Organic UV filters and their photodegradates, metabolites and disinfection by-products in the aquatic environment

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.

The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures

Substances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist, or additive effects of biological systems. This review focuses on the collection of data about the simultaneous occurrence of UV filters oxybenzone (OXYB), ethylexyl-methoxycinnamate (EMC) and 4-methylbenzylidene camphor (4-MBC) as well as other classes of chemicals (such as pesticides, bisphenols, and parabens) to understand better any such interactions considering synergy, additive effect and antagonism. Our analysis identified >20 different confirmed synergies in 11 papers involving 16 compounds. We also highlight pathways (such as transcriptional activation of estrogen receptor, promotion of estradiol synthesis, hypothalamic-pituitary-gonadal (HPG) axis, and upregulation of thyroid-hormone synthesis) and proteins (such as Membrane Associated Progesterone Receptor (MAPR), cytochrome P450, and heat shock protein 70 (Hsp70)) that can act as important key nodes for such potential interactions. This article aims to provide insight into the molecular mechanisms on how commonly used UV filters act and may interact with other chemicals.

Formation of nitrogen-containing disinfection by-products during the chloramination treatment of an emerging pollutant

Chloramination was commonly used as disinfectant for killing pathogens in water. However, in this process, nitrogen-containing disinfection by-products (N-DBPs) would accidently form and subsequently rise toxicity. Here, we investigated acute toxicity variation and by-products formation during chloramination treatment on UV filter 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone (BP-4). Under alkaline conditions, the acute toxicity of this system had significant increase. A total of 17 transformation products were tentatively identified, and for them, plausible transformation pathways were proposed. Noticeably, numerous aniline and nitrosobenzene analogs were detected, and the dramatic increase of acute toxicity in this system might be primarily attributed to the formation of benzoquinone and aniline analogs. Besides, bromophenol, iodophenol and iodobenzoquinone analogs exhibiting high toxicity were generated in the presence of bromine and iodide ions. This study indicates that chloramination treatment may significantly increase potential health risk, further management on disinfection system is reasonable.

Post-fertilization 2-ethylhexyl-4-methoxycinnamate (EHMC) exposure affects axonal growth, muscle fiber length, and motor behavior in zebrafish embryos

Organic UV filters, which are often found in the environment, have been the focus of much public health concern. 2-ethylhexyl-4-methoxycinnamate (EHMC) is one of the most common organic UV filters present in the environment. However, few studies have investigated its developmental neurotoxic (DNT) effects and the underlying molecular mechanisms. In the present study, zebrafish embryos were exposed to low concentration of EHMC (0, 0.01, 0.1, 1 mg/L) in static water starting from 6 h post-fertilization (hpf). Results showed that EHMC exposure caused a reduction in somite count at 13 hpf, a diminishment in head-trunk angle at 30 hpf, a delay in hatching at 48 hpf, and a decrease in head depth and head length at both 30 and 48 hpf. Additionally, EHMC led to abnormal motor behaviors at various developmental stages including altered spontaneous movement at both 23 and 24 hpf, and decreased touch response at 30 hpf. Consistent with these morphological changes and motor behavior deficits, EHMC inhibited axonal growth of primary motor neurons at 30 and 48 hpf, and yielded subtle changes in muscle fiber length at 48 hpf, suggesting the functional relevance of structural changes. Moreover, EHMC exposure induced excessive cell apoptosis in the head and spinal cord regions, increased the production of reactive oxygen species (ROS) and malondialdehyde (MDA), and reduced the level of glutathione (GSH). Defects of lateral line system neuromasts were also observed, but no structural deformity of blood vessels was seen in developing zebrafish. Abnormal expression of axonal growth-related genes (gap43, mbp, shha, and α1-tubulin) and apoptosis-related genes (bax/bcl-2 and caspase-3) revealed potential molecular mechanisms regarding the defective motor behaviors and aberrant phenotype. In summary, our findings indicate that EHMC induced developmental neurotoxicity in zebrafish, making it essential to assess its risks and provide warnings regarding EHMC exposure.

Organic ultraviolet absorbents in soils and typical plants from an industrial metropolis in China: Concentrations, profiles and environmental implications

There is accumulating evidence of the toxicity of organic ultraviolet absorbers (OUVAs); however, limited information is available regarding the presence of OUVAs in terrestrial environments and organisms. Therefore, this study was conducted to investigate the occurrence of 11 OUVAs in soils and typical plant species from an industrial metropolis in China. Total OUVA concentrations in soils ranged from 1.30 to 80.3 ng g-1 DW. Based on comparison with previously reported data, OUVA contamination in soil was not severe. Benzophenone and octocrylene were the dominant OUVAs in soils, with median contributions to total concentrations of 25% and 15%, respectively. Source assessment revealed that the observed OUVA contamination primarily originated from industrial activities and the use of personal care products. The concentration of 11 OUVAs in plants ranged from 159 to 4470 ng g-1 DW, at high levels. Our findings imply that great attention should be given to the presence of these chemicals in plants because of the risk they could pose as well as the potential for biomagnification as plants are eaten by insects and birds. Our results also indicate the necessity to further study the geochemical behavior of these chemicals in urban ecosystems in order to better manage the harmfulness to terrestrial ecological health caused by their exposure through the food chains.

Status quo on identified transformation products of organic ultraviolet filters and their persistence

Organic micropollutants of concern-including organic UV filters (UVF)-are getting increasing attention. Personal care products such as sunscreens or cosmetic articles often contain large quantities of UVF. These substances enter the environment either directly (during outdoor activities) or indirectly (via sewages from households). Therefore, the removal or degradation of UVF by natural or technical treatment processes is important to understand. UVF are often incompletely removed and transformed to side products of incomplete mineralization by abiotic and biotic processes. An extensive overview on transformation products (TPs) is essential to systematically identify knowledge gaps and to derive research needs. While there are many reviews on the UVF themselves, the number of reviews which focus on their TPs is limited. Consequently, this review gives an overview on the latest findings regarding TPs of UVF. In this publication, known TPs of UVF, which were formed during abiotic and biotic processes, are reviewed. Target substances were defined and a literature database was reviewed for studies on TPs of the target substances. The first list of studies was shortened stepwise, thus generating a final list of studies which contained only the relevant studies. Since biodegradation is one of the most important pathways for removal of organic compounds from the environment, this review presents an overview on known TPs of organic UVF and their biodegradability, which determines their environmental fate. In this way, all identified TPs of UVF were listed and checked for information on their biodegradability. A total of 2731 records of studies were assessed. Forty-two studies, which assessed 46 processes that lead to the formation of identified TPs, were included in this review. One hundred and seventyseven different TPs resulting from 11 different UVF were identified. Little to no data on the biodegradability was found for TPs. This indicates a severe lack of data on the biodegradability of TPs of organic UVF substances. Since most TPs lack information on biodegradability, further research should provide information on both-identity and biodegradability-of formed TPs to be able to assess their hazardousness for the environment.

