Continuous input of organic ultraviolet filters and benzothiazoles threatens the surface water and sediment of two major rivers in the Pearl River Basin

In Vitro metabolism of six representative organic UV stabilizers (OUVs) in marine fish liver microsomes: Kinetics, mechanisms and bioaccumulation evaluation

The ubiquitous occurrence of organic UV stabilizers (OUVs) poses a potential threat to marine fish, but the metabolism of OUVs in the body remains a missing piece of the puzzle in their ecotoxicology. This study investigated the in vitro metabolism of six OUVs in the liver microsomes of an economically valuable marine fish (Lateolabrax japonicus). The depletion of the six OUVs follows first-order kinetics in the microsomes, with in vitro depletion rate constants (kdepl) ranging from 0.23 to 0.40/h. The intrinsic clearance (CLint) of 1H-benzotriazole (BT) was estimated to be 0.0026 μL/(min·mg·protein). The enzyme inhibition experiments and molecular docking results highlight the importance of cytochrome P450 enzyme (CYP) 3A4 in OUVs metabolism. Among the 4 metabolizable compounds, some metabolites from hydroxylation, methylation, acetylation and conjugation were tentatively identified. In addition, the in vitro transformation rates can more accurately predict the whole-body bioconcentration potential via an in vitro to in vivo extrapolation (IVIVE) model.

Emerging contaminants in Taihu lake Basin: Multi-dimensional prioritization, colloidal adsorption, and trophic-level disruptions

Emerging contaminants (ECs) pose significant threats to aquatic ecosystems across multiple trophic levels. This year-long study in China's Taihu Lake Basin investigated the spatiotemporal distribution, environmental behavior, and ecological impacts of ECs in diverse aquatic systems. Key findings revealed strong spatiotemporal heterogeneity, with industrial areas exhibiting the highest EC concentrations (mean: 1888.28 ng/L), dominated by perfluorinated compound. Seasonal variations showed spring EC levels twice those of other seasons, linked to intensified industrial activity. Colloidal adsorption played a critical role in EC fate, contributing 0.74-45.48 % to pollutant distribution, particularly for antibiotics and bisphenols. A multidimensional prioritization framework integrating concentration, detection rate, colloidal adsorption, toxicity, persistence, and bioaccumulation identified nine priority ECs, including erythromycin, tetrabromobisphenol A (TBBPA), and perfluorooctanoic acid (PFOA). ECs significantly disrupted plankton communities, with zooplankton diversity experiencing stronger suppression than phytoplankton, indicating trophic-level-dependent impacts. This study underscores the need for integrated monitoring strategies and regulatory thresholds to mitigate EC risks in complex aquatic ecosystems.

A comprehensive reconnaissance and risk assessment of rubber additives and their transformation products (RATPs) in groundwater: 1,3-Diphenylguanidine (DPG) as a pressing ecological concern

The widespread detection of rubber additives and their transformation products (RATPs) in surface water environments is well-documented, but their pollution characteristics in groundwater remain unclear. This study comprehensively revealed the occurrence and distribution of 27 RATPs in groundwater across southern China (n = 212). RATPs were detected in groundwater at total levels of 1.21-2,345 ng/L. The primary compounds detected were 1,3-Diphenylguanidine (DPG), 1,3-diphenylurea (DPU), and 2-hydroxybenzothiazole (2-OH-BTH), each with a detection frequency of 99.5 % and mean concentrations of 125, 58.4, and 51.2 ng/L, respectively. The spatial distribution of RATPs in groundwater shows significant lateral variations but lacks vertical differences. Correlation analysis indicates a strong relationship between the RATPs pollution levels and both the type of groundwater and the level of urban economic development, with karst water exhibiting particularly high pollution levels. Five RATPs exhibited medium to high ecological risks in groundwater. The daily intake of RATPs via groundwater in South China is 3.61 × 10-8-7.00 × 10-5 mg/(kg·d). According to the multicriteria evaluation approach and persistence, mobility, and toxicity (PMT) assessment, six RATPs, including DPG, have been identified as high-priority pollutants that require significant attention in groundwater management. This study highlights the contamination characteristics and ecological risks associated with RATPs in groundwater, emphasizing the need for increased focus on these widely used yet inadequately evaluated chemicals in future research.

Effect of organic carbon enrichment on halogenated organic pollutants in wetland sediments of the Yellow River Estuary and Jiaozhou Bay, China

Coastal wetlands, vital ecosystems, are threatened by anthropogenic activities and act as significant sinks for halogenated organic pollutants (HOPs). Despite the persistent toxicity and ecological risks associated with HOPs, their spatial distribution and environmental behavior in coastal sediments, particularly the role of total organic carbon (TOC) in modulating their fate, remain poorly understood. We investigated the contamination characteristics of 25 halogenated polycyclic aromatic hydrocarbons (HPAHs) in the surface sediments of two coastal wetlands, the Yellow River estuary and Jiaozhou Bay, with different environmental backgrounds. HPAH concentrations were higher in Jiaozhou Bay (23.81-121.78 ng g-1, mean 50.58 ± 28.85 ng g-1) than in the Yellow River estuary (14.69-30.12 ng g-1, mean 23.48 ± 5.42 ng g-1), influenced by hydrodynamic conditions and anthropogenic activities. While TOC showed a weak correlation with HPAHs under the low TOC levels and dynamic sedimentary conditions of the Yellow River estuary, it showed significant positive correlations with most HPAHs in Jiaozhou Bay, where limited water exchange enhanced pollutant accumulation. Risk assessment based on the risk quotient (RQ) indicated that the overall RQ was lower in Jiaozhou Bay, despite the higher mean HPAH concentration (2.2 times higher than in the Yellow River estuary), which may be due to the higher TOC content that enhances adsorption and reduces bioaccessibility. Fish and Daphnia in both wetlands were almost always at minimal risk levels, although localized elevated risks may occur in areas with higher pollution loads. These findings highlight the importance of integrating TOC and hydrodynamic factors in coastal pollution management.

Contamination by benzothiazoles in the Arctic: First evidence in the seawater of the Greenland Sea

Benzothiazoles (BTHs), used in industrial chemistry, consumer products, and pharmaceuticals, are emerging contaminants due to their environmental presence and toxicological risks to aquatic life and human health. However, their environmental fate in seawater remains poorly investigated. This study reports for the first time the occurrence and distribution of six BTHs in the sub-Arctic seawater of the Greenland Sea. Using solid-phase extraction combined with ultrahigh performance liquid chromatography tandem mass spectrometry, total BTHs were detected at concentrations ranging from 0.2 to 1043 ng L-1. Benzothiazole, 2-hydroxy-benzothiazole, 2-methylthio-benzothiazole, and 2-methyl-benzothiazole exhibited higher mean concentrations (355 ± 335, 114 ± 80, 34 ± 7, 15 ± 8 ng L-1, respectively) compared to 2-thiocyanomethylthio-benzothiazole (0.5 ± 0.9 ng L-1) and 2-amino-benzothiazole (0.3 ± 0.2 ng L-1). Local emissions and both short- and long-range transport may account for BTHs presence in the Greenland Sea. The spatial distribution of BTHs along the 75° N transect and in the water column appears influenced by the Greenland Sea Gyre circulation and deep convection processes. Total BTHs distribution showed no significant differences between superficial and water column concentrations or between the outermost and innermost transect zones, as determined by the Mann-Whitney test, although concentrations were generally higher in the zone influenced by the Norwegian Atlantic Current. The ecological risks of BTHs, assessed using the risk quotient methodology, indicate a low threat to aquatic life. This research underscores the need for monitoring BTHs in the Arctic to understand their sources, transport, and environmental fate, providing a foundation for future studies.

