Potentiation of lethal and sub-lethal effects of benzophenone and oxybenzone by UV light in zebrafish embryos

Ecotoxicological assessment of UV filters benzophenone-3 and TiO2 nanoparticles, isolated and in a mixture, in developing zebrafish (Danio rerio)

The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.

2,4'-Dihydroxybenzophenone: A Promising Anti-Inflammatory Agent Targeting Toll-like Receptor 4/Myeloid Differentiation Factor 2-Mediated Mitochondrial Reactive Oxygen Species Production during Lipopolysaccharide-Induced Systemic Inflammation

The biochemical properties of 2,4'-dihydroxybenzophenone (DHP) have not been extensively studied. Therefore, this study aimed to investigate whether DHP could alleviate inflammatory responses induced by lipopolysaccharide (LPS) and endotoxemia. The results indicated that DHP effectively reduced mortality and morphological abnormalities, restored heart rate, and mitigated macrophage and neutrophil recruitment to inflammatory sites in LPS-microinjected zebrafish larvae. Additionally, the expression of pro-inflammatory mediators, including inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), and interleukin-12 (IL-12), was significantly reduced in the presence of DHP. In RAW 264.7 macrophages, DHP inhibited the LPS-induced inflammatory response by downregulating pro-inflammatory mediators and decreasing the expression of myeloid differentiation primary response 88 (MyD88), phosphorylation of IL-1 receptor-associated protein kinase-4 (p-IRAK4), and nuclear factor-κB (NF-κB). Molecular docking analysis demonstrated that DHP occupies the hydrophobic pocket of myeloid differentiation factor 2 (MD2) and blocks the dimerization of Toll-like receptor 4 (TLR4). A molecular dynamics simulation confirmed that DHP stably bound to the hydrophobic pocket of MD2. Furthermore, the DHP treatment inhibited mitochondrial reactive oxygen species (mtROS) production during the LPS-induced inflammatory response in both RAW 264.7 macrophages and zebrafish larvae, which was accompanied by stabilizing mitochondrial membrane potential. In conclusion, our study highlights the therapeutic potential of DHP in alleviating LPS-induced inflammation and endotoxemia. The findings suggest that DHP exerts its anti-inflammatory effects by inhibiting the TLR4/MD2 signaling pathway and reducing the level of mtROS production. These results contribute to a better understanding of the biochemical properties of DHP and support its further exploration as a potential therapeutic agent for inflammatory conditions and endotoxemia.

Toxicity of UV Filter Benzophenone-3 in Brine Shrimp Nauplii (Artemia salina) and Zebrafish (Danio rerio) Embryos

The benzophenone (BP) family, including oxybenzone (BP-3), a prevalent sunscreen ingredient and environmental contaminant, has raised concerns since the year 2005. This study investigated oxybenzone toxicity in zebrafish (Danio rerio) eleutheroembryos and brine shrimp (Artemia salina) nauplii, focusing on the LC50 and developmental impacts. Zebrafish embryos (0.100-1.50 mg/L BP-3, 96 h) and A. salina (0.100-5.00 mg/L BP-3, 48 h) were tested with ultrasound-assisted emulsified liquid-phase microextraction (UA-ELPME) used for zebrafish tissue analysis. HPLC-DAD determined BP-3 concentrations (highest: 0.74 ± 0.13 mg/L). Although no significant zebrafish embryo mortality or hatching changes occurred, developmental effects were evident. Lethal concentrations were determined (A. salina LC50 at 24 h = 3.19 ± 2.02 mg/L; D. rerio embryos LC50 at 24 h = 4.19 ± 3.60 mg/L), with malformations indicating potential teratogenic effects. A. salina displayed intestinal tract alterations and D. rerio embryos exhibited pericardial edema and spinal deformities. These findings highlight oxybenzone's environmental risks, posing threats to species and ecosystem health.

