Benzotriazole UV Stabilizers Research Articles

Effect of copper on bioconcentration of benzotriazole ultraviolet stabilizers (BUVSs) in common carp (Cyprinus carpio)

Benzotriazole ultraviolet stabilizers (BUVSs) have received increasing attention as emerging contaminants. However, most of the existing relevant studies focused on the adverse ecological effect of BUVSs under their single exposure, information about the bioconcentration potential of BUVSs and their joint exposure with heavy metals remains scarce. In this study, we investigated the bioconcentration kinetics of 6 frequently reported BUVSs in four main tissues of common carp under different Cu concentration. The bioconcentration factors (BCFs) and half-lives (t1/2) in the fish tissues ranged from 5.73 (UV-PS in kidney) to 1076 (UV-327 in liver), and 2.19 (UV-PS in kidney) to 31.5 (UV-320 in liver) days, respectively. Under the effect of Cu, an increase in BCF values was observed, which is mainly due to the decreased depuration rate (k2). These results indicated that BUVSs accumulated in fish and that Cu can affect the bioconcentration of BUVSs. This study provides important insight into the co-exposure of heavy metal and BUVSs, contributing to the perfection of BUVSs risk assessment.

Specific-accumulation and trophic transfer of UV filters and stabilizers in marine food web

The occurrence and distribution of benzotriazole UV stabilizers (BUVs) and UV filters in marine environments (sediment and seawater) and 20 biota species in the South Korea were investigated to assess their transfer through the marine food web. The total concentrations in the seawater samples were 4.73–8.60 ng/L for BUVs and 1.20–4.88 ng/L for UV filters; while, the total concentrations in the sediment samples were 0.581–6.62 ng/g dw for BUVs and 1.05–6.79 ng/g dw for UV filters, respectively. The total concentrations of BUVs and UV filters were a little higher in benthic invertebrates (BUVs: 131 ng/g lipid weight [lw], UV filters: 41.7 ng/g lw) than fish (BUVs: 99.2 ng/g lw, UV filters: 28.0 ng/g lw) but there were no statistical differences (Mann–Whitney U test, p > 0.05). UV-326 was dominant (fish: 37.9%, benthic invertebrate: 48.7%) of the total BUVs. While, benzophenone-3 (fish: 34.1%, benthic invertebrate: 40.8%) and ethylhexyl methoxy cinnamate (fish: 41.0%, benthic invertebrate: 37.8%) were the dominant UV filters. The bioaccumulation factor and trophic magnification factor indicated that UV-326 can both bioaccumulate and biomagnify (bioaccumulation factor >5000 and biota–sediment accumulation and trophic magnification factors >1). Several other BUVs were found to be able to either bioaccumulate (UV-320, UV-P, UV-329, and UV-234) or biomagnify (UV-327 and UV-928). Most of the analyzed UV filters were found not to be likely to bioaccumulate.

Benzotriazole Ultraviolet Stabilizers Promote Breast Cancer Cell Proliferation via Activating Estrogen-Related Receptors α and γ at Human-Relevant Levels

Benzotriazole ultraviolet stabilizers (BUVSs) are ubiquitous emerging pollutants that have been reported to show estrogenic disruption effects through interaction with the classic estrogen receptors (ERs) in the fashion of low activity. The present study aims at revealing the potential disruption mechanism via estrogen-related receptors α and γ (ERRα and ERRγ) pathways. By the competitive binding assay, we first found that BUVSs bond to ERRγ ligand binding domain (ERRγ-LBD) with Kd ranging from 0.66 to 19.27 μM. According to the results of reporter gene assays, the transcriptional activities of ERRα and ERRγ were promoted by most tested BUVSs with the lowest observed effective concentrations (LOEC) from 10 to 100 nM, which are in the range of human exposure levels. At 1 μM, most tested BUVSs showed higher agonistic activity toward ERRγ than ERRα. The most effective two BUVSs promoted the MCF-7 proliferation dependent on ERRα and ERRγ with a LOEC of 100 nM. The molecular dynamics simulation showed that most studied BUVSs had lower binding free energy with ERRγ than with ERRα. The structure-activity relationship analysis revealed that molecular polarizability, electron-donating ability, ionization potential, and softness were the main structural factors impacting the binding of BUVSs with ERRγ. Overall, our results provide novel insights into the estrogenic disruption effects of BUVSs.