Assessment of persistent toxic substances in sediments of Gyeonggi Bay, Korea: Distributions, sources, and potential ecological risks

Persistent toxic substances (PTSs) from anthropogenic activities are a growing concern for marine ecosystems. In addition, the specific sources and ecological consequences of PTSs, particularly in coastal regions influenced by industrial and urban developments, remain insufficiently understood. This study evaluated the distribution, sources, and risks of 54 PTSs in Gyeonggi Bay. Polycyclic aromatic hydrocarbons (PAHs) ranged from 22.0 ng g-1 dw to 2710 ng g-1 dw, and alkylphenols (APs) peaked at 21,500 ng g-1 dw in source-dominated areas. Elevated levels were observed in Incheon Port and Lake Sihwa, from industrial and urban wastewater discharges. PMF modeling identified fossil fuel combustion as the main source of PAHs and natural and agriculture for metal(loid)s. Ecological risk assessments revealed significant contributions of metal(loid)s (49.1 %) and APs (39.3 %), with nonylphenols and arsenic posing the highest risks. These findings highlight the need for continuous monitoring and stricter regulations to mitigate the impacts of PTSs in marine ecosystems.

Transcriptome analysis unveils the mechanisms of oxidative stress, immunotoxicity and neurotoxicity induced by benzotriazole UV stabilizer-328 in zebrafish embryos

As an emerging pollutant, ultraviolet stabilizer-328 (UV-328) has been frequently detected in aquatic environments and attracted great attention. Nevertheless, the toxicity and mechanisms of UV-328 to aquatic organisms are still not fully understood. In particular, the immunotoxicity and neurotoxicity of UV-328 to aquatic organisms and their mechanisms have not been reported yet. In this experiment, the developmental toxicity, oxidative stress, apoptosis, immunotoxicity and neurotoxicity in zebrafish embryos exposed to UV-328 with concentrations of 0.01, 0.1, 1, 10 and 100 µg/L for 120 h were studied. By measuring the growth and developmental indices, production of ROS, enzyme activities, MDA content and expression of genes related to oxidative, immune and nerve, and histopathological analysis, it was found that UV-328 had developmental toxicity to zebrafish larvae, and could induce oxidative stress, immunotoxicity and neurotoxicity to zebrafish larvae even at environmental concentrations with concentration-dependent effects. Moreover, the results of transcriptome analysis and qRT-PCR validation suggested that immune and nerve disorders were caused by UV-328 in zebrafish larvae through regulating the RIG-I-like receptor signaling pathway and neuroactive ligand-receptor interaction, respectively. In addition, transcriptome analysis further revealed that UV-328 could mediate the RIG-I to induce oxidative stress through p38-MAPK/p53 signaling pathway, leading to apoptosis and oxidative damage. In addition, the p38-MAPK signaling pathway enhanced ROS production and activated inflammatory cytokines to induce immunotoxicity. The results of the present work provided important information for understanding the toxicity of UV-328 to aquatic organisms and evaluating its ecological risk in aquatic environment.

Environmental fate of organic UV filters: Global occurrence, transformation, and mitigation via advanced oxidation processes

Organic UV filters are used in personal care products, plastics, paints, and textiles to protect against UV radiation. Despite regulatory limits, these compounds still enter the environment through direct wash-off during swimming, evaporation, leaching from products, and incomplete removal in wastewater treatment plants. They have been detected in various environmental matrices worldwide. Once in the environment, organic UV filters can undergo phototransformation and biotransformation, forming transformation products that, together with parent substances, pose health risks to humans and wildlife and harm marine ecosystems, especially coral reefs. The increasing concern over water scarcity and the environmental impact of pollutants underscores the importance of eliminating these contaminants from aquatic environments. This review primarily focuses on organic UV filters approved for use in sunscreens, many of which are also utilized in other materials, with a few exceptions including UV stabilizer UV-328. It includes an in-depth analysis of 155 peer-reviewed articles published from 2015 to 2024, assessing the concentrations of these filters in various environmental matrices, including water and solid matrices, air and biota. Moreover, this review explores the environmental transformation of these chemicals and assesses the effectiveness of advanced oxidation processes (AOPs) in removing these pollutants. The findings highlight the pervasive presence of organic UV filters in the environment and the promising potential of AOPs to mitigate the associated environmental challenges.

Ethylhexyl triazone sunscreen and its disinfection byproducts obtained after chlorine treatment: Ecofriendliness or ecotoxicity?

In recent years, there has been a growing demand for high-quality sunscreens that combine high efficacy with ecological characteristics. This trend has led to an increased use of triazine compounds, which represent an emerging class of UV filters. While it is well-established that sunscreens can have significant environmental impacts, there is limited data on the degradation of triazine UV filters, despite available information on their environmental persistence, particularly in relation to disinfection processes. This study investigates the chemical fate of ethylhexyl triazone (EHT) under chlorination conditions, typical of swimming pools. Twelve disinfection byproducts (DBPs) were isolated and fully identified using nuclear magnetic resonance and mass spectrometry, with three of these byproducts being identified for the first time. DBP1-DBP12 were isolated at relative percentages of 1.26, 9.68, 1.05, 0.42, 0.84, 3.37, 3.58, 1.89, 0.84, 1.47, 0.42, and 0.63. Additionally, a mechanism for their formation was proposed. The ecotoxicological assessment of EHT and of byproducts (DBP1-DBP4) was conducted using acute, sub-chronic or chronic toxicity tests in producers and primary consumers of the freshwater trophic chain. The organisms included the alga Raphidocelis subcapitata, the rotifer Brachionus calyciflorus, the crustacean anostracan Thamnocephalus platyurus and the benthic ostracod Heterocypris incongruens. EHT caused a lethal median concentration in rotifers, with values in the range of tens of mg/L. EHT, DBP1, and DBP4 exhibited sub-chronic effects in ostracods at concentrations in the μg/L range, with EC50s of 210, 9, 20 μg/L, respectively. Rotifers were slightly affected by DBP3 with a chronic EC50 of 200 μg/L. Algae were not affected by either EHT or byproducts.