Effects of the sunscreen ultraviolet filter oxybenzone (benzophenone-3) on the seagrass Posidonia oceanica (L.) Delile and its associated N2 fixers

Oxybenzone/benzophenone-3 (BP-3) is one of the most detrimental organic ultraviolet filters for marine biota, leading to legislative measures banning its presence in commercial sunscreen formulations of several countries. It remains poorly explored how this contaminant is currently threatening the persistence of critical ecosystems for conservation in the Mediterranean, such as Posidonia oceanica meadows, but it is essential for promoting sustainable coastal tourism. Our investigation aimed to determine the effects of BP-3 on P. oceanica under a short-term laboratory setup, recreating summer conditions while testing three environmentally relevant concentrations for Mallorca, Spain (minimum: 53.6 ng L-1, maximum: 557.5 ng L-1 and increased: 1115 ng L-1) and a control (0 ng L-1). Primary productivity was unaffected by the treatments, however, a reduction in leaf chlorophyll content and nitrogen fixation activity associated with rhizomes was evidenced under BP-3 addition. This may be related with oxidative damage, as reactive oxygen species production and catalase activity in P. oceanica leaves were the highest even at minimum BP-3 concentrations. Alkaline phosphatase rates showed inverted trends between old leaves and rhizomes, being enhanced in the former under BP-3 addition and reduced in the latter. These results are of great relevance for the future management of P. oceanica meadows, elucidating that even minimum concentrations of BP-3 reported in coastal waters of Mallorca can induce elevated levels of oxidative stress in the seagrass, that lead to impairments in its photosynthetic pigments production and supply of essential nutrients through belowground tissues.

Toxicity comparison of benzophenone-3 and its metabolite benzophenone-8 in different tissues of zebrafish

Benzophenone-3 (BP-3) is a commonly used ultraviolet absorber that has the potential to accumulate in organisms, leading to toxicity. Benzophenone-8 (BP-8) is one of the major metabolites of BP-3. In this study, zebrafish were exposed to different concentrations of BP-3 and BP-8 (1 μg/L, 30 μg/L, and 300 μg/L) to investigate their accumulation and toxic effects in various tissues, including zebrafish brain, gut, and liver. The analysis focused on neurotoxicity, oxidative damage, inflammation, and gene expressions. The results showed that both BP-3 and BP-8 accumulated in the tissues, with the highest concentration observed in the gut, followed by the liver and brain. BP-8 exhibited a stronger ability to accumulate. In the brain, exposure to 1 μg/L of BP-3 and BP-8 promoted cortisol production, while higher exposures (30 μg/L and 300 μg/L) inhibited acetylcholinesterase activity and suppressed cortisol production. In the gut, both BP-3 and BP-8 exposures disrupted oxidative stress, inflammatory immunity, and apoptosis functions. In the liver, BP-3 and BP-8 affected hepatic metabolism, oxidative stress, apoptosis, and inflammatory immunity. Comparing gene expression in the brain, gut, and liver, it was found that BP-3 and BP-8 had a lower effect on gene expression in the brain, while the effect on the gut and liver was significantly higher. BP-8 generally had a higher effect than BP-3, which aligns with the observed accumulation pattern. These findings provide valuable insights for the risk assessment of BP-3 and BP-8 in the aquatic environment.

Fine-scale geographic risk assessment of oxybenzone sunscreen pollution within Hanauma Bay using hydrodynamic characterization and modeling