Phase partitioning, transport and sources of Benzotriazole Ultraviolet Stabilizers during a runoff event

Benzotriazole Ultraviolet Stabilizers (BT-UVs) are ubiquitous in the environment, given their wide use as additives in consumer products. Their bio-accumulative and toxic properties are increasingly being scrutinised, evinced by the recent proposition to add UV328 to the Stockholm Convention on Persistent Organic Pollutants. Here, we measured concentrations of six BT-UVs in the dissolved and particulate phases of stream water collected from an urban and rural stream during a runoff event. Under baseflow conditions, the less hydrophobic BT-UVs were present at low concentrations in the dissolved phase, while much higher loads of particulate BT-UVs occurred during stormflow, especially in the urban creek. Time-weighted average BT-UV concentrations were up to 4 times higher in the urban than in the rural creek. BT-UVs were found to be prevalent in water obtained from laundering textiles, which plausibly constitutes a major portion of domestic wastewater, and can serve as a BT-UV source to aquatic waterways. However, the observed dilution of a sewage tracer during the run-off event suggests that unregulated wastewater seepage is not responsible for the high BT-UV loads in storm water. High levels of UV328 and UV234 were detected in a select few plastic debris items collected from the urban watershed and in artificial turf grass, respectively. Whereas this may allow for the leaching of those BT-UVs into the creek, most plastic debris is more likely a sink than a source of BT-UVs. The observed input of particle-bound BT-UVs at the onset of the rain event indicates that most of the BT-UVs reach the creek with contaminated particles that had built up on surfaces during the antecedent dry period. UV328 was the dominant BT-UV in those particles. If such particle build-up occurs on road surfaces, it may suggest that the use of UV328 in automotive applications contributes to their presence in urban storm water.

Tissue-Specific Accumulation, Biotransformation, and Physiologically Based Toxicokinetic Modeling of Benzotriazole Ultraviolet Stabilizers in Zebrafish (Danio rerio).

Benzotriazole ultraviolet stabilizers (BUVSs) are high-production-volume chemicals with ubiquitous occurrence in the aquatic environment. However, little is known about their bioconcentration and biotransformation, and physiologically based toxicokinetic (PBTK) models for BUVSs are lacking. This study selected six BUVSs for which experiments were performed with zebrafish (Danio rerio) exposed to two different levels (0.5 and 10 μg·L-1). Higher kinetic bioconcentration factors (BCFs) were observed at the lower exposure level with environmental relevance, with BCF of 3.33 × 103 L·kg-1 for 2-(2-hydroxy-3,5-di-tert-butylphenyl)-5-chlorobenzotriazole (UV-327). This phenomenon was interpreted by a nonlinear adsorption mechanism, where binding with specific protein sites contributes to bioconcentration. Muscle exhibited the lowest accumulation, in which depuration half-life of UV-327 was 19.5 d. In kidney, muscle, ovary, gill, and skin, logBCF increased with increase in log KOW of the BUVSs until log KOW was ca. 6.5, above which logBCF decreased. However, the trend was not observed in the liver and intestine. Six biotransformation products were identified and mainly accumulated in the liver and intestine. Considering the nonlinear adsorption mechanism in the PBTK model, the prediction accuracy of the model was improved, highlighting the binding of xenobiotics with specific protein sites in assessing the bioconcentration of chemicals for their risk assessment.

