Photostability and phytotoxicity of selected sunscreen agents and their degradation mixtures in water

Interplay of UV-filter pollution and temperature rise scenarios on Mytilus galloprovincialis health: Unveiling sperm quality and adult physiology, biochemistry, and histology insights

Addressing the impacts of emerging contaminants within the context of climate change is crucial for understanding ecosystem health decline. Among these, the organic UV-filters 4-methylbenzylidenecamphor (4-MBC) and benzophenone-3 (BP-3) are widely used in cosmetics and personal care products. Their unique physico-chemical properties, along with their growing commercialization and consumption, have made them ubiquitous in aquatic environments through both direct and indirect releases, raising significant concerns about their potential threats to inhabiting biota. Additionally, increasing surface water temperatures exacerbate ecological risks, making it imperative to understand the implications for non-target species at different biological levels. This study investigated the short- and long-term effects of UV-filters 4-MBC or BP-3, at ecologically relevant concentrations, combined with current and predicted warming scenarios, on the performance and male reproductive health of Mytilus galloprovincialis mussel populations. Using biomarkers across sub-cellular, cellular, tissue, and individual levels, the study revealed significant physiological and biochemical impairments in both sperm cells and adults exposed to UV-filters. Temperature emerged as the primary driver influencing mussel responses and modulating the impacts of 4-MBC/BP-3, emphasizing their sensitivity to temperatures outside the optimal range and interactive effects between stressors. Specifically, sperm motility declined with increasing UV-filter concentrations, while temperature alone influenced ROS production, leading to compromised mitochondrial activity and DNA damage in the presence of combined stressors, indicative of potential reproductive impairments. Adults exhibited high UV-filter bioconcentration potential in whole tissues, compromised physiological status, morphophysiological changes in digestive glands, oxidative stress, and alterations in metabolic capacity, antioxidant defences, and biotransformation mechanisms, correlating with UV-filter exposure and temperature increase. Among the UV-filters tested, 4-MBC was the most detrimental, especially when combined with warming. Overall, this study underscores the vulnerability of M. galloprovincialis to cumulative stressors and highlights the importance of employing a multi-biomarker approach to assess and mitigate the impacts of stressors on coastal ecosystems.

Effects of benzophenone-3 and its metabolites on the marine diatom Chaetoceros neogracilis: Underlying mechanisms and environmental implications

The wide application of benzophenones (BPs), such as benzophenone-3 (BP3), as an ingredient in sunscreens, cosmetics, coatings, and plastics, has led to their global contamination in aquatic environments. Using the marine diatom Chaetoceros neogracilis as a model, this study assessed the toxic effects and mechanisms of BP3 and its two major metabolites (BP8 and BP1). The results showed that BP3 exhibited higher toxicity on C. neogracilis than BP8 and BP1, with their 72-h median effective concentrations being 0.4, 0.8 and 4 mg/L, respectively. Photosynthesis efficiencies were significantly reduced after exposure to environmentally relevant concentrations of the three benzophenones, while cell viability, membrane integrity, membrane potential, and metabolic activities could be further impaired at their higher concentrations. Comparative transcriptomic analysis, followed by gene ontology and KEGG pathway enrichment analyses unraveled that all the three tested benzophenones disrupted photosynthesis and nitrogen metabolism of the diatom through alteration of similar pathways. The toxic effect of BP3 was also attributable to its unique inhibitory effects on eukaryotic ribosome biosynthesis and DNA replication. Taken together, our findings underscore that benzophenones may pose a significant threat to photosynthesis, oxygen production, primary productivity, carbon fixation, and the nitrogen cycle of diatom in coastal waters worldwide.

Biospectroscopic fingerprinting phytotoxicity towards environmental monitoring for food security and contaminated site remediation

Human activities have resulted in severe environmental pollution since the industrial revolution. Phytotoxicity-based environmental monitoring is well known due to its sedentary nature, abundance, and sensitivity to environmental changes, which are essential preconditions to avoiding potential environmental and ecological risks. However, conventional morphological and physiological methods for phytotoxicity assessment mainly focus on descriptive determination rather than mechanism analysis and face challenges of labour and time-consumption, lack of standardized protocol and difficulties in data interpretation. Molecular-based tests could reveal the toxicity mechanisms but fail in real-time and in-situ monitoring because of their endpoint manner and destructive operation in collecting cellular components. Herein, we systematically propose and lay out a biospectroscopic tool (e.g., infrared and Raman spectroscopy) coupled with multivariate data analysis as a relatively non-destructive and high-throughput approach to quantitatively measure phytotoxicity levels and qualitatively profile phytotoxicity mechanisms by classifying spectral fingerprints of biomolecules in plant tissues in response to environmental stresses. With established databases and multivariate analysis, this biospectroscopic fingerprinting approach allows ultrafast, in situ and on-site diagnosis of phytotoxicity. Overall, the proposed protocol and validation of biospectroscopic fingerprinting phytotoxicity can distinguish the representative biomarkers and interrogate the relevant mechanisms to quantify the stresses of interest, e.g., environmental pollutants. This state-of-the-art concept and design broaden the knowledge of phytotoxicity assessment, advance novel implementations of phytotoxicity assay, and offer vast potential for long-term field phytotoxicity monitoring trials in situ.

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.

Effects associated with exposure to the emerging contaminant octyl-methoxycinnamate (a UV-B filter) in the aquatic environment: a review

Given the increasing concern surrounding ultraviolet (UV) radiation-induced skin damage, there has been a rise in demand for UV filters. Currently, UV-filters are considered emerging contaminants. The extensive production and use of UV filters have led to their widespread release into the aquatic environment. Thus, there is growing concern that UV filters may bioaccumulate and exhibit persistent properties within the environment, raising several safety health concerns. Octyl-methoxycinnamate (OMC) is extensively employed as a UV-B filter in the cosmetic industry. While initially designed to mitigate the adverse photobiological effects attributed to UV radiation, the safety of OMC has been questioned with some studies reporting toxic effects on environment. The aim of this review to provide an overview of the scientific information regarding the most widely used organic UV-filter (OMC), and its effects on biodiversity and aquatic environment.