Hanauma Bay's coral reef system is threatened by sunscreen pollution. Understanding the hydrodynamic nature of the bay is crucial for understanding the transport and fate of pollutants within the bay. This study conducted a comprehensive hydrodynamic analysis, revealing significant aspects of current patterns and their influence on sunscreen pollutant behavior. The analysis demonstrated the formation of flows that drive currents parallel to the shoreline, resulting in increased pollutant retention time over sensitive reef areas. Direct flushing currents were identified as playing a role in reducing pollution buildup. Particle dynamics analysis highlighted the importance of considering temporal dynamics and their implications for pollutant pathways, particularly through the swash zone during high tide phases. The study identified primary current patterns near the reef area and emphasized the circular behavior within the water body, affecting corals' susceptibility to bleaching in the southwestern part of Hanauma bay. To understand where oxybenzone concentrations were a threat to wildlife, we created a geographic model that integrated ecological risk assessment with hydrodynamic behavior in a given system, which we designate the Risk Quotient Plume - the geographic area where the concentration is above the threat level for a chemical. The study found high oxybenzone concentrations throughout the bay, threatening coral, fish, and algae populations. Oxybenzone's distribution indicated a serious threat to the entire back reef habitat and a hinderance to coral restoration efforts. The study also emphasizes the need to consider the hydrodynamic behavior of pollutants and their interaction with microplastics in the bay. Overall, the findings provide insights into hydrodynamics and pollutant dispersion in Hanauma Bay, supporting effective pollution management and conservation strategies.

Assessment of the photoprotective potential and structural characterization of secondary metabolites of Antarctic fungus Arthrinium sp

Interest in Antarctic fungi has grown due to their resilience in harsh environments, suggesting the presence of valuable compounds from its organisms, such as those presenting photoprotective potential, since this environment suffers the most dangerous UV exposure in the world. Therefore, this research aimed to assess the photoprotective potential of compounds from sustainable marine sources, specifically seaweed-derived fungi from Antarctic continent. These studies led to discovery of photoprotective and antioxidant properties of metabolites from Arthrinium sp., an endophytic fungus from Antarctic brown algae Phaeurus antarcticus. From crude extract, fractions A-I were obtained and compounds 1-6 isolated from E and F fractions, namely 3-Hydroxybenzyl alcohol (1), (-)-orthosporin (2), norlichexanthone (3), anomalin B (4), anomalin A (5), and agonodepside B (6). Compounds 1, 2, and 6 were not previously reported in Arthrinium. Fraction F demonstrated excellent absorbance in both UVA and UVB regions, while compound 6 exhibited lower UVB absorbance, possibly due to synergistic effects. Fraction F and compound 6 displayed photostability and were non-phototoxic to HaCaT cells. They also exhibited antioxidant activity by reducing intracellular ROS production induced by UVA in keratinocyte monolayers and reconstructed human skin models (resulting in 34.6% and 30.2% fluorescence reduction) and did not show irritation potential in HET-CAM assay. Thus, both are promising candidates for use in sunscreens. It is noted that Fraction F does not require further purification, making it advantageous, although clinical studies are necessary to confirm its potential applicability for sunscreen formulations.

Benzophenone induces cardiac developmental toxicity in zebrafish embryos by upregulating Wnt signaling

Benzophenone (BP) is found in many popular consumer products, such as cosmetics. BP potential toxicity to humans and aquatic organisms has emerged as an increased concern. In current study, we utilized a zebrafish model to assess BP-induced developmental cardiotoxicity. Following BP exposure, zebrafish embryos exhibited developmental toxicity, including increased mortality, reduced hatchability, delayed yolk sac absorption, and shortened body length. Besides, BP exposure induced cardiac defects in zebrafish embryos, comprising pericardial edema, reduced myocardial contractility and rhythm disturbances, and altered expression levels of cardiac developmental marker genes. Mechanistically, BP exposure disturbed the redox state and increased the level of apoptosis in zebrafish cardiomyocytes. Transcriptional expression levels of Wnt signaling genes, involving lef1, axin2, and β-catenin, were upregulated after BP treatment. Inhibition of Wnt signaling with IWR-1 could rescue the BP-induced cardiotoxicity in zebrafish. In summary, BP exposure causes cardiotoxicity via upregulation of the Wnt signaling pathway in zebrafish embryos.

