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

Insight into the generation of toxic by-products during UV/H2O2 degradation of carbamazepine: Mechanisms, N-transformation and toxicity

Carbamazepine (CBZ) is a widely used anticonvulsant drug that has been detected in aquatic environments. This study investigated the toxicity of its by-products (CBZ-BPs), which may surpass CBZ. Unlike the previous studies, this study offered a more systematic approach to identifying toxic BPs and inferring degradation pathways. Furthermore, quadrupole time-of-flight (QTOF) and density functional theory (DFT) calculations were employed to analyze CBZ-BP structures and degradation pathways. Evaluation of total organic carbon (TOC) and total nitrogen (TN) mineralization rates, revealed carbon (C) greater susceptibility to mineralization compared with nitrogen (N). Furthermore, three rules were established for CBZ decarbonization and N removal during degradation, observing the transformation of aromatic compounds into aliphatic hydrocarbons and stable N-containing organic matter over time. Five potentially highly toxic BPs were screened from 14 identified BPs, with toxicity predictions guiding the selection of commercial standards for quantification and true toxicity testing. Additionally, BP207 emerged as the most toxic, supported by the predictive toxicity accumulation model (PTAM). Notably, highly toxic BPs feature an acridine structure, indicating its significant contribution to toxicity. These findings offered valuable insights into the degradation mechanisms of emerging contaminants and the biosafety of aquatic environments during deep oxidation.

Environmentally relevant concentrations of benzophenones exposure disrupt intestinal homeostasis, impair the intestinal barrier, and induce inflammation in mice

The aim of this study is to investigate the adverse effects of benzophenones (BPs) on the intestinal tract of mice and the potential mechanism. F1-generation ICR mice were exposed to BPs (benzophenone-1, benzophenone-2, and benzophenone-3) by breastfeeding from birth until weaning, and by drinking water after weaning until maturity. The offspring mice were executed on postnatal day 56, then their distal colons were sampled. AB-PAS staining, HE staining, immunofluorescence, Transmission Electron Microscope, immunohistochemistry, Western Blot and RT-qPCR were used to study the effects of BPs exposure on the colonic tissues of offspring mice. The results showed that colonic microvilli appeared significantly deficient in the high-dose group, and the expression of tight junction markers Zo-1 and Occludin was significantly down-regulated and the number of goblet cells and secretions were reduced in all dose groups, and the expression of secretory cell markers MUC2 and KI67 were decreased, as well as the expression of intestinal stem cell markers Lgr5 and Bmi1, suggesting that BPs exposure caused disruption of intestinal barrier and imbalance in the composition of the intestinal stem cell pool. Besides, the expression of cellular inflammatory factors such as macrophage marker F4/80 and tumor necrosis factor TNF-α was elevated in the colonic tissues of all dose groups, and the inflammatory infiltration was observed, which means the exposure of BPs caused inflammatory effects in the intestinal tract of F1-generation mice. In addition, the contents of Notch/Wnt signaling pathway-related genes, such as Dll-4, Notch1, Hes1, Ctnnb1and Sfrp2 were significantly decreased in each high-dose group (P < 0.05), suggesting that BPs may inhibit the regulation of Notch/Wnt signaling pathway. In conclusion, exposure to BPs was able to imbalance colonic homeostasis, disrupt the intestinal barrier, and trigger inflammation in the offspring mice, which might be realized through interfering with the Notch/Wnt signaling pathway.

Multi-omics reveals the molecular mechanism of the combined toxic effects of PFOA and 4-HBP exposure in MCF-7 cells and the key player: mTORC1

With the discovery of evidence that many endocrine-disrupting chemicals (EDCs) in the environment influence human health, their toxic effects and mechanisms have become a hot topic of research. However, investigations into their endocrine-disrupting toxicity under combined binary exposure, especially the molecular mechanism of combined effects, have rarely been documented. In this study, two typical EDCs, perfluorooctanoic acid (PFOA) and 4-hydroxybenzophenone (4-HBP), were selected to examine their combined effects and molecular mechanism on MCF-7 cell proliferation at environmentally relevant exposure concentrations. We have successfully established a model to evaluate the binary combined toxic effects of endocrine disruptors, presenting combined effects in a simple and direct way. Results indicated that the combined effect changed from additive to synergistic from 1.25 × 10-8 M to 4 × 10-7 M. Metabolomics analyses suggested that exposure to PFOA and 4-HBP caused significant alterations in purine metabolism, arginine, and proline metabolism and had superimposed influences on metabolism. Enhanced combined effects were observed in glycine, serine, and threonine metabolic pathways compared to exposure to PFOS and 4-HBP alone. Additionally, the differentially expressed genes (DEGs) are primarily involved in Biological Processes, especially protein targeting the endoplasmic reticulum, and significantly impact the oxidative phosphorylation and thermogenesis-related KEGG pathway. By integrating metabolome and transcriptome analyses, PFOA and 4-HBP regulate purine metabolism, the TCA cycle, and endoplasmic reticulum protein synthesis in MCF-7 cells via mTORC1, which provides genetic material, protein, and energy for cell proliferation. Furthermore, molecular docking confirmed the ability of PFOA and 4-HBP to stably bind the estrogen receptor, indicating that they have different binding pockets. Collectively, these findings will offer new insights into understanding the mechanisms by which EDCs produce combined toxicity.

