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Transformation of avobenzone in conditions of aquatic chlorination and UV-irradiation
Abstract
Emerging contaminants represent a wide group of the most different compounds. They appear in the environment at trace levels due to human activity. Most of these compounds are not yet regulated. Sunscreen UV-filters play an important role among these emerging contaminants. In the present research the reactions of 4-tert-butyl-4'-methoxydibenzoylmethane (avobenzone), the most common UV filter in the formulation of sunscreens, were studied under the combined influence of active chlorine and UV-irradiation. Twenty five compounds were identified by GC/MS as transformation products of avobenzone in reactions of aquatic UV-irradiation and chlorination with sodium hypochlorite. A complete scheme of transformation of avobenzone covering all the semivolatile products is proposed. The identification of the two primary chlorination products (2-chloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione and 2,2-dichloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione) was confirmed by their synthesis and GC/MS and NMR analysis. Although the toxicities of the majority of these products remain unknown substituted chlorinated phenols and acetophenones are known to be rather toxic. Combined action of active chlorine and UV-irradiation results in the formation of some products (chloroanhydrides, chlorophenols) not forming in conditions of separate application of these disinfection methods. Therefore caring for people «well-being» it is of great importance to apply the most appropriate disinfection method. Since the primary transformation products partially resist powerful UV-C irradiation they may be treated as stable and persistent pollutants.
... In one study, during the chlorination of AVO in reconstituted seawater (with a concentration of about 70 mg/L of bromide at pH 8.0, excluding the presence and possible role of the organic material normally present in solution), the presence of other brominated carbon derivatives was detected on the alpha carbon between the two carbonyl groups, namely the brominated products AVO/65 and AVO/66 as well as increasing quantities of bromoform (4, Scheme 2)-the ultimate product of oxidative degradation [38] (Scheme 6)-as a function of time. Among all solar filters, AVO has been studied in more detail; various groups have evaluated its reactivity in the chlorination reaction in distilled water [39][40][41][42][43], in water in the presence of dissolved organic material [39], in swimming pool water [44], in seawater, [40,45] and in the bromination reaction with KBrO in water [44]. In order to fill the gaps in the literature, an assessment of the toxicity of these products on human health would be both beneficial and interesting. ...
... In one study, during the chlorination of AVO in reconstituted seawater (with a concentration of about 70 mg/L of bromide at pH 8.0, excluding the presence and possible role of the organic material normally present in solution), the presence of other brominated carbon derivatives was detected on the alpha carbon between the two carbonyl groups, namely the brominated products AVO/65 and AVO/66 as well as increasing quantities of bromoform (4, Scheme 2)-the ultimate product of oxidative degradation [38] (Scheme 6)-as a function of time. Among all solar filters, AVO has been studied in more detail; various groups have evaluated its reactivity in the chlorination reaction in distilled water [39][40][41][42][43], in water in the presence of dissolved organic material [39], in swimming pool water [44], in seawater, [40,45] and in the bromination reaction with KBrO in water [44]. In addition, one study evaluated its transformation due to the effect of irradiation with UV rays, during which it was stable at a maximum absorption at 254 nm [42]. ...
... Among all solar filters, AVO has been studied in more detail; various groups have evaluated its reactivity in the chlorination reaction in distilled water [39][40][41][42][43], in water in the presence of dissolved organic material [39], in swimming pool water [44], in seawater, [40,45] and in the bromination reaction with KBrO in water [44]. In addition, one study evaluated its transformation due to the effect of irradiation with UV rays, during which it was stable at a maximum absorption at 254 nm [42]. On the contrary, it was more reactive when irradiated in a solution of water and acetonitrile (1:1)-where the formation of products in increasing quantities was observed as a function of the irradiation time (from 1 to 4 h) and generally identified by GC-MS analysis-or when irradiation and chlorination were combined [35]. ...
The development of any commercial product should also be aimed at reducing the risk associated with it, according to the safe-by-design concept; that is, risk assessment should always be at the center of the design, and the impact on human and environmental health should be assessed and eliminated during the product development phase and not afterwards. Unfortunately, even today, most operators in any production sector implement the philosophy of “risk management” or rather of managing the problem when it occurs, using spot interventions instead of changing the approach. This argument is also valid in the production of solar filters, which have reached a satisfactory degree of efficiency in the face of a substantial underestimation of the risks associated with their possible environmental fate. In fact, solar filters have been found in bathing waters and their environmental fate may depend on various factors such as the pH of the water, the presence of organic material, metal ions and light, and, above all, the chemical agents used in the disinfection of the water itself. Thus, during disinfection processes, the generation of dozens of products with a lower molecular weight and generally of an aromatic nature has been tested, where some of them did not receive an exact structural definition and a precise evaluation of their precise toxicological profile. Therefore, it is interesting to draw a complete picture of organic sunscreens and of the byproducts obtained under different conditions and their related ecotoxicological profile.
... BMDBM exists in two different tautomer forms ( Fig. 1): the ketoform that absorbs light at around 265 nm, and the enol-form that absorbs light at around 355 nm (Kojić et al., 2016). The enol-form is the dominant form in sunscreens (Trebše et al., 2016). Different photoisomerization pathways can occur during UV irradiation, including enol-keto tautomerization (Berenbeim et al., 2020). ...
... Different photoisomerization pathways can occur during UV irradiation, including enol-keto tautomerization (Berenbeim et al., 2020). Some studies have investigated the photodegradation of BMDBM in pure and chlorinated water matrices during UVC irradiation under conditions that simulated disinfection and advanced oxidation processes (Celeiro et al., 2019;Crista et al., 2015;Trebše et al., 2016). However, the photodegradation of BMDBM and the formation of TPs under conditions relevant to sunlit surface waters have not been studied in detail, and little is known about the physicochemical properties and ecotoxicity of its TPs. ...
... They were likely formed from oxidation reactions involving the abovementioned radical intermediates in the presence of O 2 and H donor compounds (Fig. 3) (Schwack and Rudolph, 1995). Some studies have reported that the aromatic acids P 2-2 and P 2-4 are the main TPs formed during the direct photolysis of BMDBM (Schwack and Rudolph, 1995;Trebše et al., 2016). P 3-1 (C 22 H 26 O 2 ) and P 3-2 (C 18 H 18 O 4 ) both contained two aromatic rings, and were likely formed from recombination reactions involving the radical intermediates II and III (Fig. 3). ...
With the widespread use of sunscreen and other personal care products, organic ultraviolet filters (OUVFs) have become widely detected in the aquatic environment. Direct and indirect photolysis are important transformation pathways of OUVFs in aquatic environments, so their transformation products (TPs) are also chemicals of concern. Butyl methoxydibenzoylmethane (BMDBM) is one of the most commonly used OUVFs worldwide due to its ability to absorb ultraviolet light across a wide range of wavelengths, and it is ubiquitously detected in aquatic environments. In this study, we investigated the photodegradation of BMDBM through direct photolysis and hydroxyl radical (•OH) photooxidation. TPs were identified using ultrahigh performance liquid chromatography-high resolution mass spectrometry, and reaction mechanisms were proposed. Our results showed that the photodegradation rates for both enol and keto tautomer forms of BMDBM during direct photolysis and •OH photooxidation were similar. The formation of TPs resulted from α-cleavage and decarbonylation reactions involving the keto form of BMDBM. Comparisons of the kinetic data and TPs revealed that the direct photolysis mechanism was a significant sink for BMDBM even during •OH photooxidation. Evaluations of environmental properties based on the predicted physicochemical properties of BMDBM and TPs suggests that some of the TPs will have higher mobility than BMDBM. The quantitative structure-activity relationship (QSAR) approach was used to evaluate the ecotoxicity of BMDBM and the identified TPs. Most TPs were found to be less ecotoxic than BMDBM; however, TPs that had a diphenyl ring structure could be more ecotoxic than BMDBM. Overall, this study provides new insights into the photochemical behavior and ecotoxicity of BMDBM and its TPs, which are important for assessing the fate, persistence, accumulation, and adverse impacts of these compounds in aquatic environments.
... The combined action of active chlorine and UVC radiation results in the formation of several dozens of compounds (including chloroanhydrides and chlorophenols). Some of them are not produced when these two disinfection methods are applied alone (Trebše et al., 2016). The primary chlorination products of avobenzone (2-chloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione and 2,2-dichloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3propanedione) were studied further for degradation at different pH, as well as for photostability (Wang et al., 2017). ...
... Finally, analysis of selected water samples, taking from swimming pools in Slovenia, filled with fresh and seawater has been performed. The results obtained with real samples were compared with that of the earlier experiments in terms of products formation identified previously as DBPs forming during aquatic chlorination of avobenzone (Kalister et al, 2016;Trebše et al, 2016;Wang et al., 2017;Chugunova et al., 2017;Detenchuk et al., 2019). ...
... Environment International 137 (2020) 105495 avobenzone in conditions of aquatic bromination. It is quite similar to that of aquatic chlorination (Trebše et al, 2016;Detenchuk et al., 2019). However, brominated compounds are formed in that case. ...
The increased use of sunscreens and other cosmetics containing UV filters causes human and environmental burden. Avobenzone is a widely used UV filter. In its pure form it is known to undergo several transformations including photo-isomerisation, photodegradation, and halogenation. Over 60 disinfection by-products were identified as transformation products of avobenzone in different disinfection reactions of chlorination and bromination in fresh and seawater. Two occasional samples of swimming pool water demonstrated the presence of some of these by-products at noticeable levels as judged by GC-MS peak areas. Although the toxicity of the majority of these products remain unknown, chlorinated phenols and acetophenones are known to be rather toxic. Aquatic bromination of avobenzone resulted in the identification of 33 disinfection by-products (DBPs). Many of them contain bromine in the molecular structure. Addition of copper salt slightly decreases conversion rate simultaneously increasing the levels of major brominated products.
Photostability of 3 commercial sunscreen products (solar protection factor 30) containing avobenzone was studied under different experimental conditions including UVA/UVB, UVC photostimulation and chlorination. The commercial sunscreen products have completely different enhancing and inhibitory effect on avobenzone degradation under UVC light. The complex composition of commercial products caused also a protective shield in case of chlorinated solutions of commercial formulations exposed to chlorine and UVA/UVB light at the same time.
... The primary products 1-(tert-butyl)-2chloro-3-(4-methoxyphenyl)-1,3-dione and 1-(tert-butyl)-2,2-dichloro-3-(4-methoxyphenyl)propan-1,3-dione were specially synthesized by us. 34 Their mass spectra and retention times repeated those observed during aqueous chlorination of avobenzone. Same reaction with the double bond took place in conditions of aqueous bromination. ...
... Advanced stages of aqueous chlorination and bromination of avobenzone in the fresh and sea water, as well as with the addition of inorganic cations (Cu 2+ and Fe 3+ ) and anions (Brand I -) to the tap water were studied in detail. [34][35][36]40 The experimental conditions dramatically influenced the range and levels of the reaction products. For example, addition of copper ions under aqueous bromination conditions resulted in 100-fold increase in the bromoform yield. ...
This work summarizes our research on synthesis, characterization and toxicity of selected UV-A filters and their antioxidant shield in commercial formulation – resveratrol. Benzophenone type of UV filters react under disinfection conditions with chlorine and form different mono- and dichlorinated products, while dibenzoylmethane derivatives, such as avobenzone, react with chlorine and form two main bridge chlorinated products followed by numerous chlorinated species at the advanced stages of the process. Resveratrol showed three main susceptible centers to chlorination, starting from the electrophilic addition to the double bond and continuing with the chlorination of the phenolic moieties. Several experiments conducted under different disinfection conditions (pool/sea water, addition of salts, irradiation) showed basically similar chlorination patterns with some variations in terms of product formation. The results of toxicity assessment using different test organisms (Vibrio fischeri, microalgae, daphnids) have shown different sensitivity of testing organisms to the parent UV filters in comparison with chlorinated products as well as different toxicity for specific UV filter in comparison to the others. As the closing loop of all experiments in the laboratory, an up-scaling to the real human skin is presented.