Benzophenone-3 sunscreen causes phytotoxicity and cytogenotoxicity in higher plants

The benzophenone-3 (BP-3) sunscreen is recurrently released into the environment from different sources, however, evaluations of its adverse effects on plants do not exist in the literature. In this study, BP-3 was evaluated, at concentrations 2; 20, and 200 µg/L, regarding phytotoxicity, based on germination and root elongation in seeds, in Lactuca sativa L., Cucumis sativus L. and Allium cepa L., and phytotoxicity, cytogenotoxicity and oxidative stress in A. cepa bulb roots. The BP-3 concentrations, except for the 200 µg/L concentration in L. sativa, caused no significant reduction in seed germination. All concentrations tested significantly reduced the elongation of roots from seeds and roots from bulbs. The 20 and 200 µg/L concentrations caused oxidation in cells, disturbances in the cell cycle, and alterations in prophase and metaphase, as well as the induction of micronuclei, in A. cepa root meristems. Furthermore, the three concentrations induced a high number of prophases in root tips. Such disorders were caused by excess H2O2 and superoxide produced in cells due to exposure to BP-3, which triggered significant phytotoxicity, cytotoxicity, and genotoxicity in root meristems. Thus, the recurrent contamination of agricultural and non-agricultural soils with BP-3, even at a concentration of 2 µg/L, represents an environmental risk for plants. These results point to the impending need to set limits for the disposal of this sunscreen into the environment since BP-3 has been used in industry for several decades.

Benzophenone-3 does not Cause Oxidative Stress or B-esterase Inhibition During Embryo Development of Octopus maya (Voss and Solís Ramírez, 1966)

Benzophenone-3 (BP-3) is an active ingredient in sunscreen lotions and personal-care products that protects against the damaging effects of ultraviolet rays. Given its worldwide dissemination, it has been linked with harmful effects on aquatic biota; however, its impact is not fully understood calling for further studies. To understand the impacts on an important economically and ecologically species, we evaluated the toxicity of BP-3 during the embryonic development of Octopus maya. Embryos were exposed to increasing concentrations of up to 500 µg BP-3/L until hatching. Antioxidant enzyme activities, oxidative-stress indicators, and B-esterases activities were measured at different developmental phases (organogenesis, activation, and growth). There were no significant differences between treatments, suggesting the lack of production of toxic metabolites that may be related to a protective chorion, an underdeveloped detoxification system, and the experimental conditions that limited phototoxicity.

The effects of UV filters on health and the environment

Sunscreens are an important means of protection against sunburns, dyspigmentation, photoaging, and photocarcinogenesis. Sunscreens come in a variety of formulations that can protect against ultraviolet B (UVB) radiation, both UVB and ultraviolet A (UVA) radiation (broad-spectrum sunscreens), and UVB, UVA, and visible light (tinted broad-spectrum sunscreens). In the USA, there is currently a paucity of FDA-approved broad-spectrum filters on the market. Studies have identified the presence of multiple UV filters in water sources globally. Many laboratory studies have implicated the potential impact of UV filters on coral reef bleaching, the food chain, and human health. However, many of these studies are performed at concentrations that are much higher than those present in the natural environment. With increasing discussion surrounding the role of organic and inorganic UV filters as potential environmental pollutants over the past decade, approval of additional broad-spectrum filters would be an important means of alleviating the use of more controversial filters. The aim of this article is to review the effects of UV filters on health and the environment and explore potential adjunctive agents for photoprotection.

Comparison of developmental toxicity of benzophenone-3 and its metabolite benzophenone-8 in zebrafish