Ultraviolet Filters: Dissecting Current Facts and Myths

Skin cancer is a global and increasingly prevalent issue, causing significant individual and economic damage. UV filters in sunscreens play a major role in mitigating the risks that solar ultraviolet ra-diation poses to the human organism. While empirically effective, multiple adverse effects of these compounds are discussed in the media and in scientific research. UV filters are blamed for the dis-ruption of endocrine processes and vitamin D synthesis, damaging effects on the environment, induction of acne and neurotoxic and carcinogenic effects. Some of these allegations are based on scientific facts while others are simply arbitrary. This is especially dangerous considering the risks of exposing unprotected skin to the sun. In summary, UV filters approved by the respective governing bodies are safe for human use and their proven skin cancer-preventing properties make them in-dispensable for sensible sun protection habits. Nonetheless, compounds like octocrylene and ben-zophenone-3 that are linked to the harming of marine ecosystems could be omitted from skin care regimens in favor of the myriad of non-toxic UV filters.

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.

Role of benzophenone-3 additive in the effect of polyethylene microplastics on Daphnia magna population dynamics

The adverse effects of microplastics (MPs) on Daphnia magna have been extensively studied; however, their population-level effects are relatively unknown. This study investigated the effect of polyethylene MP fragments (33.90 ± 17.44 μm) and benzophenone-3 (BP-3), which is a widely used plastic additive (2.91 ± 0.02% w/w), on D. magna population dynamics in a 34-day microcosm experiment. In the growth phase, neither MP nor MP/BP-3 fragments changed the population size of D. magna compared with the control. However, MP/BP-3 fragments significantly reduced (p < 0.05) the population biomass compared to that of the control, whereas MP fragments did not induce a significant reduction. The MP/BP-3 group had a significantly higher (p < 0.05) neonate proportion than that in the control and MP groups. MP/BP-3 fragments upregulated usp and downregulated ecrb, ftz-f1, and hr3, altering gene expression in the ecdysone signaling pathway linked to D. magna growth and development. These findings suggested that BP-3 in MP/BP-3 fragments may disrupt neonatal growth, thereby decreasing population biomass. In the decline phase, MP fragments significantly decreased (p < 0.05) the population size and biomass of D. magna compared with the control and MP/BP-3 fragments. This study highlights the importance of plastic additives in the population-level ecotoxicity of MPs.

A high-throughput method for the determination of 14 UV-filters in human plasma by LC-MS/MS: Minimize interferences from proteins and phospholipids in the matrix

Accurate monitoring of UV-filters exposure levels in human plasma is a challenge because of the significant differences in the physicochemical properties of UV-filters, as well as the matrix effect caused by abundant proteins and phospholipids in plasma. Therefore, an effective and rapid method for simultaneous determination of 14 UV-filters in human plasma using protein precipitation-solid phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Acetonitrile with 0.1 % formic acid and 10 % isopropanol (v/v) were used as mobile phases. A gradient elution on an ACQUITY UPLC BEH-C18 column at 30 °C and 0.3 mL/min flow rate was applied for separation. The electrospray ionization positive or negative modes were selected to determine the corresponding analyte to increase selectivity and sensitivity. Results showed that acetonitrile-tetrahydrofuran (v/v, 8:2) as the extraction solvent can effectively precipitate protein in plasma and improve the solubility of UV-filters. The HybridSPE cartridge improved the removal efficiency of phospholipids, while 1 mL of methanol elution increased the extraction recoveries of targets. Fourteen UV-filters achieved good linearities, low detection limits (0.050 to 0.10 μg/L) and quantification limits (0.10 to 1.0 μg/L). Method accuracy and precision, extraction recoveries, and storage stabilities of all analytes met the criterion of 80-120 %. Moreover, this method was successfully applied for the determination of UV-filters in plasma randomly collected from adults. Nine of 14 UV-filters were determined and their concentrations were distributed widely, suggesting a big variation of individual UV-filters exposure.

Tissue-specific distributions of organic ultraviolet absorbents in free-range chickens and domestic pigeons from Guangzhou, China

The ecological risks of organic ultraviolet absorbents (UVAs) have been of increasing concern. Studies have found that these chemicals could be accumulated in terrestrial animals and pose toxicities. However, tissue distribution of UVAs in terrestrial species was far from well understood. In this study, free-range chickens and domestic pigeons were selected to investigate the occurrence and tissue distribution of UVAs. Total concentrations of eleven UVAs in muscles ranged from 778 to 2874 (mean 1413 ± 666) ng/g lipid weight, which were higher than those in aquatic species worldwide. Since low UVA concentrations in local environment were previously reported, the results implied the strong accumulation of UVAs in studied species. Brain, stomach and kidney were main target organs for studied UVAs, differentiating from the strong liver sequestration in aquatic species. The mean tissue-to-muscle ratios of 1.02-4.23 further indicated the preferential accumulation of target UVAs in these tissues. The tissue-to-blood ratios of benzophenone (BP), 2-ethylhexyl salicylate (EHS) and homosalate (HMS) in brain were 370, 1207 and 52.0, respectively, implying their preferential accumulation in brain. More research is needed to characterize the toxicokinetics and tissue distribution of UVAs in terrestrial wild species, in order to further understand their potential risks.