Effects of Commercial Sunscreens on Survival, Reproduction and Embryonic Development of the Aquatic Snail Biomphalaria glabrata (SAY, 1818)

Over the past few years, there has been a significant increase in the use of sunscreens. Consequently, the occurrence in aquatic environments of ultraviolet filters has also increased. The present study aims to evaluate the toxicity of two commercial sunscreens to the aquatic snail Biomphalaria glabrata. Acute assays were performed with adult snails exposed to solutions of the two products in synthetic soft water. Reproduction and development assays were carried out, involving individual adult and egg masses exposure to assess fertility and embryonic development. Sunscreen A showed a LC₅₀-96 h of 6.8 g/L and reduction in number of eggs and egg masses per individual in the concentration of 0.3 g/L. Sunscreen B presented higher malformation rates in 0.4 g/L with 63% of malformed embryos. Results indicate that the formulation used in sunscreens is an important factor in aquatic toxicity and needs to be evaluated before the final product is commercialized.

Quantitation of Canadian organic ultraviolet filters using polarity switching and ultra-high performance liquid chromatography-tandem mass spectrometry

Ultraviolet filters (UVFs) absorb UV light and are comprised of numerous classes of compounds including inorganic and organic. They have been used for decades in protecting humans from skin damage and cancer. Recent studies have shown that UVFs are found in many phases of abiotic and biotic systems with their physical-chemical characteristics determining environmental fate and potential biological impacts such as bioaccumulation. This study developed a unified method to quantify eight UVFs (avobenzone, dioxybenzone, homosalate, octinoxate, octisalate, octocrylene, oxybenzone, and sulisobenzone) by solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry using polarity switching. The validated method resulted in accuracies ranging from 75 to 112%, MLD/MLQs of 0.00015/ 0.00049 to 0.0020/ 0.0067 ng mL^-1, and precisions of 1.8 to 22.6% (intraday) and 1.3 to 17.2% (interday). The method was applied to chlorinated outdoor pool waters in the City of Winnipeg, Manitoba, Canada. This method could be adapted for a variety of chlorinated and unchlorinated waters such as drinking water, wastewater, and surface waters.

Boosting elimination of sunscreen, Tetrahydroxybenzophenone (BP-2), from water using monopersulfate activated by thorny NanoBox of Co@C prepared via the engineered etching strategy: A comparative and mechanistic investigation

As sunscreens, benzophenones (BPs), are regarded as emerging contaminants, most of studies are focused on removal of 2-hydroxy-4-methoxybenzophenone (BP-3), which, however, has been employed for protecting skin. Another major class of BPs, which is used to prevent UV-induce degradation in various products, is completely neglected. Thus, this present study aims to develop a useful advanced oxidation process (AOP) for the first time to eliminate such a class of BP sunscreens from contaminated water. Specifically, 2,2',4,4'-Tetrahydroxybenzophenone (BP-2) would be focused here as BP-2 is intensively used in perfumes, lipsticks, and plastics for preventing the UV-induced degradation. As monopersulfate (MPS)-based AOP is practical for degrading emerging contaminants, a facile nanostructured cobalt-based material is then developed for maximizing catalytic activities of MPS activation by immobilizing Co nanoparticles onto carbon substrates. In particular, ZIF-67 is employed as a template, followed by the etching and carbonization treatments to afford the thorny nanobox of Co@C (TNBCC) with the hollow-nanostructure. In comparison to the solid (non-hollow) nanocube of Co@C (NCCC) from the direct carbonization of ZIF-67, TNBCC possesses not only the excellent textural features, but also superior electrochemical properties and highly reactive surfaces, making TNBCC exhibit the significantly higher catalytic activity than NCCC as well as Co₃O₄ in activating MPS to degrade BP-2. Mechanisms of BP-2 degradation are also elucidated and ascribed to both radical and non-radical routes. These advantageous features make TNBCC a useful catalyst of activating MPS in BP-2 degradation.

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.

In vitro investigation of immunomodulatory activities of selected UV-filters

Organic UV filters are ubiquitous as they are used in numerous personal care products. Consequently, people constantly come into direct or indirect contact with these chemicals. Albeit studies of the effects of UV filters on human health have been undertaken, their toxicological profiles are not complete. In this work, we investigated the immunomodulatory properties of eight UV filters representing different chemotypes, including benzophenone-1, benzophenone-3, ethylhexyl methoxycinnamate, octyldimethyl-para-aminobenzoic acid, octyl salate, butylmethoxydibenzoylmethane, 3-benzylidenecamphor, and 2,4-di-tert-butyl-6-(5-chlorobenzotriazol-2-yl)phenol. We demonstrated that none of these UV filters were cytotoxic to THP-1 cells at concentrations up to 50 μM. Importantly, our study highlighted the capacity of nontoxic concentrations of avobenzone and 3-benzylidene camphor to increase the secretion of interleukin 8 (IL-8) from both THP-1 cells and THP-1 derived macrophages. Further, they also exhibited a pronounced decrease of IL-6 and IL-10 release from lipopolysaccharide-stimulated peripheral blood mononuclear cells. The observed immune cell alterations suggest that exposure to 3-BC and BMDM could be involved in immune deregulation. Our research thus provided additional insight into UV filter safety profile.

Environmental impacts of the ultraviolet filter oxybenzone

Organic UV filters are emerging contaminants with increasing evidence of their negative impact on environmental health and water quality. One of the most common and environmentally relevant organic UV filters is oxybenzone (OBZ). While much of the initial focus has been on investigating the interaction of OBZ with coral reefs, there have been several recent studies that indicate that organic UV filters are affecting other environmental endpoints, including marine animals, algae, and plants. OBZ has been found to bioaccumulate in marine animals such as fish and mussels and then potentially acting as an endocrine disruptor. In plants, exposure to OBZ has been associated with decreased photosynthesis, inhibited seed germination, and impaired plant growth. In this review, we summarize the current state of knowledge regarding the environmental impacts of OBZ and suggest potential future directions.

Analysis of the contribution of locally derived wastewater to the occurrence of Pharmaceuticals and Personal Care Products in Antarctic coastal waters

Pharmaceuticals and Personal Care Products (PPCPs) are emerging pollutants detected in many locations of the world including Antarctica. The main objective of this review is to discuss the influence of the human population on the concentration, distribution and biological effects of PPCPs across the Antarctic coastal marine ecosystem. We carried out a review of the scientific articles published for PPCPs in Antarctic, supported by the information of the Antarctic stations reported by Council of Managers of National Antarctic Programs (CONMAP), Scientific Committee on Antarctic Research (SCAR) and Secretariat of the Antarctic Treaty (ATS). In addition, spatial data regarding the Antarctic continent was obtained from Quantarctica. Antarctic concentrations of PPCPs were more reflective of the treatment system used by research stations as opposed to the infrastructure built or the annual occupancy by station. The main problem is that most of the research stations lack tertiary treatment, resulting in elevated concentrations of PPCPs in effluents. Furthermore, the geographic distribution of Antarctic field stations in coastal areas allows for the release of PPCPs, directly into the sea, a practice that remains in compliance with the current Protocol. After their release, PPCPs can become incorporated into sea ice, which can then act as a chemical reservoir. In addition, there is no clarity on the effects on the local biota. Finally, we recommend regulating the entry and use of PPCPs in Antarctica given the difficulties of operating, and in some cases the complete absence of appropriate treatment systems. Further studies are needed on the fate, transport and biological effects of PPCPs on the Antarctic biota. It is recommended that research efforts be carried out in areas inhabited by humans to generate mitigation measures relative to potential adverse impacts. Tourism should be also considered in further studies due the temporal release of PPCPs.