Estimation of the riverine input of organic ultraviolet filters (OUVFs) from the Pearl River Estuary to the South China Sea during the early Covid-19 pandemic

Organic ultraviolet filters (OUVFs) are functional ingredients used in cosmetics to protect skin from the harmful effects of ultraviolet (UV) radiation. This study presents recent findings on the distribution of OUVFs in the Pearl River Estuary (PRE), located in southern China. This investigation was conducted during the early stages of the Covid-19 pandemic when the stay-at-home policy was implemented. Analysis revealed the presence of OUVFs in both the surface and bottom water samples collected from eight major outlets of the Pearl River. The OUVFs were detected in both the dissolved phase and suspended particulate matter, with a total concentration ranging from 7.19 ± 6.54 to 20.5 ± 9.62 ng/L. Notably, OUVFs' concentrations in the study period were significantly lower compared to those reported before the pandemic. This implies that effective reduction of OUVF emissions can be achieved through usage reduction combined with the management of direct discharge and appropriate treatment by urban wastewater treatment facilities. During the study period, the annual release of OUVFs was approximately 12.6 kg/1000 people/year, with the greatest contribution from the Hu Men outlet. Consequently, it is imperative to consider the potential ecological risks associated with the release of OUVFs from the PRE into the marine environment, particularly with the potential for an accompanying rebound in risk upon the lifting of restrictions on outdoor activities in the post Covid-19 time.

Single and mixture toxicity evaluation of avobenzone and homosalate to male zebrafish and H295R cells

Avobenzone and homosalate are widely used in sunscreens to provide ultraviolet (UV) protection, either as single compounds or in combination. Some UV filters exhibit estrogenic or anti-androgenic activities, however, studies regarding their interactions and toxicity in mixtures are limited. In this study, the effect of the toxicity of a binary mixture comprising avobenzone (0.72 μg L-1) and homosalate (1.02 and 103 μg L-1) on steroid hormone biosynthesis were investigated using male zebrafish and human adrenocortical carcinoma (H295R) cells. In fish exposed to homosalate, a significant decrease in the gonadosomatic index, testosterone level, and transcription of several genes (e.g, hsd3b2, cyp17a1, and hsd17b1) and a significant increase in the hepatosomatic index, liver steatosis, 17β-estradiol level, and transcription of vtg gene were observed. These results suggest that estrogenic and anti-androgenic effects of homosalate were mediated by the steroidogenic pathway. The presence of 0.72 μg L-1 of avobenzone augmented the anti-androgenic responses in male fish. The testosterone level in the H295R cells were significantly decreased after they were exposed to homosalate alone or in combination with avobenzone, which is consistent with observations in male zebrafish. Further studies need to be conducted to understand the endocrine disrupting properties of long-term exposure to substances typically used in sunscreens.

Hazardous radical-coupled transformation products of benzophenone-3 formed during manganese dioxide treatment

Radical-coupled transformation products (TPs) have been identified as the byproducts of various transformation processes, including both natural attenuation and artificial treatments, of phenolic micropollutants. Benzophenone-3 (BP-3), an organic UV filter of emerging concern, has been previously reported with ubiquitous occurrence in the natural environment and water bodies. Current research has demonstrated how TPs are formed from BP-3 when it is treated with manganese oxide (MnO2). The ecological and toxicological risks of these TPs have also been assessed. Polymerization of BP-3 through radical coupling was observed as the major pathway by which BP-3 is transformed when treated with MnO2. These radical-coupled TPs haven't shown further degradation after formation, suggesting their potential persistence once occurred in the environment. In silico experiments predict the radical-coupled TPs will increase in mobility, persistence and ecotoxicity. If true, they also represent an ever-increasing threat to the environment, ecosystems and, most immediately, aquatic living organisms. In addition, radical-coupled TPs produced by MnO2 transformation of BP-3 have shown escalated estrogenic activity compared to the parent compound. This suggests that radical coupling amplifies the toxicological impacts of parent compound. These results provide strong evidence that radical-coupled TPs with larger molecular sizes are having potential adverse impacts on the ecosystem and biota.

Identification of Transformation Products of Organic UV Filters by Photooxidation and Their Differential Estrogenicity Assessment

Organic ultraviolet filters (OUVFs) are extensively released into aquatic environments, where they undergo complex phototransformation. However, there is little knowledge regarding their transformation products (TPs) and associated endocrine disruption potentials. In the present study, we characterized the chemical and toxicological profiles of TPs for two common OUVFs, oxybenzone (BP3) and ethylhexyl methoxycinnamate (EHMC), by photooxidation under environmentally relevant conditions. It is hypothesized that TPs of the tested OUVFs will show varied estrogenicity at different reaction times. High-resolution liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) identified 17 TPs of 7 m/z for BP-3 and 13 TPs of 8 m/z for EHMC at confidence levels ≤2. Five novel TPs of 2 m/z were reported for the first time with structure-diagnostic MS/MS spectra. Estrogenicity assessment using the MCF-7-luc cell line showed discrepant estrogenic activities exhibited by OUVF-TPs over time. Specifically, BP3-TPs exhibited significantly greater estrogenicity than the parent at several reaction times, whereas EHMC-TPs displayed fluctuating estrogenicity with a declining trend. Correlation analysis coupled with molecular docking simulations further suggested several TPs of BP3 as potential endocrine disruptive compounds. These findings underscore the necessity of considering mixtures during chemical testing and risk assessment and highlight the potentially greater risks associated with post-transformation cocktails.

Geospatial and co-occurrence analysis of antibiotics, hormones, and UV filters in the Chesapeake Bay (USA) to confirm inputs from wastewater treatment plants, septic systems, and animal feeding operations

Previous studies have reported select contaminants of emerging concern (CECs) in limited areas of the Chesapeake Bay (USA), but no comprehensive efforts have been conducted. In this work, 43 antibiotics, 9 hormones, 11 UV filters, and sucralose, were measured in matched water, sediment, and oyster samples from 58 sites. The highest sucralose concentration was 3051 ng L-1 in a subwatershed with 4.43 million liters of wastewater effluent per day (MLD) and 4385 septic systems. Although antibiotic occurrence was generally low in subwatersheds located in less populated areas, 102 ng L-1 ciprofloxacin was detected downstream of 0.58 MLD wastewater effluent and 10 animal feeding operations. Hormones were not regularly detected in water (2%) or oysters (37%), but the high detection frequencies in sediment (74%) were associated with septic systems. UV filters were ubiquitously detected in oysters, and octisalate exhibited the highest concentration (423 ng g-1). Oyster-phase oxybenzone and aqueous-phase sucralose concentrations were significantly correlated to wastewater effluent and septic systems, respectively. Toxicity outcomes were predicted for homosalate and octisalate throughout the Bay, and antimicrobial resistance concerns were noted for the Chester River. The geospatial and co-occurrence relationships constitute crucial advances to understanding CEC occurrence in the Chesapeake Bay and elsewhere.