Endocrine Disruptors and Metabolic Changes: Impact on Puberty Control

OBJECTIVE

This study aims to explore the significant impact of environmental chemicals on disease development, focusing on their role in developing metabolic and endocrine diseases. The objective is to understand how these chemicals contribute to the increasing prevalence of precocious puberty, considering various factors, including epigenetic changes, lifestyle, and emotional disturbances.

METHODS

The study employs a comprehensive review of descriptive observational studies in both human and animal models to identify a degree of causality between exposure to environmental chemicals and disease development, specifically focusing on endocrine disruption. Due to ethical constraints, direct causation studies in human subjects are not feasible; therefore, the research relies on accumulated observational data.

RESULTS

Puberty is a crucial life period with marked physiological and psychological changes. The age at which sexual characteristics develop is changing in many regions. The findings indicate a correlation between exposure to endocrine-disrupting chemicals and the early onset of puberty. These chemicals have been shown to interfere with normal hormonal processes, particularly during critical developmental stages such as adolescence. The research also highlights the interaction of these chemical exposures with other factors, including nutritional history, social and lifestyle changes, and emotional stress, which together contribute to the prevalence of precocious puberty.

CONCLUSION

Environmental chemicals significantly contribute to the development of certain metabolic and endocrine diseases, particularly in the rising incidence of precocious puberty. Although the evidence is mainly observational, it adequately justifies regulatory actions to reduce exposure risks. Furthermore, these findings highlight the urgent need for more research on the epigenetic effects of these chemicals and their wider impact on human health, especially during vital developmental periods.

Unveiling the toxic effects, physiological responses and molecular mechanisms of tobacco (Nicotiana tabacum) in exposure to organic ultraviolet filters

Exposure to organic ultraviolet (UV) filters has raised concerns due to their potential adverse effects on environments. However, their toxic mechanisms on plants remain elusive. In this study, using integrative physiological and transcriptomic approaches we investigated the physiological and molecular responses to three representative UV filters, namely oxybenzone (OBZ), avobenzone (AVB), and octinoxate (OMC), in an agricultural model plant tobacco. The exposure to UV filters disrupts the functionality of photosystem reaction centers and the light-harvesting apparatus. Concurrently, UV filters exert a suppressive effect on the expression of genes encoding Rubisco and Calvin-Benson cycle enzymes, resulting in a decreased efficiency of the Calvin-Benson cycle and consequently hampering the process of photosynthesis. Exposure to UV filters leads to significant generation of reactive oxygen species within tobacco leaves and downregulation of oxidoreductase activities. Moreover, UV filters promote abscisic acid (ABA) accumulation by inducing the expression of ABA biosynthesis genes whereas repress indole-3-acetic acid (IAA) biosynthesis gene expression, which induce leaf yellowing and slow plant growth. In summary, the organic UV filters exert toxic effects on tobacco growth by inhibiting chlorophyll synthesis, photosynthesis, and the Calvin-Benson cycle, while generating excessive reactive oxygen species. This study sheds light on the toxic and tolerance mechanisms of UV filters in agricultural crops.

Dilute-and-shoot approach combined with in-situ formed metal-containing ionic liquids for extraction of benzophenone and related compounds from açaí-based food products

For the first time, benzophenone and related compounds were investigated in açaí-based food products. An extraction method based on the dilute-and-shoot approach, combined with the use of in-situ formed metal-containing ionic liquids (MCILs) followed by high-performance liquid chromatography, was developed and validated. A nickel and cobalt-based MCIL, in addition to the ratio of MCIL to lithium bis[(trifluoromethyl)sulfonyl]imide salt ([Li+][NTf2-]) for the ensuing metathesis reaction, were optimized. Parameters of the in-situ formed MCIL step, namely, the amount of MCIL, centrifugation time, and dilution step, were analyzed using a multivariate optimization approach, including central composite rotatable design and Derringer and Suich's tool. Optimum extraction performance was achieved using 50.98 mg of nickel-based MCIL and a MCIL to ([Li+][NTf2-]) ratio of 1:3 (m/m), a centrifuge time of 22 min, and 10.53 mL of water for the dilution step. This condition was used to perform analytical validation, which yielded satisfactory results with R2 ≥ 0.995, limits of detection (LOD) ranging from 0.0025 to 0.5 mg kg-1, and limits of quantification (LOQ) between 0.008 and 1.5 mg kg-1. The recovery rate ranged from 87 % to 107 % and precision values (as percent relative standard deviation) were equal or lower than 13 %. The validated method was applied to 25 samples of açaí-based food products purchased from Brazil and the United States. None of the samples showed analyte concentration levels above the LOD. The method's suitability was demonstrated for future monitoring of complex samples, such as foodstuffs.