An analytical survey of benzotriazole UV stabilizers in plastic products and their endocrine-disrupting potential via human estrogen and androgen receptors

Benzotriazole UV stabilizers (BUVSs) are added to various materials to prevent damage from UV-irradiation. Recently, there has been great concern regarding the endocrine-disrupting effects of exposure to microplastic-derivative BUVSs in particular. In this study, we measured the concentrations of nine representative BUVSs in the plastic bottle caps of 10 beverages, 4 food packages, and 4 plastic shopping bags purchased from Japanese grocery stores by GC–MS analysis, and found that eight BUVSs, except for 2-(3,5-di-tert-butyl-2-hydroxyphenyl)-2H-benzotriazole (UV-320), were detected from these plastic products. In particular, 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P) and 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole (UV-326) were detected from all the bottle caps at concentrations in the order of ng/g. In addition, we characterized the agonistic and/or antagonistic activities against human estrogen receptors (ERα/β) and androgen receptor (AR) of 13 BUVSs. Results revealed that, among the 13 BUVSs, UV-P, 2-(5-tert-butyl-2-hydroxyphenyl) benzotriazole (UV-PS), 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2H-benzotriazole (UV-090) and 2-(2-hydroxy-5-tert-octylphenyl)-benzotriazole (UV-329) showed ERα and/or ERβ agonistic activity, with UV-P being the most potent based on these assays. On the other hand, UV-320 and 2-(3-s-butyl-5-tert-butyl-2-hydroxyphenyl) benzotriazole (UV-350) showed both ERα and ERβ antagonistic activities, and 2-(3,5-di-tert-amyl-2-hydroxylphenyl) benzotriazole (UV-328) and UV-329 acted as ERβ antagonists. In the AR assay, UV-P and 2-(3-allyl-2-hydroxy-5-methylphenyl)-2H-benzotriazole (UV-9) showed AR antagonistic activity although none of the test compounds showed AR agonistic activity. Taken together, our findings suggest that a series of BUVSs are present in our environments via plastic materials and several of these compounds possess endocrine-disrupting potential, such as ERα/β agonistic and/or antagonistic activity and AR antagonistic activity. UV-P and its structurally similar compounds, in particular, appear to be a cause for concern.

Simultaneous determination of low molecule benzotriazoles and benzotriazole UV stabilizers in wastewater by ultrasound-assisted emulsification microextraction followed by GC\u2013MS detection

A rapid, sensitive, economically and ecologically friendly method based on one-step ultrasound-assisted emulsification microextraction and in situ derivatization followed by gas chromatography–mass spectrometry for simultaneous determination of low molecular benzotriazoles and benzotriazole-based ultraviolet filters was developed. The optimized method allows quantification of benzotriazole, 4-methylbenzotriazole, 5-methylbenzotriazole; 5-chlorobenzotriazole, 2-(2′-hydroxy-3′-tert-butyl-5′-methylphenyl)-5-chlorobenzortriazole and 2-(2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl)benzotriazole in municipal and industrial (dairy) wastewater. The method was validated using real influent and effluent wastewater and samples at various stages of the purification process. Relative recoveries obtained using wastewater as sample matrix were between 77 and 137%, method limits of detection from 0.001 to 0.035 µg/L, method limits of quantification from 0.003 to 0.116 µg/L, the repeatability expressed by the coefficient of variation did not exceed 12%. The use of the method for the determination of tested compounds in municipal and industrial wastewater showed their presence in most of the tested samples, in concentrations from LoD to 6.110 µg/L. The conducted studies of samples from municipal wastewater treatment plant located in north-east Poland showed that the effectiveness of benzotriazole removal by this plant wasfrom 29 to 84%. The load of tested compounds released into the environment by this facility ranges from 2 to 269 mg/day/1000 inhabitants.