2-Mercaptobenzothiazole-derived vulcanization accelerators in urine samples from Chinese adults

Studies have discovered wide presence of 2-mercaptobenzothiazole (2-MBT) and 2-MBT-derived vulcanization accelerators (MVAs) in household dust samples, suggesting that these chemicals may have been pervasive in the environment. However, despite the potential for human exposure, the presence of MVAs in human urine, a common matrix used for assessing exposure to environmental chemicals, has not been thoroughly investigated. The current study comprehensively analyzed 11 kinds of MVAs in urine samples from the recruited general population (n = 197) living in Taizhou city, China. Five kinds of MVAs were detectable in >50 % of human urine samples. This indicates the widespread exposure to these vulcanization accelerators among the general population. The predominant target analytes in human urine were 2-MBT and 2,2'-dithiobisbenzothiazole (MBTS), with the mean urinary concentrations of 2.7 ng/mL (range Collapse

Key Words

• 2-MBT
• Human exposuren
• MBTS
• Urinary concentration
• Vulcanization accelerators

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MESH Headings

• Humans
• Benzothiazoles/urine
• China
• Adult
• Male
• Female
• Middle Aged
• Environmental Exposure/analysis
• Environmental Monitoring
• Environmental Pollutants/urine
• East Asian People

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Affiliation(s)

Xiaoyu Wu Taizhou Central Hospital (Taizhou University Hospital), School of Medicine, Taizhou University, Taizhou, Zhejiang 318000, PR China
Yingying Zhu School of Life Sciences, Taizhou University, Taizhou, Zhejiang 318000, PR China
Ruyue Guo Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
Juxiu Huang Taizhou Central Hospital (Taizhou University Hospital), School of Medicine, Taizhou University, Taizhou, Zhejiang 318000, PR China
Hangbiao Jin Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310032, PR China
Lisha Zhou Taizhou Central Hospital (Taizhou University Hospital), School of Medicine, Taizhou University, Taizhou, Zhejiang 318000, PR China.

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Environmental contamination and risks of organic UV filters: Source, discharge, analytical methods and implications for ecological and human health

Organic Ultraviolet Filters (OUVFs), commonly used in sunscreens, cosmetics and industrial products to prevent ultraviolet radiation damage, are increasingly detected in the environment due to their widespread use and persistence. This has raised concerns over their toxicity and environmental impact, leading to the classification of OUVF 2-(2H-Benzotriazol-2-yl)-4,6-ditertpentylphenol (UV-328) as a persistent organic pollutant under the Stockholm Convention in 2023. In this review, current knowledge on the usage, discharge and environmental contamination of OUVFs is briefly discussed. The available analytical methodologies are also reviewed, especially for the extraction and detection of OUVFs in different matrix samples. Finally, the reported levels of OUVFs pollution in surface water, drinking water, aquatic organisms and human urine worldwide are discussed, along with their potential implications for ecological and human health. In general, typical OUVFs ethylhexyl methoxy cinnamate (EHMC) and Octocrylene (OC) have been shown to pose a significant potential risks in the surface waters of multiple countries such as Australia, China, Japan, the United States. Furthermore, while the OUVFs exposure concentrations in drinking water are generally low (below detection limit to 450 ng/L), prolonged exposure may still present potential health risks for humans.

Benzotriazole ultraviolet stabilizers in the environment: A review of occurrence, partitioning and transformation

Benzotriazole ultraviolet stabilizers (BUVSs) are widely used as industrial additives to protect products from photoaging and are present in a variety of environmental matrices and organisms. It raised significant concerns that BUVSs are emerging pollutants with persistence, bioaccumulation and toxicity, of which 2-(3, 5-di-tert-amyl-2-hydroxyphenyl) benzotriazole (UV-328) has been recently listed in Annex A of the Stockholm Convention Persistent Organic Pollutants (POPs) list. A comprehensive understanding of the occurrence, partitioning and transformation of BUVSs in the environment is the basis for their environmental exposure and risk studies. However, the occurrence, partitioning and transformation of BUVSs are scarcely reviewed. In this paper, the environmental occurrence of BUVSs in various matrices, including water-suspended particulate matter and sediment, soil and dust, sludge, as well as biota, were summarized. Solid matrices and organisms are predominant reservoirs for BUVSs rather than waters, but there is a lack of systematical summary on the sorption/partitioning studies of BUVSs in abiotic phases and organisms. This paper analyzed and reviewed the possible sorption/partitioning processes and mechanisms. It was found that the partitioning is dependent on the hydrophobicity of BUVSs, environmental conditions and the organic carbon contents, and the bioaccumulation is also biota-species dependent. To further assess the potential risks of BUVSs, more progress has been made in the study of transformation of BUVSs. Focusing on the most important transformation processes in the environment, involving photodegradation, chemical degradation, biodegradation and metabolism in biota, the probable transformation pathways and mechanisms of BUVSs were summarized. It was emphasized that the hydrophobicity and toxicity of metabolites should not be overlooked. Finally, the future research direction was prospected from contaminant remediation and health risk perspectives. This paper provides fundamental knowledge of the environmental behavior of BUVSs, and will facilitate the research of environmental exposure and risk assessment of BUVSs.

Understudied and underestimated impacts of organic UV filters on terrestrial ecosystems

Organic UV filters (OUVFs) are vital components in various personal care products (PCPs) and commercial goods, with the annual consumption estimated at 10,000 tons. Consequently, the unavoidable use of OUVFs in PCPs and other unregulated commercial applications could present a considerable risk to human and environmental health. These chemical entities enter terrestrial ecosystems through wastewater discharge, agriculture, atmospheric deposition, and recreational activities. Compared to aqueous ecosystems, the effects of OUVFs on terrestrial environments should be more studied and potentially underestimated. The present review addresses the abovementioned gap by summarizing 189 studies conducted between 2006 and 2024, focusing on the analytical measures, occurrence, and ecotoxicological effects of OUVFs on terrestrial ecosystems. These studies underscore the harmful effects of certain OUVFs on the development, reproduction, and endocrine systems of terrestrial organisms, highlighting the necessity for comprehensive toxicological assessments to understand their impacts on non-target species in terrestrial ecosystems. Besides, by underscoring the ecological effects of OUVFs, this review aims to guide future research and inform regulatory measures to mitigate the risks posed by these widespread contaminants. Meanwhile, interdisciplinary research is essential, integrating environmental science, toxicology, ecology, and chemistry to tackle OUVF challenges in terrestrial ecosystems.

Comprehensive analysis of benzothiazoles (BTHs), benzotriazoles (BTRs), and benzotriazole ultraviolet absorbers (BUVs) in the western South China Sea: Spatial distributions, migration tendencies and ecotoxicological relevance

Benzothiazoles (BTHs), benzotriazoles (BTRs), and benzotriazole ultraviolet absorbers (BUVs) have garnered significant attention owing to their persistent nature in the environment and adverse impacts on aquatic organisms. However, there remains a dearth of investigations and studies conducted in tropical marine environments. In this study, we undertook the inaugural distributional survey and ecotoxicological relevance of BTHs, BTRs, and BUVs in seawater and sediments of the western South China Sea (WSCS). Elevated concentrations of BTHs, BTRs, and BUVs in the seawater and suspended particulate matter (SPM) were primarily observed in the Pearl River Estuary (PRE) and the western region of the WSCS, attributed to terrestrial runoff and hydrodynamic processes. Moreover, the transport of these compounds at the seawater-SPM interface was influenced by both the intrinsic properties of the contaminants and temperature variations. Spatially, concentrations of BTHs, BTRs, and BUVs in surface sediments exhibited a diminishing trend with increasing distance from the coast to offshore areas, reflecting notable anthropogenic impacts. Concentration profiles of these compounds in sediment cores displayed a bottom-up increasing trend, with total organic carbon (TOC) identified as the primary determinant governing their accumulation within sediment cores in the WSCS. Terrestrial runoff inputs and atmospheric deposition as major contributors to the occurrence of BTHs, BTRs, and BUVs in the WSCS. Simultaneously, the study underscores the non-negligible moderate mixture risk quotient associated with BTHs, BTRs, and BUVs in the sediments.