Insights into enhanced oxidation of benzophenone-type UV filters (BPs) by ferrate(VI)/ferrihydrite: Increased conversion of Fe(VI) to Fe(V)/Fe(IV)

In this work, the oxidation performance of a new ferrate(VI)/ferrihydrite (Fe(VI)/Fh) system was systematically explored to degrade efficiently six kinds of benzophenone-type UV filters (BPs). Fe(VI)/Fh system not only had a superior degradation capacity towards different BPs, but also exhibited higher reactivity over a pH range of 6.0-9.0. The second-order kinetic model successfully described the process of BP-4 degradation by heterogeneous Fh catalyzed Fe(VI) system (R2 = 0.93), and the presence of Fh could increase the BP-4 degradation rate by Fe(VI) by an order of magnitude (198 M-1·s-1 v.s. 14.2 M-1·s-1). Remarkably, there are higher utilization efficiency and potential of Fe(VI) in Fe(VI)/Fh system than in Fe(VI) alone system. Moreover, characterization and recycling experiments demonstrated that Fh achieved certain long-term running performance, and the residual Fe content of solution after clarifying process meet World Health Organization (WHO) guidelines for drinking water. The contributions of reactive species could be ranked as Fe(V)/Fe(IV) > Fe(VI) > •OH. Fe(IV)/Fe(V) were the dominant species for the enhanced removal in the Fe(VI)/Fh system, whose percentage contribution (72 %-36 %) were much higher than those in Fe(VI) alone system (5 %-17 %). However, the contribution of Fe(VI) in oxidizing BP-4 should not be underestimated (20 %-56 %). These findings reasonably exploit available Fh resources to reduce the relatively high cost of Fe(VI), which offers a proper strategies for efficient utilization of high-valent iron species and may be used as a highly-efficient and cost-effective BPs purification method.

Endocrine-disrupting chemicals in Vietnamese marine fish: Occurrence, distribution, and risk assessment

The release of endocrine-disrupting chemicals (EDCs) into the aquatic environment, specifically the oceans, is increasing, leading to adverse effects on the marine ecosystem. Using optimized QuEChERS extraction methods, the study created the first contamination profiles of 44 EDCs, including organic ultraviolet compounds, pharmaceutically active compounds, hormones, and phthalate esters, in 114 fish muscle samples from five species collected along the Vietnamese coast. The study found that largehead hairtail exhibited the highest total EDCs at 208.3 ng g-1 lipid weight (lw), while Indian catfish displayed the lowest concentration at 105.5 ng g-1 lw. Besides, the study observed notable variations in the total EDCs across distinct fish species. This study hypothesized that the marine economic characteristics of each research location have a significant role in shaping the pollution profile of EDCs found in fish specimens taken from the corresponding area. As a result, a notable disparity in the composition of organic ultraviolet compounds has been observed among the three regions of North, Central, and South Vietnam (Mann-Whitney U test, p < 0.05). Despite these findings, EDC-contaminated fish did not pose any health risks to Vietnam's coastal population.

Self-assembled Fe3O4-NH2 @g-C3N4 composite for magnetic solid-phase extraction of benzophenones in sea water and lake water coupled with LC-MS/MS determination

Magnetic solid-phase extraction (MSPE) was developed based on a well-designed Fe3O4-NH2 @g-C3N4 nanocomposite as sorbent for a mixture of six benzophenones (BPs) in environmental water samples. The composite fabricated via in-situ self-assembled g-C3N4 shell with homogeneous polymerization of cyanuric chloride and cyanuric acid on Fe3O4-NH2 core. While high adsorption capacity was derived from g-C3N4 via hydrophobic, π-π and hydrogen bonding interactions to the targets, the fast magnetic separation was realized with Fe3O4 core for less solvent consumption. In combination with LC-MS/MS, the Fe3O4-NH2 @g-C3N4 sorbent minimized the interfering components, reduced the matrix effects, and provided the enrichment factors of 121-150 for six BPs with relative standard deviations ≤ 9.7% even after 20 times extraction-desorption cycles. The present method gave the detection limits of 0.3-2.5 ng/L for six BPs with the linear ranges of 1.0-2000 ng/L, and the recoveries of 84.6%-104% in sea water and 86.2%-107% in lake water samples. Thus, the Fe3O4-NH2 @g-C3N4-based MSPE coupled with LC-MS/MS method provided a convenient, efficient, and reliable alternative to monitor trace BPs in environmental water samples.

The associations between high-levels of urine benzophenone-type UV filters (BPs) and changes in serum lipid concentrations

Little is known about the potential health impacts of benzophenone-type UV filters (BPs) exposure among the general population. In our study conducted in Wuxi, China, we investigated the associations between the concentrations of eight BP-derivatives and five target lipid molecules. We collected basic information, serum, and urine samples from 120 residents aged 9 to 80 in Wuxi. We determined BPs in urine samples and lipid levels in serum samples. Generalized linear models were used to evaluate the differences in ln-transformed serum target lipids levels (μg/L) with different urine BPs quartiles compared to the lowest quartile. Benzophenone-4 (BP-4) had the highest detection rate (95.0%) and geometric mean concentration (1.96 μg/L) among all the BP-derivatives in our study population. The exposure levels of BPs were generally higher in females than in males. Participants in the 9-17 and 18-50 age groups exhibited greater levels of exposure to BPs than those in the 51-80 age group. We observed statistically significant changes in LysoPC (18:0), LysoPE (18:0), ΣLPL, and ΣTL concentrations between the highest and lowest quartiles of BP-4. Similar changes were found in LysoPE (18:0) concentration between the highest and lowest quartiles of ΣBP-3 and ΣBPs. High urine BP concentrations were associated with variations in our target serum lipids involved in neurological and metabolic disorders, and posed a potential health risk. Future studies are warranted to further validate and elucidate our findings.