A Highly Transparent Photo-Electro-Thermal Film with Broadband Selectivity for All-Day Anti-/De-Icing

A photo- and electro-thermal film can convert sunlight and electricity into heat to solve icing problems. Combination of them provides an efficient strategy for all-day anti-/de-icing. However, only opaque surfaces have been reported, due to the mutual exclusiveness between photon absorption and transmission. Herein, a highly transparent and scalable solution-processed photo-electro-thermal film is reported, which exhibits an ultra-broadband selective spectrum to separate the visible light from sunlight and a countertrend suppress of emission in longer wavelength. It absorbs ≈ 85% of invisible sunlight (ultraviolet and near-infrared) for light-heat conversion, meanwhile maintains luminous transmittance > 70%. The reflection of mid-infrared leads to low emissivity (0.41), which further preserves heat on the surface for anti-/de-icing purpose. This ultra-broadband selectivity enables temperature elevation > 40 °C under 1-sun illumination and the mutual support between photo-thermal and electro-thermal effects contributes to > 50% saving of electrical consumption under weak solar exposure (0.4-sun) for maintaining unfrozen surfaces at -35 °C environment. The reverberation from photo-electro-thermal and super-hydrophobic effects illustrates a lubricating removal of grown ice in short time (< 120 s). The self-cleaning ability and the durability under mechanical, electrical, optical, and thermal stresses render the film stable for long-term usage in all-day anti-/de-icing applications.

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.

Lymnaea stagnalis and Ophryotrocha diadema as Model Organisms for Studying Genotoxicological and Physiological Effects of Benzophenone-3

Benzophenone-3 (BP-3) is a lipophilic organic compound that occurs naturally in flower pigments. Since it adsorbs ultraviolet (UV) radiation in the UVA and UVB regions, it is one of the most common UV filters found in sunscreen and cosmetic products. We explored by in vivo micronuclei (MNi) assay the genotoxic effects of BP-3 on hemocytes from the freshwater gastropod Lymnaea stagnalis. We also studied its possible toxic effects on life-history traits: body growth in L. stagnalis and egg production of both L. stagnalis and the marine polychaete worm Ophryotrocha diadema. Adult individuals were exposed to increasing concentrations of BP-3 (0.025, 0.050, 0.100, and 0.200 mg/L) once a week for 4 weeks. In L. stagnalis, exposure to BP-3 at concentrations of both 0.2 and 0.1 mg/L produced genotoxic effects on the micronuclei frequencies, but only concentrations of 0.2 mg/L affected the NBUDs frequencies. Similarly, negative effects on body growth were observed at the concentrations of 0.2 and 0.1 mg/L and a significant reduction of egg production at 0.2 mg/L. In O. diadema, a negative correlation between egg production and increasing BP-3 concentrations was observed. Our findings suggest the need for more stringent measures to reduce the presence of BP-3 in the environment.

Trace analysis of benzophenone-type UV filters in water and their effects on human estrogen and androgen receptors

To carry out risk assessments of benzophenone-type UV filters (BPs), fast and accurate analytical methods are crucial to determine and monitor levels in the environment. This study presents an LC-MS/MS method that requires minimal sample preparation and yet can identify 10 different BPs in environmental samples such as surface or wastewater resulting in a LOQ range from 2 to 1060 ng/L. The method suitability was tested through environmental monitoring, which showed that, BP-4 is the most abundant derivative found in the surface waters of Germany, India, South Africa and Vietnam. BP-4 levels correlate with the WWTP effluent fraction of the respective river for selected samples in Germany. Peak values of 171 ng/L for 4-hydroxybenzophenone (4-OH-BP), as measured in Vietnamese surface water, already exceed the PNEC value of 80 ng/L, elevating 4-OH-BP to the status of a new pollutant that needs more frequent monitoring. Moreover, this study reveals that during biodegradation of benzophenone in river water, the transformation product 4-OH-BP is formed which contain structural alerts for estrogenic activity. By using yeast-based reporter gene assays, this study provides bio-equivalents of 9 BPs, 4-OH-BP, 2,3,4-tri-OH-BP, 4-cresol and benzoate and complements the existing structure-activities relationships of BPs and their degradation products.

Occurrence, bioaccumulation and ecological risk of organic ultraviolet absorbers in multiple coastal and offshore coral communities of the South China Sea

The occurrence of organic ultraviolet absorbers (OUVAs) in coral reef regions has aroused widespread concern. This study focused on the occurrence, distribution, bioaccumulation and ecological risk of ten OUVAs in both coastal and offshore coral reef regions in the South China Sea. While the Σ₁₀OUVAs was 85 % lower in the offshore seawater (15.1 ng/L) than in the coastal seawater (102.1 ng/L), the Σ₁₀OUVAs was 21 % lower in the offshore corals (1.82 μg/g dry weight (dw)) than in the coastal corals (2.31 μg/g dw). This difference was speculated to relate to the high intensity of human activities in the coastal regions. Moreover, the offshore corals showed higher bioaccumulative capability toward OUVAs (log bioaccumulation factors (BAFs): 1.22-5.07) than the coastal corals (log BAFs: 0.17-4.38), which was presumably the influence of varied physiological status under different environmental conditions. The results of the ecological risk assessment showed that BP-3 resulted in 73 % of coastal corals and 20 % of offshore corals at a risk of bleaching. Therefore, the usage and discharge of BP-3 should be managed and controlled by the countries adjacent to the South China Sea for the protection of coral reefs.

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.