Plastic additives and legacy persistent organic pollutants in the preen gland oil of seabirds sampled across the globe

Plastic pollution, and its associated impacts on marine fauna due to chemical contamination, is an area of growing global concern. We analyzed 145 preen gland oil samples from 32 seabird species belonging to 8 families with different foraging habits and life history strategies from around the world for plastic additives and legacy persistent organic pollutants. The additives included two brominated flame retardants (decabromodiphenyl ether, BDE209; decabromo diphenyl ethane, DBDPE) and six benzotriazole UV stabilizers (BUVSs; UVP, UV326, UV329, UV328, UV327, and UV234). Polychlorinated biphenyls (PCBs) and organochlorine pesticides (Dichlorodiphenyltrichloroethane and its metabolites: DDTs and hexachlorocyclohexane: HCHs) were detected ubiquitously. High concentrations of PCBs (up to 20,000 ng/g-lipid) were observed in the seabirds from higher-trophic level taxa. These patterns can be attributed to PCB exposure via their diet and associated biomagnification. DDT concentrations showed strong positive correlations with PCB concentrations, suggesting that DDTs in seabirds are also a result of diet and biomagnification. Plastic additives were detected sporadically as BDE209 and DBDPE were detected in 16 seabirds from 10 species (range: 3–379 ng/g-lipid) and BUVSs were detected in 46% (67) of the examined individuals (range: 2–7,055 ng/g-lipid). UV stabilizers were more frequently detected than flame retardants because UV stabilizers are more widely applied to plastic products. None of the plastic additives were correlated to the presence of PCBs, nor were they explained by the foraging area or trophic level. High concentrations of additives were detected in the species with high levels of plastic in their digestive tracts. In some of these species, such as Hawaiian petrels (Pterodroma sandwichensis) from Hawaii and flesh-footed shearwaters (Ardenna carneipes) from Western Australia, plastics were directly observed in the stomach. For other species, including great shearwaters (Ardenna gravis) from Gough Island, blue petrels (Halobaena caerulea) from Marion Island, and black-footed and Laysan albatrosses (Phoebastria nigripes and P. immutabilis) from Hawaii, plastic ingestion has been documented in literature. These patterns can be explained if the additives are mainly from ingested plastics rather than diet. The detection of BFRs and BUVSs demonstrated that a significant proportion of the examined seabirds accumulated chemicals from ingested plastics.

Fate and distribution of benzotriazole UV filters and stabilizers in environmental compartments from Gran Canaria Island (Spain): A comparison study

Tourism is an economic sector of great importance worldwide. In coastal areas, this activity is associated with the use of personal care products, such as ultraviolet (UV) filters and stabilizers. Therefore, assessing their presence and the exposure of living organisms to the impact of this kind of pollutant in such areas could be especially important. The Canary Islands (Spain) are considered an outermost region, and their main economic activity is based on tourism, both national and international. Thus, this area could be remarkably vulnerable to this kind of pollution, and its characterization could be useful to infer conclusions for other similar regions.With this aim, the occurrence of organic UV filters and stabilizers in different environmental matrices in Gran Canaria Island is presented in this work. Six benzotriazole compounds, UV-P, UV-326, UV-327, UV-328, UV-329 and UV-360, were found in wastewater, seawater, sludge, sediment, seaweed and fish samples. The numerous studies devoted to establishing the distribution of these target compounds in many different matrices on a touristic and particularly overcrowded island such as Gran Canaria can be used to understand the pollution situation in similar locations. The works in which determination procedures using different extraction techniques were optimized and validated for the analysis of liquid and solid samples are summarized. They are critically discussed regarding their characteristics and analytical parameters.This research is of interest to environmental managers specializing in the conservation of coastal areas where tourism is an important industry since the active components of UV filters and stabilizers can bioaccumulate and biomagnify in the trophic chain.

