Benzophenone-3 and ovarian reserve

OBJECTIVE

To evaluate the association between urinary benzophenone-3 concentrations and measures of ovarian reserve (OR) among women in the Environment and Reproductive Health (EARTH) Study seeking fertility treatment at Massachusetts General Hospital in Boston, Massachusetts.

DESIGN

Prospective cohort study.

METHODS

Women from the EARTH cohort contributed spot urine samples before assessment of OR outcomes. Antral follicle count (AFC) and day-3 follicle stimulating hormone (FSH) levels were evaluated as part of standard infertility workups during unstimulated menstrual cycles. Quasi-Poisson and linear regression models were used to evaluate the association of specific gravity (SG)-adjusted urinary benzophenone-3 concentrations with AFC and FSH, respectively, with adjustment for age and physical activity. In secondary analyses, models were stratified by age. Sensitivity analyses assessed for confounding by season by restricting to women with exposure and outcome measured in the same season and stratifying by summer vs. non-summer months and for confounding by sunscreen use by restricting to women who filled out product questionnaires and adjusting for and stratifying by average sunscreen use score.

RESULTS

The study included 142 women (mean age ± SD, 36.1 ± 4.6; range, 22-45 years) enrolled between 2009 and 2017 with both urinary benzophenone-3 and AFC and 57 women with benzophenone-3 and FSH measurements. Most women were white (78%) and highly educated (49% with a graduate degree). Women contributed a mean of 2.7 urine samples (range, 1-10) with 37% contributing 2 or more samples. Benzophenone-3 was detected in 98% of samples. Geometric mean (GM) SG-corrected urinary benzophenone-3 concentration was 85.9 μ g/L (geometric standard deviation 6.2). There were no associations of benzophenone-3 with AFC and day-3 FSH in the full cohort. In stratified models, a 1-unit increase in log GM benzophenone-3 was associated with AFC 0.91 (95% CI, 0.86, 0.97) times lower among women ≤35 years old and was associated with FSH 0.73 (95% CI, 0.12, 1.34) IU/L higher among women >35 years old. Effect estimates from models stratified by season and sunscreen use were null.

CONCLUSION

In main models, urinary benzophenone-3 was not associated with OR. However, younger may be vulnerable to potential effects of benzophenone-3 on AFC. Further research is warranted.

Single and mixture effects of bisphenol A and benzophenone-3 on in vitro T helper cell differentiation

Immune homeostasis is key to guarantee that the immune system can elicit effector functions against pathogens and at the same time raise tolerance towards other antigens. A disturbance of this delicate balance may underlie or at least trigger pathologies. Endocrine disrupting chemicals (EDCs) are increasingly recognized as risk factors for immune dysregulation. However, the immunotoxic potential of specific EDCs and their mixtures is still poorly understood. Thus, we aimed to investigate the effect of bisphenol A (BPA) and benzophenone-3 (BP-3), alone and in combination, on in vitro differentiation of T helper (TH)17 cells and regulatory T (Treg) cells. Naïve T cells were isolated from mouse lymphoid tissues and differentiated into the respective TH population in the presence of 0.001-10 μM BP-3 and/or 0.01-100 μM BPA. Cell viability, proliferation and the expression of TH lineage specific transcription factors and cytokines was measured by flow cytometry and CBA/ELISA. Moreover, the transcription of hormone receptors as direct targets of EDCs was quantified by RT-PCR. We found that the highest BPA concentration adversely affected TH cell viability and proliferation. Moreover, the general differentiation potential of both TH populations was not altered in the presence of both EDCs. However, EDC exposure modulated the emergence of TH17 and Treg cell intermediate states. While BPA and BP-3 promoted the development of TH1-like TH17 cells under TH17-differentiating conditions, TH2-like Treg cells occurred under Treg polarization. Interestingly, differential effects could be observed in mixtures of the two tested compounds compared with the individual compounds. Notably, estrogen receptor β expression was decreased under TH17-differentiating conditions in the presence of BPA and BP-3 as mixture. In conclusion, our study provides solid evidence for both, the immune disruptive potential and the existence of cumulative effects of real nature EDC mixtures on T cell in vitro differentiation.