Occurrence, effects, and ecological risks of chemicals in sanitizers and disinfectants: A review

In response to the novel coronavirus referred to as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – a virus that causes COVID-19 disease has led to wide use of sanitizers and disinfectants. This, in turn, triggered concerns on their potential deleterious effects to human health and the environment due to numerous chemicals incorporated in both product categories. Here, the current state of science regarding the occurrence and ecological effects of different classes of chemicals in these products (e.g., ultraviolent filters, fragrances, etc.) are summarized in different natural (e.g., rivers) and engineered (e.g., wastewater treatment plants) systems. Data collected in the literature suggests chemicals incorporated in sanitizers and disinfectants are present in the environment, and a large portion are toxic to fish, algae, and daphnia. Using the risk quotient approach based on occurrence data, we found eight chemicals that posed the highest risk to aquatic organisms in freshwater systems were benzalkonium chloride, 4-chloro-m-cresol, sodium ortho phenyl phenate, hydrogen peroxide, 1, 2-propanediol, 4-Methyl-benzilidine-camphor, ethylhexyl methoxy cinnamate, and octocrylene. Considering limited occurrence and effects information for most chemicals, further studies on environmental monitoring and potential consequences of long-term exposure in aquatic ecosystems are recommended.

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.

Occurrence and distribution of organic ultraviolet absorbents in soils and plants from a typical industrial area in South China

Organic ultraviolet absorbents (UVAs) have attracted increasing concern due to their ubiquity, bioaccumulation, and potential toxicity. However, available information on their occurrence and transfer in terrestrial environment is still extremely insufficient. In this study, we investigated twelve UVAs in the soils and five terrestrial plant species from a typical industrial area in South China, and found their total concentrations were 5.87-76.1 (median 13.1) and 17.9-269 (median 82.9) ng/g dry weight, respectively. Homosalate was dominant in soils while benzophenone and octrizole were predominant in plants, likely due to their complex sources and bioaccumulation preferences. The bioaccumulation factors (BAFs) were further evaluated based on the ratios of UVA concentrations in plants and soils. The observed BAFs of UVAs were compound and species-specific, and most of them were much >1.0, indicating the chemicals could be transferred from soils to plants. To the best of our knowledge, this is the first report of organic UVAs in field soil-plant systems, providing information that may improve our understanding of the bioaccumulability of these chemicals in terrestrial environment and the associated risks. More studies are needed to investigate the transfer and bioaccumulation of such chemicals in soils and terrestrial biota.

Acute toxicity characterization of organic UV-filters and chronic exposure revealing multigenerational effects in DAPHNIA MAGNA

Organic ultraviolet (UV) filters have often been detected in aquatic ecosystems in concentrations ranging from ng/L to μg/L. However, both their acute and chronic effects on aquatic organisms have been insufficiently explored. This study aimed to evaluate acute toxicity of some of the main UV filters used worldwide (2-ethylhexyl,4-methoxycinnamate/EHMC, avobenzone/AVO, benzophenone-3/BP-3, and octocrylene/OC), in three aquatic organisms (Artemia salina, Desmodesmus subspicatus, and Daphnia magna), and to further investigate multigenerational effects in D. magna. After acute toxicity was confirmed, daphnids were chronically exposed to environmentally relevant concentrations of UV filters for two consecutive generations (F0 and F1), and reproductive endpoints, as well as catalase (CAT) and glutathione-S-transferase (GST) activities, were assessed. EHMC showed the most toxic potential, with the lowest EC₅₀ values for the three organisms. On the other hand, reproductive delays and a decrease in the reproduction rate were observed in the F1 generation exposed to AVO (4.4 µg/L), BP-3 (0.17 µg/L), EHMC (0.2 µg/L), and MIX. An increase of the CAT activity in organisms exposed to BP-3 and EHMC suggested induction of the antioxidant system. Although no reproductive effect was observed in the first generation, toxic effects obtained in the F1 revealed the importance of multigenerational studies and the potential harm of UV filters to the life cycle of D. magna, even at environmentally relevant concentrations. This emphasizes the need for further studies considering these levels of exposure and more realistic experimental designs to better understand their potential risks. Environmentally relevant concentrations of Organic UV filters are not lethal to aquatic organisms, however may affect reproductive parameters in Daphnia magna though multigenerational exposures.

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 filters and their impact on marine life: state of the science, data gaps, and next steps

Sunscreens containing broad-spectrum ultraviolet (UV) filters play an essential role in protecting the skin against the damage induced by sun overexposure. However, the widespread use of sunscreens and other personal care products containing these filters has led to these compounds being widely detected in the environment and being identified as emerging pollutants in marine waters. Concerns raised by laboratory studies investigating the potential impact of UV filters on coral communities have already led to bans on the use of some sunscreens in a few tourist hotspots. Although UV filter pollution may be just one of the many environmental factors impacting coral health worldwide, the media attention surrounding these studies and the legislative changes may lead patients to question dermatologists about the environmental safety of some sunscreen products. This review provides an overview of current knowledge on the impact of UV filters on marine ecosystems, concentrating on recent studies examining the effects of commonly used filters on organisms at low trophic levels and of how alternative approaches, such as metabolomics, can be used to further assess UV filter ecotoxicity. Current gaps in our knowledge are also discussed, most notably the need to increase our understanding of the longer-term fate and behaviour of UV filters in the marine environment, develop more adapted standardized ecotoxicity tests for a wider range of marine species, and evaluate the impact of UV filters on the marine food web. We then discuss future perspectives for the development of new, more environmentally friendly, filters that may enable the use of the most toxic compounds to be reduced without compromising the effectiveness of sunscreen formulations. Finally, we consider how dermatologists play a key role in educating patients on the need for a balanced approach to sun exposure, sun protection, and conservation of the marine environment.

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.

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.

Mediterranean seagrass Posidonia oceanica accumulates sunscreen UV filters

Certain ultra-violet filter (UVF) components of solar creams have negative impacts on coral reefs and have been prohibited in international tourism destinations (i.e., Hawaii, Florida, and Palau) to protect coral reefs. In the Mediterranean coasts which are also hotspots of international tourism and where endemic seagrass Posidonia oceanica forms extensive meadows, the accumulation of UVF components have not been studied. We report for the first time, that the rhizomes of P. oceanica internally accumulated UVFs BP3, BP4, AVO, 4MBC and MeBZT and the paraben preservative MePB. The components BP4 and MePB occurred in higher concentrations reaching up to 129 ng g^-1 dw and 512 ng g^-1 dw, respectively. This work emphasizes the need for more experimental studies on the effects of UVFs on seagrasses and check if we should follow suit to prohibit certain UVFs to protect this species as what has been done in other regions to protect corals.