Dynamic impact of different human activities on the distribution of organic ultraviolet absorbers in coastal aquatic environments: A case study in Beibu Gulf, South China Sea

The increasing environmental concern surrounding organic ultraviolet absorbers (OUVAs) has prompted heightened attention, particularly their presence in personal care products (organic ultraviolet filters, OUVFs) and industrial products (organic ultraviolet stabilizers, OUVSs). This study investigates the impact of human activities and environmental factors on the occurrence, spatiotemporal distribution, and ecological risk of eight commonly utilized OUVFs and OUVSs in the coastal region of Beibu Gulf, South China Sea. The study area is characterized by multiple functional zones with distinct human activities. Results reveal elevated concentrations of OUVAs during summer compared to winter, attributed to increased residential usage, tourist activities, industrial releases, and intensified ultraviolet (UV) radiation. Interestingly, the proportion of OUVFs increases during summer, while OUVSs decrease. Correlation analysis between OUVAs and sampling sites reveals that tourism and domestic wastewater are the main contributors to OUVF contamination in summer, whereas mariculture and port trade significantly impact OUVS contamination in winter. The ecological risk assessment indicates predominantly low or medium risk levels for most OUVAs in both local seawater and freshwater ecosystems. Nevertheless, OUVFs, with a particular focus on 4-methylbenzylidene camphor (4-MBC), and OUVSs, specifically 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P), exhibit a heightened risk compared to alternative substances. These findings provide crucial insights into the development of targeted mitigation strategies for OUVAs, taking into account the varying contamination levels of OUVFs and OUVSs resulting from diverse human activities, aiming to protect the health of aquatic ecosystems in diverse functional zones.

Presence of benzotriazole ultraviolet stabilizers in human urine

Health exposure to benzotriazole ultraviolet stabilizers (BUVSs) may pose diverse toxic impacts on health. Presently, the occurrence of BUVSs in human urine remains inadequately understood. This study analyzed 13 kinds of BUVSs in human urine (n = 182) from the general Chinese adult participants. Totally, nine BUVSs were measurable in these human urine samples. Among the detected BUVSs, 2-(2H-benzotriazol-2-yl)-p-cresol (UV-P) was the most predominant BUVS in the human urine, with the mean concentration of 1.6 μg/g creatinine ( Collapse

Key Words

• Benzotriazole ultraviolet stabilizers
• Human exposure
• Human urine
• UV-326
• UV-328

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MESH Headings

• Humans
• Male
• Female
• Triazoles/urine
• Adult
• Middle Aged
• Young Adult
• Aged
• Ultraviolet Rays
• China
• Environmental Pollutants/urine
• Biological Monitoring/methods

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Affiliation(s)

Weili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China
Hangbiao Jin Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China; Innovation Research Center of Advanced Environmental Technology, Eco-Industrial Innovation Institute ZJUT, Quzhou, Zhejiang, 324400, PR China
Ruyue Guo Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang, 310032, PR China
Kaili Mao Department of Pharmacy, Quzhou Affiliated Hospital of Wenzhou Medical University, Quzhou People's Hospital, Quzhou, Zhejiang, 324000, PR China.

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Benzotriazole ultraviolet absorbents in surface waters and sediments of the Bohai Sea and North Yellow Sea: Spatial trends and influencing factors

Benzotriazole ultraviolet absorbents (BUAs) of emerging concern were recently monitored in seawater and sediments from the Bohai Sea (BS) and North Yellow Sea (NYS), which are impacted by human activities, to elucidate their regional occurrence patterns, phase distributions, and contamination profiles. Although environmental variables such as sedimentary organic carbon, particle size, and salinity, as well as hydrological conditions, affected the environmental occurrence of BUAs in the BS and NYS, the source dependence of BUA distributions associated with urban impacts and riverine inputs was highlighted. Substantial spatial variability in the composition patterns and contamination profiles of BUAs identified through correlation and principal component analyses were likely caused by region-specific sources and characteristics. The distribution of target BUAs between the sediment and seawater phases showed no dependence on the octanol-water partition coefficient (KOW) but exhibited marked spatial variations. The diversity of BUA sorption behaviors was further explained by the total organic carbon (TOC)-normalized distribution coefficient (KTOC). Classic logKTOC-logKOW linear relationships accurately predicted the phase distributions of UV-326, UV-328, and UV-234, but deviations were found for lighter and heavier BUAs, possibly due to the influences of physical disturbance and microparticle binding.

Oxidative damage and cardiotoxicity induced by 2-aminobenzothiazole in zebrafish (Danio rerio)

There is limited information available on cardiovascular toxicity of 2-Aminobenzothiazole (NTH), a derivative of benzothiazole (BTH) commonly used in tire production, in aquatic organisms. In the present study, the zebrafish embryos were exposed to varying concentrations of NTH (0, 0.05, 0.5, and 5 mg/L) until adulthood and the potential cardiovascular toxicity was assessed. NTH exposure resulted in striking aberrations in cardiac development, including heart looping failure and interference with atrioventricular canal differentiation. RNA-sequencing analysis indicated that NTH causes oxidative damage to the heart via ferroptosis, leading to oxygen supply disruption, cardiac malformation, and ultimately, zebrafish death. Quantitative real-time polymerase chain reaction (qPCR) analysis demonstrated the dysregulation of genes associated with early heart development, contraction, and oxidative stress. Additionally, reactive oxygen species accumulation and glutathione/malondialdehyde levels changes suggested a potential link between cardiac developmental toxicity and oxidative stress. In adult zebrafish, NTH exposure led to ventricular enlargement, decreased heart rate, reduced blood flow, and prolonged RR, QRS, and QTc intervals. To the best of our knowledge, this study is the first to provide evidence of cardiac toxicity and the adverse effects of ontogenetic NTH exposure in zebrafish, revealing the underlying toxic mechanisms connected with oxidative stress damage. These findings may provide crucial insights into the environmental risks associated with NTH and other BTHs.