Assessing the Fate of Benzophenone-Type UV Filters and Transformation Products during Soil Aquifer Treatment: The Biofilm Compartment as Bioaccumulator and Biodegrader in Porous Media

The fate of selected UV filters (UVFs) was investigated in two soil aquifer treatment (SAT) systems, one supplemented with a reactive barrier containing clay and vegetable compost and the other as a traditional SAT reference system. We monitored benzophenone-3 (BP-3) and its transformation products (TPs), including benzophenone-1 (BP-1), 4,4'-dihydroxybenzophenone (4DHB), 4-hydroxybenzophenone (4HB), and 2,2'-dihydroxy-4-methoxybenzophenone (DHMB), along with benzophenone-4 (BP-4) and avobenzone (AVO) in all involved compartments (water, aquifer sediments, and biofilm). The reactive barrier, which enhances biochemical activity and biofilm development, improved the removal of all detected UVFs in water samples. Among monitored UVFs, only 4HB, BP-4, and AVO were detected in sediment and biofilm samples. But the overall retained amounts were several orders of magnitude larger than those dissolved. These amounts were quantitatively reproduced with a specifically developed simple analytical model that consists of a mobile compartment and an immobile compartment. Retention and degradation are restricted to the immobile water compartment, where biofilm absorption was simulated with well-known compound-specific Kow values. The fact that the model reproduced observations, including metabolites detected in the biofilm but not in the (mobile) water samples, supports its validity. The results imply that accumulation ensures significant biodegradation even if the degradation rates are very low and suggest that our experimental findings for UVFs and TPs can be extended to other hydrophobic compounds. Biofilms act as accumulators and biodegraders of hydrophobic compounds.

Urinary phenols and parabens exposure in relation to urinary incontinence in the US population

BACKGROUND

Our study aimed to investigate the impact of urinary concentrations of personal care products (PCPs)-related phenols (PNs) and parabens (PBs), including Triclosan (TCS), Bisphenol A (BPA), Benzophenone-3 (BP-3), Butylparaben (BPB), Ethylparaben (EPB), Methylparaben (MPB), and Propylparaben (PPB), on urinary incontinence (UI) occurrence.

METHOD

We conducted a cross-sectional analysis using data from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2007 to 2016. Regression analysis was employed to investigate the relationship between exposure to PCPs-related substances, various levels of exposure, and UI within both the general population and the female demographic. Additionally, the Bayesian Kernel Machine Regression (BKMR) model was used to assess the effects of mixtures on UI.

RESULTS

Our analysis comprised 7,690 participants who self-reported their diagnosis. Among them, 12.80% experienced stress urinary incontinence (SUI), 11.80% reported urge urinary incontinence (UUI), and 10.22% exhibited mixed urinary incontinence (MUI). In our fully adjusted multivariable models, BP-3 exposure exhibited a positive association with SUI (OR 1.07, 95% CI 1.02-1.14, p = 0.045). BPA exposure correlated with an increased risk of UUI (OR 1.21, 95% CI 1.01-1.44, p = 0.046) and MUI (OR 1.26, 95% CI 1.02-1.54, p = 0.029). TCS exposure displayed a negative correlation with the incidence of MUI (OR 0.87, 95% CI 0.79-0.97, p = 0.009). No significant links were observed between parabens and urinary incontinence. Notably, among the female population, our investigation revealed that BPA exposure heightened the risk of MUI (OR 1.28, 95% CI 1.01-1.63, p = 0.043). Participants in the highest tertile of BP-3 exposure demonstrated elevated likelihoods of SUI and MUI compared to those in the lowest tertile. In the BKMR analysis, negative trends were observed between the mixture and the risks of UUI and MUI when the mixture ranged from the 25th to the 40th and 35th to the 40th percentiles or above, respectively. Additionally, a positive trend was identified between the mixture and MUI when it was in the 40th to 55th percentile.

CONCLUSION

In conclusion, our findings suggest that exposure to BPA, TCS, and BP-3 may contribute to the development of urinary incontinence.