Transport of emerging organic ultraviolet (UV) filters in ceramic membranes: Role of polyethylene (PE) microplastics

Microplastics can be considered potential carriers of emerging organic ultraviolet (UV) filters due to their considerable adsorption capacity in wastewater treatment. The adsorption behavior of organic UV filters, which are commonly contained in personal care products to preserve the skin against UV radiation, onto polyethylene (PE) microplastics were systematically studied to investigate their combined effects. Kinetics and isotherm analyses revealed that the adsorption of four organic UV filters onto PE microplastic surfaces followed a multi-rate and a heterogeneous multi-layer pattern. Several factors including salinity, microplastic size, and dosage also influenced the adsorption efficiency due to hydrophobic interactions. A bench-scale cross-flow ceramic membrane filtration experiment was investigated to evaluate the role of PE microplastics on the retention performance of organic UV filters. The retentions for organic UV filters were 34.2%-37.8% in the non-existence of PE microplastics. Conversely, organic UV filter retentions were significantly increased up to 82.2%-97.9% when they were adsorbed onto the PE microplastics, which were almost completely retained by the ceramic membrane. Therefore, organic UV filters can likely migrate and eventually be carried by PE microplastics, thus increasing the retention of both emerging organic UV filters and microplastics prior to discharge from wastewater treatment facilities.

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.

Environmental contamination status with common ingredients of household and personal care products exhibiting endocrine-disrupting potential

The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, benzophenones and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review was therefore to examine the sources and occurrence of these noteworthy contaminants (i.e. parabens, bisphenols, benzophenones, alkylphenol ethoxylates), to summarise the available research on their environmental presence and to highlight their bioaccumulation potential. The most notable environmental contaminants appear to be MeP and PrP among parabens, BPA and BPS among bisphenols, BP-3 among benzophenones and NP among alkylphenols. Their maximum detected concentrations in the environment are mostly in the range of ng/L, while in human tissues, their maximum concentrations achieved μg/L due to bioaccumulation, with BP-3 and nonylphenol showing the highest potential to bioaccumulate. Finally, of another great concern is the fact that even the unapproved parabens and benzophenones have been detected in the environment.

Environmental photochemistry of organic UV filter butyl methoxydibenzoylmethane: Implications for photochemical fate in surface waters

With the widespread use of sunscreen and other personal care products, organic ultraviolet filters (OUVFs) have become widely detected in the aquatic environment. Direct and indirect photolysis are important transformation pathways of OUVFs in aquatic environments, so their transformation products (TPs) are also chemicals of concern. Butyl methoxydibenzoylmethane (BMDBM) is one of the most commonly used OUVFs worldwide due to its ability to absorb ultraviolet light across a wide range of wavelengths, and it is ubiquitously detected in aquatic environments. In this study, we investigated the photodegradation of BMDBM through direct photolysis and hydroxyl radical (•OH) photooxidation. TPs were identified using ultrahigh performance liquid chromatography-high resolution mass spectrometry, and reaction mechanisms were proposed. Our results showed that the photodegradation rates for both enol and keto tautomer forms of BMDBM during direct photolysis and •OH photooxidation were similar. The formation of TPs resulted from α-cleavage and decarbonylation reactions involving the keto form of BMDBM. Comparisons of the kinetic data and TPs revealed that the direct photolysis mechanism was a significant sink for BMDBM even during •OH photooxidation. Evaluations of environmental properties based on the predicted physicochemical properties of BMDBM and TPs suggests that some of the TPs will have higher mobility than BMDBM. The quantitative structure-activity relationship (QSAR) approach was used to evaluate the ecotoxicity of BMDBM and the identified TPs. Most TPs were found to be less ecotoxic than BMDBM; however, TPs that had a diphenyl ring structure could be more ecotoxic than BMDBM. Overall, this study provides new insights into the photochemical behavior and ecotoxicity of BMDBM and its TPs, which are important for assessing the fate, persistence, accumulation, and adverse impacts of these compounds in aquatic environments.

UV-filters in marine environments: a review of research trends, meta-analysis, and ecotoxicological impacts of 4-methylbenzylidene-camphor and benzophenone-3 on marine invertebrate communities

The potential adverse effects of UV-filter pollution in marine environments have been the focus of research in recent years. This systematic review aims to determine the extent of this emerging problem, both quantitatively and qualitatively, combining temporal and science mapping analyses to explore the development of the field of UV-filters in the marine environment (from 1990 to 2021), and to outline new research frontiers. The temporal trend analysis revealed an exponential growth of published studies over the last decade (70% since 2016), confirming the emerging role of this topic in environmental science. The meta-analysis determined that 4-methylbenzylidene-camphor (4-MBC) and benzophenone-3 (BP-3) are top-priority environmental pollutants due to their increasing usage and, in turn, a frequent occurrence in marine ecosystems. This meta-analysis determined the focus on these two contaminants for this review. A critical discussion of the applications, regulatory aspects, and environmental occurrences of these selected compounds was provided. The present study also focused on the most recent (2015-2021) field and laboratory studies investigating the ecotoxicological impacts of 4-MBC and BP-3 on marine invertebrates. This review highlights the need for more research efforts to fill the knowledge gaps on the realistic effects these compounds may have when considered individually, in combination, or as subsequent exposures. Overall, this review aims to establish guidelines for further studies to understand the effect of UV-filters on marine ecosystems and marine invertebrate communities.