Review of the environmental fate and effects of two UV filter substances used in cosmetic products

Sunscreens containing UV filters, such as octocrylene (OCR) and butyl-methoxydibenzoylmethane (BMDBM), have been increasingly used to protect human skin against UV radiation. Both substances have been detected in monitoring studies in the freshwater and marine environment, and there has been concern about potential effects on aquatic organisms. In the present work, the environmental fate and occurrence, bioaccumulation and ecotoxicity including endocrine effects of OCR and BMDBM are reviewed focusing on the aquatic environment. The two UV filters have low water solubilities and a high sorption potential. The available data indicate that OCR is poorly biodegradable. BMDBM lacks anaerobic and inherent biodegradability. However, it was biodegraded to variable degrees in simulation studies. Measured concentrations in the freshwater and marine environment were found to vary considerably between sites, depending on the extent of recreational activities or wastewater discharges. While the bioconcentration factor of OCR in fish is below the threshold value for bioaccumulation according to EU REACH, the available data for BMDBM do not allow a definitive conclusion on its bioaccumulation potential. Analysis of the aquatic toxicity data showed that data quality was often limited, e.g. in the case of effect concentrations substantially exceeding maximum achievable dissolved concentrations. Up to their limit of water solubility, OCR and BMDBM showed no toxicity to microorganisms, algae, and corals, and no acute toxicity to daphnids and fish. In chronic daphnid tests, OCR was highly toxic, whereas BMDBM lacked toxicity. Reliable water-sediment toxicity tests are required to further evaluate possible effects on benthic invertebrates. The available data do not provide evidence for endocrine effects of the two UV filters on fish. In order to assess potential environmental risks caused by OCR and BMDBM, a validated exposure model for estimating direct emission of UV filters into the aquatic environment and data from systematic, longer-term monitoring studies are needed.

Environmental Fate and Toxicity of Sunscreen-Derived Inorganic Ultraviolet Filters in Aquatic Environments: A Review

An increasing number of inorganic ultraviolet filters (UVFs), such as nanosized zinc oxide (nZnO) and titanium dioxide (nTiO2), are formulated in sunscreens because of their broad UV spectrum sunlight protection and because they limit skin damage. However, sunscreen-derived inorganic UVFs are considered to be emerging contaminants; in particular, nZnO and nTiO2 UVFs have been shown to undergo absorption and bioaccumulation, release metal ions, and generate reactive oxygen species, which cause negative effects on aquatic organisms. We comprehensively reviewed the current study status of the environmental sources, occurrences, behaviors, and impacts of sunscreen-derived inorganic UVFs in aquatic environments. We find that the associated primary nanoparticle characteristics and coating materials significantly affect the environmental behavior and fate of inorganic UVFs. The consequential ecotoxicological risks and underlying mechanisms are discussed at the individual and trophic transfer levels. Due to their persistence and bioaccumulation, more attention and efforts should be redirected to investigating the sources, fate, and trophic transfer of inorganic UVFs in ecosystems.

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.

Solar Energy Storage: Competition between Delocalized Charge Transfer and Localized Excited States in the Norbornadiene to Quadricyclane Photoisomerization

We describe for the first time the full reaction coordinate regarding the photoisomerization of red-absorbing norbornadienes (NBDs) to quadricyclanes (QCs). Our studies go beyond steady-state investigations by using an arsenal of time-resolved techniques. Importantly, the red absorption of NBDs is made possible by a different charge-transfer character; adjusting its strength enables control over the photoreversibility of the rearrangement. In the case of strong charge-transfer character (a weakly electron-withdrawing ester and a strongly electron-donating dimethylaniline), photoirradiation with visible light into the delocalized charge-transfer absorption of NBD affords QC reversibly. In stark contrast, UV photoirradiation into the NBD localized excited state leads to a photoinduced degradation and cannot be back-isomerized to NBD under any circumstances. If the charge-transfer character is weak (a weakly electron-withdrawing ester and a weakly electron-donating phenyl), reversibility is seen independently of the photoirradiation light.

UV-filter pollution: current concerns and future prospects

UV-filters are widely used in cosmetics and personal care products to protect users' skin from redamage caused by ultraviolet (UV) radiation from the sun. Globally, an estimated 16,000 to 25,000 tonnes of products containing UV-filters were used in 2014 with modern consumption likely to be much higher. Beyond this use in cosmetics and personal care products, UV-filters are also widely used to provide UV-stability in industrial products such as paints and plastics. This review discusses the main routes by which UV-filters enter aquatic environments and summarises the conclusions of studies from the past 10 years that have investigated the effects of UV-filters on environmentally relevant species including corals, microalgae, fish, and marine mammals. Safety data regarding the potential impact of UV-filters on human health are also discussed. Finally, we explore the challenges surrounding UV-filter removal and research on more environmentally friendly alternatives to current UV-filters.

Enhanced sorption of the UV filter 4-methylbenzylidene camphor on aged PET microplastics from both experimental and theoretical perspectives

In this study, the morphology and sorption behavior of polyethylene terephthalate (PET) microplastics during the aging process are investigated. To clarify the sorption mechanism of aged PET microplastics, the common sunblock 4-methylbenzylidene camphor (4-MBC) was chosen as the target contaminant, and UV irradiation was used for the laboratory aging simulation. The results show that oxygen-containing functional groups (carboxylic, carbonyl, ketone and hydroxyl groups) increase on the surface of aged PET microplastics. Based on density functional theory (DFT) simulations, the camphor part of 4-MBC acts as a hydrogen bond acceptor, whereas the carboxylic group on aged PET microplastics acts as a hydrogen bond donor. The formation of hydrogen bonding causes increased sorption of 4-MBC on aged PET microplastics. The sorption capacity increased from 5 to 11 μg g^-1 for 50 ppb 4-MBC with 100 mg PET microplastics after a five-day aging process. Other environmental factors that affect sorption were also identified; a higher pH value and the presence of salinity reduced the amount of sorption. The sorption of virgin PET ranged from 8.0 to 3.4 μg g^-1 and the sorption of aged PET ranged from 22 to 5 μg g^-1 at pH 4 to 10. In the presence of salinity (10% seawater), the virgin PET sorption dropped to 2.1 μg g^-1 while the aged PET sorption dropped to 4 μg g^-1. A similar phenomenon was also observed in the sorption behavior under natural sunlight (the sorption of PET increased from 0.4 to 0.8 μg g^-1 after 6 months of aging). The potential risk to ecosystems of aged PET microplastics under prolonged sunlight exposure in the natural environment could be greater than that predicted for virgin microplastics.

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.