... The UV/Cl process, or rather UV/NaOCl process, is a rather new type of AOP, that has gained much attention recently (Trebše et al., 2016, Yang et al., 2021. Often a broad range of TP is formed (Pan et al., 2017, Dao et al., 2018. ...
... The combined action of active chlorine and UV irradiation results in the formation of e.g. chloro anhydrides and chlorophenols (Trebše et al., 2016). The reactions proceed primarily via chlorine addition and hydrogen abstraction, with the possibility of electron transfer. ...
This guidance document provides a tiered framework for risk assessors and facilitates risk managers in making decisions concerning the approval of active substances (AS) that are chemicals in plant protection products (PPPs) and biocidal products, and authorisation of the products. Based on the approaches presented in this document, a conclusion can be drawn on the impact of water treatment processes on residues of the AS or its metabolites in surface water and/or groundwater abstracted for the production of drinking water, i.e. the formation of transformation products (TPs). This guidance enables the identification of actual public health concerns from exposure to harmful compounds generated during the processing of water for the production of drinking water, and it focuses on water treatment methods commonly used in the European Union (EU). The tiered framework determines whether residues from PPP use or residues from biocidal product use can be present in water at water abstraction locations. Approaches, including experimental methods, are described that can be used to assess whether harmful TPs may form during water treatment and, if so, how to assess the impact of exposure to these water treatment TPs (tTPs) and other residues including environmental TPs (eTPs) on human and domesticated animal health through the consumption of TPs via drinking water. The types of studies or information that would be required are described while avoiding vertebrate testing as much as possible. The framework integrates the use of weight-of-evidence and, when possible alternative (new approach) methods to avoid as far as possible the need for additional testing.
... AVO (4-tert-butyl-4 -methoxydibenzoylmethane), also known by the commercial names of Parsol Ò 1789 or Eusolex Ò 9020, is a chemical UV filter associated to a strong UVA protection and photo instability [4,11]. AVO exists as a mixture of two tautomeric forms: enol and keto [11,12]. ...
... AVO (4-tert-butyl-4 -methoxydibenzoylmethane), also known by the commercial names of Parsol Ò 1789 or Eusolex Ò 9020, is a chemical UV filter associated to a strong UVA protection and photo instability [4,11]. AVO exists as a mixture of two tautomeric forms: enol and keto [11,12]. The keto-enol tautomerism guarantees the chemical balance between the two isoforms, favoring the enol form in almost all media because of its ability to form intramolecular hydrogen bonds [2,12]. ...
Given the growing harmful effects of ultraviolet (UV) radiation there is an urgent need to develop effective strategies to prevent skin damages. Therefore, hydrogel or cotton and wool fabrics were impregnated with avobenzone (AVO)-loaded and omega-3 (ω3)-enriched lipid formulations (liposomes – LIP, nanostructured lipid carriers – NLC and solid lipid nanoparticles – SLN) to obtain UV blocking sunscreen gel or functional textiles. To evaluate the physicochemical characteristics of AVO and the sun blocking performance of the formulations incorporated in hydrogels or textiles, in silico and in vitro studies were conducted. In silico studies indicated that AVO can permeate the epithelium, and lipid formulations could be a promising strategy for incorporating and retaining AVO. Furthermore, all lipid formulations showed an entrapment efficiency of AVO of ca. 100 % and a loading capacity between 7 and 12 %. The presence of AVO was confirmed by ATR-FTIR and SEM analysis. In vitro release profiles showed that the UV filter was almost totally retained within the lipid formulations (release of only 4.2 ± 2.5 % at 6 h) with similar results obtained for textiles. After assessing the cytotoxicity, cationic formulations loaded with AVO showed to be cytotoxic in a human keratinocyte cell line (NCTC 2544 cells) as opposed to AVO-loaded anionic formulations after 24 h. Photodegradation studies demonstrated that lipid formulations have photoprotective properties by stabilizing AVO but the photoprotective role could not be attributed to ω3 despite its antioxidant effect evaluated by ATR-FTIR. Overall, it is possible to conclude that SLN and NLC were more effective as UV protectors than LIP, and that each formulation can have different applications. Negatively charged NLC and SLN can be used for UV protection in contact with the skin either in sunscreen gel or clothing, while positively charged NLC and SLN should be reserved as UV protectors of tissues not in contact with skin (e.g., umbrellas, curtains, etc.).
... Indeed, avobenzone and octinoxate (Scheme 1) are two ingredients contributing to coral bleaching; if they do not directly kill corals, they put them under significant stress and subject them to increased mortality levels. Moreover, the (photo)degradation of these products in water promotes the formation of chlorinated phenols well-known to be mostly toxic [17]. Endocrine disruption related to these products has also been highlighted for several years [18,19] and repeated exposures may induce serious developmental effects on reproductive organs and the central nervous system. ...
... Moreover, the (photo)degradation of these products in water promotes the formation of chlorinated phenols well-known to be mostly toxic [17]. Endocrine disruption related to these products has also been highlighted for several years [18,19] and repeated exposures may induce serious developmental effects on reproductive organs and the central nervous system. ...
Faced with the ban of some organic UV filters such as octinoxate or avobenzone, especially in Hawaii, it became essential to offer new alternatives that are both renewable and safe for humans and the environment. In this context, a class of bio-based molecules displaying interesting UV filter properties and great (photo)stability has been developed from Meldrum's acid and bio-based and synthetic p-hydroxycinnamic acids, furans and pyrroles. Moreover, p-hydroxycinnamic acid-based Meldrum's derivatives possess valuable secondary activities sought by the cosmetic industry such as antioxidant and anti-tyrosinase properties. The evaluation of the properties of mixture of judiciously chosen Meldrum's acid derivatives highlighted the possibility to modulate secondary activity while maintaining excellent UV protection. Meldrum's acid derivatives are not only competitive when benchmarked against organic filters currently on the market (i.e., avobenzone), but they also do not exhibit any endocrine disruption activity.
... Octocrylene is classified as an emerging pollutant because it is not included in environmental regulations [4,5]. Conventional treatments are not efficient in completely removing it from wastewater [4,6] and it is commonly found in surface waters on the oxygen and hydrogen break their bonds with the carbonic mass, detaching from the molecular structure [26,27]. This calcination process forms a porous structure of the biochar, and its adsorption capacity will depend on the physical-chemical properties of the material obtained and can be enhanced by the type of activation, chemical, physical, or biological, pyrolysis time, and temperature [26,27]. ...
The emerging pollutant octocrylene is not efficiently removed from effluents by conventional treatment and is recurrently found in rivers. This study evaluated the adsorption of octocrylene using commercial carbon and biochar from spent coffee grounds activated with ZnCl2. The two adsorbents had an efficiency of approximately 100% in pollutant removal throughout the experimental design. The kinetics and equilibrium isotherms showed a good correlation with the experimental data. The kinetics showed adsorption of the contaminant in 40 min for both adsorbents. The model equilibrium isotherms with the best fit and adsorption capacity was Langmuir for biochar, with a capacity of 37.822 ± 0.005 µg∙mg−1 compared to 33.602 ± 0.202 µg∙mg−1 for commercial carbon. Furthermore, a toxicity analysis of a 600 µg∙L−1 octocrylene solution was carried out before and after adsorption with the two charcoals separately, using Allium cepa roots. Before adsorption, the solution was phytotoxic and cytogenotoxic. After adsorption, the solution obtained for each charcoal no longer caused toxicity to the roots. The charcoals tested had high removal efficiency and adsorption capacity, a condition reiterated by the toxicity results. However, biochar better represented the Langmuir model in the adsorption process when removing octocrylene from the aqueous medium.
... AVO has got a low photostability, it is soluble in water at 25°C (2,200 μg/L) and is a lipophilic chemical due to its high partition coefficient octanol-water (log K ow ) of 4.51, which may affect aquatic biota at low concentrations (Wang et al., 2013;Sánchez Rodríguez et al., 2015;National Center for Biotechnology Information, 2022). This organic UV filter absorbs mainly UVA radiation (320-400 nm) and also UVC radiation (260-280 nm) when photoisomerized, exhibiting a maximum absorption at 350-365 nm (Mturi and Martincigh, 2008;Trebše et al., 2016). ...
Marine organisms are constantly exposed to multiple stressors including pollutants released into the environment, such as personal care products (PCPs), and climate change-derived factors, namely warming, which are aggravated by anthropogenic drivers and pose increasing pressure on coastal ecosystems. Avobenzone (AVO) is one of the most used ultraviolet (UV) filters in PCPs which have been increasingly used and, thereby, identified in aquatic environments. However, data regarding the influence of warming on the impacts caused by AVO in bivalves is lacking. Mussels are considered bioindicators thus being often employed in ecotoxicology studies. Hence, the present study aimed to evaluate the toxic effects of an environmentally relevant concentration of AVO (0.5 μg/L) and warming (21 °C) on sperm and adults of the Mediterranean mussel species Mytilus galloprovincialis, acting alone or in combination, through in vitro and in vivo tests, respectively. AVO and warming effects were evaluated by assessing oxidative status, viability, genotoxicity, motility, and kinetics in sperm, together with the quantification of energy content, metabolic capacity, biological defence mechanisms, cellular damage, and neurotoxicity in adults. AVO induced genotoxicity and increased respiration rate in sperm while enhancing the biotransformation enzymes' activity in adults. Exposure to warming led to an increase in respiration rate, ROS overproduction, cellular damage, and viability decrease in sperm whereas metabolic capacity increased in adults. AVO combined with warming caused oxidative stress, cellular damage, genotoxicity, and decreased motility in sperm, while only antioxidant enzymes' activity was enhanced in adults. Overall, the present study demonstrated that when acting in combination the effects of both stressors were more prominent. Furthermore, considering the multiple-stressor scenario tested, major toxic effects occurred in male gametes in comparison to adults.
... However, their removal from wastewaters is relatively efficient, with a study in Switzerland reporting high elimination rate for BP-3 (68-96%) (Balmer et al. 2005). Since organic UV filters are designed to absorb UV radiation, they are susceptible to photodegradation (Trebše et al. 2016). BP-3, however, proved to be resistant to photodegradation in neutral pH, implying that it also does not undergo photodegradation in surface waters (Y. ...
The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, benzophenones and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review was therefore to examine the sources and occurrence of these noteworthy contaminants (i.e. parabens, bisphenols, benzophenones, alkylphenol ethoxylates), to summarise the available research on their environmental presence and to highlight their bioaccumulation potential. The most notable environmental contaminants appear to be MeP and PrP among parabens, BPA and BPS among bisphenols, BP-3 among benzophenones and NP among alkylphenols. Their maximum detected concentrations in the environment are mostly in the range of ng/L, while in human tissues, their maximum concentrations achieved μg/L due to bioaccumulation, with BP-3 and nonylphenol showing the highest potential to bioaccumulate. Finally, of another great concern is the fact that even the unapproved parabens and benzophenones have been detected in the environment.
Graphical abstract
... For this reason, AVO can be defined as a lipophilic chemical compound (National Center for Biotechnology Information, 2022). This compound is an organic UV filter containing two tautomeric forms, an enol tautomer that absorbs mainly in the UVA range of 320 to 400 nm, that when photoisomerized its keto tautomer absorbs UVC radiation from 260 to 280 nm, losing its UVA protection effectiveness (Mturi and Martincigh, 2008;Trebše et al., 2016). Despite AVO reduced photostability, it is often included in sunscreens formulations due to the lack of approved and efficient UVA filters (Mancuso et al., 2017). ...