Mechanism of Microglial Cell Activation in the Benzophenone-3 Exposure Model

Benzophenone-3 (BP-3) is the most commonly used UV filter in cosmetics, which is absorbed through the skin and crosses the blood-brain barrier. This compound increases extracellular glutamate concentrations, lipid peroxidation, the number of microglia cells and induces process of apoptosis. The aim of this study was to determine the effect of BP-3 on the activation and polarization of microglial cells in the frontal cortex and hippocampus of adult male rats exposed to BP-3 prenatally and then for two weeks in adulthood. It has been found, that exposure to BP-3 reduced the expression of the marker of the M2 phenotype of glial cells in both examined brain structures. An increase in the CD86/CD206 microglial phenotype ratio, expression of transcription factor NFκB and activity of caspase-1 were observed only in the frontal cortex, whereas BP-3 increased the level of glucocorticoid receptors in the hippocampus. The in vitro study conducted in the primary culture of rat frontal cortical microglia cells showed that BP-3 increased the LPS-stimulated release of pro-inflammatory cytokines IL-1α, IL-1β, TNFα, but in cultures without LPS there was decreased IL-1α, IL-6 and TNFα production, while the IL-18 and IP-10 was elevated. The obtained results indicate that differences in the level of immunoactivation between the frontal cortex and the hippocampus may result from the action of this compound on glucocorticoid receptors. In turn, changes in cytokine production in microglial cells indicate that BP-3 aggravates the LPS-induced immunoactivation.

Assessing the Effects of Ozonation on the Concentrations of Personal Care Products and Acute Toxicity in Sludges of Wastewater Treatment Plants

The aim of this study was to understand the distribution of the personal care products nonylphenol (NP), triclosan (TCS), benzophenone-3 (BP-3), and caffeine in the sludges from three wastewater treatment plants (WWTP-A, -B, and -C) in southern Taiwan. The four compounds were analyzed from activated sludge and dewatered sludge samples, and then the samples were treated with pressure-assisted ozonation under different conditions and removal efficiencies. All four target compounds were detected, especially NP, which was detected in the highest concentrations in the activated sludges of WWTP-A and dewatered sludges of WWTP-C at 17.19 ± 4.10 and 2.41 ± 1.93 µg/g, respectively. TCS was dominant in dewatered sludges from WWTP-B, and the highest detected concentration was 13.29 ± 6.36 µg/g. Removals of 70% and 90% were attained under 150 psi at 40 cycles for NP and TCS, respectively, with 5 min of ozonation reaction time, a solid/water ratio of 1:20, and 2% ozone concentration. Ecological risk quotients (RQs) were calculated by the ratios of the 10-day Hyalella azteca (freshwater amphipod) LC50 to the environmental concentrations of the target compounds. High RQs were found to be >10 for NP, TCS, and BP-3 in untreated sludges, resulting in significant ecological risks to aquatic organisms when the sludges are arbitrarily disposed. However, the toxic effects on Hyalella azteca were not significantly different among ozone sludge treatments. The reason for this may be related to the formation of toxic oxidation by-products and incomplete mineralization of organic compounds. This could also be true for unknown intermediates. The relatively high detection frequencies of these emerging compounds in WWTP sludges requires further applications and treatments.

Toxicokinetics, Percutaneous Absorption and Tissue Distribution of Benzophenone-3, an UV Filtering Agent, in Rats

The aim of this study was to evaluate in vitro skin permeation and deposition, in vivo toxicokinetics, percutaneous absorption and tissue distribution of benzophenone-3 (BP-3) in rats. Four transdermal formulations containing BP-3 were prepared and evaluated for in vitro skin permeation and deposition of BP-3 using Franz diffusion cells. A gel formulation was used in subsequent in vivo percutaneous absorption due to its high in vitro skin permeation and deposition. Compared to intravenous (i.v.) injection, the prolonged terminal t_1/2 (3.1 ± 1.6 h for i.v. injection and 18.3 ± 5.8 h for topical application) was observed indicating occurrence of flip-flop kinetics after topical application. The bioavailability of BP-3 after topical application was 6.9 ± 1.8%. The tissue-to-plasma partition coefficient (kp) for testis, considered a toxic target for BP-3, was less than 1.. Overall, findings of this study may be useful for risk assessment of BP-3.

Prenatal exposure to phenols and benzophenones in relation to markers of male reproductive function in adulthood

INTRODUCTION

Environmental exposure during fetal life may disrupt testicular development. In humans, a limited number of studies have investigated whether these adverse effects persist into adulthood. Using data from a prospective, population-based birth cohort study, The Copenhagen Mother-Child cohort, the objective was to assess if there is an association between fetal exposure to selected phenols and benzophenones and markers of testicular function in adult men.