Occurrence of benzotriazole UV stabilizers in coastal fishes

Chemicals added in personal care products are of emerging concern because their fate and their effect on the environment is not completely known. Benzotriazole UV stabilizers (BUVSs) are compounds used in different cosmetic products, which may reach the marine environment through marine discharge from treated waters or directly from bathing areas. Once released into the aquatic ecosystem, BUVSs can be bioaccumulated by aquatic organisms. To identify the human exposure risk, it is important to have suitable analytical methods to determine the presence of BUVSs in these organisms. Because of the complexity of such a biological matrix, selective extraction and detection techniques are required to isolate and quantify these kinds of pollutants at trace levels. In the present work, we optimized a method based on microwave-assisted extraction combined with ultra-high performance liquid chromatography and mass spectrometry detection to determine six benzotriazole compounds in fish samples. The absolute extraction yields provided by the proposed method were higher than 40% for most compounds, with intra-day and inter-day relative standard deviations ranging from 0.27 to 6.06 and 1.12–21.3%, respectively. The limits of quantification were in the range of 1.13–9.66 ng g−1 (dry weight). The method was applied to the study of three species of fish (Boops boops, Sphyraena viridensis, Sphoeroides marmoratus) that were collected close to three marine outfalls of treated waters on the Gran Canaria Island (Spain) for two years. Four of the six studied compounds, UV-326, UV-328, UV-329 and UV-360, were found with concentrations ranging from 1.34 ng g−1 to 45.6 ng g−1 (dry weight).

Estrogenic activity of benzotriazole UV stabilizers evaluated through in vitro assays and computational studies

Benzotriazole UV stabilizers (BUVs) are used in a variety of products to prevent yellowing and degradation. However, knowledge of the estrogenic activity of BUVs is still lacking. In the present study, a strategy combining in vitro assays and computational studies was adopted to evaluate the estrogenic activity of BUVs. 2-(2-Hydroxy-5-methlphenyl) benzotriazole (UV-P), 2-(5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-PS), and 2-(3-Allyl-2-hydroxy-5-methylphenyl)-2H-benzotriazole (UV-9) induced partial estrogenic activity while 2-(2-hydroxy-5-tert-octyl-phenyl)benzotriazole (UV-329), 2-(3-s-butyl-5-tert-butyl-2-hydroxyphenyl)benzotriazole (UV-350), and 3-(2H-benzotriazolyl)-5- (1,1-di-methylethyl)-4-hydroxy-benzene-propanoic acid octyl esters (UV-384) showed no estrogenic activity in MVLN assays. The results of in vitro assays were in accord with the results of computational studies. Moreover, ICI 182,780 suppressed the estrogenic activity of BUVs both in the absence and presence of E2, demonstrating that the estrogen responsive element (ERE) transcription activities of BUVs are generated through an estrogen receptor (ER) mediated pathway. Our findings suggest that the endocrine disruption effects of BUVs are a cause for concern.

Food-Borne Exposure of Juvenile Rainbow Trout (Oncorhynchus mykiss) to Benzotriazole Ultraviolet Stabilizers Alone and in Mixture Induces Specific Transcriptional Changes.

Benzotriazole ultraviolet-stabilizers (BZT-UVs) are commonly used as additives to protect from light-induced degradation in a variety of consumer goods. Despite their widespread presence in aquatic ecosystems, information on the effects of these compounds remains largely unknown. The objectives of the present study were to evaluate the chronic effects of 2 BZT-UVs alone and in a mixture, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV-234) and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328), in juvenile rainbow trout (Oncorhynchus mykiss) chronically exposed (for 28 d) through the diet. Chemical analyses of livers from exposed trout suggested liver accumulation and potential metabolism of the 2 compounds. Hepatic RNA-sequencing analyses revealed specific effects of each compound on gene transcription profiles; UV-234 affected mainly genes involved in cellular metabolism, whereas UV-328 induced the transcription of ribosomal proteins and downregulated genes involved in immune responses. Both compounds regulated iron homeostasis genes in an opposite manner. The mixture of both BZT-UVs did not produce significant evidence of additive or synergistic effects. Environ Toxicol Chem 2020;39:852-862. © 2020 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry © 2020 SETAC.