Easy determination of benzophenone and its derivatives in sunscreen samples by direct-immersion solid-phase microextraction and gas chromatography-mass spectrometry

Benzophenones (BPs) absorb different sun radiation wavelengths, making them effective UVA and UVB filters, widely used in industry. In Europe, sunscreen products contain regulated amounts (6 % w/w) of benzophenone-3 (BP-3), usually combined with other filters like octocrylene. BPs are mutagens in UV radiation, and octocrylene may degrade into BPs, making their monitoring crucial. The present manuscript proposed a novel procedure based on liquid-liquid extraction followed by direct-immersion solid-phase microextraction (LLE-DI-SPME) to isolate and determine 10 BPs in sunscreen lotions with potential results. Parameters like extraction solvent, pH, adsorption, desorption time, stirring, sating effect, and presence of organic solvents were optimized and compared with different SPME fibers, being polyacrylate (PA) fiber the most effective. Detection and quantification were performed by gas chromatography-mass-spectrometry. Analytical parameters as limits of detection were 0.05-0.10 µg kg-1, while the linear range was 0.16 up to 2000 µg kg-1. In terms of recovery, the method ranged from 83 % to 103 %; the precision of the method was good in terms of relative standard deviation (RSD) from 3.2 % to 18.7 % and without a remarkable matrix effect (-15.06-8.45 %). Despite the complexity of the samples and the difficulty posed by the DI-SPME technique, the method proved robust. The proposed method successfully detected 10 BPs in 6 different sunscreen lotions. The total presence of BPs in sunscreens ranged from 165 to 931 mg kg-1, with BP-3 detected in all samples from 4.2 to 740 mg kg-1.

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.

The environmental sources of benzophenones: Distribution, pretreatment, analysis and removal techniques

Benzophenones (BPs) have wide practical applications in real human life due to its presence in personal care products, UV-filters, drugs, food packaging bags, etc. It enters the wastewater by daily routine activities such as showering, impacting the whole aquatic system, then posing a threat to human health. Due to this fact, the monitoring and removal of BPs in the environment is quite important. In the past decade, various novel analytical and removal techniques have been developed for the determination of BPs in environmental samples including wastewater, municipal landfill leachate, sewage sludge, and aquatic plants. This review provides a critical summary and comparison of the available cutting-edge pretreatment, determination and removal techniques of BPs in environment. It also focuses on novel materials and techniques in keeping with the concept of "green chemistry", and describes on challenges associated with the analysis of BPs, removal technologies, suggesting future development strategies.

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.

Toxic effects and molecular mechanisms of estuarian crustaceans (Scylla paramamosain) exposed to five commonly used benzophenones

Benzophenones (BPs) are commonly used in personal care products like sunscreens and are increasingly being released into the environment, raising concerns about their potential ecotoxic effects. BPs as emerging environmental contaminants, little is known about their toxic effects on estuarine organisms. This study firstly investigated the toxic effects of five commonly used BPs on mud crabs (Scylla paramamosain). The crabs were exposed to varying concentrations of BPs for 14 days. The results showed that BPs caused damage to antioxidant systems in crabs. Transcriptome sequencing revealed that BP-3 and BP-1 had a greater impact on the crabs compared to the other BPs. Specifically, BP-1 and BP-3 caused severe damage to organelles and ribosomes. BP affected catalytic activity and hydrolase activity, BP-2 affected phosphoenolpyruate carboxykinase activity, and BP-4 affected tRNA aminoacylation and hydrolase activity. These findings can enhance our understanding of the ecotoxicity of BPs and may help to protect estuarine ecosystems.

Health risks posed by environmental benzophenone-type ultraviolet filters (BP-UVFs): An investigation into the binding of BP-UVFs to trypsin and their adverse effects