Avobenzone (AVO) is one of the most frequent ultraviolet (UV) filters in personal care products (PCPs). The Mediterranean mussel Mytilus galloprovincialis is a bioindicator often used for ecotoxicological research. Since UV filters reach higher peaks during summer in aquatic bodies, coincident with mussels' spawning period, and bivalves are sessile, both male gametes and adults of this species were used in this experiment. Therefore, the present study aimed to assess how AVO affects caused in M. galloprovincialis at different biological levels. In vitro experiments on sperm (30 min-exposure) and in vivo experiments on adults (28 days-exposure) were carried out at 0.1, 1.0 and 10.0 μg/L of AVO concentrations. The oxidative and physiological status together with neurotoxicity and genotoxicity in exposed sperm were assessed. Several biochemical parameters related to enzymatic antioxidant defences, biotransformation enzymes, cell membrane damage, energy reserves, and neurotoxicity were evaluated in adults’ mussels. Results of in vitro sperm exposure to AVO showed significant overproduction of superoxide anions and DNA damages in all treatments and a decrease in sperm viability at 1.0 and 10.0 μg/L. AVO exposure in sperm also led to complete inhibition of motility at the highest concentration, while a significant increase of curvilinear velocity and decrease of wobble occurred at 1.0 μg/L. Exposed adults exhibited a significant decrease in metabolic capacity at 0.1 μg/L, a significant increase in the total proteins content, and enzymatic turnover as superoxide dismutase (antioxidant defence) at 10 μg/L. This study revealed an ecological issue related to the higher sensitivity of sperm respectively to adults at environmentally relevant concentrations of AVO, underpinning a hypothesis of impairment in male reproductive functions.
... In both cases, parent UV filters, providing UV protection, degrade and may lose their photoprotective role. Several studies reported various reactions of UV filters in swimming waters under chlorinated conditions, leading mainly to the formation of chlorinated DBPs, with an emphasis on the determination of primary chlorinated derivatives, or their further degradation [21][22][23][24][25]. Photostability studies showed that dichloro-derivatives in chlorinated waters are less stable than the parent compound, which is not the case for monochloro-derivatives (formed initially) [22] in the case of BP-3. ...
Sunscreens ensure thorough protection against sunburn. The delivery of UV filters into the stratum corneum and viable epidermis could be reduced by the use of antioxidants (such as β-carotene and trans-resveratrol, alone or combined). The presence/absence of antioxidants (trans-resveratrol and β-carotene) in formulations containing benzophenone-3 (UV-filter) and their efficiency under disinfection and neutral conditions are studied and compared. The trial was conducted on 38 people. The prepared ointments were applied to the participants’ forearms, irradiated and monitored by reflectance colorimetry after 0, 4, 6, and 8 min. Descriptive statistics were used to describe the skin color’s main characteristics and the F-ratio was used to test overall differences. The ointments containing antioxidants and benzophenone-3 were the most efficient, followed by those with benzophenone-3 alone. It was proven that photoprotection with benzophenone-3 is still effective, despite the formation of its chlorinated products. Due to the short time of exposure to disinfecting conditions, it could be assumed that benzophenone-3 was only partially chlorinated. This clinical study demonstrated that formulations containing antioxidants are likely to be more suitable for protecting skin against UVB irradiation than a UV filter alone.
... Так, например, методом ЖХ / МС исследовано водное хлорирование УФ-протектора гексил-2-[4-(диэтиламино)-2-гидроксибензоил]-бензоата гипохлоритом натрия [52]. В результате хромато-массспектрометрического исследования хлорирования УФ-протектора авобензона в водной среде [53] и его трансформации под действием УФ-облучения [54] идентифицированы продукты его реакций хлорирования и бромирования в пресной и морской воде [33,40,55,56], протекание реакции в присутствии неорганических солей и их влияние на образование конечных продуктов дезинфекции [35]. ...
Качество питьевой воды – один из важнейших показателей сохранения здоровья населения. Наиболее распространенным способом дезинфекции питьевой воды является ее хлорирование. Однако обработка природных вод хлором с одной стороны обеспечивает эпидемиологическую безопасность, а с другой – приводит к образованию разнообразных хлорорганических соединений, которые оказывают негативное влияние на здоровье человека. Источником этих ксенобиотиков являются как природные органические вещества (гумус), так и антропогенные соединения, присутствующие в природной воде. К настоящему времени обнаружено более 700 побочных продуктов дезинфекции (ППД), причем токсикологические характеристики большинства из них остаются неизученными. Методы хромато-масс-спектрометрии показали себя наиболее эффективными в выявлении новых и определении нормируемых ППД. Эти же методы используются и для установления механизмов водного хлорирования органических соединений.
... Thus the number of products forming from resveratrol in chlorinated water may be rather high. Our earlier studies on the aquatic chlorination of the known UV-protectors diethylaminohydroxybenzoyl hexyl benzoate (DHHB) (Grbovi c et al., 2013) and especially avobenzone (Treb se et al., 2016;Wang et al., 2017;Detenchuk et al., 2019;Lebedev et al., 2020) demonstrated formation of various disinfection products mainly with the unknown biological activity. Belonging to the classes of halogenated phenols, aldehydes, acetophenones, these compounds may be rather harmful for humans. ...
Trans-resveratrol becomes more and more popular all over the world as a powerful antioxidant. Since its positive properties, including antioxidant, anti-inflammatory, anti-tumor are indisputable, nowadays trans-resveratrol is used as a component of various products from nutriceutics to body care formulations, where it is supposed to behave as natural antioxidant and anti-aging compound. It is also added to food pack aging materials to increase their stability or/and prevent oxidation. Nevertheless, being released to the environment resveratrol easily forms various transformation products with potentially negative environmental and health effects. The present paper deals with transformation of pure resveratrol and its formulation used as UV protectors in conditions of aquatic chlorination. Over 80 transformation products were tentatively identified using gas chromatography-high resolution mass spectrometry (GC-HRMS) and ultra pressure liquid chromatography-high resolution mass spectrometry (UPLC-HRMS). Chlorinated phenols and biphenyls are the most relevant among them. Estimation of toxicity of resveratrol products was carried out using luminescent bacteria V. fischeri tests.
... Gong et al. 74 showed that chlorination of linear alkylbenzenesulfonate surfactants in the absence and presence of bromide produced chlorinated DBPs, yet the overall formation of TOX was relatively small. Chlorinated DBPs were produced during chlorination of tamoxifen metabolites, 75 a UV filter used in sunscreens (avobenzone), 76 and antibiotics (ciprofloxacin, trimethoprim, sulfamethoxazole, levofloxacin, and ofloxacin), 77 all of which may contribute to the TOX pool. ...
The formation of disinfection by-products (DBPs) is challenging from both public health and drinking water treatment perspectives. Over 700 DBPs have been identified, however, a large proportion of halogenated DBPs are unknown, and the compounds responsible for the observed associations between consumption of disinfected drinking water and adverse health outcomes have yet to be identified. The measurement of total organic halogen (TOX) provides the only measure of the overall formation of halogenated DBPs, and is an attractive alternative to the measurement of individual DBPs. This paper presents a critical review of the analysis of TOX and the utility of TOX as a water quality parameter in drinking water treatment. In TOX analysis, the evolution of instrument technology has improved the sensitivity and selectivity of the measurement, and the use of good quality activated carbon was found to be crucial to achieving good recoveries (>90%). The concentrations of TOX in drinking water are not static, with the transformation or degradation of TOX over time forming smaller DBPs. Advanced oxidation processes (AOPs) could reduce or promote the formation of TOX as a result of transformations of precursor materials. Evaluation of the available existing data showed strong correlations between molar concentrations of TOX, and THMs and HAAs. Positive correlations between the concentrations of TOX and the in vitro toxicity of disinfected waters have also been reported. Therefore, one measurement of TOX can potentially provide information on the levels of regulated DBPs and toxicity in a sample, which means that a comprehensive assessment of water quality can potentially be achieved with a single measurement of TOX.
... Apart from NOM, anthropogenic compounds such as chlorinated phenols have been considered as important precursors of DBPs (Trebše et al. 2016;Xiang et al. 2016;Zhang et al. 2016;Li et al. 2017). Previous studies reported that during chlorination, acesulfame, a widely used artificial sweetener, and oxybenzone, a common component of sunscreens, formed TCAA and DCAA, and TCAA and chloroform, respectively. ...
During drinking water treatment processes, anthropogenic compounds act as important precursors of disinfection by-products such as haloacetic acids (HAAs). Several transformations in these precursors occur prior to the disinfection stage, such as partial biodegradation. We hypothesized that this partial biodegradation of anthropogenic compounds potentially affects their HAA formation potentials (HAAFPs). In this study, the HAAFPs of 51 anthropogenic compounds after short-term contact (less than 1 h) and long-term contact (24 h) with activated sludge were compared. Considerable changes were observed particularly in trichloroacetic acid (TCAA) formation potentials (FPs) of phenols, demonstrating that biodegradation should be considered in investigations of potential precursors of HAAs. Phenols with low HAAFPs, such as hydroquinone, show higher HAAFPs after biodegradation, but HAAFPs of most phenols and anilines decreased after biodegradation. Thus, biodegradation will most likely have a positive impact on water quality from the standpoint of HAAFP reduction. For most aliphatic compounds, changes in HAAFP were negligible, but the dichloroacetic acid (DCAA) FP of acrylic acid largely increased. This study illustrates that biodegradation may have a large effect on the HAAFPs of anthropogenic compounds.
... Studies on the environmental contamination and organismal/environmental fate of these UV filters have mainly focused on chemical migration, transformation and removal from aqueous solutions (Buchberger, 2010;Caliman and Gavrilescu, 2010;Trebše et al., 2016) and their light stability in PPCPs (Kawakami and Gaspar, 2015). Wastewater influent and effluent contamination is an issue of concern for environmental engineering because of the considerable inefficiency of current wastewater treatment systems, which results in significant environmental contamination (Ekpeghere et al., 2016;O'Malley et al., 2019). ...
Oxybenzone (OBZ), avobenzone (AVB), octocrylene (OCR) and octinoxate (OMC) are ultraviolet (UV) filters commonly added to chemical sunscreens. These UV filters are known to widely contaminate the environment through a variety of anthropogenic sources, including sewage discharge. However, systematic studies of the damage caused by these four UV filters and their toxicopathological differences in a variety of plant species are lacking. In this study, we demonstrated that irrigation with water containing these four UV filters could significantly inhibit the aboveground growth of cucumber plant. All of the UV filters decreased photosynthesis through nonstomatal factors but via different inhibitory mechanisms. Only OBZ inhibited photosynthesis by directly inhibiting photosynthetic electron transport, while the other three (AVB, OCR, and OMC) inhibited photosynthesis by inhibiting the Calvin-Benson cycle. Additionally, these four UV filters also decreased plant respiration under long-term treatment. Photosynthesis and respiration inhibition led to the over production of reactive oxygen species (ROS) and the formation of lipid peroxidation damage products, which further damaged the structure and function of plant cells, causing secondary pathologies and potentially leading to reduced crop yields. The study also demonstrated that these four UV filters caused different degrees of phototoxic damage to cucumber plants. On the basis of comprehensive evaluation, we speculated that the order of the four UV filters in terms of plant damage was OBZ > AVB > OMC > OCR. Because of the severe damaging effects of these UV filters on plant growth, the application of contaminated biosolids/reclaimed water in agriculture reduces agricultural production and may damage ecosystems. The results of this study can advance recognition of the hazards associated with environmental and agricultural pollution via UV filters and encourage consumers and the industry to limit or reduce the application of cosmetics and over-the-counter drugs containing these substances.
... This UV filter can act as a metabolic obesogen disruptor in human 21 . The transformation of avobenzone under chlorination and UV-irradiation conditions has been studied and several toxic species can be formed through these processes 22 . Also, UV light has been shown to cause homolytic bond cleavage, resulting in radical formation, followed by the oxidative damage to protein in vitro, and therefore is potentially linked to adverse health effects 23 . ...
