UV-absorbing chemicals (UV filters) are widely used for protection against UV radiation in sunscreens and in a variety of cosmetic products and materials. Depending on the breadth and factor of UV protection, they are added as single compounds or as a combination thereof. Some UV filters have estrogenic activity, but their activity and interactions in mixtures are largely unknown. In this work, we analyzed 8 commonly used UV filters, which are pure or partial hERα agonists, for their estrogenic activity in equieffective mixtures in a recombinant yeast assay carrying the human estrogen receptor alpha (hERα). Mixtures of two, four and eight UV filters alone, or in combination with 17 β estradiol (E2), were assessed at different effect levels and no-observed-effect-concentrations (NOEC). Predictions of the joint effects of these mixtures were calculated by employing the concentration addition (CA) and independent action (IA) model. Most binary mixtures comprising of pure hERα agonists showed a synergistic activity at all mixture combinations. Only in combination with benzophenone-1, antagonistic activity was observed at some effect levels. All mixtures of four or eight, pure or pure and partial hERα agonists, alone or including E2, showed synergistic activity at concentrations giving an increase of 10% of basal activity (BC10). This occurred even at concentrations that were at the NOEC level of each single compound. Hence, there were substantial mixture effects even though each UV filter was present at its NOEC level. These results show that significant interactions occur in UV filter mixtures, which is important for the hazard and risk assessments of these personal care products.
In this work, we evaluate whether in vitro systems are good predictors for in vivo estrogenic activity in fish. We focus on UV filters being used in sunscreens and in UV stabilization of materials. First, we determined the estrogenic activity of 23 UV filters and one UV filter metabolite employing a recombinant yeast carrying the estrogen receptor of rainbow trout (rtER alpha) and made comparisons with yeast carrying the human hER alpha for receptor specificity. Benzophenone-1 (BP1), benzophenone-2 (BP2), 4,4-dihydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4-trihydroxy-benzophenone, and phenylsalicylate showed full dose-response curves with maximal responses of 81-115%, whereas 3-benzylidene camphor (3BC), octylsalicylate, benzylsalicylate, benzophenone-3, and benzophenone-4 displayed lower maximal responses of 15-74%. Whereas the activity of 17 beta-estradiol was lower in the rtER alpha than the hER alpha assay, the activities of UV filters were similar or relatively higher in rtER alpha, indicating different relative binding activities of both ER. Subsequently, we analyzed whether the in vitro estrogenicity of eight UV filters is also displayed in vivo in fathead minnows by the induction potential of vitellogenin after 14 days of aqueous exposure. Of the three active compounds in vivo, 3BC induced vitellogenin at lower concentrations (435 mu g/l) than BP1 (4919 mu g/l) and BP2 (8783 mu g/l). The study shows, for the first time, estrogenic activities of UV filters in fish both in vitro and in vivo. Thus we propose that receptor-based assays should be used for in vitro screening prior to in vivo testing, leading to environmental risk assessments based on combined, complementary, and appropriate species-related assays for hormonal activity.
The fate of polycyclic musks (PCMs) (HHCB, AHTN, ADBI, AHDI, ATII, DPMI), UV filters (3-(4-methylbenzylidene) camphor, 4-MBC; octyl-methoxycinnamate, OMC; octocrylene, OC; octyl-triazone, OT) and biocides (permethrin, carbendazim) during wastewater treatment was studied on a full-scale plant. Average influent concentrations of OMC, HHCB, OC, AHTN, 4-MBC and OT were at 20070, 4420, 1680, 1430, 960 and 720 ng L , respectively. The other PCMs, permethrin and carbendazim ranged between 99% and were at 92% and 37% for permethrin and carbendazim, respectively. Removal during wastewater treatment was mainly driven by sorption onto solids and biodegradation. For anaerobic sludge digestion, elimination of PCMs, OMC and the biocides was observed.