Benzophenone-type ultraviolet filters (BP-UVFs) are ubiquitous in the environment, and people frequently ingest them via food chain and drinking water. However, there is no clear information about whether BP-UVFs are detrimental to human health. Herein, experiments using multi-spectroscopy revealed typical BP-UVFs, i.e., benzophenone (BP), 2-hydroxybenzophenone (2-OHBP), 4-hydroxybenzophenone (4-OHBP), 2,2'-dihydroxybenzophenone (2,2'-OHBP), 2,4-dihydroxybenzophenone (2,4-OHBP), 4,4'-dihydroxybenzophenone (4,4'-OHBP), 2,4,4'-trihydroxybenzophenone (2,4,4'-OHBP), 2,2',4,4'-tetraphydroxybenzophenone (2,2',4,4'-OHBP), 2-hydroxy-4-methoxybenzophenone (2-OH-4-MeOBP) and 2,2'-dihydroxy-4-methoxybenzophenone (2,2'-OH-4-MeOBP), could bind to the active site of trypsin with different binding constants (2.69 × 104-1.07 × 106 L/mol), cause structural abnormalities and inhibit the enzymatic activity in varying degrees, indicating that the BP-UVFs ingestion poses a risk to human health. In contrast to previous research, this study systematically analysed the binding mechanism using an innovative combination of molecular docking and advanced quantum chemistry calculations, including molecular dynamics simulations, energy calculations, etc. The results revealed that most amino acids that make up trypsin have a greater positive electrostatic surface potential (ESP). Therefore, the greater the area and distribution of negative ESP in a particular BP-UVFs, the more easily it will bind to trypsin. This provides new insight into the binding of pollutants to proteins. This study suggests a need for better monitoring and control of environmental BP-UVFs.

Novel visible-light-active P-g-CN-based α-Bi2O3/WO3 ternary photocatalysts with a dual Z-scheme heterostructure for the efficient decomposition of refractory ultraviolet filters and environmental hormones: Benzophenones

The ubiquitous and refractory benzophenone (BP)-type ultraviolet filters, which are also endocrine disruptors, were commonly detected in the aquatic matrix and could not be efficiently removed by conventional wastewater treatment processes, thus causing extensive concern. Herein, a novel ternary nanocomposite, P-g-CN/α-Bi2O3/WO3 (P-gBW), was successfully fabricated by mixing cocalcinated components and applied to the decomposition of BP-type ultraviolet filters. The dual-Z-scheme heterostructure of P-gBW enhances visible-light absorption, efficiently facilitates separation and mobility, and prolongs the lifetime of photoinduced charge carriers via double charge transfer mechanisms. The optimum 95 wt% P-gBW exhibited excellent photocatalytic activity, degrading 96% 4-hydroxy benzophenone (4HBP) within 150 min and 93% 2,2',4,4'-tetrahydroxybenzophenone (BP-2) within 100 min under visible-light illumination, respectively. The pseudo-first-order rate constant of 4HBP (1.15 h-1) was 6.8-, 3.1-, 3.3- and 2.2-fold higher than those of WO3, P-g-CN, α-Bi2O3, and P-g-CN/α-Bi2O3, respectively, while that of BP-2 (1.71 h-1) was 5.2-, 2.2-, 3.2- and 1.5-fold higher, respectively. The improved photocatalytic degradation was attributed to efficient photoinduced charge carrier separation and migration and prevented the recombination of electron holes, as verified by photoluminescence, transient photocurrent response, and electrochemical impedance spectroscopy. Trapping experiments, electron paramagnetic resonance, and band energy position indicated an efficient dual-Z-scheme heterostructure.

Safety of benzophenone-type UV filters: A mini review focusing on carcinogenicity, reproductive and developmental toxicity

Consumer products containing benzophenone-type ultraviolet (UV) filters (BPs) have been widely accepted by the public, resulting in the widely existence of various BPs in the human body and environment. In recent years, more and more evidences show that BPs are endocrine disruptors. In view of the continuous exposure risk of BPs and their endocrine disrupting characteristics, the carcinogenicity of BPs and their effects on reproduction and development are of particular concern. However, due to the wide varieties of BPs and the scattered toxicity studies on BPs, people have a limited understanding on the safety of BPs. Therefore, this paper systematically reviews the carcinogenicity, reproductive and developmental toxicity of BPs in order to expand people's knowledge on the health risks of BPs and screen for more safe BPs. Although existing toxicological studies are insufficient, it can be determined that BPs have different potentials for carcinogenicity, and reproductive and developmental toxicity. Among those BPs, 2-hydroxyl-4-methoxyl benzophenone needs to be used with caution due to its adverse effects on cancer cell proliferation and migration, reproductive ability, sex differentiation, neurodevelopment, and so on. It is worth noting that functional group substitutions significantly affect the interaction between BPs and biomolecules such as DNA, cancer cells, and seminal fluid, resulting in different levels of toxicity. In short, it is very necessary to evaluate the carcinogenicity, reproductive and developmental toxicity of BPs, which is of great significance for establishing reasonable BPs content standards in cosmetics, water quality treatment standards for BPs, and so on.

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.

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.

Primary and ultimate degradation of benzophenone-type UV filters under different environmental conditions and the underlying structure-biodegradability relationships

Ten common benzophenone-based UV filters (BPs), sharing the same basic structure and differing only in their substituents, were investigated with respect to their primary and ultimate biodegradability. This study was carried out in order to gain deeper insights into the relationship between structure and biodegradability. The primary biodegradation of the selected BPs was studied in river water at environmentally relevant concentrations (1 µg/L) while varying specific, crucial environmental conditions (aerobic, suboxic, supplementation of nutrients). For this purpose, both batch and column degradation tests were performed, which allowed a systematic study of the effects. Subsequently, the ultimate biodegradation, i.e. the potential to achieve full mineralization of BPs, was examined according to OECD guideline 301 F. The results indicate that mineralization is limited to derivatives in which both aromatic rings contain substituents. This hypothesis was supported by docking simulations showing systematic differences in the orientation of BPs within the active site of the cytochrome P450 enzyme. These differences in orientation correspond to the substitution pattern of the BPs. This study provides valuable insights for assessing the environmental hazards of this class of trace organic compounds.