Rationale:
Exposure to UV light can induce adverse effects on human health, such as photo-aging, immunosuppression, and cancer. Sunscreens are used to prevent the absorption of UV rays, but certain UV-filtering compounds have been shown to disrupt endocrine systems or act as carcinogens. To assess the effects of the exposure to such compounds, it is important to study the pathways in which they are biotransformed in the body.
Methods:
Liquid chromatography coupled to high-resolution tandem mass spectrometry (LC/HRMS/MS) was employed to evaluate the oxidative metabolism and, specifically, the formation of reactive metabolites of six active ingredients commonly used in sunscreen formulations: oxybenzone, avobenzone, homosalate, octisalate, octocrylene, and octinoxate. In vitro incubations were performed with human and rat liver microsomes in the presence of β-nicotinamide adenine dinucleotide phosphate and glutathione. An LC/HRMS/MS method was developed to identify metabolites employing a biphenyl reverse-phase column for separating parent molecules, metabolites, and glutathione adducts.
Results:
Each tested compound resulted in the formation of several metabolites, including at least one GSH adduct. Compounds containing ester groups were hydrolyzed, and some metabolites of the free acid forms were also detected. High-resolution MS/MS data was crucial for the structural elucidation of metabolites and GSH adducts. Fragmentation pathways were proposed for all parent compounds, as well as each described metabolite and adduct.
Conclusions:
The results of this study will help better understand the metabolism and detoxification pathways of these xenobiotics.
... According to the data presented in Table 6, this substance was moderately removed from conventional WWTPs. The case of avobenzone was further complicated since it forms chloro-metabolites and chlorophenols under disinfection (chlorination, UV-irradiation) [94,95]. These products are generally toxic and little research has been carried out on their environmental fate, mainly on swimming pools and not on WWTP effluents. ...
Wastewater is not a waste but a valuable resource that should be reused. Nevertheless, it should be devoid of physical, chemical, and microbiological parameters that can harm the consumer. Along with the multitude of possible pollutants found in wastewater treatment plants (WWTPs), emerging pollutants, such as Personal Care Products (PCPs), have arisen. The present research examines some of the main ingredients commonly found in PCPs, focusing on their toxicological profile on their occurrence in WWTPs influents and effluents worldwide and on their persistence and biodegradability. A small-scale market sampling of PCPs was performed in Athens, Greece, in June 2019, and their individual ingredients were recorded, coded according to their main activity, scanned for the presence of ingredients of important toxicological profile, and finally analyzed for the presence of other candidates of toxicological interest. Results show that some ingredients of concern (i.e., parabens and triclosan) are a decreasing trend. On the other hand, information on the presence of synthetic musks and perfume synthesis is scarce and encumbered by brand protection. Finally, UV filters are numerous, and they are used in various combinations, while other ingredients of toxicological interest are also present. Since the reclaimed water may well be used to cover irrigation needs in Greek areas with water deficiency or to enrich bodies of surface water, it is important to know what PCP ingredients are on the rise in the market, to monitor their presence in WWTPs influents and effluents and to extend research on their environmental fate and behavior
... Competition of reactive centers in the reaction of aquatic chlorination is very important. It is difficult to predict the site of the primary attack (Lebedev, 2007;Treb se et al., 2016). It is the absence of other reactive centers in BAC molecules that makes radical substitution competitive. ...
The maintenance of public swimming pools requires numerous technological steps. One of the most important issues involves microbiological safety. Benzalkonium chloride (BAC) encompasses homologous alkylbenzyldimethylammonium chlorides with various alkyl chains, in particular C12 and C14, and is known as a popular algaecide for keeping water clean. In addition to BAC, NaOCl and UV-irradiation are also used to treat pool water as additional technological steps. Therefore, BAC itself can become a precursor of disinfection byproducts (DBPs). High-performance liquid chromatography – tandem mass spectrometry (HPLC-MS/MS), with accurate mass measurements, has allowed the discovery of several groups of DBPs that are related to BAC in public pool water in Arkhangelsk (Russia). These DBPs include numerous isomeric monochlorinated derivatives ([C21H37ClN]+ and [C23H41ClN]+), hydroxyl derivatives ([C21H38NO]+ and [C23H42NO]), carbonyl ([C21H36NO]+ and [C23H40NO]+), and dicarbonyl derivatives ([C21H34NO2]+ and [C23H38NO2]+). In addition, chlorinated alcohols, ketones and ketoalcohols of BAC were also detected, including [C21H35ClNO]+, [C21H37ClNO]+ and [C21H35ClNO2]+ for BAC-12; and [C23H39ClNO]+, [C23H41ClNO]+ and [C23H39ClNO2]+ for BAC-14. MS/MS allowed reliable elucidation of the structures of novel DBPs, proving that chlorination starts via radical substitution in the long aliphatic chains of BAC. UV-irradiation dramatically accelerates the reaction completely destroying the original compounds in less than an hour, while the array of the intermediate products remains the same as in the dark. The formation of other DBPs proceeds due to further reactions of these primary products. The concentrations of novel DBPs in pool water reach μg L−1 levels. These conclusions were proved by conducting model reactions of BAC with NaOCl.
... Organic UV filters have also been shown to cause harmful effects on coral communities (Danovaro et al., 2008;Tsui et al., 2017). Furthermore, some organic UV filters are transformed into toxic halogenated products in chlorinated waters (Manasfi et al., 2017;Treb se et al., 2016). Considering their potential negative effects on aquatic organisms and quality of drinking water source, it is necessary to better understand the fate and transformation of these chemicals in engineered and natural urban water cycles. ...
... Furthermore, the reaction of UV filters with chlorine added for disinfection of swimming pool water or in wastewater treatment plants has received the attention of researchers since several years. In these studies, halogenated transformation products and disinfection byproducts (DBPs) have been identified for several organic UV filters ( Santos et al., 2012;Duirk et al., 2013;Sakkas et al., 2003;Negreira et al., 2008;Manasfi et al., 2015Manasfi et al., , 2017aTrebše et al., 2016;Kalister et al., 2016). Despite evidence of transformation and formation of DBPs, there have been very few studies investigating the toxicity of the formed transformation products. ...
The mutagenicity of four organic UV filters namely oxybenzone (benzophenone-3), dioxybenzone (benzophenone-8), avobenzone, and octyl methoxycinnamate, in chlorinated bromide-rich water (artificial seawater) was investigated. Mutagenicity was evaluated using Ames test in Salmonella typhimurium TA98 without S9 mix. Chemical analysis using high-resolution mass spectrometry was carried out to elucidate the mutagenic transformation products. Among the studied UV filters, only dioxybenzone exhibited a clear mutagenic activity following chlorination in seawater at ratio 1:10 (UV filter:chlorine). In contrast, no mutagenic activity was detected when chlorine was added at higher doses (ratio 1:1000). High-resolution mass spectrometry analysis showed that mutagenic extracts contained several brominated transformation products of dioxybenzone. Time course analysis of the transformation products at increasing chlorine doses showed that they were unstable and disappeared more quickly at higher chlorine doses. This instability explained the absence of mutagenic activity of dioxybenzone when 1000-fold excess chlorine was added, as no transformation products were detected. Relevance of these findings to the context of swimming pool is discussed. Further investigations taking into consideration the mutagenicity of not only the intermediate transformation products but also the final disinfection byproducts are needed to determine the overall impact of high levels of chlorine on the overall mutagenicity. This study highlights the importance of considering the reactivity of organic UV filters and their transformation products in disinfected recreational waters when sunscreen formulations are prepared.
... Наиболее легко опознавае мой группой ППД являются галогензамещенные фенолы, детектируемые в режиме ХИАД (-). Фено лы очень активны в реакциях водного хлорирова ния [22,23], если, конечно, в составе молекулы нет еще более реакционноспособных центров [24,25]. В случае водопроводной воды г. ...
Disinfection of drinking water with chlorine-containing reagents leads to the formation of a large number of disinfection by-products resulting from the chlorination of natural dissolved organic matter. High-performance liquid chromatography/high-resolution mass spectrometry with preliminary solid-phase concentration on a polymeric sorbent was used to study the component composition of halogencontaining disinfection by-products in the tap water in Arkhangelsk. Fourteen chlorinated and brominated organic compounds belonging to classes of halophenols, aromatic acids and carbonyl compounds, chlorine-substituted nitrogen-containing heterocyclic compounds have been found. Based on the analysis of MS/MS spectra data, the possible structures of detected disinfection by-products are proposed.
... An appropriate example involves rather safe UV-filter avobenzone widely used all over the world in different personal care preparations. Appearing in chlorinated fresh (Treb se et al., 2016) or sea water (Chugunova et al., 2017) as well as simply being dissolved in fresh water subjected to UV-light (Cheng et al., 2017) avobenzone transforms with formation of several dozens of products with unknown toxicity of the majority of them. ...
An array of similar halogenated nitrogen-containing compounds with elemental composition CnH2nNO2X, CnH2n–2NO2X and CnH2n-1NOX2 (X = Cl, Br; n = 16, 18, 22) was detected in drinking water with high pressure liquid chromatography – high resolution mass spectrometry (HPLC-HRMS) method. Compounds of this type were never mentioned among disinfection by-products. Tandem mass spectrometry allowed referring them to halohydrines or dihalogenated fatty amides, the products of conjugated electrophilic addition of halogens to the double bonds of unsaturated fatty amides. The proposed structures were confirmed by conducting aqueous chlorination with standard solution of oleamide. These compounds may be considered as a brand new class of disinfection by products, while their toxicities require special study.
Objective:
Organic micropollutants of concern - including organic UV filters (UVF) - are getting increasing attention. Personal care products such as sun screens or cosmetic articles often contain large quantities of UVF. These substances enter the environment either directly (during outdoor activities) or indirectly (via sewages from households). Therefore, the removal or degradation of UVF by natural or technical treatment processes is important to understand. UVF are often incompletely removed and transformed to side products of incomplete mineralization by abiotic and biotic processes. An extensive overview on transformation products (TPs) is essential to systematically identify knowledge gaps and to derive research needs. Whilst there are many reviews on the UVF themselves, the number of reviews which focus on their TPs is limited. Consequently, this review gives an overview on the latest findings regarding TPs of UVF.
Methods:
In this publication, known TPs of UVF, which were formed during abiotic and biotic processes, are reviewed. Target substances were defined and a literature database was reviewed for studies on TPs of the target substances. The first list of studies was shortened stepwise, thus generating a final list of studies which contained only the relevant studies. Since biodegradation is one of the most important pathways for removal of organic compounds from the environment, this review presents an overview on known TPs of organic UVF and their biodegradability, which determines their environmental fate. In this way, all identified TPs of UVF were listed and checked for information on their biodegradability.
Results:
2,731 records of studies were assessed. 42 studies, which assessed 46 processes that lead to the formation of identified TPs, were included in this review. 177 different TPs resulting from eleven different UVF were identified.
Conclusion:
Little to no data on the biodegradability was found for TPs. This indicates a severe lack of data on the biodegradability of TPs of organic UVF substances. Since most TPs lack information on biodegradability, further research should provide information on both - identity and biodegradability - of formed TPs to be able to assess their hazardousness for the environment.
Although being successfully applied all over the world for more than 100 years water disinfection by means of chlorination possesses certain drawbacks, first of all formation of hazardous disinfection by-products (DBP). Aromatic halogenated DBPs significantly contribute to the total organic halogen and developmental toxicity of chlorinated water. The present study deals with investigation of possible substitution of one halogen for another in aromatic substrates in conditions of aqueous chlorination/bromination. The reaction showed high yields especially in case of substrates with proper position of an activating group in the aromatic ring. Thus, ipso-substitution of iodine by chlorine is the main process of aqueous chlorination of para-iodoanisole. Oxidation of the eliminating I⁺ ions into non-reactive IO3⁻ species facilitates the substitution. Oxidation of eliminating Br⁺ is not so easy while being highly reactive it attacks initial substrates forming polybrominated products. Substitution of iodine and bromine by chlorine may also involve migration of electrophilic species inside the aromatic ring resulting in larger number of isomeric DBPs. Substitution of chlorine by bromine in aromatic substrates during aqueous bromination is not so pronounced as substitution of bromine by chlorine in aqueous chlorination due to higher electronegativity of chlorine atom. However, formation of some chlorine-free polybrominated products proves possibility of that process.