UV-filter octyl methoxycinnamate causes reproductive toxicity associated with germline apoptosis and vitellogenin decrease in Caenorhabditis elegans

Octyl methoxycinnamate (OMC) is a common UV filter found in personal care products such as sunscreen and cosmetics. However, OMC's presence in wastewater has raised concerns that it could potentially pollute aquatic ecosystems because of its limited biodegradability and its estrogenic disrupting properties. In this study, we investigated the environmental toxicity of OMC and its potential biomarkers using the nematode Caenorhabditis elegans. Our results showed that body length, eggs in utero, and total brood size decreased with increasing dose (experimental concentrations = 0, 1, 5, 10, 100, 500 μM for body length and eggs in utero, and 0, 5, 10 μM for total brood size) in C. elegans after L1 larval stage (the first larval stage for 0 - 12 hours post-hatching) larval stage exposure to OMC. The minimum effective concentrations were 1, 5, and 10 μM, respectively. Modeling results demonstrated that the threshold concentration of OMC inducing 10% inhibited eggs in utero was 0.33 μM (95.11 μg/L). Furthermore, germline apoptosis was induced in 10 μM OMC-treated worms (experimental concentrations = 0, 5, 10 μM). Decreased mRNA levels of vitellogenin-related genes (vit-2 and vit-6) and increased mRNA levels of apoptosis-related genes (egl-1 and ced-3) were observed in 10 μM OMC-treated C. elegans (experimental concentrations = 0, 10 μM), suggesting that reproductive toxicity was associated with decreased vitellogenin levels and germline apoptosis. In summary, our study shows that OMC is reproductively toxic and leads to reduced egg formation and decreased brood size in C. elegans by reducing vitellogenin levels and promoting germline apoptosis.

Structure-related endocrine-disrupting potential of environmental transformation products of benzophenone-type UV filters: A review

Benzophenone-type UV filters (BPs) represent a very diverse group of chemicals that are used across a range of industrial sectors around the world. They are found within different environmental compartments (e.g. surface water, groundwater, wastewater, sediments and biota) at concentrations ranging from ng/L to mg/L. Some are known as endocrine disruptors and are currently within the scope of international regulations. A structural alert for high potential of endocrine disrupting activity was assigned to 11 BP derivatives. Due to the widespread use, distribution and disruptive effects of some BPs, knowledge of their elimination pathways is required. This review demonstrates that biodegradation and photolytic decomposition are the major elimination processes for BP-type UV filters in the environment. Under aerobic conditions, transformation pathways have only been reported for BP, BP-3 and BP-4, which are also the most common derivatives. Primary biodegradation mainly results in the formation of hydroxylated BPs, which exhibit a structure-related increase in endocrine activity when compared to their parent substances. By combining 76 literature-based transformation products (TPs) with in silico results relating to their receptor activity, it is demonstrated that 32 TPs may retain activity and that further knowledge of the degradation of BPs in the environment is needed.

Theoretical Study on the Atom-Substituted Quinazoline Derivatives with Faint Emission as Potential Sunscreens

Two novel compounds (HQS and HQSe) with excited-state intramolecular proton transfer (ESIPT) properties were designed based on the compound 2-(2-hydroxy-3-ethoxyphenyl)-3H-quinazolin-4-one (HQ). The parameters related to the ESIPT properties and electronic spectra of HQ and its derivatives were calculated using density functional theory and time-dependent density functional theory methods. The obtained geometric configurations, infrared vibrational spectra, and reduced density gradient scatter plots have shown that the intramolecular hydrogen bond O₁···H₁-N₁ has been weakened upon photoexcitation. Moreover, from the scanned potential energy curves, it can be found that the ESIPT processes of the three compounds have no energy barriers. It is noteworthy that HQS and HQSe can strongly absorb light in the UVA region (∼340 nm) and exhibit weak fluorescence emission in the visible light region, which comes from the keto configuration. The special optical properties of HQS and HQSe can promote their application as potential sunscreen agents.

Stability and Removal of Benzophenone-Type UV Filters from Water Matrices by Advanced Oxidation Processes

Benzophenone (BP) type UV filters are common environmental contaminants that are posing a growing health concern due to their increasing presence in water. Different studies have evidenced the presence of benzophenones (BP, BP-1, BP-2, BP-3, BP-4, BP-9, HPB) in several environmental matrices, indicating that conventional technologies of water treatment are not able to remove them. It has also been reported that these compounds could be associated with endocrine-disrupting activities, genotoxicity, and reproductive toxicity. This review focuses on the degradation kinetics and mechanisms of benzophenone-type UV filters and their degradation products (DPs) under UV and solar irradiation and in UV-based advanced oxidation processes (AOPs) such as UV/H₂O₂, UV/persulfate, and the Fenton process. The effects of various operating parameters, such as UV irradiation including initial concentrations of H₂O₂, persulfate, and Fe²⁺, on the degradation of tested benzophenones from aqueous matrices, and conditions that allow higher degradation rates to be achieved are presented. Application of nanoparticles such as TiO₂, PbO/TiO₂, and Sb₂O₃/TiO₂ for the photocatalytic degradation of benzophenone-type UV filters was included in this review.

Chromatographic methods for the determination of a broad spectrum of UV filters in swimming pool water

This paper describes an analytical approach based on solid-phase extraction (SPE) followed by analysis using liquid and gas chromatography coupled to mass spectrometry detectors for a determination of 18 organic UV filters from water samples. Extraction method parameters were optimized: 250 ml of water sample loaded on Chromabond C18 cartridges after adjustment to pH 4 and then eluted with acetonitrile. The mobile phase and the parameters of the mass spectrometer, as well as those of the ionization source, were tested to enhance detection sensitivity. During method validation, the extracted target compounds showed good recoveries (> 68%) with acceptable values in terms of repeatability (RSD_r) and reproducibility (RSD_R), where relative standard deviations values were lower than 20%. The validated method was applied to 10 water samples collected from different swimming pools located in Lebanon from which eight UV filters among the eighteen targets compounds were detected at concentrations ranged between 1 and 2526 µg L^-1. The most detected compounds were padimate-O (OD-PABA) and octocrylene (OCR). This study represents the first available data on the occurrence of UV filter residues in Lebanese swimming pool opening hence future perspectives and insights to evaluate their degradation by-products and their toxicity on human health and marine ecosystem.

Occurrence and distribution of organic ultraviolet absorbents in sediments from small urban rivers, Tianjin, China: Implications for risk management

Organic ultraviolet absorbents (OUVAs) in the environment have been of increasing concern because of their potential hazards. However, the OUVAs in waters is far from being well studied and little is known about their occurrence in small urban rivers. This study investigated the concentrations and distribution of eleven OUVAs in the sediments from five small urban rivers of Tianjin, China, and found total concentrations in the range of 11.6-189 ng/g dry weight. Relative to other rivers and lakes, no high concentrations of sediment OUVAs were observed in the small rivers. Benzophenone, homosalate and octocrylene were the dominant OUVAs, representing medians of 13.3%, 12.4% and 12.3% of the total concentrations, respectively. Our observed composition profiles of these chemicals were different from those found in most of other waters. The sediment OUVAs may originate more from industrial activities than the use of cosmetics and personal care products in this area. The risk to aquatic organisms from exposure to the sediment OUVAs in these small urban rivers was considered low, except for benzophenone. However, more researches are needed to investigate the pollution and associated risks of these chemicals in urban rivers due to the complexity of their toxicity to aquatic organisms.

