPs and hence the risk for secondary contamination such as plant uptake. To delineate the effect of biosolids on PPCPs persistence, triclosan and triclocarban were used as model compounds in this study and their sorption (Kd) and persistence (t1/2) were determined in different soils before and after biosolid amendment. Biosolids consistently increased sorption of triclosan and triclocarban in soil. The Kd of triclosan increased by 3.9-21 times following amendment of a sandy loam soil with biosolids at 2-10%. The persistence of both compounds was prolonged, with t1/2 of triclosan increasing from 10 d in the unamended soil to 63 d after biosolid amendment at 10%. The relationship between t1/2 and Kd was further examined through a meta-analysis using data from this study and all relevant published studies. A significant linear relationship between t1/2 and Kd was observed for triclosan (r(2) = 0.69, p < 0.01) and triclocarban (r(2) = 0.38, p < 0.05) in biosolid-amended soils. On the average, when biosolid amendment increased by 1%, t1/2 of triclosan was prolonged by 7.5 d, while t1/2 of triclocarban was extended by 4.7 d. Therefore, biosolid amendment greatly enhances persistence of triclosan and triclocarban, likely due to enhanced sorption or decreased chemical bioavailability. This finding highlights the importance to consider the effect of biosolids when evaluating the environmental risks of these and other biosolid-borne PPCPs.

Degradation of triclocarban by a triclosan-degrading Sphingomonas sp. strain YL-JM2C

Bacterial degradation plays a vital role in determining the environmental fate of micropollutants like triclocarban. The mechanism of triclocarban degradation by pure bacterium is not yet explored. The purpose of this study was to identify metabolic pathway that might be involved in bacterial degradation of triclocarban. Triclosan-degrading Sphingomonas sp. strain YL-JM2C was first found to degrade up to 35% of triclocarban (4 mg L(-1)) within 5 d. Gas chromatography-mass spectrometry detected 3,4-dichloroaniline, 4-chloroaniline and 4-chlorocatechol as the major metabolites of the triclocarban degradation. Furthermore, total organic carbon results confirmed that the intermediates, 3,4-dichloroaniline (4 mg L(-1)) and 4-chloroaniline (4 mg L(-1)) could be degraded up to 77% and 80% by strain YL-JM2C within 5 d.

Insights into reductive dechlorination of triclocarban in river sediments: Field measurements and in vitro mechanism investigations

Triclocarban (TCC) reductive dechlorination was investigated using a combination of field and laboratory experiments. Field monitoring revealed that TCC reductive dechlorination in river sediments leads to formation of two isomers of its lesser chlorinated congener namely 3,4'-dichlorocarbanilide and 4,4'-dichlorocarbanilide. Monochlorocarbanilide was not detected in sediments supporting that transformation of dichlorocarbanilide into monochlorocarbanilide is the rate limiting step of TCC dechlorination. In vitro experiments were conducted to study TCC potential reductive dechlorination mechanisms. These experiments demonstrated that 4,4'-dichlorocarbanilide was specifically formed upon a nucleophilic addition reaction under anaerobic conditions. The 3,4'-diclorocarbanilide was formed upon a two steps radical mechanism under aerobic conditions which includes TCC activation by one electron oxidation followed by a nucleophilic substitution reaction with glutathione. In vitro results suggested that strict anaerobic conditions might not be required for TCC reductive dechlorination in the environment. Moreover, in vitro reactions were performed using biomimetic or enzymatic systems supposing that TCC dechlorination might occur through microbial action in situ. Measured dichlorocarbanilide isomers/triclocarban ratios were used to evaluate the relative significance of both dechlorination pathways and the pathway leading to 3,4'-dichlorocarbanilide was found significant in all investigated river sediment samples.

Ecological risks of home and personal care products in the riverine environment of a rural region in South China without domestic wastewater treatment facilities