Benzophenone-3 (BP-3) as one of frequently used organic UV filters has been considered an emerging pollutant due to its toxicities. Benzophenone-8 (BP-8) is one of the main metabolites of BP-3 in organisms. Current reports show that BP-8 may be more toxic than BP-3. However, difference of their toxicities on embryonic development has rarely been reported. In this study, zebrafish embryos were chosen as the target organism to explore the developmental toxicities of BP-3 and BP-8. Non-targeted metabolomic analysis was performed to compare their modes of action. Results showed that BP-8 exposures led to higher bioaccumulation and lower hatching rate of zebrafish larvae than BP-3. Both BP-8 and BP-3 exposures caused behavioral abnormalities of zebrafish larvae, but no significant difference was found between them. At the metabolome level, 1 μg/L BP-3 and 1 μg/L BP-8 exposures altered neuroactive ligand-receptor interaction pathway and FoxO signaling pathway, respectively, which might be involved in the abnormal behaviors in zebrafish larvae. For higher exposure groups (30 and 300 μg/L), both BP-3 and BP-8 exposures changed metabolism of cofactors and vitamins of zebrafish larvae. Exposure of BP-3 altered the metabolism by pantothenate and CoA biosynthesis pathway, while BP-8 exposure changed riboflavin metabolism and folate biosynthesis. The above results indicated different modes of action of BP-3 and BP-8 in zebrafish embryonic development. This study sheds new light to biological hazards of BP-3 due to its metabolism in aquatic organisms.

The binding mechanism of benzophenone-type UV filters and human serum albumin: The role of site, number, and type of functional group substitutions

Benzophenone-type UV filters (BPs) are common in natural aquatic environments. They can cause endocrine disruption or other adverse effects once they enter the human body via the food chain or drinking water. The primary cause of BPs accumulation and toxicity is the transport of BPs into the human body. Functional group substitutions can have a significant impact on the interactions of BPs and transporters, resulting in a variety of impact effects. Therefore, we explored the interaction between human serum albumin (HSA, a typical transporter) and ten typical BPs [benzophenone (BP1), 2-hydroxybenzophenone (BP2), 4-hydroxybenzophenone (BP3), 2,2'-dihydroxybenzophenone (BP4), 2,4-dihydroxybenzophenone (BP5), 4,4'-dihydroxybenzophenone (BP6), 2,4,4'-trihydroxybenzophenone (BP7), 2,2',4,4'-tetrahydroxybenzophenone (BP8), 2-hydroxy-4-methoxybenzophenone (BP9), and 2,2'-dihydroxy-4-methoxybenzophenone (BP10)] to study the role of functional group substitutions in binding. The results showed that BPs could bind to HSA at site 2, with binding constants ranging from 2.01 × 10³ to 4.57 × 10⁵ L/mol. Compared to BP1, hydroxyl and methoxy substitutions enhanced the BPs-HSA binding. The combined effect of the number and site of hydroxyl substitution at BPs determined the binding strength between BPs and HSA. It was more accessible to bind HSA when BPs were substituted with para-hydroxyl (4-hydroxyl) groups than with ortho-hydroxyl (2-hydroxyl) groups. Moreover, the additional para-methoxy (4-methoxy) group increased the BP-HSA binding strength by approximately 47 times under the same hydroxyl substitution conditions. Theoretical calculations revealed that functional group substitutions increased the intermolecular binding force by increasing the negative electrostatic potential surface area of BPs, which significantly increased the electrostatic and dispersion forces between the BPs and HSA. This BPs-HSA binding decreased the α-helix of HSA and influenced the ratio of other secondary structures, including β-sheet, β-turn, and random coil of HSA. This study provides a theoretical and experimental foundation for understanding the human health risks associated with BPs.

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.

Target and Nontarget Screening of Organic Chemicals and Metals in Recycled Plastic Materials

Increased demand for recycling plastic has prompted concerns regarding potential introduction of hazardous chemicals into recycled goods. We present a broad screening of chemicals in 21 plastic flake and pellet samples from Canadian recycling companies. From target analysis, the organophosphorus ester flame retardants and plasticizers exhibited the highest detection frequencies (DFs) (5-100%) and concentrations (<DL-4,700 ng/g), followed by brominated/chlorinated flame retardants (<DL-2,150 ng/g, 5-76% DFs). The perfluoroalkyl acids were least detected at the lowest concentrations (<0.01-0.70 ng/g, 5-19% DFs). Using nontargeted analysis, 217 chemicals were identified as Level 1 (authentic standard) or 2 (library match), with estimated individual concentrations up to 1030 ng/g (highest: 2-hexyl hydroxy benzoate, 100% DF). Total (Σ60) element concentrations were between 0.005 and 2,980 mg/kg, with highest concentrations for calcium (2,980 mg/kg), sodium (617 mg/kg), and iron (156 mg/kg). Collectively >280 chemicals were detected in recycled plastic pellets and flakes, suggesting potential incorporation into recycled goods. Individual concentrations indicate unintentional trace contamination following European Union threshold limits for recycled granules (500 mg/kg) and waste plastic flakes (1,000 mg/kg), although do not reflect toxicological thresholds, if any. Our study highlights that while recycling addresses sustainability goals, additional screening of goods and products made from recycled plastics is needed to fully document potentially hazardous chemicals and exposure.