Developing highly transparent yet ultraviolet blocking fully biocomposite films based on chitin and lignin using ethanol/water as processing solvents

Developing fully biobased products with functionality in a green fashion is highly desirable to meet the increasing demand for environmental sustainability and mitigate "white pollution" by petroleum-based counterparts. Here, chitin from shrimp shells was propionylated to obtain chitin propionate (CP) with significantly improved solubility in organic solvents, organosolv lignin (OSL) was extracted from the forest harvest residuals. The fully biobased composite consisting of CP as a matrix and OSL as a UV-blocker were successfully prepared using acidic ethanol/water as a green processing solvent. The results indicated that the 5% OSL addition enabled the CP film to block approximately 98% UV light while allowing 71% visible light transmittance; tensile and thermal properties were also retained. Nearly 100% UV light was blocked with 20% OSL addition, but visible light transmittance was moderately sacrificed. This study provides an alternative solution to produce novel fully biobased films with high transparency yet excellent UV protection for potential packaging applications.

Comparison of extraction and clean-up methods for comprehensive screening of organic micropollutants in fish using gas chromatography coupled to high-resolution mass spectrometry

Monitoring the vast number of micropollutants in the environment by using comprehensive chemical screening is a major analytical challenge. The aim of this study was to evaluate a comprehensive analysis method for screening purposes of fish muscle samples by comparing sample preparation methods for a broad range of mid-to non-polar contaminants. Five extraction and three clean-up methods were evaluated for the analysis of 60 compounds with a log Kow range between 0.8 and 8.3 in fish. Both fresh and freeze-dried muscle tissue and extraction sodium sulphate blanks were included to assess recoveries and matrix effects. The performance of the different methods was evaluated using both comprehensive target and nontarget analysis using high resolution mass spectrometry (HRMS). The results showed that open-column and ultrasonication extractions (recoveries mostly between 20 and 160 %) resulted in higher recoveries than accelerated solvent extraction (ASE) (recoveries mostly between 20 and 80 %) and bead mixer homogenization extractions (recoveries between 0 and 50 % for the whole Kow range). Multilayer silica was the clean-up method resulting in the lowest matrix effects and highest recoveries, however some compounds (mostly pesticides) were denatured under the acidic conditions used. The convenient and time efficient ultrasonication extraction followed by deactivated silica clean-up proved to be promising for both target and nontarget approaches. The large difference in recoveries and number of detected peaks using target and nontarget approaches between fresh and freeze-dried fish seen for all methods calls for careful consideration, and further studies are needed to improve performance for screening of mid-to non-polar compounds in freeze-dried fish.

Ecotoxicological screening of UV-filters using a battery of marine bioassays

The present study aimed to assess the toxicity of seven UV-filters: zinc oxide nanoparticles (nZnO, particle size <100 nm), titanium dioxide nanoparticles (nTiO₂, primary particle size 21 nm), 2-ethylhexyl-4-methoxycinnamate (EHMC), 4-methylbenzylidene camphor (4-MBC), avobenzone (AVO), octocrylene (OCTO) and benzophenone-3 (BP-3) on three species: Aliivibrio fischeri (inhibition of bioluminescence), Phaeodactylum tricornutum (growth inhibition) and Ficopomatus enigmaticus (larval development success). Results showed nTiO₂ to be the most toxic for P. tricornutum (EC₅₀ 0.043 mg L^-1), while no effect was observed in A. fischeri and F. enigmaticus. EHMC was the most toxic to A. fischeri (EC₅₀ 0.868 mg L^-1 (15 min) and 1.06 mg L^-1 (30 min)) and the second most toxic to P. tricornutum. For F. enigmaticus, the lowest percentages of correct development resulted from 4-MBC exposure, with EC₅₀ of 0.836 mg L^-1. Overall, AVO induced low toxicity to every assessed species and OCTO was the least toxic for F. enigmaticus larvae. Considering the results obtained for F. enigmaticus, further larval development assays were performed with nZnO and EHMC under different light (light vs darkness) and temperature (20 and 25 °C) conditions, showing higher percentages of correct development at 25 °C, independently on light/darkness conditions. Under different temperature and photoperiod conditions, nZnO was more toxic than EHMC. Overall, nZnO and EHMC were among the most toxic UV filters tested and, when testing the effects of these UV-filters with temperature the results highlight that the impacts are liable to be lessened at higher temperatures (25 °C compared with 20 °C), in the case of this estuarine polychaete species. Nevertheless, further experiments are necessary to describe the effects of these two UV-filters at different organization levels, to study the toxicity of eventual degradation by-products and to provide more information on the combination of different stressors.

Investigating the exposure and impact of chemical UV filters on coral reef ecosystems: Review and research gap prioritization

Coral reefs are among the world's most productive and biologically diverse ecosystems. In recent decades, they have experienced an unparalleled decline resulting from various anthropogenically induced stressors. Ultraviolet (UV) filters found in personal care products, such as sunscreen, are chemical pollutants that are emerging as a growing toxic threat to reef organisms. In this study, a systematic literature review was conducted to (1) determine the current understanding of spatial distribution and the occurrence of UV filters exposed to the marine environment, (2) synthesize current ecotoxicological thresholds of relevant reef organisms under various UV-filter exposures, (3) identify research gaps related to both exposure and toxicity of UV filters in coral reef ecosystems. With gaps identified, a survey was developed and distributed to experts in the field representing academic, governmental, not-for-profit, and industry researchers in order to prioritize research gaps and inform future research efforts. The survey identified the need for better understanding of the impacts of co-stressors, long-term exposure, mixture, and degradation product exposure and realistic environmental conditions. Ultimately, this review will help guide priority research efforts to understand the risks of UV-filter exposure to coral reef ecosystems. Integr Environ Assess Manag 2021;17:967-981. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Sunscreens’ UV Filters Risk for Coastal Marine Environment Biodiversity: A Review

Considering the rapid growth of tourism in recent years and the acknowledgement that exposure to solar UV radiation may cause skin cancer, sunscreens have been widely used by beachgoers in recent decades. UV filters contained in sunscreens, however, were recently identified as emerging pollutants in coastal waters since they accumulate in the marine environment with different adverse effects. In fact, exposure to these components was proven to be toxic to most invertebrate and vertebrate marine species. Some UV filters are linked to the production of significant amounts of reactive oxygen species (ROS), such as hydrogen peroxide, and the release of inorganic micronutrients that may alter the status of coastal habitats. Bioaccumulation and biomagnification have not yet been fully addressed. This review highlights recent progress in research and provides a comprehensive overview of the toxicological and ecotoxicological effects of the most used UV filters both on the abiotic and biotic compartments in different types of coastal areas, to gain a better understanding of the impacts on coastal biodiversity.