Elucidating mechanisms of immunotoxicity by benzotriazole ultraviolet stabilizers in zebrafish (Danio rerio): Implication of the AHR-IL17/IL22 immune pathway

Benzotriazole ultraviolet stabilizers (BUVSs) are widely used additives in industrial materials and personal care products that protect products from ultraviolet damage. Due to their high production volume and potential to bioaccumulate, BUVSs are an environmental pollutant of concern. In this study, juvenile zebrafish (Danio rerio) were exposed to 4 BUVSs (UV-234, UV-326, UV-329, and UV-P) at 10 and 100 μg/L for 28 d. BUVSs induced hepatic vacuolization and nuclei pyknosis in the liver following 100 μg/L UV-234 and UV-329 exposure. Transcriptomic analysis in the liver uncovered pathways related to inflammation that were affected by BUVSs. Based upon these data, we measured the expression levels of 9 genes involved in AHR-IL17/IL22 pathway in zebrafish larvae exposed to each BUVSs at one dose of either 10 or 100 μg/L for 6 days in a second set experiment. Transcript levels of interleukins il17a and il22 were decreased, while il6 mRNA was increased with exposure to UV-234, UV-329, and UV-P. No change to targeted transcripts was observed with UV-326 treatments. Moreover, cyp1a1 and ahr2 levels were increased in larvae treated with 100 μg/L UV-329 or UV-P. Consistent with expression data, protein abundance of IL22 was decreased by 29% with exposure to 100 μg/L UV-P. Taken together, these results demonstrate that exposure to different benzotriazole congeners may be associated with immunotoxicity in zebrafish through the AHR-IL17/IL22 pathway, and this may be associated with hepatic damage with prolonged exposures. This study provides new insight into unique pathways perturbed by specific BUVSs congeners.

Intra- and intermolecular H-bonding of benzotriazole UV stabilizers evidenced using 1D nuclear Overhauser effect experiments

The UV absorber protection mechanism of 2-hydroxyphenylbenzotriazoles is based upon energy dissipation via an excited state proton transfer from the phenolic OH group to the triazole nitrogen(s). Using 1H-NMR NOE experiments we have established that 2-(2’hydroxy-5′- methylphenyl)-benzotriazole (UVA1) exists in chloroform as an intramolecularly H-bonded form whereas in DMSO this bond is disrupted by the formation of intermolecular H-bonding to the solvent. Conversely, for compounds 2-(2′-hydroxy-3′,5′-di(1,1-dimethyl propane))-benzotriazole (UVA2), and 3′-methylene-hydantoin-2-(2′-hydroxy-5′-methylphenyl)-benzotriazole (UVA3) having bulky substituents ortho to the phenolic OH group 1H-NMR NOE experiments indicate that upon changing solvent from DMSO to chloroform the strength of the intramolecular H-bond is not appreciably affected. The implication of the H-bond strength upon the UV stabilizing effectiveness is discussed.

Tissue Distribution, Growth Dilution, and Species-Specific Bioaccumulation of Organic Ultraviolet Absorbents in Wildlife Freshwater Fish in the Pearl River Catchment, China.