Home and personal care products (HPCPs) including biocides, benzotriazoles (BTs) and ultraviolet (UV) filters are widely used in our daily life. After use, they are discharged with domestic wastewater into the receiving environment. This study investigated the occurrence of 29 representative HPCPs, including biocides, BTs and UV filters, in the riverine environment of a rural region of South China where no wastewater treatment plants were present, and assessed their potential ecological risks to aquatic organisms. The results showed the detection of 11 biocides and 4 BTs in surface water, and 9 biocides, 3 BTs and 4 UV filters in sediment. In surface water, methylparaben (MeP), triclocarban (TCC), and triclosan (TCS) were detected at all sites with median concentrations of 9.23 ng/L, 2.64 ng/L and 5.39 ng/L, respectively. However, the highest median concentrations were found for clotrimazole (CLOT), 5-methyl-1H-benzotriazole (MBT) and carbendazim (CARB) at 55.6 ng/L, 33.7 ng/L and 13.8 ng/L, respectively. In sediment, TCC, TCS, and UV-326 were detected with their maximum concentrations up to 353 ng/g, 155 ng/g, and 133 ng/g, respectively. The concentrations for those detected HPCPs in surface water and sediment were generally lower in the upper reach (rural area) of Sha River than in the lower reach of Sha River with close proximity to Dongjiang River (Pt-test<0.05), indicating other input sources of HPCPs in the lower reach. Biocides showed significantly higher levels in surface water in the wet season than in the dry and intermediate seasons. Preliminary risk assessment demonstrated that the majority of HPCPs monitored represented low risk in surface waters. There are potentially greater risks to aquatic organisms from the use of TCS and TCC in the wet season than in dry and intermediate seasons in surface waters. This preliminary assessment also indicates potential concerns associated with TCC, TCS, DEET, CARB, and CLOT in sediments, although additional data should be generated to assess this fully. Thus future research is needed to investigate ecological effects of these HPCPs on benthic organisms in sediment of rural rivers receiving untreated wastewater discharge.

Investigating differences in the root to shoot transfer and xylem sap solubility of organic compounds between zucchini, squash and soybean using a pressure chamber method

A pressure chamber method was used to examine differences in the root to shoot transfer and xylem sap solubility of caffeine (log Kow=-0.07), triclocarban (log Kow=3.5-4.2) and endosulfan (log Kow=3.8-4.8) for zucchini (cucurbita pepo ssp pepo), squash (cucurbita pepo ssp ovifera), and soybean (glycine max L.). Transpiration stream concentration factors (TSCF) for caffeine (TSCF=0.8) were statistically equivalent for all plant species. However, for the more hydrophobic endosulfan and triclocarban, the TSCF values for zucchini (TSCF=0.6 and 0.4, respectively) were 3 and 10 times greater than the soybean and squash (TSCF=0.2 and 0.05, respectively). The difference in TSCF values was examined by comparing the measured solubilities of caffeine, endosulfan and triclocarban in deionized water to those in soybean and zucchini xylem saps using a modified shake flask method. The measured solubility of organic contaminants in xylem sap has not previously been reported. Caffeine solubilities in the xylem saps of soybean and zucchini were statistically equal to deionized water (21500mgL(-1)) while endosulfan and triclocarban solubilities in the zucchini xylem sap were significantly greater (0.43 and 0.21mgL(-1), respectively) than that of the soybean xylem sap (0.31 and 0.11mgL(-1), respectively) and deionized water (0.34 and 0.11mgL(-1), respectively). This suggests that the enhanced root to shoot transfer of hydrophobic organics reported for zucchini is partly due to increased solubility in the xylem sap. Further xylem sap characterization is needed to determine the mechanism of solubility enhancement.

Biocides in the Yangtze River of China: spatiotemporal distribution, mass load and risk assessment

Nineteen biocides were investigated in the Yangtze River to understand their spatiotemporal distribution, mass loads and ecological risks. Fourteen biocides were detected, with the highest concentrations up to 166 ng/L for DEET in surface water, and 54.3 ng/g dry weight (dw) for triclocarban in sediment. The dominant biocides were DEET and methylparaben, with their detection frequencies of 100% in both phases. An estimate of 152 t/y of 14 biocides was carried by the Yangtze River to the East China Sea. The distribution of biocides in the aquatic environments was significantly correlated to Gross Domestic Product (GDP), total phosphorus (TP) and total nitrogen (TN), suggesting dominant input sources from domestic wastewater of the cities along the river. Risk assessment showed high ecological risks posed by carbendazim in both phases and by triclosan in sediment. Therefore, proper measures should be taken to reduce the input of biocides into the river systems.

Dissipation of triclosan, triclocarban, carbamazepine and naproxen in agricultural soil following surface or sub-surface application of dewatered municipal biosolids

In many jurisdictions land application of municipal biosolids is a valued source of nutrients for crop production. The practice must be managed to ensure that crops and adjacent water are not subject to contamination by pharmaceuticals or other organic contaminants. The broad spectrum antimicrobial agents triclosan (TCS) and triclocarban (TCC), the anti-epileptic drug carbamazepine (CBZ), and the nonsteroidal anti-inflammatory drug naproxen (NAP) are widely used and are carried in biosolids. In the present study, the effect of biosolids and depth of placement in the soil profile on the rates of TCS, TCC, CBZ, and NAP dissipation were evaluated under semi-field conditions. Aggregates of dewatered municipal biosolids (DMBs) supplemented with (14)C-labeled residues were applied either on the soil surface or in the subsurface of the soil profile, and incubated over several months under ambient outdoor conditions. The dissipation of TCS, TCC and NAP was significantly faster in sub-surface than surface applied biosolid aggregates. In contrast the dissipation rate for CBZ was the same in surface applied and incorporated aggregates. Overall, the present study has determined a significant effect of depth of placement on the dissipation rate of biodegradable molecules.