Development toxicity and cytotoxicity of pyroxsulam on embryos and adults of zebrafish (Danio rerio)

Pyroxsulam is a typical triazolopyrimidine sulfonamide herbicide, which plays a vital role in weed control for wheat production. Previous studies on pyroxsulam have mainly focused on weed resistance, control effects, and soil microorganisms, however, research on aquatic ecotoxicity is lacking. This study evaluated the toxicity of pyroxsulam in zebrafish embryos (120 h) and adults (14 and 28 d). Chronic exposure to pyroxsulam (0.2, 2, and 10 μg L^-1) reduced reactive oxygen species (ROS) content in embryos but increased ROS content in adults. Pyroxsulam caused lipid peroxidation and DNA damage in embryos and adults. The expression of p53, bcl-2/bax, and caspase 3/8/9 indicated that pyroxsulam inhibited apoptosis in embryos but induced apoptosis in adults. By calculating integrated biomarker response, apoptosis was more readily affected than oxidative damage in embryos and adults. The toxicity of pyroxsulam increased with increasing concentration, however, with increasing exposure time, the toxicity of pyroxsulam to adults decreased. Pyroxsulam exerted toxic effects on zebrafish at different life stages (embryos and adults), and different stages had different toxicity. These results indicate that in future studies on the toxicity of pyroxsulam to zebrafish, different life stages (embryos and adults) need to be studied. The present study evaluated the toxicity of environmentally relevant concentrations of pyroxsulam to zebrafish embryos and adults, providing worthy data for assessing its effects on aquatic ecosystems.

Benzophenones in the Environment: Occurrence, Fate and Sample Preparation in the Analysis

The ubiquitous presence of emerging contaminants in the environment is an issue of great concern. Notably, for some of them, no established regulation exists. Benzophenones are listed as emerging contaminants, which have been identified in the environment as well as in human fluids, such as urine, placenta, and breast milk. Their accumulation and stability in the environment, combined with the revealed adverse effects on ecosystems including endocrine, reproductive, and other disorders, have triggered significant interest for research. Benzophenones should be extracted from environmental samples and determined for environmental-monitoring purposes to assess their presence and possible dangers. Numerous sample preparation methods for benzophenones in environmental matrices and industrial effluents have been proposed and their detection in more complex matrices, such as fish and sludges, has also been reported. These methods range from classical to more state-of-the-art methods, such as solid-phase extraction, dispersive SPE, LLE, SBSE, etc., and the analysis is mostly completed with liquid chromatography, using several detection modes. This review critically outlines sample preparation methods that have been proposed to date, for the extraction of benzophenones from simple and complex environmental matrices and for cleaning up sample extracts to eliminate potential interfering components that coexist therein. Moreover, it provides a brief overview of their occurrence, fate, and toxicity.