Chronic feeding exposure to virgin and spiked microplastics disrupts essential biological functions in teleost fish

Toxicity of polyethylene (PE) and polyvinyl chloride (PVC) microplastics (MPs), either virgin or spiked with chemicals, was evaluated in two short-lived fish using a freshwater species, zebrafish, and a marine species, marine medaka. Exposures were performed through diet using environmentally relevant concentrations of MPs over 4 months. No modification of classical biomarkers, lipid peroxidation, genotoxicity or F0 behaviour was observed. A significant decrease in growth was reported after at least two months of exposure. This decrease was similar between species, independent from the type of MPs polymer and the presence or not of spiked chemicals, but was much stronger in females. The reproduction was evaluated and it revealed a significant decrease in the reproductive output for both species and in far more serious numbers in medaka. PVC appeared more reprotoxic than PE as were MPs spiked with PFOS and benzophenone-3 compared to MPs spiked with benzo[a]pyrene. Further, PVC-benzophenone-3 produced behavioural disruption in offspring larvae. These results obtained with two species representing different aquatic environments suggest that microplastics exert toxic effects, slightly different according to polymers and the presence or not of sorbed chemicals, which may lead in all cases to serious ecological disruptions.

Trends in environmental and toxicity research on organic ultraviolet filters: A scientometric review

In recent decades, the potential toxicological and environmental effects of organic ultraviolet filters (OUVF) have received growing attention. The number of studies in this area has increased; however, presently there is no scientometric perspective addressing this topic. The purpose of this study is to identify the intellectual base and research front using the visualization and analysis software, CiteSpace. We retrieved 453 articles, published in print or online as an early-access article between 2002 and 2020, from the Web of Science with a topic search related to OUVFs, environment, and toxicology. We then analysed synthesized networks of co-authorship (author, institution, country), co-citation (author, document, journal) and co-occurring keywords. The annual publication output has trended upwards since 2002. Authors based in China accounted for 29.4% of the total publications, followed by USA (17.4%); but overall publications from Switzerland and Spain were more influential. Major research themes identified included OUVF concentrations in aquatic environments, and hormonal effects. Emerging themes included improving the sensitivity of analytical detection methods for both OUVFs and their metabolites, consequences of OUVF transport to the marine environment, and concerns over prenatal exposure. Based on keyword analysis, benzophenone-3, 4-methylbenzylidene-camphor, 3-benzylidene camphor, and ethylhexyl-methoxycinnamate are the most studied OUVFs, and effects on estrogenic activity, gene expression, reproduction, and more recently, oxidative stress, have received most attention from a toxicological perspective. Other prominent topics were sources of environmental contamination and ecological risk assessments. This study maps the major research domains of OUVF environmental toxicology research; explanations and implications of the findings are discussed; and emerging trends highlighted.

Mechanistic aspects of carotenoid health benefits - where are we now?

Dietary intake and tissue levels of carotenoids have been associated with a reduced risk of several chronic diseases, including cardiovascular diseases, type 2 diabetes, obesity, brain-related diseases and some types of cancer. However, intervention trials with isolated carotenoid supplements have mostly failed to confirm the postulated health benefits. It has thereby been speculated that dosing, matrix and synergistic effects, as well as underlying health and the individual nutritional status plus genetic background do play a role. It appears that our knowledge on carotenoid-mediated health benefits may still be incomplete, as the underlying mechanisms of action are poorly understood in relation to human relevance. Antioxidant mechanisms - direct or via transcription factors such as NRF2 and NF-κB - and activation of nuclear hormone receptor pathways such as of RAR, RXR or also PPARs, via carotenoid metabolites, are the basic principles which we try to connect with carotenoid-transmitted health benefits as exemplified with described common diseases including obesity/diabetes and cancer. Depending on the targeted diseases, single or multiple mechanisms of actions may play a role. In this review and position paper, we try to highlight our present knowledge on carotenoid metabolism and mechanisms translatable into health benefits related to several chronic diseases.

Anthropogenic contaminants in freshwater from the northern Antarctic Peninsula region

This study aimed to evaluate the presence of ultraviolet filters (UV-Fs), benzotriazoles, pyrethroids and per- and polyfluoroalkyl substances (PFASs) in freshwater and wastewater from the northern Antarctic Peninsula region. All water samples analyzed contained UV-Fs residues and high concentrations were detected in anthropogenic impacted sites (< LOD up to 1300 ng/L). Likewise, benzotriazoles were detected in all water samples (< LOQ-920 ng/L). Regarding suspended particulate matter, almost all UV-Fs and all benzotriazoles were measured at concentrations ranging from < LOQ to 33 µg/g dry weight. Pyrethroids were also detected (< LOQ-250 ng/L) and their presence implies the existence of a gateway to the Antarctica Peninsula from other regions. The data confirmed the presence of PFASs (< LOD-7500 ng/L) in this area, in agreement with previous studies. In light of these results, extended monitoring in Antarctica should be carried out to perform a reliable environmental risk assessment leading to propose recommendations to minimize the anthropic impact.

Synergistic effect of microplastic fragments and benzophenone-3 additives on lethal and sublethal Daphnia magna toxicity

The interactive effect of polyethylene microplastic (MP) fragments and benzophenone-3 (BP-3) additives on Daphnia magna was assessed in the present study. The 48 h median effective concentration (EC₅₀) revealed that MP fragments (37.24 ± 11.76 μm; 3.90 mg L^-1) were over 80 times more acutely toxic than polyethylene microbeads (37.05 ± 3.96 μm; 323 mg L^-1), possibly because of their irregular shape and high specific surface area. Moreover, the addition of BP-3 (10.27 ± 0.40 % w/w) to MP fragments (MP + BP-3) resulted in greater acute toxicity to D. magna (EC₅₀ = 0.99 mg L^-1) compared to MP fragments (EC₅₀ = 3.90 mg L^-1) or BP-3 (EC₅₀ = 2.29 mg L^-1) alone. Additionally, MP + BP-3 exposure induced a synergistic increase in reactive oxygen species, total antioxidant capacity, and lipid peroxidation in D. magna. These synergistic effects can be attributed to enhanced bioconcentrations of BP-3 in D. magna caused by MP fragments. These findings suggest that MP fragments containing chemical additives represent a synergistic ecological risk and have the potential to harm aquatic organisms.

A Systematic Review on Occurrence and Ecotoxicity of Organic UV Filters in Aquatic Organisms

The growing production of cosmetic products such as organic UV filters (OUVFs) in recent years has raised concern regarding their safety to human and environmental health. The inability of wastewater treatment plants in removing these chemical entities and their high octanol-water partition coefficient values tend to result in the persistence of OUVFs in several environmental matrices, leading these to be categorized as "emerging environmental contaminants" because of their unknown risk. Besides aquatic ecosystem contamination, the application of sludge disposal equally threatens terrestrial biota. Besides, the available reviews focusing on levels of OUVFs in aqueous systems (freshwater and marine), instrumental analysis from various samples, and specific toxicity effects, compiled information on the ecotoxicity of OUVFs is currently lacking. Hence, the present manuscript systematically reviews the ecotoxicity of OUVFs in freshwater and marine organisms occupying lower to higher trophic levels, including the underlying mechanisms of action and current knowledge gaps. The available scientific evidence suggests that OUVFs are a prime candidate for environmental concern due to their potential toxic effects. To the best of our knowledge, this is the first document detailing the toxicological effects of OUVFs in aquatic organisms.