Occurrence of halogenated organic contaminants in surface sediments of the Yangtze River estuary and its adjacent marine area

Halogenated organic contaminants, such as chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs), are some of the most important emerging environmental pollutants. However, empirical data on Cl/Br-PAHs in estuarine and marine ecosystems are limited, rendering assessments of Cl/Br-PAH contamination in estuarine and offshore environments uncertain. Here the occurrence, sources, and ecological risks of 7 Cl-PAHs and 18 Br-PAHs were determined in surface sediments of the Yangtze River Estuary (YRE), a highly urbanized and industrialized area, and its adjacent marine area. The concentrations of Cl-PAHs ranged from 4.50 to 18.38 ng g-1 (average 7.19 ng g-1), while those of Br-PAHs ranged from 4.80 to 61.18 ng g-1 (average 14.11 ng g-1). The dominant Cl-PAH and Br-PAH in surface sediment were 9-chlorofluorene (17.79%) and 9-bromofluorene (58.49%), respectively. The distributions and compositions of Cl/Br-PAHs in the surface sediments varied considerably due to complex hydrodynamic and depositional conditions in the YRE and its adjacent marine area, as well as differences in physicochemical properties of different Cl/Br-PAHs. Positive matrix factorization revealed that the primary sources of Cl/Br-PAHs in the study area were e-waste dismantling (33.6%), waste incineration (23.2%), and metal smelting (11.0%). According to the risk quotient, the Cl/Br-PAHs in sediments posed no toxic risk to aquatic organisms.

Organic UV filters: Occurrence, risks and (anti-)progestogenic activities in samples from the Czech aquatic environment and their bioaccumulation in fish

The occurrence, environmental risks and contribution of organic UV filters to detected (anti-)progestogenic activities were examined in samples of wastewater treatment plant influents and effluents, various surface waters and fish from the Czech Republic. Of the 20 targeted UV filters, 15 were detected in the WWTP influent samples, 11 in the effluents, and 13 in the surface water samples. Benzophenone-3, benzophenone-4, and phenyl benzimidazole sulfonic acid (PBSA) were found in all water samples. Octocrylene, UV-327 and 4-methylbenzylidene camphor exceeded the risk quotient of 1 at some sites. In the anti-progestogenic CALUX assay, 10 out of the 20 targeted UV filters were active. Anti-progestogenic activities reaching up to 7.7 ng/L, 3.8 ng/L, and 4.5 ng/L mifepristone equivalents were detected in influents, effluents, and surface waters, respectively. UV filters were responsible for up to 37 % of anti-progestogenic activities in influents. Anti-progestogenic activities were also measured in fish tissues from the control pond and Podroužek (pond with the highest number of detected UV filters) and ranged from 2.2 to 9.5 and 1.9 to 8.6 ng/g dw mifepristone equivalents, respectively. However, only benzophenone was found in fish, but it does not display anti-progestogenic activity and thus could not explain the observed activities.

First Evidence of the Bioaccumulation and Trophic Transfer of Tire Additives and Their Transformation Products in an Estuarine Food Web

The discovery of the significant lethal impacts of the tire additive transformation product N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) on coho salmon has garnered global attention. However, the bioaccumulation and trophic transfer of tire additives and their transformation products (TATPs) within food webs remain obscure. This study first characterized the levels and compositions of 15 TATPs in the Pearl River Estuary, estimated their bioaccumulation and trophic transfer potential in 21 estuarine species, and identified priority contaminants. Our observations indicated that TATPs were prevalent in the estuarine environment. Eight, six, seven, and 10 TATPs were first quantified in the shrimp, sea cucumber, snail, and fish samples, with total mean levels of 45, 56, 64, and 67 ng/g (wet weight), respectively. N,N'-Diphenyl-p-phenylenediamine (DPPD) and N,N'-bis(2-methylphenyl)-1,4-benzenediamine (DTPD) exhibited high bioaccumulation. Significant biodilution was only identified for benzothiazole, while DPPD and DTPD displayed biomagnification trends based on Monte Carlo simulations. The mechanisms of bioaccumulation and trophodynamics of TATPs could be explained by their chemical hydrophobicity, molecular mass, and metabolic rates. Based on a multicriteria scoring technique, DPPD, DTPD, and 6PPD-Q were characterized as priority contaminants. This work emphasizes the importance of biomonitoring, particularly for specific hydrophobic tire additives.

Spatiotemporal variation, partitioning, and ecological risk assessment of benzothiazoles, benzotriazoles, and benzotriazole UV absorbers in the Yangtze River Estuary and its adjacent area

The distributions and toxicities of the pollutants benzothiazoles (BTHs), benzotriazoles (BTRs), and benzotriazole ultraviolet stabilizers (BUVs) have attracted much attention, but most research has focused on freshwater environments and few have examined their levels in marine environments. This study, for the first time, investigated the spatial and temporal variability and ecological risks of BTHs, BTRs and BUVs in the Yangtze River estuary and its adjacent area, and further elucidated how environmental factors influence the transport of these contaminants. The concentrations of BTHs, BTRs, and BUVs in seawater showed significant seasonal variability, with the highest concentrations in summer, followed by autumn, and then winter-spring. The spatiotemporal variability in BTHs, BTRs and BUVs in the seawater and sediments samples showed decreasing trends from nearshore to offshore, reflecting the influence of river discharge. Marine debris and continuous discharge from cities were responsible for the high detection frequency of these contaminants in the YRE and its adjacent area. Furthermore, the moderate risk from the presence of BTHs, BTRs, and BUVs as they accumulate in sediments should not be ignored. Our study provides new insights into the fate and ecological risk of BTHs, BTRs, and BUVs in the estuary.

Neurotoxicity of Benzotriazole Ultraviolet Stabilizers in Teleost Fishes: A Review

Plastic additives that maintain integrity have been extensively studied for potential toxicity to fish; however, chemicals that protect polymers from (artificial) UV degradation are less studied. Benzotriazole UV stabilizers (BUVSs) are the most widely used UV stabilizers in plastics and are often used in sunscreens, cosmetics, paint, and food packaging. BUVSs can negatively affect aquatic wildlife when released into the environment via plastic degradation. In this review, we summarize the distribution of BUVSs globally and discuss neurotoxicological endpoints measured in fish to understand how these plastic additives can affect the neurological health of teleost fishes. BUVSs have been detected in aquatic environments at concentrations ranging from 0.05 up to 99,200 ng/L. Studies show that BUVSs affect behavioral responses and acetylcholinesterase activity, indicators of neurotoxicity. Our computational analysis using transcriptome data suggests certain pathways associated with neurodegeneration are responsive to exposure to BUVSs, like "Complement Activation in Alzheimer's Disease". Based on our review, we identify some research needs for future investigations: (1) molecular studies in the central nervous system to define precise mechanisms of neurotoxicity; (2) a wider range of tests for assessing aberrant behaviors given that BUVSs can affect the activity of larval zebrafish; and (3) histopathology of the nervous system to accompany biochemical analyses. These data are expected to enhance understanding of the neurotoxicity potential of benzotriazoles and other plastic additives.