Tissue distributions and body-size dependent and species-specific bioaccumulation of 12 organic ultraviolet absorbents (UVAs) were investigated in 9 species of wildlife freshwater fish from the Pearl River catchment, South China. The concentrations of the 12 UVAs were from 109 to 2320 ng/g lipid weight in the fish tissue samples. The UVAs 2-hydroxy-4-methoxybenzophenone (BP-3), octocrylene(OCR), UV531, and 5 benzotriazole UV stabilizers (UVP, UV329, UV234, UV328, and UV327) were detected in more than half of the fish tissue samples. The UVA UV531 showed an obvious potential for bioaccumulation in the wild freshwater fish, with an estimated bioaccumulation factor (log BAF) and a biota-sediment accumulation factor (BSAF) of 4.54 ± 0.55 and 4.88 ± 6.78, respectively. Generally, liver (989 ± 464 ng/g lipid wt) contained the highest level of UVAs, followed in decreasing order by belly fat (599 ± 318 ng/g lipid wt), swimming bladder (494 ± 282 ng/g lipid wt), dorsal muscle (470 ± 240 ng/g lipid wt), and egg (442 ± 238 ng/g lipid wt). The bioaccumulation of UVAs in the freshwater wild fish was species specific and compound dependent. Bottom-dwelling detritus-ingesting omnivorous fish contained obviously higher UVA concentrations, suggesting that detritus/sediment ingestion is a significant pathway for exposure of the wild freshwater fish to the UVAs. The UVAs UV531 and BP-3 demonstrated a potential for growth dilution. Metabolism might play a significant role in elimination of the UVAs in the fish tissues, with the highest rate of metabolism in the liver. The UVAs did not demonstrate obvious trophic magnification in the freshwater ecosystem of the Pearl River catchment. More research is warranted to elucidate maternal transfer of the UVAs. Environ Toxicol Chem 2020;39:343-351. © 2019 SETAC.

Pharmaceutical and personal care product residues in a macrophyte pond-constructed wetland treating wastewater from a university campus: Presence, removal and ecological risk assessment

Pharmaceuticals and personal care products (PPCPs) constitute a group of chemicals of concern because of their potential toxicity when reaching aquatic environments. Wastewaters are one of the main pathways of introduction into the environment of the chemical compounds used in PPCPs because, in most cases, wastewater treatment facilities are not 100% efficient in their removal. This problem is accentuated in rural zones and isolated communities where conventional treatment systems are too expensive to build and operate. Waste-stabilization ponds and constructed wetlands (CWs) are natural wastewater treatment systems which are used to improve the quality of sewage from small communities because of their low cost and easy maintenance. There is growing interest in combining the two technologies to make a more robust system, taking into account their respective strengths and weaknesses.In this work, a combined macrophyte pond-CW system was evaluated for the presence at three sampling points (influent, pond effluent and CW effluent) of fifteen steroid hormones and six benzotriazole ultraviolet stabilizers (BUVSs). None of the targeted BUVS compounds were detected in either the influent or effluent, probably because of the particular characteristics of the population served by the wastewater system. In contrast, eight different steroid hormone compounds were detected at concentrations ranging from 17.3 to 247.7 ng·L−1 in influent samples and from 8.1 to 22.1 ng·L−1 in final effluent samples. The pond-CW system showed high elimination rates of steroid hormone residues with average removal efficiencies of over 77%. This efficacy was confirmed in the ecological risk assessment evaluation that was performed. Final effluents showed a low ecological risk associated with steroid hormones in contrast to the medium-high ecological risks found in the influent samples.

Photodegradation of 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P) in coastal seawaters: Important role of DOM

Benzotriazole UV stabilizers (BT-UVs) have attracted concerns due to their ubiquitous occurrence in the aquatic environment, and their bioaccumulative and toxic properties. However, little is known about their aquatic environmental degradation behavior. In this study, photodegradation of a representative of BT-UVs, 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P), was investigated under simulated sunlight irradiation. Results show that UV-P photodegrades slower under neutral conditions (neutral form) than under acidic or alkaline conditions (cationic and anionic forms). Indirect photodegradation is a dominant elimination pathway of UV-P in coastal seawaters. Dissolved organic matter (DOM) from seawaters accelerate the photodegradation rates mainly through excited triplet DOM (3DOM⁎), and the roles of singlet oxygen and hydroxyl radical are negligible in the matrixes. DOM from seawaters impacted by mariculture exhibits higher steady-state concentration of 3DOM⁎ ([3DOM⁎]) relative to those from pristine seawaters, leading to higher photosensitizing effects on the photodegradation. Halide ions inhibit the DOM-sensitized photodegradation of UV-P by decreasing [3DOM⁎]. Photodegradation half-lives of UV-P are estimated to range from 24.38 to 49.66 hr in field water bodies of the Yellow River estuary. These results are of importance for assessing environmental fate and risk UV-P in coastal water bodies.