Degradation studies of UV filter hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]-benzoate (DHHB) in aqueous solution

High performance liquid chromatography coupled with ultra-violet, diode array detection (HPLC-UV-DAD), was used to study the degradation reactions of ultraviolet (UV) filter hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]-benzoate (DHHB). Degradation by-products were detected and identified by means of liquid chromatography coupled with diode array detection and mass spectrometry (LC-DAD-MS). Environmentally-relevant characteristics, such as water pH, chlorine levels, water temperature and dissolved organic matter (DOM) concentration, were modulated and studied in order to determine their influence on the degradation reactions. Results show that DHHB degrades quite rapidly in typical drinking water disinfection conditions, displaying a kinetic rate constant of k_obs = 0.0060 ± 0.0002 s^-1 and a half-life period of merely t_1/2 = 116 ± 4 s. As far as the non-volatile disinfection by-products (DBPs) are concerned, only the mono and dichlorinated forms of DHHB were detected in the degradation reactions. Regarding influential variables on DHHB degradation, the presence or absence of DOM in solution did not alter the trends that were found (degradation of DHHB is more significant at lower pH values and higher levels of active chlorine in solution). Chlorinated DBPs have also been found to predominate under higher pH values and lower levels of chlorine, whereas they were found to be unstable and further degradable, quite likely into smaller and more volatile compounds, when in lower pH and higher chlorine concentrations. As for the photo-degradation studies, DHHB was found to be extremely photo-stable, with only about 15% degradation rate detected during artificial irradiation periods of 6 h.

Occurrence and Gas-Particle Partitioning of Organic UV-Filters in Urban Air

A retrospective analysis of a comprehensive series of high-volume air samples (n = 70) collected during 2010-2011 in Toronto (Canada) was performed. Seven UV compounds were analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS) with sum of concentrations (gas + particle phase) ranging from 80 to 2030 pg/m³. Homosalate (HMS) was the most prevalent organic UV-filter in air (47% of the total concentration), followed by 2-ethylhexyl salicylate (EHS, ∼29%), E- and Z-2-ethylhexyl 4-methoxycinnamate (EHMC, ∼17%). Ambient air (gas + particle phase) concentrations of organic UV-filters showed a strong seasonality, with peak levels during the summer. An analysis of Clausius-Clapeyron slopes indicated that much of the ambient burden of organic UV-filters are explained by volatilization from terrestrial and aquatic surfaces and supplemented with human activities and use of lotions and sunscreens, containing organic UV-filters, in addition to its use in plastics, textiles, paints, and pesticides. The results showed that organic UV-filters exist mainly in the gas phase with some exceptions, for instance, octocrylene (OCR), which was associated with both gas and particle phases, and avobenzone (AVB), which was predominantly in the particle phase. Lastly, this study revealed the need for basic physical chemical property data for organic UV-filters, including information on transformation rates and products, for better evaluating their environmental fate and effects.

Estimation of Dietary Exposure to Contaminants Transferred from the Packaging in Fatty Dry Foods Based on Cereals

Food packaging has received special attention from the food safety standpoint since it could be a potential source of contamination through the migration of chemical substances from the packaging material into food. The assessment of the exposure through the diet to these contaminants from food packaging is necessary. In this work, an estimation of dietary exposure of the young Spanish population (1–17 years) to target chemicals from packaging for fatty dried foods based on cereals was assessed. For this purpose, a gas chromatography coupled to mass spectrometry (GC–MS) method was developed for screening of volatile and semivolatile compounds, potential migrants from the packaging. Then, this technique was used to quantify 8 target analytes, which were previously identified in the packaging (including phthalates, acetyl tributyl citrate (ATBC), butylated hydroxytoluene (BHT) and octocrylene), in composite food samples of fatty cereals prepared according to the consumption data for different age groups. Among the phthalates, exposure to diethyl phthalate (DEP) was the highest for the three groups considered (0.0761–0.545 µg/kg body weight/day), followed by bis(2-ethylhxyl)phathalate (DEHP), while the lowest mean intake was found for di-n-octyl phathalate (DNOP; 0.00463–0.0209 µg/kg body weight/day). The estimated dietary exposures did not exceed for any of the analytes the corresponding established tolerable daily intakes.

Comparative toxicity of UV-filter Octyl methoxycinnamate and its photoproducts on zebrafish development

In the present study, we explored the adverse effects of Octyl methoxycinnamate (OMC), and its photoproducts, namely 2-ethylhexanol (2-EH) and 4-methoxybenzaldehyde (4-MBA) on the developmental stages of zebrafish using various biomarkers such as developmental toxicity, oxidative stress, antioxidant response, neurotoxicity and histopathological changes. The 96 h effective concentrations (EC₅₀) of OMC, 2-EH and 4-MBA were found to be 64.0, 34.0 and 3.5 µg/mL, respectively in the embryo toxicity test. Embryos exposed to the EC₅₀ of OMC, 2-EH and 4-MBA showed time-dependent increases in the malformation, heart rate and hatching delay. The lipid peroxidation (LPO) level was significantly (p < 0.05) increased and both induction and inhibition of SOD, CAT, GPx and GST activities were observed in the zebrafish embryos exposed to OMC, 2-EH and 4-MBA. GSH activity was significantly (p < 0.05) decreased in the highest exposure groups, when compared with the control. AChE activity was increased in lower concentrations of OMC, 2-EH and 4-MBA exposed embryos whereas, the activity was found to be decreased in highest concentration. Moreover, the histopathological studies showed severe damage to the muscle fibers and yolk sac regions of the larvae with 4-MBA treatment. The photoproduct 4-MBA has the highest toxic effect, followed by 2-EH and OMC. Our results provide useful insights into the impacts of OMC and its photoproducts on zebrafish development.

Formation of haloacetic acids from different organic precursors in swimming pool water during chlorination

Haloacetic acids (HAAs) were reported to be the most abundant category of DBPs in swimming pool water. In this study, the formation of HAAs from different organic precursors in swimming pool water, including UV filters, human body fluids, and natural organic matter (NOM), during chlorination was examined, and the effects of chlorine dose and halide concentrations on the formation of HAAs were evaluated. The results show that the total HAA yields from benzophenone-3 (BP-3) and Suwannee River humic acid (SRHA) were the highest among the nine organic precursors, and the yields of dichloroacetic acid and bromochloroacetic acid were higher than that of the other HAA species. In all the chlorinated samples of different organic precursors, longer chlorination time enhanced HAA formation. Both chlorine dose and bromide concentration significantly affected the formation of HAAs from BP-3 and SRHA during chlorination. With the increasing chlorine dose, the total HAA yields from SRHA and BP-3 significantly increased. Besides, the proportion of trihaloacetic acids (THAAs) rose while that of dihaloacetic acids (DHAAs) and monohaloacetic acids (MHAAs) declined with the increasing chlorine dose. With the increasing bromide concentration, HAA formation from SRHA increased while that of BP-3 decreased. The bromine incorporation factor (BIF) of the formed MHAAs, DHAAs and THAAs from SRHA and BP-3 both increased with the increasing bromide concentration in the following order: BIF_DHAAs > BIF_THAAs > BIF_MHAAs, indicating that bromine was easier to be incorporated into DHAAs rather than MHAAs or THAAs. Moreover, bromide promoted the formation of Br-HAAs.