Spatial distribution, partitioning, and ecological risk assessment of benzotriazoles, benzothiazoles, and benzotriazole UV absorbers in the eastern shelf seas of China

Benzotriazoles (BTRs), benzothiazoles (BTHs), and benzotriazole UV stabilizers (BUVs) have attracted increasing attention due to their ubiquity in the environment, toxicity, and potential ecological risks. However, information on their distributions in the ocean is scarce. In this study, BTRs, BTHs, and BUVs were firstly determined in the surface seawater, sea-surface microlayer (SML), suspended particulate matter (SPM), and sediments of the Yellow Sea (YS) and East China Sea (ECS). The spatial distributions of BTRs, BTHs, and BUVs in the YS and ECS showed offshore decreasing trend in their concentrations, indicating that terrestrial inputs from runoff and rivers had important influences on their distributions. The organic carbon normalized partition coefficients (log Koc) of target contaminants in surface seawater-SPM (3.06-4.16 L/g) and bottom seawater-sediment (2.55-4.82 L/kg) systems were determined. SPM showed greater sorption capacities for most target contaminants than the sediment. The burial capacities of BTHs, BTRs, and BUVs from SPM to surface sediments were evaluated using their respective log Kow values and their sedimentary fluxes in the YS and ECS were quantified. BTRs, BTHs, and BUVs were enriched in the SML, with the enrichment extents of the suspended particulate phase being obviously lower than those of the dissolved phase. The ecological risks of BTRs, BTHs, and BUVs were evaluated using the risk quotient (RQ) method, which showed no toxic risk to aquatic organisms throughout the water phases, but high risk in nearshore sediments.

Acute toxicity assessment of nine organic UV filters using a set of biotests

UV filters in environmental compartments are a source of concern related to their ecotoxicological effects. However, little is known about UV filters' toxicity, particularly those released into the environment as mixtures. Acute toxicity of nine organic UV filters benzophenone-1, benzophenone-2, benzophenone-3, 4-methoxy benzylidene camphor, octocrylene, ethylhexyl methoxycinnamate, 2-ethylhexyl salicylate, homosalate, and butyl methoxydibenzoylmethane was determined. UV filter solutions were tested as single, binary, and ternary mixtures of various compositions. Single solutions were tested using a set of bio tests, including tests on saline crustaceans (Artemia franciscana), freshwater crustaceans (Daphnia magna), marine bacteria (Aliivibrio fischeri), and freshwater plants (Lemna minor). The tests represent different stages of the trophic chain, and hence their overall results could be used to risk assessment concerning various water reservoirs. The toxicity of binary and ternary mixtures was analyzed using the standardized Microtox® method. Generally, organic UV filters were classified as acutely toxic. Octocrylene was the most toxic for Arthemia franciscana (LC50 = 0.55 mg L-1) and Daphnia magna (EC50 = 2.66-3.67 mg L-1). The most toxic against freshwater plants were homosalate (IC50 = 1.46 mg L-1) and octocrylene (IC50 = 1.95 mg L-1). Ethylhexyl methoxycinnamate (EC50 = 1.38-2.16 mg L-1) was the most toxic for marine bacteria. The least toxic for crustaceans and plants were benzophenone-1 (EC50 = 6.15-46.78 mg L-1) and benzophenone-2 (EC50 = 14.15-54.30 mg L-1), while 4-methoxy benzylidene camphor was the least toxic for marine bacteria (EC50 = 12.97-15.44 mg L-1). Individual species differ in their sensitivity to the tested organic UV filters. An assessment of the toxicity of mixtures indicates high and acute toxicity to marine bacteria after exposition to a binary mixture of benzophenone-2 with octocrylene, 2-ethylhexyl salicylate, or homosalate. The toxicity of mixtures was lower than single solutions predicting antagonistic interaction between chemicals.

Graphical abstract

Screening and prioritization of organic chemicals in a large river basin by suspect and non-target analysis

Many organic chemicals are present in aquatic environments, but how to screen and prioritize these chemicals has always been a difficult task. Here we investigated organic chemicals in the West River Basin by using a developed non-target identification workflow. A total of 957 chemicals were tentatively identified, with 96 assigned as high confidence levels by matching with reference standards, MassBank spectral library, and using CompTox Chemistry Dashboard database as the compound library for MetFrag. More pesticides and their transformation products (e.g., metolachlor ESA, acetochlor ESA, deethylatrazine, and hydroxyatrazine) were detected in the wet season due to the increasing usage. High detection of pharmaceutical and personal care products and their transformation products in the tributaries was linked to rural farming and human activities. Irbesartan that is used to treat high blood pressure was recognized in the river and positive correlations between some detected chemicals and irbesartan were observed, indicating a domestic wastewater source. Ecological risks of the identified chemicals were calculated by toxicological prioritization ranking schemes, and 24 chemicals showed high ToxPi scores in the river. The results from this study show the presence of a large number of emerging organic chemicals in our waterways, and demonstrated conceptual schemes for integrating risk assessment into a non-target screening workflow.

Short-term effects of an environmentally relevant concentration of organic UV filters on signal crayfish Pacifastacus leniusculus

Personal care products, including organic UV filters, are considered emerging contaminants, with their toxic effects being a concern in recent decades. UV filters continually enter surface waters via wastewater and human activity. Despite the presence of organic UV filters in the freshwater environment, little is known of their impact on aquatic biota. In this study, we evaluated the cardiac and locomotor responses of signal crayfish Pacifastacus leniusculus exposed to environmentally relevant concentrations of either 2-Phenylbenzimidazole-5-sulfonic acid (PBSA, 3 µg/L) or 5-Benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BP4, 2.5 µg/L). Specimens exposed to the tested compounds for 30 min exhibited significantly greater changes in distance moved and time active than did unexposed controls. Significant differences of mean heart rate change compared to control were detected in both PBSA and BP4 experimental groups. Such behavior and physiological alterations demonstrate ecological effects of personal care products with the tested sunscreen compounds even with a short exposure. Evidence of the consequences of organic UV filters on aquatic organisms is scarce and is an important topic for future research.

Spatiotemporal trends of ultraviolet absorbents in oysters from the Pearl River Estuary, south China during 2015-2020

Ultraviolet absorbents (UVAs) are widely used in various industrial materials, pharmaceuticals, and personal care products, resulting in their frequent occurrences in sediment, water, and biota. However, our understanding of the spatiotemporal characteristics and long-term contamination status of UVAs is still limited. Here, a 6-year biomonitoring study with oysters during wet and dry seasons was conducted to examine the annual, seasonal, and spatial characteristics of UVAs in the Pearl River Estuary (PRE), China. The concentrations of Σ₆UVA ranged from 9.1 to 119 (geometric mean ± standard deviation: 31 ± 22) ng/g dry wt. and peaked in 2018. Significant spatiotemporal variations in UVA contamination were observed. The concentrations of UVAs in oysters during the wet season were higher than the dry season, and concentrations in the more industrialized eastern coast were higher than the western coast (p < 0.05). Environmental factors, including precipitation, temperature, and salinity in water significantly impacted the UVA bioaccumulation in the oysters. The present study highlights that long-term biomonitoring with oysters provided valuable insight in the magnitude and seasonal variation of UVAs in this highly dynamic estuary.