Effects of benzotriazole ultraviolet stabilizers on rat PXR, CAR and PPARα transcriptional activities

Effects of benzotriazole ultraviolet stabilizers on rat PXR, CAR and PPARα transcriptional activities

Occurrence of substituted diphenylamine antioxidants and benzotriazole UV stabilizers in Arctic seabirds and seals

Substituted diphenylamine antioxidants (SDPAs) and benzotriazole UV stabilizers (BZT-UVs) are contaminants of emerging environmental concern. However, little is known about the occurrence of these contaminants in the Arctic. In this study, we investigated the levels of 11 SDPAs and 6 BZT-UVs in livers and eggs of two seabird species, the black-legged kittiwake (Rissa tridactyla) and northern fulmar (Fulmarus glacialis), as well as the liver of ringed seals (Pusa hispida) from Canadian high- and sub-Arctic sites. The concentrations of ΣSDPAs in seabird livers (median 336 pg g−1, wet weight (ww)) were significantly higher than the eggs (median 24 pg g−1, ww) and the seal livers (median 38 pg g−1, ww), suggesting liver was a primary tissue of SDPA accumulation in seabirds and that seabirds were at greater risk of exposure to SDPAs than marine mammals in the Arctic. The predominant SDPA was monostyryl octyl-diphenylamine and this compound was detected in every seabird and seal sample, indicating the widespread distribution of this contaminant in Arctic food webs. Unlike SDPAs, the detection rate and concentrations of BZT-UVs in seals were higher than in seabirds. The compound 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (UV329) or its isomer 2-(2H-benzotriazol-2-yl)-4-(tert-butyl)-6-(sec-butyl) phenol (UV350) was the predominant BZT-UVs in seals, with the concentrations of ΣBZT-UVs between <method quantification limits and 1.66 × 104 pg g−1 (ww) (median: 2.36 × 103 pg g−1, ww). This is the first report of the different distribution patterns of SDPAs and BZT-UVs in wildlife from Canadian Arctic sites.

Monitoring and environmental risk assessment of benzotriazole UV stabilizers in the sewage and coastal environment of Gran Canaria (Canary Islands, Spain)

Benzotriazole UV stabilizers (BUVSs) are emerging contaminants that are widely used in personal care products, such as cosmetics and sunscreens, to absorb ultraviolet light. These compounds have been described as bioaccumulative, pseudo-persistent and toxic; therefore, it is of great importance to investigate them and determine their presence and distribution in the environment. In this research, we performed a two-year monitoring study to identify six BUVS compounds (UV-P, UV-326, UV-327, UV-328, UV-329 and UV-360) in different environmental compartments from Gran Canaria (Canary Islands, Spain): influent and effluent from five wastewater treatment plants (WWTPs) and seawater and sediment samples from three marine areas influenced by sewage outfalls discharges from WWTPs. Two methods based on on-line solid-phase extraction and microwave-assisted extraction coupled with ultra-high-performance liquid chromatography with mass spectrometry detection were applied to quantify the analytes in liquid and solid samples, respectively. The target BUVSs were measured in sewage, coastal seawater and sediment samples in concentrations in the ranges of 13.12–1933 ng L−1, 67.01–2419 ng L−1 and 4.42–2162 ng kg−1 dry weight, respectively. The studied compounds exhibited different trends of occurrence in aqueous and solid samples due to their different coefficients of hydrophobicity. The majority of the positive samples belonged to the most touristic sampling location of the island. The estimated hazard quotient, HQ, revealed no risk from the target compounds at the measured concentrations levels.