Sunscreens containing UV filters, such as octocrylene (OCR) and butyl-methoxydibenzoylmethane (BMDBM), have been increasingly used to protect human skin against UV radiation. Both substances have been detected in monitoring studies in the freshwater and marine environment, and there has been concern about potential effects on aquatic organisms. In the present work, the environmental fate and occurrence, bioaccumulation and ecotoxicity including endocrine effects of OCR and BMDBM are reviewed focusing on the aquatic environment. The two UV filters have low water solubilities and a high sorption potential. The available data indicate that OCR is poorly biodegradable. BMDBM lacks anaerobic and inherent biodegradability. However, it was biodegraded to variable degrees in simulation studies. Measured concentrations in the freshwater and marine environment were found to vary considerably between sites, depending on the extent of recreational activities or wastewater discharges. While the bioconcentration factor of OCR in fish is below the threshold value for bioaccumulation according to EU REACH, the available data for BMDBM do not allow a definitive conclusion on its bioaccumulation potential. Analysis of the aquatic toxicity data showed that data quality was often limited, e.g. in the case of effect concentrations substantially exceeding maximum achievable dissolved concentrations. Up to their limit of water solubility, OCR and BMDBM showed no toxicity to microorganisms, algae, and corals, and no acute toxicity to daphnids and fish. In chronic daphnid tests, OCR was highly toxic, whereas BMDBM lacked toxicity. Reliable water-sediment toxicity tests are required to further evaluate possible effects on benthic invertebrates. The available data do not provide evidence for endocrine effects of the two UV filters on fish. In order to assess potential environmental risks caused by OCR and BMDBM, a validated exposure model for estimating direct emission of UV filters into the aquatic environment and data from systematic, longer-term monitoring studies are needed.
Avobenzone is an ultraviolet (UV) filter that is often included in sunscreen formulations despite its lack of photostability. Its inclusion is necessary due to few existing alternatives for photoprotection in the UVA region (320-400 nm). To better understand and predict the photostability of avobenzone, ultrafast transient electronic absorption spectroscopy (TEAS) has been used to study the effects of solvent (including emollients), concentration and skin surface temperature on its excited-state relaxation mechanism, following photoexcitation with UVA radiation (∼350 nm). Subtle differences between the excited-state lifetimes were found between the systems, but the TEAS spectral features were qualitatively the same for all solution and temperature combinations. Alongside TEAS measurements, UV filter/emollient blends containing avobenzone were irradiated using simulated solar light and their degradation tracked using steady-state UV-visible spectroscopy. Sun protection factor (SPF) and UVA protection factor (UVA-PF) assessments were also carried out on representative oil phases (higher concentration blends), which could be used to formulate oil-in-water sunscreens. It was found that there was an apparent concentration dependence on the long-term photoprotective efficacy of these mixtures, which could be linked to the ultrafast photodynamics by the presence of a ground-state bleach offset. This combination of techniques shows potential for correlating long-term behaviours (minutes to hours) of avobenzone with its ultrafast photophysics (femtoseconds to nanoseconds), bridging the gap between fundamental photophysics/photochemistry and commercial sunscreen design.
Ethylhexyl methoxycinnamate (EHMC) (CAS number: 5466-77-3) and butyl methoxydibenzoylmethane (BMDM) (CAS number: 70356-09-1) are important sunscreens. However, frequent application of large amounts of these compounds may reflect serious environmental impact, once it enters the environment through indirect release via wastewater treatment or immediate release during water activities. In this article, we reviewed the toxicological effects of EHMC and BMDM on aquatic ecosystems and the human consequences. According to the literature, EHMC and BMDM have been detected in water samples and sediments worldwide. Consequently, these compounds are also present in several marine organisms like fish, invertebrates, coral reefs, marine mammals, and other species, due to its bioaccumulation potential. Studies show that these chemicals are capable of damaging the aquatic beings in different ways. Further, bioaccumulation studies have shown that EHMC biomagnifies through trophic levels, which makes human seafood consumption a concern because the higher position in the trophic chain, the more elevate levels of ultraviolet (UV) filters are detected, and it is established that EHMC present adverse effects on the human organism. In contrast, there are no studies on the BMDM bioaccumulation and biomagnification potential. Different strategies can be adopted to avoid the damage caused by sunscreens in the environment and human organism. Two of them include the use of natural photoprotectors, such as polyphenols, in association with UV filters in sunscreens and the development of new and safer UV filters. Overall, this review shows the importance of studying the impacts of sunscreens in nature and developing safer sunscreens and formulations to safeguard marine fauna, ecosystems, and humans.
Nanoplastics with small particle sizes and high surface area/volume ratios easily absorb environmental pollutants and affect their bioavailability. In this study, polystyrene nanoplastic beads (PS-NPBs) with a particle size of 100 nm and butyl methoxydibenzoylmethane (BMDBM) sunscreen in personal-care products were chosen as target pollutants to study their developmental toxicity and interactive effects on zebrafish embryos. The exposure period was set from 2 to 12 h postfertilization (hpf). BMDBM and PS-NPBs significantly upregulated genes related to antioxidant enzymes and downregulated the gene expression of aromatase and DNA methyltransferases, but the influenced genes were not exactly the same. The combined exposure reduced the adverse effects on the expression of all genes. With the help of the single-cell RNA sequencing technology, neural mid cells were identified as the target cells of both pollutants, and brain development, head development, and the notch signaling pathway were the functions they commonly altered. The key genes and functions that are specifically affected by BMDBM and/or PS-NPBs were identified. BMDBM mainly affects the differentiation and fate of neurons in the central nervous system through the regulation of her5, her6, her11, lfng, pax2a, and fgfr4. The PS-NPBs regulate the expression of olig2, foxg1a, fzd8b, six3a, rx1, lhx2b, nkx2.1a, and sfrp5 to alter nervous system development, retinal development, and stem cell differentiation. The phenotypic responses of zebrafish larvae at 120 hpf were tested, and significant inhibition of locomotor activity was found, indicating that early effects on the central nervous system would have a sustained impact on the behavior of zebrafish.
The present paper deals with the study of condensation reaction of aniline with acetone under electrospray
ionization (ESI) conditions . An experimental setup is described for conducting reactions under ESI
conditions with a possibility of the accumulation of reaction products. The aniline and acetone condensation
products were analyzed by gas chromatography–mass spectrometry. Spraying this mixture with high concentration
of formic acid, results in the formation of N-phenylformamide, N,N'-diphenylmethaneimidamide,
and 1,2-dihydro-2,2,4-trimethylquinoline; the last one is the only product of the reaction of aniline with acetone.
Thus, the Schiff base formation reaction radically changes its direction. The results obtained using the
proposed experimental setup open up new prospects both for studying chemical reactions in charged microdroplets
and for the use of ESI as a preparative method for the synthesis of organic compounds.
Graphene oxide (GO) that has many advanced properties, has been applied in various fields, such as water treatments and removal of contaminations. Hypochlorite is widely used in water treatments. However, the effects of hypochlorite on the transformations and risks of GO, and the toxicological responses remain largely unknown, especially under visible-light irradiation. The present work found that visible-light irradiation promoted the breakdown of sp² structures of GO by hypochlorite, producing alkanes and arenes with short carbon skeletons. Compared to oxygen-containing radicals, chlorine-related radicals contributed to the breakdown of carbon atomic rings of GO. Compared to pristine GO, the transformed GO inhibited algal reproduction, reduced photosynthesis, and promoted oxidative stress and membrane permeability. Substantial plasmolysis and increased numbers of starch grains were observed in the exposure groups. Metabolomics analysis found that oxidative stress and increased membrane permeability linked to downregulated proline. The downregulated pathways of alanine, aspartate and glutamate metabolism were associated with the inhibition of algal reproduction. The downregulated pathways related to protein synthesis and the secondary metabolism explained the strong toxicity induced by GO with hypochlorite and visible-light irradiation. The above results provide insight into the safety assessment of GO.
A comprehensive characterisation of four phenolic compounds in surface water and various emission sources was conducted simultaneously in a typical industrial city upstream of the Taihu Lake watershed. The overall concentrations of the target compounds ranged from 0.15 to 2.75 μg/L in the surface water and from 0.43 to 377 μg/L in the emission sources. Relatively high concentration levels were observed in August, during which the rainy season typically occurred in the study area, indicating seasonal emission sources. The spatial distribution revealed severe phenolic-compound contamination in the northeast part of the study area. According to the relationships between the surface water and emission sources, combined-sewer overflow and surface runoff from agricultural activities were identified as seasonal emission sources that were responsible for the increased concentration levels in wet seasons. Indirect discharge of industrial wastewater was proposed as a persistent emission source responsible for the severe contamination level in the northeast region over the entire sampling period, accounting for 16.5% of the phenolic-compound load in a demonstration river section. The findings of this study are useful for identifying the sources of phenolic compounds and controlling the contamination from the main sources in a typical industrial city.
Disinfection is an essential technological stage in water treatment. It is used not only for potable water but also for, e. g., swimming pool water. Water chlorination is the most common method for eliminating microorganisms today. However, active chlorine reacting with natural and anthropogenic compounds dissolved in water gives rise to the formation of numerous compounds that may be hazardous to human health. The assortment of anthropogenic contaminants grows every year; UV filters are well represented among them. Since recently, they are referred to as ecotoxicants, while their application to skin protection becomes more and more popular all over the world. Over 30 compounds, including numerous halogenated derivatives forming in the aquatic chlorination of a popular UV filter avobenzone in the presence of inorganic salts of iron and copper, as well as bromides and iodides, were identified by gas-chromatography–high-resolution mass spectrometry. The study demonstrated the notable variation of the qualitative and quantitative composition of the reaction products depending on the added salt. It is worth mentioning the formation of brominated and iodinated products.
Developing of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and 2D molecular descriptor calculations. Based on the intensities of two characteristic MS peaks, namely, [M] and [M-35], two classification criterions were proposed. According to criterion I, class 1 comprises [M] signals with the intensity higher than 800 NIST units, while class 2 consists of signals with the intensity lower or equal than 800. According to criterion II, class 1 consists of [M-35] signals with the intensity higher than 100, while signals with the intensity lower or equal than 100 belong to class 2. As a result of ANNs learning stage, five models for both classification criterions were generated. The external model validation showed that all ANNs are characterized by high predicting power; however, criterion I-based ANNs are much more accurate and therefore are more suitable for analytical purposes. In order to obtain another confirmation, selected ANNs were tested against additional dataset comprising popular sunscreen agents disinfection by-products reported in previous works.
While the disinfection of drinking water has largely eliminated the threat of waterborne diseases, it has resulted in an unintended consequence; the byproducts produced as a result of the disinfection process (DBPs). Every aspect of the water treatment process from source water acquisition to treated water distribution has an impact on this trade-off between microbial and chemical risk. Water utilities must consider how these variables interact within a complex system. Optimization of water treatment to balance microbial and chemical risks requires expertise from analytical chemists, toxicologists, engineers, and epidemiologists to characterize the classes of DBPs that are driving the toxicity associated with disinfected water beyond currently regulated DBPs. This chapter discusses how decisions made from source to tap affect water quality and the formation of DBPs using case studies from around the world.