Toxic effects of octocrylene on zebrafish larvae and liver cell line (ZFL)

Octocrylene (OC) is a broad-spectrum ultraviolet-absorbing chemical used in sunscreen and other personal care products. Its health effects are a concern because it has been detected in water, fish, humans, and food chains. In vivo and in vitro investigations were performed in zebrafish (Danio rerio) larvae and a zebrafish liver cell line (ZFL), respectively, to understand the potential risks and molecular mechanisms of OC toxicity. The 96-h median lethal concentration (LC₅₀) of OC was determined to be 251.8 μM in larvae and 5.5 μM in ZFL cells. Quantitative real-time PCR (qRT-PCR) showed that OC induced the expression of genes for CYPs (CYP1A, CYP3A65), estrogen receptors (ERα, ERβ1, GPER), vitellogenin (VTG1), and sex determination (BRCA2, CYP19A, DMRT1, SOX9A), both in vitro and in vivo. A whole-transcriptome sequencing method was used to evaluate the gene expression profile of larvae exposed to OC. OC was found to mediate the biosynthesis of estrogens (such as estriol) and affect the antioxidant pathway (glutathione transferases and peroxisome). These findings clarify the toxic effects and molecular mechanisms of OC and support banning its use in cosmetics.

Ethylhexyl methoxycinnamate and butyl methoxydibenzoylmethane: Toxicological effects on marine biota and human concerns

Ethylhexyl methoxycinnamate (EHMC) (CAS number: 5466-77-3) and butyl methoxydibenzoylmethane (BMDM) (CAS number: 70356-09-1) are important sunscreens. However, frequent application of large amounts of these compounds may reflect serious environmental impact, once it enters the environment through indirect release via wastewater treatment or immediate release during water activities. In this article, we reviewed the toxicological effects of EHMC and BMDM on aquatic ecosystems and the human consequences. According to the literature, EHMC and BMDM have been detected in water samples and sediments worldwide. Consequently, these compounds are also present in several marine organisms like fish, invertebrates, coral reefs, marine mammals, and other species, due to its bioaccumulation potential. Studies show that these chemicals are capable of damaging the aquatic beings in different ways. Further, bioaccumulation studies have shown that EHMC biomagnifies through trophic levels, which makes human seafood consumption a concern because the higher position in the trophic chain, the more elevate levels of ultraviolet (UV) filters are detected, and it is established that EHMC present adverse effects on the human organism. In contrast, there are no studies on the BMDM bioaccumulation and biomagnification potential. Different strategies can be adopted to avoid the damage caused by sunscreens in the environment and human organism. Two of them include the use of natural photoprotectors, such as polyphenols, in association with UV filters in sunscreens and the development of new and safer UV filters. Overall, this review shows the importance of studying the impacts of sunscreens in nature and developing safer sunscreens and formulations to safeguard marine fauna, ecosystems, and humans.

Oxidation of benzophenone-3 in aqueous solution by potassium permanganate: kinetics, degradation products, reaction pathways, and toxicity assessment

Benzophenone-3 (BP-3) is used in a wide range of personal care products and plastics to resist ultraviolet light, which has aroused considerable public concern due to its endocrine-disrupting effects. In this work, we systematically investigated the chemical oxidation process of BP-3 by KMnO₄. The influences of several factors, such as pH, oxidant dose, temperature, coexisting water constituents, and water matrices, on BP-3 degradation efficiency were evaluated. The removal rate of 10 μM BP-3 could reach 91.3% in 2 h under the conditions of pH = 8.0, [BP-3]₀:[KMnO₄]₀ = 1:20, and T = 25 °C, with the observed rate constant (k_obs) value of 0.0202 min^-1. The presence of typical anions (Cl^-, NO₃^-, SO₄^2-) and HA could slightly increase BP-3 removal, while HCO₃^- caused a relatively significant promotion of BP-3 degradation. On the basis of mass spectrometry and theoretical calculations, hydroxylation, direct oxidation, and carbon-carbon bridge bond cleavage were mainly involved in the oxidation process. Toxicity assessment revealed that the acute and chronic toxicities were reduced significantly, which suggested KMnO₄ is a promising technique for BP-3 removal.

Biodegradation of 2-ethylhexyl-4-methoxycinnamate in river sediments and its impact on microbial communities

Numerous studies have evaluated the toxicity and endocrine disrupting properties of organic UV filters for aquatic organisms, but little is known about their biodegradation in river sediments and their impact on microorganisms. We have set up the sterile and microbiological systems in the laboratory, adding 2-ethylhexyl-4-methoxycinnamate (EHMC), one of organic UV filters included in the list of high yield chemicals, at concentrations of 2, 20 and 200 μg/L, and characterized the microbial community composition and diversity in sediments. Monitoring of EHMC degradation within 30 days revealed that the half-life in the microbial system (3.49 days) was much shorter than that in the sterile system (7.55 days). Two potential degradation products, 4-mercaptobenzoic acid and 3-methoxyphenol were identified in the microbial system. Furthermore, high-throughput 16s and 18s rRNA gene sequencing showed that Proteobacteria dominated the sediment bacterial assemblages followed by Chloroflexi, Acidobacteria, Bacteroidetes and Nitrospirae; Eukaryota_uncultured fungus dominated the sediment fungal assemblages. Correlation analysis demonstrated that two bacterium genera (Anaerolineaceae_uncultured and Burkholderiaceae_uncultured) were significantly correlated with the biodegradation of EHMC. These results illustrate the biodegradability of EHMC in river sediments and its potential impact on microbial communities, which can provide useful information for eliminating the pollution of organic UV filters in natural river systems and assessing their potential ecological risks.

A post-HF approach to the sunscreen octyl methoxycinnamate

Octyl methoxycinnamate (2-ethylhexyl 4-methoxycinnamate, OMC) is a commercial sunscreen known as octinoxate with excellent UVB filter properties. However, it is known to undergo a series of photodegradation processes that decrease its effectiveness as a UVB filter. In particular, the trans (E) form-which is considered so far as the most stable isomer-converts to the cis (Z) form under the effect of light. In this work, by using post-Hartree-Fock approaches [CCSD, CCSD(t), and CCSD + T(CCSD)] on ground state OMC geometries optimized at the MP2 level, we show that the cis and trans forms of the gas-phase OMC molecule have comparable stability. Test calculations on the same structures with a series of dispersion-corrected density functional theory-based approaches including the B2PLYP double hybrid predict the trans structures to be energetically favored, missing the subtle stabilization of cis-OMC. Our results suggest that the cis form is stabilized by intra-molecular dispersion interactions, leading to a folded more compact structure than the trans isomer.