UV filters have been detected in surface water, wastewater and fish, and some of them are estrogenic in fish. At present, little is known about their additional hormonal activities in different hormonal receptor systems despite their increasing use and environmental persistence. Besides estrogenic activity, UV filters may have additional activities, both agonistic and antagonistic in aquatic organisms. In our study, we investigate a series of UV filters for multiple hormonal activities in human receptor systems and evaluate the predictive value of these findings for the activity in fish and . First we systematically analysed the estrogenic, antiestrogenic, androgenic, and antiandrogenic activity of 18 UV filters and one metabolite at non-cytotoxic concentrations with recombinant yeast systems carrying either a human estrogen (hERα) or androgen receptor (hAR). All 19 compounds elicited hormonal activities, surprisingly most of them multiple activities. We found 10 UV-filters having agonistic effects towards the hERα. Surprisingly, we identified for the first time six UV filters with androgenic activities and many of them having pronounced antiestrogenic and antiandrogenic activities. As much as 17 compounds inhibited 4,5-dihydrotestosterone activity in the hAR assay, while 14 compounds inhibited estradiol activity in the hERα assay, indicating antiandrogenic and antiestrogenic activity, respectively. In particular, the antiandrogenic activities of phenyl- and benzyl salicylate, benzophenone-1 and -2, and of 4-hydroxybenzophenone were higher than that of flutamide, a known hAR antagonist. In a second series of experiments, we investigated the predictive power of the hERα assay for aquatic organisms by further investigating the estrogenic UV filter ethyl 4-aminobenzoate (Et-PABA) and in fish. Et-PABA showed estrogenic activity in a recombinant yeast system carrying the rainbow trout estrogen receptor (rtERα) with higher activity than in the hERα assay. In addition, Et-PABA induced vitellogenin after 14 days of exposure in juvenile fathead minnows at 4394 μg/L. Our study shows estrogenic activity of this UV filter in fish both and . In conjunction with human receptor-based systems our results give a more detailed picture about distinct hormonal activities of UV filters occurring in aquatic systems. We conclude that receptor-based assays are important for assessment of UV-filters prior to or concurrently with assays, which ultimately provide data for the environmental risk assessment of these important personal care products.
A novel method has been developed to simultaneously determine and quantify seven organic UV filters employing liquid (solid)–liquid extraction, derivatization with -methyl- -(trimethylsilyl) trifluoroacetamide (MSTFA) and gas chromatography with mass spectrometric detection in various environmental matrices. The UV filters determined were: benzophenone (BP), benzhydrol (BH), 4-hydroxybenzophenone (HBP), 2-hydroxy-4-methoxybenzophenone (HMB), 2,4-dihydroxybenzophenone (DHB), 2,2′-dihydroxy-4-methoxybenzophenone (DHMB) and 2,3,4-trihydroxylbenzophenone (THB). Under optimal conditions, the analysis required 23 min and good linearity over the range of 10–2500 ng/L in water and 100–25000 ng/kg in soil for each UV filter obtained. The high recovery (62–114% and 60–125% for water and soil samples, respectively) and the low RSD values (less than 13.9 and 17.2% for water and soil samples, respectively) indicated the high performance of this method. The method detection limits (MDLs) were relatively low, ranging from 5 to 100 ng/L or kg and quantification limits ranged between 25 and 500 ng/L or kg for all test compounds. This validated method was applied in the analysis of seven BP-type UV filters collecting water and soil samples in Korea, between April and May 2003. The overall concentration of UV filters in the soil sample (500–18380 ng/kg) was highly distributed in water sample (27–204 ng/L). The established method was successfully applied to monitor the residue measurement of the BP-type UV filters in environmental water and soil samples.
Many substances related to human activities end up in wastewater and accumulate in sewage sludge. The present study focuses on the analysis of widely used UV filters 3-(4-methylbenzylidene) camphor (4-MBC), octyl-methoxycinnamate (OMC), octocrylene (OC) and octyl-triazone (OT) in sewage sludge originating from a monitoring network in Switzerland. Mean concentrations in stabilised sludge from 14 wastewater treatment plants were 1780, 110, 4840 and 5510 μg/kg dry matter for 4-MBC, OMC, OC and OT, respectively. Specific loads in sewage sludge show that UV filters originate mainly from private households, but surface runoff and industries may be considered as additional sources. This indicates that besides use for sunscreens and cosmetics UV filters might occur in plastics and other materials and be released to the environment by volatilization or leaching. Differences between the modeled per capita loads of UV filters in sewage sludge and the observed specific loads in sewage sludge are probably due to erroneous figures of production volumes, degradation and sorption during wastewater treatment as well as degradation processes during transport in the sewer or sludge treatment. Thus, further research is needed to elucidate the fate of UV filters after application and release into the environment. Other compounds used as UV filters should be included in future studies.