Developing of theoretical tools can be very helpful for supporting new pollutant detection. Nowadays, a combination of mass spectrometry and chromatographic techniques are the most basic environmental monitoring methods. In this paper, two organ-ochlorine compound mass spectra classification systems were proposed. The classification models were developed within the framework of artificial neural networks (ANNs) and fast 1D and 2D molecular descriptor calculations. Based on the intensities of two characteristic MS peaks, namely, [M] and [M-35], two classification criterions were proposed. According to criterion I, class 1 comprises [M] signals with the intensity higher than 800 NIST units, while class 2 consists of signals with the intensity lower or equal than 800. According to criterion II, class 1 consists of [M-35] signals with the intensity higher than 100, while signals with the intensity lower or equal than 100 belong to class 2. As a result of ANNs learning stage, five models for both classification criterions were generated. The external model validation showed that all ANNs are characterized by high predicting power; however, criterion I-based ANNs are much more accurate and therefore are more suitable for analytical purposes. In order to obtain another confirmation, selected ANNs were tested against additional dataset comprising popular sunscreen agents disin-fection by-products reported in previous works.
2,4-Dihydroxybenzophenone (BP-1) is an important component and metabolite of benzophenone-type (BPs) UV filters, it is widely used in commercial products and frequently detected in environmental media and organism samples. The transformation characteristics and genotoxicity changes of BP-1 during chlorination disinfection process were explored. Nineteen transformation products were separated and tentatively identified, eleven of which were not previously reported. Most importantly, nine novel by-products including one chlorobenzoquinone, four phenyl benzoquinones, and four polycyclic aromatic hydrocarbons were formed during BP-1 chlorination. Plausible transformation pathways for BP-1 during chlorination treatment were proposed, in which chlorination substitution, Baeyer-Villiger oxidation, hydrolysis, and C–C coupling reactions were involved. The C–C coupling reaction is firstly observed in chlorination disinfection system. Higher pH values and chlorine doses would be a benefit for BP-1 transformation. The genotoxicity of the reaction mixture increased significantly with increasing chlorine dose under acid and neutral conditions due to the formation of benzoquinones and polycyclic aromatic hydrocarbons. It was noted that BP-1 and its chlorinated products were found in swimming pool water samples. This work inferred that BP-1 and its analogs are transformed during the chlorination disinfection process and may cause potential ecological and health risks.
Disinfection of drinking water with chlorine-containing reagents leads to the formation of a large number of disinfection by-products, resulting from the chlorination of natural dissolved organic matter. High-performance liquid chromatography/high-resolution mass spectrometry with solid-phase preconcentration on a polymeric sorbent was used to study the component composition of halogen-containing disinfection by-products in Arkhangelsk tap water. Fourteen chlorinated and brominated organic compounds, which belong to the classes of halophenols, aromatic acids, carbonyl compounds, and chlorine-substituted nitrogen-containing heterocyclic compounds, have been found. Based on the analysis of MS/MS spectral data, possible structures of the detected disinfection by-products are proposed.
Homosalate is an organic ultraviolet filter used in most sunscreens but has been reported to be toxic to marine organisms. The estrogenic activity of homosalate has also been reported, but its endocrine-disrupting effect remains unclear. Although homosalate has been detected in human placental tissues, its effect on the survival of human trophoblast cells needs to be investigated. Therefore, in this study, we evaluated if HTR8/SVneo, a human trophoblast cell line, treated with homosalate showed decreasing proliferative activity in a dose-dependent manner. Homosalate promoted the death of HTR8/SVneo cells with elevated lipid peroxidation and intracellular Ca2+ concentration. It also induced endoplasmic reticulum stress and mitochondrial morphological disturbances associated with the differentiation of human trophoblast cells. However, when the intracellular Ca2+ or reactive oxygen species were removed using BAPTA-AM or N-acetyl-L-cysteine (NAC), the cell proliferation suppressed by homosalate was restored. Homosalate also significantly inhibited the invasion of HTR8/SVneo cells. Furthermore, it modulated phosphoinositide 3-kinase (PI3K)/AKT and mitogen-activated protein kinase (MAPK) signaling pathways, which were involved in the cross-talk between both signaling pathways in HTR8/SVneo cells. Thus, homosalate adversely affects the survival, proliferation, and invasiveness of human trophoblast cells and therefore pregnant women should practice caution while using personal care products containing homosalate.
This biennial review covers developments in water analysis for emerging environmental contaminants over the period of October 2015-October 2017. Analytical Chemistry’s policy is to limit reviews to a maximum of ~250 significant references and to mainly focus on new trends. Therefore, only a small fraction of the quality research publications are discussed. The previous Water Analysis review (with Susana Kimura) was published in 2016.1 This year, Thomas Ternes has joined back again to cover the section on Pharmaceuticals and Hormones. We welcome any comments you have on this Review (richardson.susan@sc.edu).
SBA-15 and Cu²⁺ amino grafted SBA-15 adsorbents (CuNH2_g_SBA-15) were prepared to investigate the equilibrium and dynamic adsorptive removal of a set of contaminants of emerging concern (CECs; carbamazepine, caffeine, clofibric acid, salicylic acid, and naproxen) from water. Multi-component and CEC metabolites adsorption was also evaluated to elucidate effects on adsorption capacity and selectivity. Equilibrium adsorption studies showed that CuNH2_g_SBA-15 is capable of removing anionic and acidic CECs even at trace level concentrations. However, multi-component tests revealed a decrease of 30% in adsorption capacity in the case of the acids. The CuNH2_g_SBA-15 variant was the less affected by multi-component competitive adsorption, probably due to the ability of this adsorbent to interact with CECs through several, simultaneous adsorption mechanisms (i.e., electrostatic interaction, hydrogen bonds, and metal coordination complexes). These were confirmed via X-ray photoelectron spectroscopy (XPS) analyses. Preliminary fixed-bed adsorption tests showed that beds made CuNH2_g_SBA-15 are prone to mass-transfer resistance in comparison to those made of unmodified SBA-15, causing a decrease in both adsorption capacity and degree of bed utilization. Adsorption of parent/metabolites CEC binary mixtures resulted in a reduction in adsorption capacity of the parent CECs, but the adsorbents showed a remarkable selectivity toward the metabolites, particularly CuNH2_g_SBA-15. In general, this study provides substantial evidence that the anchoring of amine/copper species onto the surface of mesoporous silica may provide a platform for the development of CEC selective adsorbents for water treatment.
Disinfection is an important step in the purification of drinking and swimming pool water. The most common procedure includes chlorination, which efficiently eliminates microorganisms. However, the reaction of active chlorine with dissolved organic matter produces numerous organochlorine compounds posing a hazard to the environment and human health. UV filters belong to emerging contaminants, as their application to skin protection from UV irradiation becomes increasingly popular all over the world. Certain components of UV filters were detected in swimming pools and result in the emergence of new ecotoxicants. In the present study, 40 compounds, including numerous brominated derivatives, which result from the chlorination of avobenzone in sea water, were identified by gas chromatography–high resolution mass spectrometry. In addition, the applicability of photocatalysis to the destruction of chlorination products was studied. The procedure was found to be rather efficient and allows a decrease in the total amount of avobenzone transformation products by a factor of 10. The only compound class demonstrating stability under the applied conditions is exemplified by halogenated acetophenone derivatives.
In this work is presented a synthesis pathway for the UV filter hexyl 2-(4-diethylamino-2-hydroxybenzoyl) benzoate (DHHB) and its chlorinated by-products in order to investigate the transformation behaviour and toxicity changes of DHHB during chlorination disinfection treatment. Acute toxicity was measured using standardised tests with aquatic model organisms. The potency of DHHB was compared with other benzophenone-like UV filters tested in the same experimental set-up. The toxicity of chlorinated compounds tested with photobacteria was found to be in a similar range to that of the starting compound. Microalgae were more sensitive to DHHB than to its chlorinated by-products, whereas daphnids were affected more by DHHB's chlorinated products. The comparative toxicity data showedDHHBand even more its chlorinated by-products as more highly biologically potent to daphnids than other testedUVfilters. The toxic potential of benzophenone-like UV filters should be interpreted together with data on their chemical properties, chlorination effects and affected organisms.
The possibility of the formation of toxic products at the stage of drinking water disinfection as a result of interaction of disinfectants, such as chlorine and sodium hypochlorite, with model organic compounds, structural fragments of natural humic substances is investigated using gas chromatography-mass spectrometry (GC-MS). Both qualitative and quantitative analysis of the products of water chlorination of dibenzoylmethane and cinnamic acid by chlorine and sodium hypochlorite was performed under the conditions of an equimolar amount and five- and fiftyfold excess of the chlorinating agent. Detailed diagrams of the transformation of organic compounds under the conditions simulating the process of natural water disinfection are drawn. The studies indicate that the use of chlorine leads to a greater variety and higher concentrations of chlorinated products compared to sodium hypochlorite.
In this work was presented the synthesis pathway for the UV filter diethylaminohydroxybenzoylbenzoate (DHHB) and its chlorinated by-products in order to investigate the transformation behavior and toxicity changes of DHHB during chlorination disinfection treatment. The acute toxicity was measured using standardized tests with aquatic model organisms. The potency of DHHB was compared with other benzophenone-like UV filters tested in the same experimental set-up. Toxicity of chlorinated compounds tested by photobacteria was found to be in the similar range as that of the starting compound. Microalgae were more sensitive to DHHB than to its chlorinated by-products, while daphnids were affected more by DHHB's chlorinated products. The comparative toxicity data showed DHHB and even more its chlorinated by-products as highly biologically potent to daphnids than other tested UV filter. The toxic potential of benzophenone-like UV filters should be interpreted together with data on their chemical properties, chlorination effects and affected organism.
RESUMO: Os parques nacionais são unidades de conservação com funções de preservar os ecossistemas e servir à sociedade, por tratar-se de um bem público. Com o presente estudo objetivou-se caracterizar a realidade vivida pelos parques nacionais brasileiros (Parnas), con-siderando a aplicabilidade da legislação pertinente e a existência ou não da presença humana, entre outros fatores impactantes. Na metodologia de análise, foram utilizadas a pesquisa ex-ploratória e a pesquisa descritiva. Concluiu-se que existe a necessidade de regularização da situação fundiária das áreas dos Parnas; os órgãos federais e organizações ligadas ao meio ambiente desconhecem a problemática existente em diversas condições de gestão dos parques nacionais brasileiros. Palavras-chave: unidades de conservação, legislação ambiental, parques nacionais. BRAZILIAN NATIONAL PARKS: NEGLIGENCE OF THE LAWS ABSTRACT: The national parks are protected areas with functions to preserve ecosystems and serve society, because it is a public good. The present study aimed to characterize the reality experienced by the Brazilian national parks (Parnas), considering the applicability of legislation and the presence or absence of human presence, among other factors impacting. For analysis methodology, were used the exploratory and descriptive research. It was concluded that there is a need for regularization of land tenure areas of Parnas; federal agencies and organizations related to the environment are unaware of the problems existing in various management conditions of Brazilian national parks.
4-tert-Butyl-4’-methoxydibenzoylmethane (BMDM) is a widely used UVA filter. In this work we have studied the effect of chlorine and dissolved organic matter (DOM) concentrations on the stability of UV filter (BMDM) present in two commercial sunscreen cream formulations in water. An experimental design was used to assess the effect of the two experimental factors on the degradation of BMDM. Higher concentrations of chlorine lead to higher degradation percentages of BMDM and higher concentrations of DOM inhibit its degradation. Moreover, a mono and a dichloro derivate of BMDM were identified as by-products.
The use of sunscreen products is very important nowadays. The photostability of UV filters incorporated in these products must be preserved during its storing and application processes in order to achieve the claims about photoprotection of the commercial products. The photostability of avobenzone, one of the most common UVA filters in commercial sunscreens, is assessed in solvents intended for cosmetic formulations. The study is carried out by following the spectral behavior of avobenzone solutions under irradiation and after storing them in the dark. Different photobehaviors of the avobenzona are found in the selected solvents, some of which can be explained in the same way than in analytical solvents; but for others, the structural and physical properties of the solvents must be taken into account. The most appropriate solvents for ensuring the photostability of avobenzona are mineral oil and isopropyl myristate.