Effects of the organic UV-filter, 3-(4-methylbenzylidene) camphor, on benthic invertebrates and ecosystem function in artificial streams

In the last decades, the use of organic ultraviolet-filters (UV-filters) has increased worldwide, and these compounds are now considered emerging contaminants of many freshwater ecosystems. The present study aimed to assess the effects of 3-(4-methylbenzylidene) camphor (4-MBC) on a freshwater invertebrate community and on associated ecological functions. For that, artificial streams were used, and a natural invertebrate benthic community was exposed to sediments contaminated with two concentrations of 4-MBC. Effects were evaluated regarding macroinvertebrate abundance and community structure, as well as leaf decomposition and primary production. Results showed that the macroinvertebrate community parameters and leaf decomposition rates were not affected by 4-MBC exposure. On the other hand, primary production was strongly reduced. This study highlights the importance of higher tier ecotoxicity experiments for the assessment of the effects of low concentrations of organic UV-filters on freshwater invertebrate community structure and ecosystem functioning.

Biocompatible Organosilica Nanoparticles with Self-Encapsulated Phenyl Motifs for Effective UV Protection

With increasing ozone depletion, ultraviolet (UV) exposure from sunlight has become a significant health risk. Although commercially available sun protectants provide reasonable protection, they have limitations in terms of safety and aesthetics. Here, we have developed biocompatible and biodegradable sunscreens by facile synthesis of organosilica nanoparticles (o-SNPs) with self-encapsulated phenyl motifs using phenylsilane precursors. The physical structure of o-SNPs is elaborately controlled such that they are large enough to reflect UVA but small enough to be imperceptible when applied on the skin. The chemically attached phenyl motifs to o-SNPs facilitate filtering UVB via their delocalized π-orbitals. The o-SNPs generate a negligible amount of reactive oxygen species under UV exposure. Ex vivo two-photon microscopy reveals that the o-SNPs tend to adhere to the outer layers of skin without further intradermal penetration, resulting in less skin irritation. In vivo UV protection tests confirmed the excellent sunscreen effect of o-SNPs compared with conventional organic and inorganic UV filters.

Evaluation of the Oxidative Stress Status in Zebrafish (Danio rerio) Liver Induced by Three Typical Organic UV Filters (BP-4, PABA and PBSA)

Organic UV filters are a kind of emerging pollutants, which have been widely used in personal care products (PCPs). This study evaluated the effects of benzophenone-4 (BP-4), 4-aminobenzoic acid (PABA), and 2-phenylbenzimidazole-5-sulfonic acid (PBSA) on the selected indices of antioxidative responses in zebrafish (Danio rerio) liver. Zebrafish were exposed to two different doses (i.e., 0.5 and 5 mg L^-1) of semi-static water with three individual compounds. Liver samples were collected on 7 and 14 days to analyze biochemical indicators, including superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH), and malondialdehyde (MDA). Oxidative stress occurred in zebrafish liver with significantly changed indicators during the whole exposure period. Different experimental groups could induce or inhibit the activity of antioxidant enzymes with varying degrees. With a prolonged exposure time and increased exposure dose, the hepatic lipid peroxidation was also obviously observed. Moreover, the toxicity order of three organic UV filters was analyzed using the integrated biomarker response (IBR) index and the results indicate that exposure to PABA for 7 days at 0.5 mg L^-1 and PBSA for 7 days at 5 mg L^-1 induced the most severe oxidative stress in the liver of zebrafish.

Predicted no-effect concentrations determination and ecological risk assessment for benzophenone-type UV filters in aquatic environment

Benzophenones (BPs), a group of widely used ultraviolet filters, have been frequently detected out in multiple environment matrices even in organism bodies. Although a variety of toxicological effects of BPs have been disclosed recently, it is barely to evaluate the potential ecological risk of BPs due to lack of reference criteria. Therefore, the determination of predicted no-effect concentration (PNEC) values is necessary for assessing ecological risk of BPs and for protecting safety of aquatic organisms. The toxicological data of 14 BPs from both in vivo tests on aquatic organisms and in vitro tests on strains/cell lines were collected from previous reports, and two methods including assessment factor (AF) and species sensitivity distribution (SSD) were applied to calculate PNECs, respectively. Four groups of PNECs were obtained and compared, a final PNEC value was recommended for each BP based on reliable and conservative consideration. With these PNECs values, the risk quotients of 8 BPs from 35 ambient freshwater samples were calculated, the results demonstrated that 3 BPs including 2,2',4,4'-tetrahydroxyl-BP, 2-hydroxyl-4-methoxyl- BP, and 2-hydroxyl-4-methoxyl-5-sulfonic acid-BP exhibited high ecological risk, and the ecological risk posed by BPs in River Tiff in UK was great. It is anticipated that these results would provide useful reference for assessing and managing BP-type compounds, and for selecting toxicity data and methods to derive PNECs for emerging contaminants.

Photolysis of mixtures of UV filters octocrylene and ethylhexyl methoxycinnamate leads to formation of mixed transformation products and different kinetics

The treatment with ultraviolet (UV) light is a well-known technique for water disinfection. Photodegradation by UV light is in discussion as measure for advanced water treatment that could provide a potential removal option for micropollutants. Micropollutants such as ingredients from personal care products are also present in grey water. Grey water gets increasingly attention as a source for water reuse. For that purpose it has to be treated. UV-treatment is an option. However, the knowledge on the fate of micropollutants within such a treatment is little. Therefore, we investigated the fate of the UV filters ethylhexyl methoxycinnamate (EHMC), and octocrylene (OCR) as for both UV filters the presence in grey water was reported. OCR as a single compound was investigated with regard to its degradation kinetics and possible photo-transformation products (photo-TPs). These results were compared with those of EHMC previously reported in literature. The mixture of the two UV filters was also investigated to reveal if mixture effects occur regarding the elimination of the UV filters and the formation of TPs. A medium pressure mercury vapor lamp (200-400 nm) was employed for photolysis. This study shows that OCR itself was eliminated below the limit of detection after 256 min and that photo-TPs were formed. The photolysis of the mixture demonstrated alterations of the degradation rates and patterns. Additional TPs were formed by the reaction of the UV filters or TPs with each other. The study shows that more attention should be paid to mixture-effects and mixture-TPs that may cause further follow-up effects.