Simultaneous determination of benzothiazoles, benzotriazoles, and benzotriazole UV absorbers by solid-phase extraction-gas chromatography-mass spectrometry

Benzotriazoles (BTRs), benzothiazoles (BTHs), and benzotriazole ultraviolet absorbers (BUVs) are common products in plastic rubber and personal care products. Due to their toxicity and bioaccumulation, they have been identified as emerging contaminants (ECs) in the environment. Solid-phase microextraction (SPME) and solid-phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) were used for the enrichment and detection of the contaminants in seawater and sediment, respectively. The conditions of SPE and SPME were optimized in terms of material, temperature, time, pH, ionic strength, extraction solvent, and elution solvent. Although SPME requires a small sample volume, it is not reliable for the extraction efficiency and reproducibility of BTHs, BTRs, and BUVs in seawater. However, the precision of SPE-GC-MS for the determination of BTHs, BTRs, and BUVs was around 10%, with recoveries of 67.40-102.3% and 77.35-101.8% in seawater and sediment, respectively. The limits of detection of 14 contaminants in seawater and sediment were 0.03-0.47 ng/L and 0.01-0.58 ng/g, respectively. Secondly, BTHs, BTRs, and BUVs were detected with low ecological risk when SPE-GC-MS was applied to the analysis of seawater and sediment samples from the Yangtze estuary and its adjacent areas. The SPE-GC-MS was highly precise with lower detection limits relative to previous studies and thus was able to meet the requirements for the detection of BTHs, BTRs, and BUVs in seawater and sediments.

Occurrence and risks of 23 tire additives and their transformation products in an urban water system

Tire wear particles (TWPs) enter road surface with the friction between tires and road surfaces. Under the volatilization, leaching, and transformation action on TWPs by sunlight and rain, tire additives are released into urban water systems, such as surface rainfall runoff, wastewater treatment plants (WWTPs), receiving surface waters, and drinking water treatment plant (DWTP). In this study, we investigated the occurrence of 23 tire additives and their transformation products in the urban water system of the Pearl River Delta region, South China. Nineteen target compounds were detected in the surface runoff, with 1,3-Diphenylguanidine (DPG) showing highest maximum concentration of 58780 ng/L. Benzothiazole and its transformation products are detected at the frequency of 100 % with the total concentrations of 480-42160 ng/L. The antioxidant derivative N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q) was also detected up to 1562 ng/L, which was considerably higher than that of the parent compound 6PPD (the maximum concentration of 7.52 ng/L). Eleven and 8 compounds were detected in WWTPs influents and effluents, respectively, with removal rates of - 62-100 %. Seventeen compounds were detected in the receiving Zhujiang and Dongjiang rivers, while 9 compounds were detected in drinking water sources and DWTP samples. Road runoff, with total concentrations of target compounds up to 79200 ng/L, is suggested as the main non-point source for receiving rivers, while WWTPs effluents are the point sources due to incomplete removal of target compounds after accepting the initial runoff. 6PPD-Q and other 10 compounds displayed median to high ecological risks in surface waters, and the human daily intake of tire additives was estimated to be 2.63 × 10^-8-3.16 × 10^-5 mg/(kg d) via drinking water. This is the first report of the 6PPD-Q and 1,3-Diphenylurea levels in surface waters in China.

Freshwater Environmental Risk Assessment of Down-the-Drain Octinoxate Emissions in the United States

Organic ultraviolet (UV) filters are used in a variety of cosmetic and personal care products (CPCPs), including sunscreens, due to their ability to absorb solar radiation. These UV filters can be washed down the drain through bathing, cleansing, or the laundering of clothing, therefore UV filters can enter the freshwater environment via wastewater treatment plant effluent, and so a freshwater risk assessment is necessary to establish the environmentally safe use of these important CPCP ingredients. In the present study, an environmental safety assessment for a UV filter of regulatory concern, octinoxate, was conducted. An established risk assessment framework designed specifically for CPCPs released to the freshwater environment in the United States was used for the assessment. A distribution of predicted environmental concentrations (PECs) representative of conditions across the region was calculated using the spatially resolved probabilistic exposure model iSTREEM. A review of available hazard data was conducted to derive a predicted no-effect concentration (PNEC). The safety assessment was conducted by comparing the PEC distribution to the PNEC. A substantial margin of safety was found between the 90th percentile PEC, which is representative of the reasonable worst-case environmental exposure, and the PNEC. Owing to this finding of negligible risk, further refinement of the risk assessment through the generation of experimental data or refinement of conservative assumptions is not prioritized. These results are critical for demonstrating the environmental safety of UV filters in the US freshwater environment and will help guide future work. Environ Toxicol Chem 2022;41:3116-3124. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Concentrations, Compound Profiles, and Possible Sources of Organic UV Filters in Human Milk in China

Ultraviolet (UV) filters are of great concern due to their wide occurrence, bioaccumulation, and toxicity. Little is known about human exposure to UV filters. A total of 3467 individual human milk samples from 24 Chinese provinces were collected during 2017-2019. The concentrations of 12 UV filters in 100 pooled milk samples were determined. The total UV filter concentration was 78-846 (mean 235 ± 120) ng/g lipid weight. The highest and lowest total mean concentrations were for samples from Qinghai and Sichuan provinces, respectively. A significant positive correlation was found between UV radiation levels and UV concentrations in the samples. The dominant UV filters were 2-(2-hydroxy-5-methylphenyl) benzotriazole (UV-P) and ethylhexyl methoxycinnamate (EHMC), which contributed means of 32 and 22%, respectively, to the total concentrations. Plastic products and sunscreens were probably the sources of UV-P and EHMC in the human milk from China, respectively. The mean 2-(3,5-di-tert-amyl-2-hydroxyphenyl) benzotriazole (UV-328) concentration was 2.6 ± 2.6 ng/g lipid weight. The UV filter profiles were similar to profiles for samples from Japan, the Philippines, and Switzerland but not for samples from Korea and Vietnam. The estimated daily UV filter intake for breastfed infants was below the corresponding reference dose. This was the first large-scale study of UV filters in human milk and will help assess the risks posed.

Occurrence and distribution of organic corrosion inhibitors (OCIs) in riverine sediments from the Pearl River Delta, South China

Although soluble organic corrosion inhibitors (OCIs) have been observed globally in surface water, data on their exposures in sediments are still scarce. In this study, a comprehensive investigation on spatial variations and potential sources of OCIs were conducted in riverine sediments from the Pearl River Delta (PRD), one of the most developed and urbanized areas in China. Of 12 OCIs, 7 were detected with the total concentrations ranging from 81.8 to 401.2 ng/g. When the results were compared with those of the water phase, OCIs in the riverine sediments exhibited relatively low concentrations, which was likely due to their low K_ow, and they were not expected to be adsorbed onto sediments. The spatial variation of OCIs suggested that the discharge of sewage treatment plants (STPs) effluent could be a major source of OCIs in the PRD region. The total concentrations of OCIs had a significant positive correlation with total organic carbon (TOC) contents, suggesting that they have similar sources. This study strongly indicated that the high consumption of OCIs have led to their wide exposure in different environments in the PRD region and additional ecotoxicological data are needed to evaluate their potential risks in riverine sediments in the future.