Efficient removal of persistent and emerging organic pollutants by biosorption using abundant biomass wastes

Persistent and emerging organic pollutants represent a serious and global threat to human health and ecosystems. We describe here a simple, efficient and affordable technology for removing such organic pollutants from aquatic systems. Biosorption process was chosen, meeting these three criteria, and so that biosorbents should be biomass wastes combining the following characteristics: natural, cheap and abundant. Powdered dead roots from invasive alien species (Eichhornia crassipes, Pistia stratiotes and Fallopia japonica), and wastes rich in tannins such as coffee grounds and green tea grounds were tested as biosorbents for removing extensively used organic pollutants: organic UV-filters, insecticides and herbicides. The elemental composition and morphology of the biosorbents were fully determined. The biosorption kinetics for each pair of biosorbent/pollutant was described by a pseudo-second order model. Excellent biosorption efficiency was obtained for 10 μM solution of oxybenzone (89 ± 1%), octocrylene (90 ± 2%), lindane (88 ± 0%) and diuron (90 ± 1%) in only 2 h. And total removal of 10 μM of chlordecone (100 ± 0%) could be achieved, which could be of high concern for the population living in chlordecone-contaminated areas. As such pollutants can be found in aquatic ecosystems, an interference study with salts showed that biosorption efficiency remained as efficient in reconstituted seawater. A principal component analysis was performed as an attempt to rationalise the biosorption results. The solubility of the organic pollutants in water and the concentration of tanins in the biosorbents were key parameters.

Binding of common organic UV-filters to the thyroid hormone transport protein transthyretin using in vitro and in silico studies: Potential implications in health

Several anthropogenic contaminants have been identified as competing with the thyroid hormone thyroxine (T₄) for binding to transport proteins as transthyretin (TTR). This binding can potentially create toxicity mechanisms posing a threat to human health. Many organic UV filters (UVFs) and paraben preservatives (PBs), widely used in personal care products, are chemicals of emerging concern due to their adverse effects as potential thyroid-disrupting compounds. Recently, organic UVFs have been found in paired maternal and fetal samples and PBs have been detected in placenta, which opens the possibility of the involvement of TTR in the transfer of these chemicals across physiological barriers. We aimed to investigate a discrete set of organic UVFs and PBs to identify novel TTR binders. The binding affinities of target UVFs towards TTR were evaluated using in vitro T₄ competitive binding assays. The ligand-TTR affinities were determined by isothermal titration calorimetry (ITC) and compared with known TTR ligands. In parallel, computational studies were used to predict the 3-D structures of the binding modes of these chemicals to TTR. Some organic UVFs, compounds 2,2',4,4'-tetrahydroxybenzophenone (BP2, Kd = 0.43 μM); 2,4-dihydroxybenzophenone (BP1, Kd = 0.60 μM); 4,4'-dihydroxybenzophenone (4DHB, Kd = 0.83 μM), and 4-hydroxybenzophenone (4HB, Kd = 0.93 μM), were found to display a high affinity to TTR, being BP2 the strongest TTR binder (ΔH = -14.93 Kcal/mol). Finally, a correlation was found between the experimental ITC data and the TTR-ligand docking scores obtained by computational studies. The approach integrating in vitro assays and in silico methods constituted a useful tool to find TTR binders among common organic UVFs. Further studies on the involvement of the transporter protein TTR in assisting the transplacental transfer of these chemicals across physiological barriers and the long-term consequences of prenatal exposure to them should be pursued.

Contaminants of emerging concern in marine areas: First evidence of UV filters and paraben preservatives in seawater and sediment on the eastern coast of Tunisia

UV filters (UVFs) and paraben preservatives (PBs) are widely used components in many personal care products. However, there has been a rising concern for their endocrine-disrupting effects on wildlife once they reach aquatic ecosystems via recreative activities and wastewater treatment plants effluents. This study addresses UVFs and PBs occurrence in seawater and sediment impacted by tourism and sewage discharges along the coast of Mahdia, center East Tunisia. Samples of water and sediment were collected for 6 months from 3 coastal areas. Among the 14 investigated UVFs, 8 were detected in seawater and 4 were found in sediment. All PBs were present in seawater and only methylparaben (MePB) was detected in sediment. Benzophenone-3 (oxybenzone, BP3), benzocaine (EtPABA), and MePB were present in all water samples with concentrations in the ranges 16.4-66.9, 7.3-37.7, and 17.6-222 ng/L, respectively. However, the highest value, 1420 ng/L, corresponded to octinoxate (EHMC). In sediments, avobenzone (AVO), 4-methyl benzylidene camphor (4MBC), EHMC, 5-methyl-1-H-benzotriazole (MeBZT), and MePB were detected at concentrations within the range 1.1-17.6 ng/g dw, being MePB the most frequently detected (89%). MePB and MBZT presented the highest sediment-water partition coefficients and MePB also showed a positive correlation with total suspended solids' water content. Overall, pollutants concentrations remained rather constant along the sampling period, showing little seasonal variation. This study constitutes the first monitoring of UVFs and PBs on the Tunisian coastline and provides occurrence data for reference in further surveys in the country.