Soil degradation kinetics of oxybenzone (Benzophenone-3) and toxicopathological assessment in the earthworm, Eisenia fetida

A preponderance of recent evidence indicates that oxybenzone and other personal-care product chemicals threaten the biota inhabiting various ecological niches. What is understudied is the ecotoxicological impact of oxybenzone, a UV filter in sunscreens and anti-aging products, to terrestrial/soil organisms that are keystone species in these habitats. In the present study, acute exposure (14-day) to oxybenzone resulted in earthworm mortality (LC₅₀ of 364 mg/kg) and growth rate inhibition. Environmentally relevant concentration of oxybenzone (3.64, 7.28 and 36.4 mg/kg) at exposures of 7-day, 14-day, 28-day induced oxidative stress and neurotoxicity followed by perturbations in reproduction processes and changes in vital organs. Decreased levels of superoxide dismutase (SOD) and catalase (CAT) activity were statistically lower than controls (p < 0.05) on day 14 for all three concentrations, while glutathione-s-transferase (GST) activity was significantly elevated from controls on days 7 and 14. On day 28, SOD and CAT activities were either not significantly different from the control or were higher, demonstrating a temporal multiphasic response of anti-oxidant enzymes. GST activity on day 28 was significantly reduced compared to controls. Acetylcholinesterase levels across the three-time points exhibited a complicated behaviour, with every exposure concentration being significantly different from the control. Chronic exposure negatively influences earthworm health status with elevated biomarker values analysed using IBRv2 index. This, in turn, impacted higher levels of hierarchical organization, significantly impairing reproduction and organismal homeostasis at the histological level and manifesting as decreasing cocoon formation and successful hatching events. Thus, the overall findings demonstrate that oxybenzone is toxic to Eisenia fetida at low-level, long-term exposure. Based on the concentration verification analysis and application of the EPA PestDF tool, oxybenzone undergoes single first-order kinetics degradation in OECD soil with DT50 and DT90 as 8.7-28.9 days, respectively.

Quantum mechanical study of interactions between sunscreen ingredients and nucleotide bases

Interactions between the popular sunscreen ingredients oxybenzone and homosalate and DNA bases have been studied using density functional theory and ab initio methods. Low-energy structures for each sunscreen ingredient interacting with each nucleotide base in either a pi-stacked or hydrogen-bonded fashion were found. The binding energies are comparable to those for the Watson-Crick-Franklin Ade-Thy and Cyt-Gua pairs. Pi-stacked and hydrogen-bonded structures are comparable in energy, with hydrogen-bonded structures having a more negative counterpoise-corrected binding energy, while the final pi-stacked structures are lower in energy. This is due to a geometrical rearrangement required to form the hydrogen bonds that raise the total energy of the complex. It was also found that when using the M06-2X density functional, the STO-3G basis set favors hydrogen bonding, but 6-31G(d) and 6-31 + G(s) basis sets predict similar binding geometries.

Conversion of oxybenzone sunscreen to phototoxic glucoside conjugates by sea anemones and corals

The reported toxicity of oxybenzone-based sunscreens to corals has raised concerns about the impacts of ecotourist-shed sunscreens on corals already weakened by global stressors. However, oxybenzone's toxicity mechanism(s) are not understood, hampering development of safer sunscreens. We found that oxybenzone caused high mortality of a sea anemone under simulated sunlight including ultraviolet (UV) radiation (290 to 370 nanometers). Although oxybenzone itself protected against UV-induced photo-oxidation, both the anemone and a mushroom coral formed oxybenzone-glucoside conjugates that were strong photo-oxidants. Algal symbionts sequestered these conjugates, and mortality correlated with conjugate concentrations in animal cytoplasm. Higher mortality in anemones that lacked symbionts suggests an enhanced risk from oxybenzone to corals bleached by rising temperatures. Because many commercial sunscreens contain structurally related chemicals, understanding metabolite phototoxicity should facilitate the development of coral-safe products.