UV filters are widely used compounds in many personal care products and cosmetics, such as sunscreens. After use, UV filters are washed off from skin and clothes and enter the aquatic environment. Recent studies indicate that some lipophilic UV filters do accumulate in biota and act as endocrine disruptors. In this study, concentrations of 4-MBC (4-methylbenzylidene camphor) and OC (octocrylene), two widely used UV filters, were determined in the muscle tissue of fish (brown trout, Salmo trutta fario) from seven small Swiss rivers, all receiving inputs from wastewater treatment plants (WWTPs). Lipid-weight based concentrations of up to 1800 (4-MBC) and 2400 ng g(-1) (OC) were found. These levels were distinctly higher than those previously observed in white fish (Coregonus sp.) and roach (Rutilus rutilus) from Swiss lakes with inputs from WWTPs. This suggests a higher availability of these contaminants for fish in rivers than in lakes and identifies WWTPs as a major source for UV filters in the aquatic environment. As compared to lake fish, individual fish from a river showed much greater variation in 4-MBC and OC concentrations, likely as a result of a wider range of exposure in rivers than in lakes. 4-MBC concentrations correlated reasonably well with concentrations of methyl triclosan, a chemical marker for lipophilic WWTP-derived contaminants. The ratio P/Q of population (P) in a watershed to water throughflow (Q) is considered to be a measure of the domestic burden from WWTPs. A correlation of methyl triclosan with P/Q was previously observed with lake fish. However, such a correlation could not be confirmed with river fish. The higher average concentrations of OC as compared to 4-MBC in river fish, and the fact that OC was mostly absent in lake fish, suggests differences in bioaccumulation and availability of these two UV filters.
Development of photostable sunscreens is extremely important to preserve the UV protective capacity and to prevent the reactive intermediates of photounstable filter substances behaving as photo-oxidants when coming into direct contact with the skin. Thus, the objective of this study was to evaluate the photostability of four different UV filter combinations in a sunscreen by using HPLC analysis and spectrophotometry. The formulations that were investigated included four different UV filter combinations often used in SPF 15 sunscreens. The UV filter combinations were: octyl methoxycinnamate (OMC), benzophenone-3 (BP-3) and octyl salicylate (OS) (formulation 1); OMC, avobenzone (AVB) and 4-methylbenzilidene camphor (MBC) (formulation 2); OMC, BP-3 and octocrylene (OC) (formulation 3); OMC, AVB and OC (formulation 4). In the photostability studies, 40 mg of each formulation were spread onto a glass plate and left to dry before exposure to different UVA/UVB irradiation. Exposed samples were then immersed in isopropanol and the dried film dissolved ultrasonically. The filter components in the resulting solution were quantified by HPLC analysis with detection at 325 nm and by spectrophotometry. In this study, the four UV filter combinations showed different photostability profiles and the best one was formulation 3 (OMC, BP-3 and OC), followed by formulations 4, 1 and 2. In addition, OC improved the photostability of OMC, AVB and BP-3.
An analytical method for the determination of UV filter substances in fish tissue has been developed and validated using benzophenone-3, 3-(4-methylbenzylidene)-camphor, 2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate and 2-ethylhexyl 3-(methoxyphenyl)-2-propenoate as target analytes. The fish fillets were homogenised and extracted by Soxhlet extraction. The extracts were run through a clean-up process including gel permeation chromatography followed by solid-phase extraction. Quantification of the compounds was performed using liquid chromatography with tandem mass spectrometric detection. Blank fish as well as spiked blank fish were analysed to validate the analytical method. The analytical method developed has the multiple advantages of enabling separation, simultaneous identification and quantification of each of the four selected compounds in a single run. Contamination of blank samples and abnormally high concentrations in spiked samples were avoided by taking extensive precautions during the fish preparation procedure. The method was validated in accordance with internationally accepted criteria, such as specificity, accuracy and repeatability. The combination of LC with tandem mass spectrometry ensures a high level of specificity. The accuracy of the method was reported as the mean recovery rate for the analytes in the sample matrix. Mean recoveries were in the range 86–108%. The precision is expressed as the relative standard deviation, and in all but one of the cases was 20% or below. The accuracy of the method allows residue analyses to be performed on biological matrices at ng/g levels. The determined limit of quantification for each analyte was 8 ng/g fish. For all spiking levels ≥8 ng/g, relative standard deviations were ≤ 20%.
UV filters protect the human lens and retina from UV light-induced damage. Here, we report the identification of a new UV filter, cysteine- -3-hydroxykynurenine -β- -glucoside, which is present in older normal human lenses. Its structure was confirmed by independent synthesis. It is likely this novel UV filter is formed in the lens by nucleophilic attack of cysteine on the unsaturated ketone derived from deamination of 3-hydroxykynurenine -β- -glucoside. Quantitation studies revealed considerable variation in normal lens levels that may be traced to the marked instability of the cysteine adduct. The novel UV filter was not detected in advanced nuclear cataract lenses.