[Determination of triclosan and triclocarban in human breast milk by solid-phase extraction and ultra performance liquid chromatography-tandem mass spectrometry]

OBJECTIVE

An analytical method was developed to simultaneously detect triclosan (TCS) and triclocarban (TCC) in human breast milk using solid-phase extraction (SPE) with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

METHODS

Samples were extracted by acetonitrile and purified with C -18 SPE cartridge after enzymolysis with β-glucuronidase/arylsulfatase. The chromatographic separation was performed on a Waters ACQUITY UPLC™ HSS T3 column (100 mm x 2. 1 mm, 1. 8 µm) with gradient elution using methanol and water at a flow rate of 0. 3 ml/min. The target analytes were assayed by triple quadrupole mass spectrometer operating in the negative ion mode. Quantification was performed by isotopic internal standard calibration.

RESULTS

Satisfactory linearity (r2 > 0. 999) was obtained over the range of 0. 2 - 20. 0 µg/L and 0. 02 - 2. 0 µg/L for triclosan and triclocarban, respectively, with the limits of quantifications (LOQs) of 0. 41 and 0. 03 µg/kg. Average recoveries of two target compounds (spiked at three concentration levels) ranged from 100. 2% to 119. 3%, with the relative standard deviations (RSDs) between 5. 91% and 11. 31% (n =6). Twenty-five real samples (n = 25) were detected containing TCS and TCC at concentrations of < LOQ - 0. 77 µg/kg and < LOQ - 4. 28 µg/kg, respectively.

CONCLUSION

Due to its high sensitivity and good reproductivity, this method can be applied to analyze TCS and TCC in human breast milk.

Epistemology of contaminants of emerging concern and literature meta-analysis

A meta-analysis was conducted to inform the epistemology, or theory of knowledge, of contaminants of emerging concern (CECs). The CEC terminology acknowledges the existence of harmful environmental agents whose identities, occurrences, hazards, and effects are not sufficiently understood. Here, data on publishing activity were analyzed for 12 CECs, revealing a common pattern of emergence, suitable for identifying past years of peak concern and forecasting future ones: dichlorodiphenyltrichloroethane (DDT; 1972, 2008), trichloroacetic acid (TCAA; 1972, 2009), nitrosodimethylamine (1984), methyl tert-butyl ether (2001), trichloroethylene (2005), perchlorate (2006), 1,4-dioxane (2009), prions (2009), triclocarban (2010), triclosan (2012), nanomaterials (by 2016), and microplastics (2022 ± 4). CECs were found to emerge from obscurity to the height of concern in 14.1 ± 3.6 years, and subside to a new baseline level of concern in 14.5 ± 4.5 years. CECs can emerge more than once (e.g., TCAA, DDT) and the multifactorial process of emergence may be driven by inception of novel scientific methods (e.g., ion chromatography, mass spectrometry and nanometrology), scientific paradigm shifts (discovery of infectious proteins), and the development, marketing and mass consumption of novel products (antimicrobial personal care products, microplastics and nanomaterials). Publishing activity and U.S. regulatory actions were correlated for several CECs investigated.

Long-term trends of PBDEs, triclosan, and triclocarban in biosolids from a wastewater treatment plant in the Mid-Atlantic region of the US

In the US, land application of biosolids has been utilized in government-regulated programs to recycle valuable nutrients and organic carbon that would otherwise be incinerated or buried in landfills. While many benefits have been reported, there are concerns that these practices represent a source of organic micropollutants to the environment. In this study, biosolids samples from a wastewater treatment plant in the Mid-Atlantic region of the US were collected approximately every 2 months over a 7-year period and analyzed for brominated diphenyl ethers (BDE-47, BDE-99, and BDE-209), triclosan, and triclocarban. During the collection period of 2005-2011, concentrations of the brominated diphenyl ethers BDE-47+BDE-99 decreased by 42%, triclocarban decreased by 47%, but BDE-209 and triclosan remained fairly constant. Observed reductions in contaminant concentrations could not be explained by different seasons or by volumetric changes of wastewaters arriving at the treatment plant and instead may be the result of the recent phaseout of BDE-47 and BDE-99 as well as potential reductions in the use of triclocarban.