Comprehensive Survey of 14 Benzophenone UV Filters in Sunscreen Products Marketed in the United States: Implications for Human Exposure

Benzophenone (BP)-type ultraviolet (UV) filters are estrogenic chemicals used extensively in sunscreen products, leading to concerns over human exposure. To assess exposure to BP derivatives in sunscreens, we tested 14 BP UV filters in 50 products representing 44 brands marketed in the United States in 2021, finding BP, 2-hydroxy-4-methoxybenzophenone (BP-3 or oxybenzone), 2,2'-dihydroxy-4-methoxybenzophenone (BP-8), 2-hydroxy-4-methoxy-4'-methylbenzophenone (BP-10), 2,3,4-trihydroxybenzophenone (2,3,4-OH-BP), and 4-methylbenzophenone (4-Me-BP) in ≥70% of the samples. The geometric mean (GM) concentration of the sum of these BPs (∑₁₄BPs) in the 50 products was 6600 ng/g. BP-3 was the predominant BP in oxybenzone-containing products (accounting for >99% of the total concentration), with a concentration 5-6 orders of magnitude higher than that in "oxybenzone-free" products (GM: 35 600 000 vs 113 ng/g). BP was present in >90% of products analyzed, including those labeled "oxybenzone-free" (GM: 2100 ng/g). BP concentrations were ∼100-fold higher in octocrylene-containing vs "octocrylene-free" products (GM: 15900 vs 151 ng/g). Dermal exposure doses of BP-3 from oxybenzone-containing products (GM: 4140 000 ng/kg body weight (BW)/day) and of BP in some (24%) octocrylene-containing products (GM: 12 200 ng/kg BW/day) were above reference values (2 000 000 and 30 000 ng/kg BW/day for BP-3 and BP, respectively). This study provides evidence that BP and BP-3 concentrations in sunscreen products vary widely and may be noteworthy even in products labeled oxybenzone- or octocrylene-free, making dermal exposure a continuing concern.

Halogenated ingredients of household and personal care products as emerging endocrine disruptors

The everyday use of household and personal care products (HPCPs) generates an enormous amount of chemicals, of which several groups warrant additional attention, including: (i) parabens, which are widely used as preservatives; (ii) bisphenols, which are used in the manufacture of plastics; (iii) UV filters, which are essential components of many cosmetic products; and (iv) alkylphenol ethoxylates, which are used extensively as non-ionic surfactants. These chemicals are released continuously into the environment, thus contaminating soil, water, plants and animals. Wastewater treatment and water disinfection procedures can convert these chemicals into halogenated transformation products, which end up in the environment and pose a potential threat to humans and wildlife. Indeed, while certain parent HPCP ingredients have been confirmed as endocrine disruptors, less is known about the endocrine activities of their halogenated derivatives. The aim of this review is first to examine the sources and occurrence of halogenated transformation products in the environment, and second to compare their endocrine-disrupting properties to those of their parent compounds (i.e., parabens, bisphenols, UV filters, alkylphenol ethoxylates). Albeit previous reports have focused individually on selected classes of such substances, none have considered the problem of their halogenated transformation products. This review therefore summarizes the available research on these halogenated compounds, highlights the potential exposure pathways, and underlines the existing knowledge gaps within their toxicological profiles.

In Vivo Bioconcentration, Distribution and Metabolization of Benzophenone-3 (BP-3) by Cyprinus carpio (European Carp)

Organic UV-filters, such as oxybenzone (BP-3), have attracted researcher attention in recent years due to its capacity to interfere with the proper functioning of the endocrine system and its widespread presence in the aquatic environment. The aim of this study was to investigate the bioconcentration, distribution and metabolization of BP-3 in one of the most common fish species in Romania, namely Cyprinus carp (European carp). Exposure experiments were performed for 11 weeks using a BP-3 nominal concentration level of 100 µg/L. The BP-3 concentration level decreased over time and needed to be re-established daily. Biological samples (fish organs and tissues) from control and test were taken at t0 (before contamination) and at t3, t5, t8 and t11 weeks from the beginning of the experiment. From the third week, BP-3 was identified and quantified, in all organs, in concentration values ranging between 3.2 and 782 ng/g d.w., the highest concentration being detected in the intestinal content, followed by gonads (up to 468 ng/g d.w.) and skin (up to 453 ng/g d.w.). In the case of gill and liver, the BP-3 concentration increased in the first five weeks, and then decreased to 15 and 6 ng/g d.w., respectively, which could be explained by a fast BP-3 metabolization. During the exposure period, six metabolites were identified through LC-MS/MS, all of them known for their endocrine disruptor and toxic properties being higher than those of the parent compound. The study is important from an ecological perspective and also in view of human health concerns involving food quality.