Nano-Structured Lignin as Green Antioxidant and UV Shielding Ingredient for Sunscreen Applications

Green, biocompatible, and biodegradable antioxidants represent a milestone in cosmetic and cosmeceutical applications. Lignin is the most abundant polyphenol in nature, recovered as a low-cost waste from the pulp and paper industry and biorefinery. This polymer is characterized by beneficial physical and chemical properties which are improved at the nanoscale level due to the emergence of antioxidant and UV shielding activities. Here we review the use of lignin nanoparticles in cosmetic and cosmeceutical applications, focusing on sunscreen and antiaging formulations. Advances in the technology for the preparation of lignin nanoparticles are described highlighting structure activity relationships.

Determination of environmental properties and toxicity of octyl-dimethyl-para-aminobenzoic acid and its degradation products

Octyl-dimethyl-para-aminobenzoic acid (ODPABA) is one of compounds of emerging concern. It undergoes transformations under the influence of oxidizing or chlorinating agents and UV radiation forming products with different properties. There is very little experimental data concerning the environmental fate of ODPABA and its transformation products. Therefore, the purpose of the studies was to determine environmental parameters: water solubility, soil - water partition coefficient, octanol - air partition coefficient, bioconcentration factor as well as half-life in air, water and soil. Based on the results obtained, the persistence and migration possibilities of ODPABA and its transformation products in the aquatic environment were estimated. Moreover, the ecological toxicity of oxidation and chlorination products was investigated. Microtox®, Daphtoxkit F® and Artoxkit M® tests were used to determine toxicity. LC₅₀ for Fish and Daphnia magna was calculated by Ecosar module. Studies have shown that as a result of ODPABA transformations, chloroorganic products are formed, which are lipophilic, are bioconcentrated in organic matter, are characterized by significant environmental persistence, can spread over considerable distances and are toxic. Oxidation products have significantly smaller impact on the environment. They are characterized by higher water solubility, lower bioconcentration factor and are less toxic.

The presence of selected UV filters in a freshwater recreational reservoir and fate in controlled experiments

UV filters present in sunscreen and other cosmetics are directly released into the environment during aquatic recreational activities. The extent to which the wide range of UV filters pose a risk to the environment remains unclear. This study investigated the occurrence and dissipation of selected organic UV filters at a recreational site (Enoggera Reservoir, Queensland, Australia) over 12 h. Furthermore, different possible degradation processes were investigated in a controlled off-site experiment with surface water exposed to natural light. Half-lives were estimated for ten UV filters. In Enoggera Reservoir, seven UV filters were detected, of which the most prevalent were octocrylene, avobenzone (BMDBM) and enzacamene (4-MBC). Summed concentrations of the seven UV filters ranged from 7330 ng L^-1 at 13:00 h to 2550 ng L^-1 at 21:00 h. In the degradation experiment, four UV filters showed no significant change over time. The fate of these compounds in the environment is likely to be mainly influenced by dispersion. Half-lives of the remaining UV filters were 6.6 h for amiloxate (IMC), 20 h for benzophenone 1, 23 h for octinoxate (EHMC), 30 h for 3-benzylidene camphor, 34 h for 4-MBC and 140 h for dioxybenzone (BP8). The degree of susceptibility to photodegradation and biodegradation was generally consistent within a structural class. The fate and half-lives of UV filters are variable and should be considered on a per site basis when assessing environmental risk.

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.

A burning issue: The effect of organic ultraviolet filter exposure on the behaviour and physiology of Daphnia magna

Ultraviolet (UV) filters are compounds utilized in many manufacturing processes and personal care products such as sunscreen to protect against UV-radiation. These highly lipophilic compounds are emerging contaminants of concern in aquatic environments due to their previously observed potential to bioaccumulate and exert toxic effects in marine ecosystems. Currently, research into the toxic effects of UV filter contamination of freshwater ecosystems is lacking, thus the present study sought to model the effects of acute and chronic developmental exposures to UV filters avobenzone, oxybenzone and octocrylene as well as a mixture of these substances in the freshwater invertebrate, Daphnia magna, at environmentally realistic concentrations. Median 48-hour effect and lethal concentrations were determined to be in the low mg/L range, with the exception of octocrylene causing 50% immobilization near environmental concentrations. 48-hour acute developmental exposures proved to behaviourally impair daphnid phototactic response; however, recovery was observed following a 19-day post-exposure period. Although no physiological disruptions were detected in acutely exposed daphnids, delayed mortality was observed up to seven days post-exposure at 200 μg/L of avobenzone and octocrylene. 21-day chronic exposure to 7.5 μg/L octocrylene yielded complete mortality within 7 days, while sublethal chronic exposure to avobenzone increased Daphnia reproductive output and decreased metabolic rate. 2 μg/L oxybenzone induced a 25% increase in metabolic rate of adult daphnids, and otherwise caused no toxic effects at this dose. These data indicate that UV filters can exert toxic effects in freshwater invertebrates, therefore further study is required. It is clear that the most well-studied UV filter, oxybenzone, may not be the most toxic to Daphnia, as both avobenzone and octocrylene induced behavioural and physiological disruption at environmentally realistic concentrations.

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 Distribution of UV Filters in Beach Sediments of the Southern Baltic Sea Coast

The interest in UV filters’ occurrence in the environment has increased since they were recognized as “emerging contaminants” having potentially adverse impacts on many ecosystems and organisms. Increased worldwide demand for sunscreens is associated with temperature anomalies, high irradiance, and changes in the tourist market. Recently, it has been demonstrated that personal care products, including sunscreens, appear in various ecosystems and geographic locations causing an ecotoxicological threat. Our goal was to determine for the first time the presence of selected organic UV filters at four beaches in the central Pomeranian region in northern Poland and to assess their horizontal and vertical distribution as well as temporal variation at different locations according to the touristic pressure. In this pioneering study, the concentration of five UV filters was measured in core sediments dredged from four exposed beaches (Darłowo, Ustka, Rowy, and Czołpino). UV filters were detected in 89.6% of collected cores at detection frequencies of 0–22.2%, 75–100%, 0–16.7%, and 2.8–25% for benzophenone-1 (BP-1), benzophenone-2 (BP-2), benzophenone-3 (BP-3), and enzacamene (4-MBC), respectively. In terms of seasonality, the concentration of UV filters generally increased in the following order: summer > autumn > spring. No detectable levels of 3-BC (also known as 3-benzylidene camphor) were recorded. No differences were found in the concentration of UV filters according to the depth of the sediment core. During the summer and autumn seasons, all UV filters were detected in higher concentrations in the bathing area or close to the waterline than halfway or further up the beach. Results presented in this study demonstrate that the Baltic Sea coast is not free from UV filters. Even if actual concentrations can be quantified as ng·kg−1 causing limited environmental threat, much higher future levels are expected due to the Earth’s principal climatic zones shifting northward.