Screening triclocarban and its transformation products in river sediment using liquid chromatography and high resolution mass spectrometry

An analytical method was developed and validated for the target screening of triclosan (TCS), triclocarban (TCC) and its lesser and higher chlorinated congeners namely, 4,4'-dichlorocarbanilide (DCC) 3,3',4,4'-tetrachlorocarbanilide (3-Cl-TCC) and 2,3',4,4'-tetrachlorocarbanilide (2-Cl-TCC) in river sediment. Sediment samples were extracted by pressurized liquid extraction and quantification and identification of target compounds were carried by liquid chromatography high resolution mass spectrometry (LC-HRMS). The overall method recoveries were 89% with relative standard deviations below 6%. Method detection limits ranged from 0.01 to 0.12 ng/g. The usefulness of the method was demonstrated on sediment samples collected downstream of three wastewater treatment plants in an attempt to provide with a set of occurrence data of these biocides in France and for a better understanding of their fate in river. Major results are the following: TCC, DCC and 3-Cl-TCC were ubiquitously detected demonstrating that these emerging contaminants have been probably overlooked in France. Reductive dechlorination of TCC into DCC was also ubiquitous but predominated in anoxic sediment. 3-Cl-TCC is probably more persistent than TCC and LC-HRMS enabled the detection and identification of a suite of other chlorinated biocides in river sediment.

Enzyme-linked immunosorbent assay for triclocarban in aquatic environments

A sensitive, competitive indirect enzyme-linked immunosorbent assay (ELISA) was developed for the detection of triclocarban (TCC) in waters and sediments. Haptens were synthesized by derivatizing the paraposition of a phenyl moiety of TCC. The synthesized hapten was then coupled to bovine thyroglobulin to be used as an immunogen, based on which, a high affinity monoclonal antibody 4D5 was produced with the hybridoma technique. Under the optimized conditions, using the monoclonal antibody, excellent performances of the assay were obtained: satisfactory sensitivity (IC50 (50% inhibition concentration) value, 0.43 ng/mL; limit of detection, 0.05 ng/mL); good linear range (0.05-10 ng/mL); and satisfactory accuracy (recoveries 70.7-107% in waters; 74.8-98.3% in sediments). Furthermore, TCC was found with the concentration ranging from not detected to 422.12 ng/L in waters and from 6.68 ng/g to 78.67 ng/g in sediments in Yunliang River, Ancient Canal and Hongqiao Port in Zhenjiang City. In conclusion ELISA could be applied for monitoring TCC in aquatic environments.

Occurrence and fate of triclosan and triclocarban in a subtropical river and its estuary

The occurrence of triclosan (TCS) and triclocarban (TCC) in a subtropical river (Jiulong River) and its estuary was investigated for two years. TCS and TCC were ubiquitously detected in the Jiulong River and its estuary. The levels of TCS and TCC ranged from less than the method detection limit to 64 ng/L and from 0.05 to 14.1 ng/L in the river, respectively. The levels of TCS and TCC in the estuary ranged from 2.56 to 27.25 ng/L and 0.38 to 5.76 ng/L, respectively. Temporal and spatial variations of TCS and TCC in the Jiulong River and its estuary were observed during the investigation. The weather conditions did not show significant correlations with TCS and TCC, whereas several water quality parameters showed high correlations with TCS and TCC. The microcosm studies showed that both direct photolysis and biodegradation contributed to TCS removal, whereas indirect photolysis was important for TCC removal in the surface water.

Field dissipation of four personal care products in biosolids-amended soils in North China

The present study investigated the dissipation behaviors of 4 typical personal care products (PCPs)-triclocarban (TCC), triclosan (TCS), tonalide (AHTN), and galaxolide (HHCB)- in soils amended with biosolids under field conditions in North China. The results showed that the 4 target compounds were detected in all biosolids-amended soils at levels of a few nanograms per gram to thousands of nanograms per gram (dry wt). The residual concentrations of the 4 PCPs were found in the following order: TCC > TCS > AHTN > HHCB. Significant dissipation of the 4 PCPs was observed in the biosolids-amended soils, with half-lives ranging from 26 d to 133 d. Furthermore, repeated biosolids applications and a higher biosolids application rate could lead to higher accumulation of the 4 PCPs in the agricultural soils. Based on the detected concentrations in the field trial and limited ecotoxicity data, high risks to soil organisms are expected for TCC, whereas low to medium risks are expected in most cases for AHTN, HHCB, and TCS.