In our study, the transformation of two most widely used UV filters, benzophenone-3 (BP3) and benzophenone-4 (BP4), in chlorinated water with disinfection reagents sodium hypochlorite (NaClO) and trichloroisocyanuric acid (TCCA) was studied. Based on the HPLC/MS and UV-Vis analysis the formation of two different chlorinated products (5-chloro-2-hydroxy-4-methoxybenzophenone and 3,5-dichloro-2-hydroxy-4-methoxybenzophenone) was established. Identity of chlorinated products was confirmed by means of comparison of retention times with independently synthesized standards. Photostability study showed that dichloro-derivative in water is less stable then parent compounds, which is not the case for monochloro-derivatives. Toxicity of chlorinated compounds tested by Vibrio fischeri was found to be in the same range as that of the starting compounds. Preliminary testing of real water samples from swimming pools and sea swimming areas confirmed the presence of BP3 and its 3,5-dichloro derivative.
The fate of modern personal care products in the environment is becoming a matter of increasing concern because of the growing production and assortment of these compounds. More and more chemicals of this class are treated as emerging contaminants. Transformation of commercially available products in the environment may result in the formation of a wide array of their metabolites. Personal care products in swimming pools and in drinking water reservoirs may undergo oxidation or chlorination. There is much data on the formation of more toxic metabolites from original low toxicity commercial products. Therefore, reliable identification of all possible transformation products and a thorough study of their physicochemical and biological properties are of high priority. The present study deals with the identification of the products of the aquatic chlorination of the hexyl 2-[4-(diethylamino)-2-hydroxybenzoyl]-benzoate ultraviolet filter. High-performance liquid chromatography/mass spectrometry (HPLC/MS) and HPLC/MS/MS with accurate mass measurements were used for this purpose. As a result, three chlorinated transformation products were identified. Copyright © 2013 John Wiley & Sons, Ltd.
The stability of the UV filters 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-tert-butyl-4′-methoxydibenzoylmethane (BDM) in chlorinated water was studied. High-performance liquid chromatography (HPLC)-UV-diode array detection (DAD) was used to follow the reaction kinetics of both UV filters and HPLC-tandem mass spectrometry (MS/MS) was used to tentatively identify the major transformation by-products. Under the experimental conditions used in this work both UV filters reacted with chlorine following pseudo-first order kinetics: rate constant k=0.0095±0.0007min-1 and half-life t1/2=73±4min for EHMC and rate constant k=0.006±0.001min-1 and half-life t1/2=119±14min for BDM (mean±standard deviation). The chemical transformation of the UV filters in chlorinated water led to the formation of chlorinated by-products that were tentatively identified as mono-and dichloro-substituted compounds that resulted from substitution of the hydrogen atoms in the benzene rings by one or two chlorine atoms. Experimental Box-Behnken designs were used to assess the effect of experimental factors: pH, temperature, chlorine concentration, dissolved organic matter and artificial sunlight irradiation on the transformation of the UV filters.
Ozone, chlorine and sodium hypochlorite are commonly used as disinfecting agents for drinking water production. The reaction pathways of ozonation and chlorination of o-methoxybenzoic acid in aqueous solution were studied using gas chromatography-mass spectrometry (GC-MS) and high pressure liquid chromatography (HPLC). The results show that less than 1% of o-methoxybenzoic acid remains in reaction. The final major products using ozone oxidation are oxalic and glyoxalic acids. Phenols appear only at insufficient ozone levels. Sodium hypochlorite leads to higher levels of primary products. Molecular chlorine leads to the formation of higher amounts of polychlorinated derivatives. Model experiments allow to propose schemes of o-methoxybenzoic acid transformation under the conditions simulating water treatment processes.
We studied the reactions of 4-tert-butyl-4'-methoxydibenzoylmethane (avobenzone), the most common UV filter in formulations of sunscreens, under the conditions of disinfection. Three chlorinated compounds were identified as the main products. Their structures were confirmed by high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS 2) with accurate mass measurements and by gas chromatography–mass spectrometry (GC/MS). It was reliably proved, that the substitution involved the double bond of the enolic form of the diketone, rather than the activated aromatic ring, leading to the formation of 2-chloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione and 2,2-dichloro-1-(4-tert-butylphenyl)-3-(4-methoxyphenyl)-1,3-propanedione as the main products. The third identified product was 2-chloro-1-(4-methoxyphenyl)ethanone.
UV-filters are a group of compounds which have been massively used in the past years due to the recent concerns with sunburns, premature skin ageing and the risk of developing skin cancer, related to sun exposure. At the moment, these compounds have been identified by the scientific community as emerging pollutants, due to their persistence in the environment, potential to accumulate in biota and potential threat as endocrine disruptors. At some point, the majority of sunscreens will find their way into wastewater (due to bathing and washing activities) and because wastewater treatment plants (WWTPs) are not able to remove and/or degrade them, consequently they find their way into rivers, lakes and ocean, so it is not surprising that UV-filters are found in the environment. Therefore, wastewater treatment plants should be the focus of the scientific community aiming to better understand the fate of the UV-filters and develop new technologies to remove them from wastewater and sludge. This review, aims to provide the current state of the art in the occurrence and fate of UV-filters in wastewater treatment plants and how the technologies that are being used are successfully removing these compounds from both wastewater and sludge.
Irritant incapacitants, also called riot control agents, lacrimators and tear gases, are aerosol-dispersed chemicals that produce eye, nose, mouth, skin and respiratory tract irritation. Tear gas is the common name for substances that, in low concentrations, cause pain in the eyes, flow of tears and difficulty in keeping the eyes open. Only three agents are likely to be deployed: (i) 1-chloroacetophenone (CN); (ii) 2-chlorobenzylidene malononitrile (CS); or (iii) dibenz[b,f]-1,4-oxazepine (CR). CN is the most toxic lacrimator and at high concentrations has caused corneal epithelial damage and chemosis. It has accounted for at least five deaths, which have resulted from pulmonary injury and/or asphyxia. CS is a 10-times more potent lacrimator than CN but is less systemically toxic. CR is the most potent lacrimator with the least systemic toxicity and is highly stable.
CN, CS and CR cause almost instant pain in the eyes, excessive flow of tears and closure of the eyelids, and incapacitation of exposed individuals. Apart from the effects on the eyes, these agents also cause irritation in the nose and mouth, throat and airways and sometimes to the skin, particularly in moist and warm areas. In situations of massive exposure, tear gas, which is swallowed, may cause vomiting. Serious systemic toxicity is rare and occurs most frequently with CN; it is most likely to occur when these agents are used in very high concentrations within confined non-ventilated spaces. Based on the available toxicological and medical evidence, CS and CR have a large safety margin for life-threatening or irreversible toxic effects. There is no evidence that a healthy individual will experience long-term health effects from open-air exposures to CS or CR, although contamination with CR is less easy to remove.
In this work was presented the synthesis pathway for the UV filter diethylaminohydroxybenzoylbenzoate (DHHB) and its chlorinated by-products in order to investigate the transformation behavior and toxicity changes of DHHB during chlorination disinfection treatment. The acute toxicity was measured using standardized tests with aquatic model organisms. The potency of DHHB was compared with other benzophenone-like UV filters tested in the same experimental set-up. Toxicity of chlorinated compounds tested by photobacteria was found to be in the similar range as that of the starting compound. Microalgae were more sensitive to DHHB than to its chlorinated by-products, while daphnids were affected more by DHHB's chlorinated products. The comparative toxicity data showed DHHB and even more its chlorinated by-products as highly biologically potent to daphnids than other tested UV filter. The toxic potential of benzophenone-like UV filters should be interpreted together with data on their chemical properties, chlorination effects and affected organism.
UV-filters are a group of compounds designed mainly to protect skin against UVA and UVB radiation, but they are also included in plastics, furniture, etc., to protect products from light damage. Their massive use in sunscreens for skin protection has been increasing due to the awareness of the chronic and acute effects of UV radiation. Some organic UV-filters have raised significant concerns in the past few years for their continuous usage, persistent input and potential threat to ecological environment and human health. UV-filters end up in wastewater and because wastewater treatment plants are not efficient in removing them, lipophilic compounds tend to sorb onto sludge and hydrophilics end up in river water, contaminating the existing biota. To better understand the risk associated with UV-filters in the environment a thorough review regarding their physicochemical properties, toxicity and environmental degradation, analytical methods and their occurrence was conducted.
Disinfection of swimming pool water is essential to deactivate pathogenic microorganisms. Many swimming pools apply chlorine or bromine based disinfectants to prevent microbial growth. The chlorinated swimming pool water contains higher chlorine residual and is maintained at a higher temperature than a typical drinking water distribution system. It constitutes environments with high levels of disinfection by-products (DBPs) in water and air as a consequence of continuous disinfection and constant organic loading from the bathers. Exposure to those DBPs is inevitable for any bather or trainer, while such exposures can have elevated risks to human health. To date, over 70 peer-reviewed publications have reported various aspects of swimming pool, including types and quantities of DBPs, organic loads from bathers, factors affecting DBPs formation in swimming pool, human exposure and their potential risks. This paper aims to review the state of research on swimming pool including with the focus of DBPs in swimming pools, understand their types and variability, possible health effects and analyze the factors responsible for the formation of various DBPs in a swimming pool. The study identifies the current challenges and future research needs to minimize DBPs formation in a swimming pool and their consequent negative effects to bathers and trainers.
The most widely used UVA absorber in broad-spectrum sunscreens is 4-tert-butyl-4′-methoxydibenzoylmethane (avobenzone). However, the photostability of avobenzone is solvent-dependent. The aim of this work was to investigate the photostability of avobenzone in solvents of different polarity and proticity. Four solvents were employed, namely, cyclohexane, ethyl acetate, dimethylsulfoxide and methanol. The cause of the instability of avobenzone in these solvents was determined by means of UV spectroscopy, high performance liquid chromatography, gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy. The effect of oxygen on the photo-instability was also determined. Avobenzone was found to lose absorption efficacy as a result of photoisomerisation from the enol to the keto form and/or photodegradation to form photoproducts that absorb principally in the UVC region, depending on the solvent. It was found to be essentially photostable in the polar protic solvent methanol but photoisomerised in the polar aprotic solvent dimethylsulfoxide. In the nonpolar solvent cyclohexane, it photodegraded appreciably. Both photoisomerisation and photodegradation occurred to a similar extent in the moderately polar aprotic solvent ethyl acetate. Photoisomerisation occurred only in the presence of oxygen whereas photodegradation occurred irrespective of oxygen. This knowledge is important in order to achieve the correct formulation for sunscreens incorporating avobenzone.
Environmental mass spectrometry is an extremely important brunch of science providing a basis for conclusions directly influencing the health of people and ecosystems in general. Nowadays environmnetal mass spectrometry experiences rapid development. Several directions may be put forward as the most relevant: i. a significant broadening of the list of target compounds with parallel interest towards non target chemicals, as the main risk may be associated with these ingredients; ii. an increase of reliability of analyses involving accurate mass measurements, tandem mass spectrometry, and isotopically labeled standards; iii. shift toward faster high-troughput analysis with minimal sample preparation involving various approaches, including ambient ionization techniques and miniature instruments. A real revolution in analytical chemistry could be triggered with appearance of robust, simple, and sensitive portable mass spectrometers applying ambient ionization techniques. If the cost of such instruments is red...
Increased attendance at swimming pools is correlated with higher input of organic and minerals pollutants introduced by swimmers in the swimming pool water. In most swimming pools, microbiological control is performed by disinfection with the addition of chlorine. Chlorine is now well-known to lead to the formation of many disinfection by-products (DBPs) including trihalomethanes and chloramines. The hypothesis of a link between the presence of eye and skin irritation syndromes in swimmers and contact with swimming pool water treated with chlorine was initially proposed by Mood (1953). During recent decades many epidemiological studies have described the importance of DBPs generated with natural or imported organic matter present in water. Many of these DBPs are suspected to be toxic or even carcinogenic. Trihalomethanes and haloacetic acid families are the most studied but others DBPs, like chloral hydrate, haloacetonitriles, N-nitrosodimethylamine and the bromate ion, are emerging compounds of interest. Epidemiological data about the risk of cancer are still controversial. However, numerous publications highlight a toxic risk especially the risk of allergy and respiratory symptoms for babies and elite swimmers. The few publications dedicated to risk assessment do not suggest increased risk, other than for elite swimmers. These publications are likely to underestimate the risk associated with DBPs because of the lack of data in the literature precludes the calculation of risk associated with certain compounds or certain pathways. Thus for regulations, the need to take into account the risks associated with disinfection by-products is now important without forgetting the need of the control of microbiological hazards in swimming pools.