The transformation of Benzophenone-3 in natural waters and AOPs: The roles of reactive oxygen species and potential environmental risks of products

Benzophenone-3 (BP-3) is a widespread emerging organic pollutant. However, little is known about the synergistic effect of various reactive oxygen species (ROS) in natural waters and wastewater treatment plants on its transformation. In this study, the indirect photochemical behavior of BP-3 in the natural aquatic environments and the degradation process in the AOPs system were investigated by theoretical chemistry calculations. Besides the potential eco-toxicity effects, health effects, and bioaccumulation of the transformation products were assessed by computational toxicology. Results of transformation mechanism and kinetics showed that OH· and ¹O₂ are the keys to the transformation of BP-3, whereas the role of HO₂· and O₃ can be ignored. AOPs based on OH· and ¹O₂ could lead to the rapid transformation of BP-3, while the transformation of BP-3 in natural waters is slow, and even environmental persistence can be observed. However, dissolved organic matter (DOM) promotes the indirect phototransformation of BP-3 in natural waters. A variety of transformation products are generated under the synergistic effects of ROS, H₂O, and ³O₂. Assessments of environmental risks indicated that the potential eco-toxicity and health effects of the main products are significantly lower than that of the parent BP-3. More importantly, low bioaccumulation of transformation products would not enlarge their eco-toxicity and health effects. This study not only gives valuable insights into the indirect phototransformation of BP-3 in natural waters but also provides theoretical support for the feasibility of BP-3 degradation in industrial wastewater by AOPs based on OH· and ¹O₂.

Oxybenzone contamination from sunscreen pollution and its ecological threat to Hanauma Bay, Oahu, Hawaii, U.S.A

Hanauma Bay is a 101-acre bay created by the partial collapse of a volcanic cone and once supported a vibrant coral reef system. It is the most popular swimming area in the Hawaiian Islands and has been reported to have averaged between 2.8 and 3.5 million visitors a year between the 1980s and the 2010s, with visitors averaging between 3000-4000 a day and peaking around 10,000-13,000 per day. Concentrations of oxybenzone and other common UV filters were measured in subsurface water samples and in sands from the beach-shower areas in Hanauma Bay. Results demonstrate that beach showers also can be a source of sunscreen environmental contamination. Hydrodynamic modeling indicates that oxybenzone contamination within Hanauma Bay's waters could be retained between 14 and 50 h from a single release event period. Focusing on only oxybenzone, two different Hazard and Risk Assessment analyses were conducted to determine the danger of oxybenzone to Hanauma Bay's coral reef system. Results indicate that oxybenzone contamination poses a significant threat to the wildlife of Hanauma Bay. To recover Hanauma Bay's natural resources to a healthy condition and to satisfactorily conserve its coral reef and sea grass habitats, effective tourism management policies need to be implemented that mitigate the threat of sunscreen pollution.

Do Single-Component and Mixtures Selected Organic UV Filters Induce Embryotoxic Effects in Zebrafish (Danio rerio)?

UVs are important ingredients in common cosmetic products (e.g., sunscreens, hairsprays, soap). After their use, they can enter the aquatic ecosystem and negatively affect non-target aquatic organisms. The aim of our study was to evaluate acute embryotoxicity of selected organic UVs 2-phenylbenzimidazole-5-sulfonic acid (PBSA), ethylhexyl methoxycinnamate (EHMC), octocrylene (OC), 4-methylbenzylidene camphor (4-MBC) and benzophenone-3 (BP-3). The chemicals were tested both as a single substance and their mixtures. The types of mixtures were chosen as follows: the combination of OC and 4-MBC; the combination of PBSA, EHMC and BP-3 and the combination of all five UV filters. The embryotoxicity was evaluated using a modified method of the Fish Embryo Acute Toxicity Test-OECD guideline 236 and zebrafish (Danio rerio) was selected as a suitable fish model organism. The toxic effects were studied by assessing mortality, hatching and the occurrence of malformations at 24, 48, 72 and 96 h post fertilization. The obtained results indicate that especially the mixture of OC and 4-MBC presents a potential risk of embryotoxicity for zebrafish due to a significant increase in mortality, which was 41.7% in the experimental group exposed to 10 μg/L at 96 h post fertilization. Based on our results, the most effected sub-lethal endpoints were hatching and malformation (e.g., edema of pericard, bent spine, yolk edema), but with no statistically significant effect. These results differ within groups with single UVs and with their mixtures, suggesting the interaction of these substances when they are exposed together.