Repellency and mortality effects of sunscreens on the shrimp Palaemon varians: Toxicity dependent on exposure method

Contamination by sunscreens has become a serious environmental problem due to the increasing use of these products in coastal regions. Their complex chemical composition supposes an input of different chemical compounds capable of producing toxic effects and repelling organisms. The aim of the current study was to experimentally check the repellency of three commercial sunscreens [A (lotion), B (gel) and C (milk spray)] by assessing the escape (displacement towards areas with lower sunscreen levels) of the estuarine shrimp Palaemon varians exposed (4 h) to a gradient (0-300 mg/L) of the sunscreens in a heterogeneous non-forced exposure scenario. Additionally, mortality and immobility (72 h) were checked in a traditional forced exposure scenario. Considering that the toxicity of sunscreens is a little controversial regarding their chemical availability in the medium, two different methods of sunscreen solubilisation were tested: complete homogenization and direct immersion. Very low mortality was observed in the highest concentration of sunscreens A and C applied by direct immersion; however, for sunscreen B, the main effect was the loss of motility when homogenization was applied. Repellency was evidenced for two sunscreens (A and B) applied by direct immersion. The homogenization in the medium seemed to lower the degree of repellency of the sunscreens, probably linked to the higher viscosity in the medium, preventing the motility of shrimps. By integrating both short-term responses (avoidance and mortality/immobility), the PID (population immediate decline) calculated showed that avoidance might be the main factor responsible for the reduction of the population at the local scale.

Effect of the UV filter, Benzophenone-3, on biomarkers of the yellow clam (Amarilladesma mactroides) under different pH conditions

This work aimed to investigate effects of the ocean contamination by the sunscreen Benzophenone-3 (BP3) and acidification, caused by CO₂ enrichment, to the yellow clam, Amarilladesma mactroides. Biochemical biomarkers were analyzed in tissues (gills, digestive gland, and mantle) of clams exposed to the environmental concentration of 1 μg/L BP3, at seawater natural pH (pH 8.1) and at lower pH (pH 7.6). The tissues responded in different ways considering their physiological roles. In general, BP3 altered activity of the enzymes, glutathione-S-transferase (GST) and glutathione cysteine ligase (GCL); but mostly increased the level of glutathione (GSH). These effects were enhanced by acidification, without augmenting lipid peroxidation (LPO). Carbonic anhydrase activity (CA) increased after BP3 exposure in the digestive gland and decreased in the gills at pH 7.6, while Ca²⁺-ATPase activity was affected by acidification only. Changing levels of these enzymes can alter shell formation and affect the bivalve maintenance in impacted environments.

Occurrence, distribution, and health risk assessment of 20 personal care products in indoor and outdoor swimming pools

The distribution of 20 personal care products (PCPs), including seven preservatives, six UV filters, five anticorrosion agents, and two antimicrobials, were determined in 40 swimming pools using solid phase extraction followed by liquid chromatography-tandem mass spectrometry. Among 14 targets detected, 1H-benzotriazole and triclocarban were observed in all samples. The detected concentrations of preservatives, UV filters, anticorrosion agents, and antimicrobials were in the ranges of not detected (nd)-179 ng L^-1, nd-289 ng L^-1, nd-58.4 ng L^-1, and nd-56.9 ng L^-1, respectively. The presence of preservatives, UV filters and antimicrobials in pool waters might be mainly brought in by human activities while anticorrosion agents were mainly from the source water. Furthermore, the concentrations of methylparaben, ethylparaben, 1H-benzotriazole, 5-methyl-1H-benzotriazole, 5-chloro-1H-benzotriazole, and 5,6-dimethyl-1H-benzotriazole in indoor pools were found higher than those in outdoor pools. The longer opening time and weaker light intensity for indoor pools might cause the difference. The redundancy analysis showed significantly negative correlations between the concentrations of parabens and the contents of residual chlorine in the pool waters. A higher chlorine residue may promote the decomposition of parabens. Health risk assessment showed that skin penetration would be the main approach for the intake of PCPs by swimmers while swimming. Compared with the non-athletic swimmers, the athletic swimmers might be more sensitive, but the health risks for both groups of swimmers could be negligible.

Toxicity of UV filters on marine bacteria: Combined effects with damaging solar radiation

Organic UV filters are of emerging concern due to their occurrence and persistence in coastal ecosystems. Because marine bacteria are crucial in the major biogeochemical cycles, there is an urgent need to understand to what extent these microorganisms are affected by those chemicals. This study deciphers the impact of five common sunscreen UV filters on twenty-seven marine bacteria, combining both photobiology and toxicity analysis on environmentally relevant species. Seven bacteria were sensitive to different organic UV filters at 1000 μg L^-1, including octinoxate and oxybenzone. This is the first report demonstrating inhibition of bacterial growth from 100 μg L^-1. None of the UV filters showed any toxicity at 1000 μg L^-1 on stationary phase cells, demonstrating that physiological state was found to be a key parameter in the bacterial response to UV-filters. Indeed, non-growing bacteria were resistant to UV filters whereas growing cells exhibited UV filter dependent sensitivity. Octinoxate was the most toxic chemical at 1000 μg L^-1 on growing cells. Interestingly, photobiology experiments revealed that the toxicity of octinoxate and homosalate decreased after light exposure while the other compounds were not affected. In terms of environmental risk characterization, our results revealed that the increasing use of sun blockers could have detrimental impacts on bacterioplanktonic communities in coastal areas. Our findings contribute to a better understanding of the impact of the most common UV filters on bacterial species and corroborate the importance to consider environmental parameters such as solar radiation in ecotoxicology studies.