This biennial review covers developments in water analysis for emerging environmental contaminants over the period of 2011-2013. Analytical Chemistry's policy is to limit reviews to a maximum of 250 significant references and to mainly focus on new trends. As a result, only a small fraction of the quality research publications could be discussed. I am excited to again have Thomas Ternes join me this year to cover the section on Pharmaceuticals and Hormones. Thomas coauthored the previous 2011 Review on Water Analysis,1 and as before, this Review is so much better with his contribution. We welcome any comments you have on this Review (richardson.susan@sc.edu). Numerous abstracts were consulted before choosing the best representative ones to present here. Abstract searches were carried out using Web of Science, and in many cases, full articles were obtained. A table of acronyms is provided (Table 1) as a quick reference to the acronyms of analytical techniques and other terms discussed in this Review, and Table 2 provides some useful websites.
Benzophenones and benzotriazoles are widely used as ultraviolet (UV) light filters and stabilizers in cosmetics, skin creams, and body lotions and as corrosion inhibitors in building materials, automobile components, and automotive antifreeze cooling systems. Benzophenones and benzotriazoles have been reported to occur in the environment. Some of these UV filters have been reported to possess significant estrogenic activity. Despite this, very few studies have examined their occurrence and profiles in the environment. In this work, we determined five benzophenone-type UV filters and two benzotriazole-type corrosion inhibitors, namely, 2-hydroxy-4-methoxybenzophenone (2OH-4MeO-BP), 2,4-dihydroxybenzophenone (2,4OH-BP), 2,2'-dihydroxy-4-methoxybenzophenone (2,2'OH-4MeO-BP), 2,2',4,4'-tetrahydroxybenzophenone (2,2',4,4'OH-BP), 4-hydroxybenzophenone (4OH-BP), 1H-benzotriazole (1H-BT), and 5-methyl-1H-benzotriazole (5Me-1H-BT), in sediment and sewage sludge samples, using liquid-liquid extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In addition, four benzotriazole-type UV stabilizers, namely, 2-(3-t-butyl-2-hydroxy-5-methylphenyl)-5-chlorobenzotriazole (UV-326), 2,4-di-t-butyl-6-(5-chloro-2H-benzotriazole-2-yl) phenol (UV-327), 2-(2H-benzotriazole-2yl)-4,6-di-t-pentylphenol (UV-328), and 2-(5-t-butyl-2-hydroxyphenyl) benzotriazole (TBHPBT) were determined by gas chromatography (GC)-mass spectrometry (MS). The limits of quantitation (LOQ) were in the ranges of 0.06-0.33 ng g⁻¹ dry weight (dw) and 0.1-1.65 ng g⁻¹ dw for sediment and sludge samples, respectively. Recoveries of target compounds spiked into sample matrices and passed through the entire analytical procedure ranged from 70% to 116% (RSD: 3.32-13.8%) and from 82% to 106% (RSD: 2.89-8.09%) for the compounds analyzed by LC-MS/MS and GC-MS, respectively. The methods were applied to the analysis of sediment samples from the Songhua, Saginaw, and Detroit Rivers; the sum concentrations of target compounds were 3.29-9.93, 5.81-22.5, and 190-389 ng g⁻¹ dw, respectively. Five sludge samples collected from five wastewater treatment plants in northeastern China contained the sum concentrations of target compounds in the range of 104-6370 ng g⁻¹ dw. The concentration of UV-328 in sludge was the highest (mean: 1300 ng g⁻¹ dw) among the target compounds. To our knowledge, this is the first work to report the occurrence of 2OH-4MeO-BP, 2,4OH-BP, 2,2'OH-4MeO-BP, 2,2',4,4'OH-BP, and 4OH-BP in sediment and sludge samples.
2-Chloracetophenone (CN) is widely used as tear gas by police and civilians for self-defence. It may affect the eyes, respiratory system and skin, sometimes causing serious injuries. Both irritative and allergic contact dermatitis have been described. We report three police officers who experienced accidental escape of CN from their professional tear gas canisters. All of them showed localized dermatitis at the site of contact to CN, while widespread lesions appeared after 4 days in one case. Patch tests with the original involved tear gas dissolved in acetone (at 0.1-0.0001%) indicated an allergic reaction in two patients and an irritative reaction in the third. Occupational contact dermatitis due to CN seems to occur among police officers more often than is generally known. Infrequently, extensive health problems may be caused by CN when lesions spread over the integument. Therefore, an improvement of safety measures in occupational CN gas use is needed, especially aiming at avoidance of accidental leakage of canisters.
Consumer care products often contain UV filters, organic compounds which absorb ultraviolet light. These compounds may enter surface waters directly (when released from the skin during swimming and bathing) or indirectly via wastewater treatment plants (when released during showering or washed from textiles). Predicted and measured UV filter concentrations were compared in a regional mass balance study for two Swiss lakes: Lake Zurich, a typical midland lake which is also an important drinking water resource, and Hüttnersee, a small bathing lake. Both lakes are extensively used for recreational activities and considerable direct input of UV filters is thus expected. This input was estimated from the number of visitors at swimming areas around the lakes and a survey of the usage of sunscreen products among these visitors. Possible additional indirect input via wastewater treatment plants was not considered in this study. The quantitatively most important UV filters, as indicated by the survey data, ethylhexyl methoxycinnamate, octocrylene, 4-methylbenzylidene camphor, butyl methoxydibenzoylmethane, and benzophenone-3, all lipophilic compounds, were selected for analysis by gas chromatography-mass spectrometry. Concentrations of individual UV filters in water from Lake Zurich were low, ranging from <2 ng l(-1) (detection limit) to 29 ng l(-1), and somewhat higher at Hüttnersee, ranging from <2 to 125 ng l(-1), with the highest concentrations found in summer, consistent with direct inputs to the lakes during this time. The concentrations were clearly lower than predicted from input estimates based on the surveys. This may be in part due to (i) an overestimation of these inputs (e.g. less than the 50% wash-off of UV filters assumed to occur during swimming), and (ii) some removal of these compounds from the lakes by degradation and/or sorption/sedimentation. UV filters were also detected in semipermeable membrane devices (SPMDs) deployed at Lake Zurich and Greifensee, another midland lake, at concentrations of 80-950 ng SPMD(-1), confirming the presence of the compounds in surface waters and indicating a certain potential for bioaccumulation. SPMD-derived water concentrations were in the range of 1-10 ng l(-1) and thus corresponded well with those determined in water directly. No UV filters were detected above blank levels in SPMDs deployed at a remote mountain lake used for background measurements.
Irritant incapacitants, also called riot control agents, lacrimators and tear gases, are aerosol-dispersed chemicals that produce eye, nose, mouth, skin and respiratory tract irritation. Tear gas is the common name for substances that, in low concentrations, cause pain in the eyes, flow of tears and difficulty in keeping the eyes open. Only three agents are likely to be deployed: (i) 1-chloroacetophenone (CN); (ii) 2-chlorobenzylidene malononitrile (CS); or (iii) dibenz[b,f]-1,4-oxazepine (CR). CN is the most toxic lacrimator and at high concentrations has caused corneal epithelial damage and chemosis. It has accounted for at least five deaths, which have resulted from pulmonary injury and/or asphyxia. CS is a 10-times more potent lacrimator than CN but is less systemically toxic. CR is the most potent lacrimator with the least systemic toxicity and is highly stable. CN, CS and CR cause almost instant pain in the eyes, excessive flow of tears and closure of the eyelids, and incapacitation of exposed individuals. Apart from the effects on the eyes, these agents also cause irritation in the nose and mouth, throat and airways and sometimes to the skin, particularly in moist and warm areas. In situations of massive exposure, tear gas, which is swallowed, may cause vomiting. Serious systemic toxicity is rare and occurs most frequently with CN; it is most likely to occur when these agents are used in very high concentrations within confined non-ventilated spaces. Based on the available toxicological and medical evidence, CS and CR have a large safety margin for life-threatening or irreversible toxic effects. There is no evidence that a healthy individual will experience long-term health effects from open-air exposures to CS or CR, although contamination with CR is less easy to remove.
The reaction pathways of aqueous chlorination of anisole, ethylbenzene and o-methoxybenzoic acid being structural fragments of humic matter were studied using gas chromatography-mass spectrometry. Chlorine and sodium hypochlorite were used as commonly employed disinfecting agents. Comparison of the chlorinating agents was performed in terms of the assortment and relative amounts of reaction products. Detailed schemes of the selected substrates transformation were proposed. Quantum chemical calculations were applied to propose structures of the reacting particles and a numerical parameter to estimate an extent of conversion of aromatic substrates during chlorination.
Four UV filters, benzophenone-3 (BP-3), 4-methylbenzylidence camphor (4-MBC), ethylhexyl methoxycinnamate (EHMC), and octocrylene (OC), have been examined along the different units of a wastewater reclamation plant (WWRP) located in Tianjin, North China. The analytical procedure included solid-phase extraction and gas chromatographic/mass spectrometric analyses. All four UV filters were detected in the influent during the three sampling campaigns (February, July, and September), and the concentrations ranged from 34 to 2128 ng L(-1). The concentrations of the four UV filters were higher in hot weather (July and September) than in cool weather (February). The monthly average removal ranged from 7.6% to 21% for the selected UV filters during coagulation-flocculation (C-F) treatment. The ozonation treatment achieved the maximum removal (16-28%); on the contrary, the continuous microfiltration (CMF) achieved the lowest removal (3.6-8.2%). The total removal efficiencies along the plant varied from 28% to 43%. These results indicate that the UV filters are not completely removed during WWRP treatment and may be carried over into the environment during the reuse applications.
Emerging issues on degradation by-products deriving from personal care products and pharmaceuticals during disinfection processes of water used in swimming pools
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- S Caroli
Bottoni, P., Bonadonna, L., Chirico, M., Caroli, S., Z aray, G., 2014. Emerging issues on
degradation by-products deriving from personal care products and pharmaceuticals during disinfection processes of water used in swimming pools.
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Comparison of chlorine and sodium hypochlorite activity in the chlorination of structural fragments of humic substances in water using GC-MS
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- J C G E Da Silva
- N A Sinikova
- G M Shaydullina
- A T Lebedev
Santos, A.J.M., Crista, D.M.A., Miranda, M.S., Almeida, I.F., de Silva, J.P.S., Costa, P.C.,
Amaral, M.H., Lobão, P.A.L., Lobo, J.M.S., da Silva, J.C.G.E., 2013. Degradation of
UV
filter
2-ethylhexyl-4-methoxycinnamate
and
4-tert-butyl-4-methoxydibenzoylmethane in chlorinated water. Environ. Chem. 10 (2),
127e134.
Sinikova, N.A., Shaydullina, G.M., Lebedev, A.T., 2014. Comparison of chlorine and
sodium hypochlorite activity in the chlorination of structural fragments of
humic substances in water using GC-MS. J. Anal. Chem. 69 (14), 1300e1306.
Original Russian version in Mass-spektrometria (Rus), 2014, 11 (1), 22e28.
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sodium hypochlorite. Environ. Chem. Lett. 3, 1e5.
The Encyclopedia of UV Filters, 2007. In: Shaath, N.A. (Ed.), The Encyclopedia of UV
Filters. Allured Publications, Illinois, p. 222.