Development and validation of a simultaneous method for the analysis of benzothiazoles and organic ultraviolet filters in various environmental matrices by GC-MS/MS

The presence of benzothiazoles (BTHs) and organic ultraviolet filters (UV filters) in aquatic ecosystems has emerged as a significant environmental issue, requiring urgent and efficient determination methods. A new, rapid, and sensitive determination method using gas chromatography triple quadrupole mass spectrometer (GC-MS/MS) was developed for the simultaneous extraction and analysis of 10 commonly used BTHs and 10 organic UV filters in surface water, wastewater, sediment, and sludge. For aqueous samples, solid-phase extraction (SPE) method was employed with optimizing of SPE cartridge type, pH, and elution solvent. For solid samples, ultrasonic extraction-solid-phase extraction purification (UE-SPE) and pressurized liquid extraction (PLE) methods were compared. And extraction conditions for ultrasonic extraction method (extraction solvents and extraction times) and PLE method (extraction temperatures and extraction cycles) were optimized. The limits of quantification for the 20 target compounds in surface water and wastewater were 0.01-2.12 ng/L and 0.05-6.14 ng/L, while those for sediment and sludge with UE-SPE method were 0.04-5.88 ng/g and 0.22-6.61 ng/g, respectively. Among the 20 target compounds, the recoveries ranged from 70 to 130% were obtained for 16, 15, 15, and 15 analytes in the matrix-spiked samples of surface water, wastewater, sediment, and sludge with three levels, respectively. And the precision was also acceptable with relative standard deviation (RSD) below 20% for all analytes. The developed methods were applied for the determination and quantification of target compounds in surface water, sediment, wastewater, and sludge samples collected from two wastewater treatment plants (WWTPs) and the Pearl River in Guangzhou, China. BTHs were frequently detected in surface water and wastewater, while UV filters were mainly found in sediment and sludge. Benzotriazole (BT) and 2-hydroxybenzothiazole (2-OH-BTH) were the two major BTHs in influent wastewater and surface water, respectively, with concentrations up to 966 and 189 ng/L. As for sediment and sludge, 2-(2'-hydroxy-5'-octylphenyl)-benzotriazole (UV-329) was a predominant chemical, detected at concentrations of 111 and 151 ng/g, respectively.

Gene expression profiling in liver of zebrafish exposed to ethylhexyl methoxycinnamate and its photoproducts

In recent decades, the ecotoxicological potential of organic ultraviolet filters (OU-VFs) has received growing attention. However, the toxicity of its photoproducts or transformation products on freshwater vertebrates has been little explored. Therefore, the aim of the present study is to evaluate the possible adverse effects of ethylhexyl methoxycinnamate (EHMC) and its photoproducts [2-ethylhexanol (2-EH) and 4-methoxybenzaldehyde (4-MBA)] on the expression of stress-responsive and antioxidant genes. For this, zebrafish (Danio rerio) adults were exposed to pollutants at an environmentally relevant concentration (3 μg/L) and evaluated after 7, 14, and 21 days of exposure. The results of the principal component analysis (PCA) and two-way repeated measures (RM) ANOVA revealed that EHMC, 2-EH, and 4-MBA exposure caused significant downregulation of the genes hsp70, nrf2, cyp1a, ahr, sod1, sod2, cat, gstp1, gpx1a, gss, and gsr (on all trial days) in the liver of the animals. On the other hand, taken together, our data did not show significant differences between the effects induced by EHMC and its photoproducts. The genes evaluated in the present study play a major role in regulating the defensive antioxidant response against EHMC and its photoproducts. Additionally, our study provides an insight into the mechanisms of those OU-VFs in freshwater fish.

Selection of formulated sediment and feeding condition for 10-day spiked-sediment toxicity test with estuarine amphipod Grandidierella japonica

This study was performed to select formulated sediment with appropriate feeding conditions for the evaluation of estuarine sediment toxicity. Grandidierella japonica, which inhabits seawater worldwide, was examined for 10-day survival, and the repeatability was evaluated under nine test conditions. The formulated sediment feeding condition combined with the highest survival rate was applied to evaluate fluoranthene toxicity in the sediment. The KB-T10 feeding condition showed the highest survival rate of 93.5%, with sufficient repeatability (4.6%). In the fluoranthene spiked-sediment toxicity test, the estimated LC50 (95% significance level) was successfully achieved under the KB-T10 condition but not under the OE-T10 condition. Therefore, we propose the use of TetraMin® (1 mg/org./day) and Kemble sediment in 10-day static spiked-sediment toxicity tests with G. japonica. Further improvements are needed for OECD sediment in seawater to increase the survival rate and prevent chemical loss due to overlying water renewal.

1,2,3-benzotriazole adversely affects early-life stage of Oryzias latipes

1,2,3-benzotriazole (BT) is used in large amounts around the world and is one of the substances derived from household chemicals that are of concern for risk when discharged to aquatic environments. Therefore, several studies have been conducted on the aquatic toxicity effects of BT, but the chronic impact assessment studies to evaluate the developmental effects on the early-life stage of fish are insufficient. In this study, the acute toxicity test and subchronic toxicity test (fish, early-life stage toxicity test, ELS test) using embryos of Japanese medaka (Oryzias latipes) were performed to evaluate the acute toxicity, developmental toxicity, growth (indicated by total length and weight at the end of the test), and histopathological effect of BT. In the short-term toxicity test on embryo and sac-fry stage, toxicity value was calculated to be 41 mg/L (NOEC). Based on this value, the exposure concentration of the ELS test was determined as 0.04, 0.4, 4 and 40 mg/L, and total exposure duration was 42 days. At the highest concentration group (40 mg/L), failure of swim bladder inflation and decrease of survival and size (total length and weight) were observed. Moreover, in the histopathological analysis, abnormal findings were detected in swim bladders from the 40 mg/L group such as inflammation and tumor changes. On the other hands, condition index (weight-length relationships, CI) was statistically significantly lower in all exposed groups compared to the control group. NOEC for the survival of BT was calculated to be 4 mg/L. LOEC for CI was 0.04 mg/L, which means BT inhibited weight gain relative to its length on larvae of medaka.

Screening of organic chemicals in surface water of the North River by high resolution mass spectrometry

Wide use of various chemicals has resulted in water pollution, which has become a global environmental concern. So far limited information is available on what chemicals in our water. Here we investigated the occurrence and profiles of organic chemicals in the North River, South China by applying non-target screening analysis with high resolution mass spectrometry. A total of 402 organic chemicals belonging to eleven categories were identified in the North River, with notable presence of industrial chemicals, pharmaceuticals and pesticides. Among these detected chemicals, over half of the tentatively identified compounds were rarely reported in the surface water, with a few compounds, e.g., sisomicin, simeton, 2-methyl-4,6-dinitrophenol, xanthurenic acid and indole-3-carboxylic acid that have never been documented in the North River before, while the metabolites like 4-acetamidoantipyrine were also observed. The maximum concentration of the identified chemicals in the North River was above 300 ng/L (Sulfamonomethoxine). Principle component analysis results of the obtained dataset showed significant seasonal distribution, which could be linked to variations in wastewater discharge, river dilution and anthropogenic activities such as pesticide spray. Agricultural activities in the upper reaches led to detection of various pesticides in the river basin, especially in the wet season. The findings from this study demonstrated the widespread presence of chemicals in our waterway, and further retrospective analysis would reveal more information about chemicals of emerging concern.