METHODS

Pregnant women were recruited in 1997-2001. Their sons were examined clinically at 18-20 years of age, with focus on adult markers of reproductive function (anogenital distance (AGD), semen quality and reproductive hormones). In total, 101 18-20-year-old men were included, whose mothers during pregnancy had a serum sample drawn and analyzed for bisphenol A (BPA) and seven other simple phenols, as well as six benzophenones. To investigate the association between chemical levels (in tertiles, T1-T3) in relation to markers of reproductive function, univariate and multiple linear regression analyses were performed.

RESULTS

In fully adjusted analyses, increased levels of luteinizing hormone (LH) were observed with higher fetal exposure to BPA (percentage difference (95%CI)) (T2: 12% (-8%,36%) and T3: 33% (10%,62%), compared to T1) and benzophenone-3 (BP-3) (T2: 21% (-2%,49%), T3: 18% (-4%,45%)), while no clear association was seen to total testosterone (TT). Higher levels of BPA and BP-3 were associated with a lower TT/LH ratio, although only significant for BPA (p-trend=0.01). No associations were seen to AGD or markers of semen quality.

CONCLUSION

In conclusion, high exposure to BPA and BP-3 was associated with a compensated reduced Leydig cell function but no other changes in markers of reproductive health. As maternal levels of BPA and BP-3 were not correlated, separate effects may be at play. Larger studies on long-term reproductive consequences of prenatal exposures are warranted to validate our findings.

Analyzing the Photoprotection Efficiency of Sunscreens Containing Antioxidants under Disinfection Conditions

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.

The Beneficial Effect of Rosmarinic Acid on Benzophenone-3-Induced Alterations in Human Skin Fibroblasts

Benzophenone-3 (BP-3) is one of the most widely used chemical sunscreens. The results of many in vitro and in vivo tests confirm its high percutaneous penetration and systemic absorption, which question the safety of its wide use. The aim of our research was to assess the effect of this compound on components of the skin extracellular matrix, and to investigate whether rosmarinic acid (RA) could reduce BP-3-induced changes in human skin fibroblasts. BP-3 used at concentrations of 0.1-100 µM caused a number of unfavorable changes in the level of type I collagen, decorin, sulfated glycosaminoglycans, hyaluronic acid, elastin, and expression or activity of matrix metalloproteinases (MMP-1, MMP-2), elastase and hyaluronidase. Moreover, the intracellular retention of collagen was accompanied by changes in the expression of proteins modifying and controlling the synthesis and secretion of this protein. Most importantly, RA at a concentration of 100 µM significantly reduced or completely abolished the adverse effects of BP-3. Based on these findings, it can be concluded that this polyphenol may provide effective protection against BP-3-induced disturbances in skin cells, which may have important clinical implications.

A Novel Approach to Derive the Predicted No-Effect Concentration (PNEC) of Benzophenone-3 (BP-3) Using the Species Sensitivity Distribution (SSD) Method: Suggestion of a New PNEC Value for BP-3

The necessity for the aquatic ecological risk assessment for benzophenone-3 (BP-3) is increasing due to its high toxic potential and high detection frequency in freshwater. The initial step in the ecological risk assessment is to determine predicted no-effect concentration (PNEC). This study derived PNEC of BP-3 in freshwater using a species sensitivity distribution (SSD) approach, whilst existing PNECs are derived using assessment factor (AF) approaches. A total of eight chronic toxicity values, obtained by toxicity testing and a literature survey, covering four taxonomic classes (fish, crustaceans, algae, and cyanobacteria) were used for PNEC derivation. Therefore, the quantity and quality of the toxicity data met the minimum requirements for PNEC derivation using an SSD approach. The PNEC derived in this study (73.3 μg/L) was far higher than the environmental concentration detected in freshwater (up to 10.4 μg/L) as well as existing PNECs (0.67~1.8 μg/L), mainly due to the difference in the PNEC derivation methodology (i.e., AF vs. SSD approach). Since the SSD approach is regarded as more reliable than the AF approach, we recommend applying the PNEC value derived in this study for the aquatic ecological risk assessment of BP-3, as the use of the existing PNEC values seems to unnecessarily overestimate the potential ecological risk of BP-3 in freshwater.

Benzophenone-3 promotion of mammary tumorigenesis is diet-dependent

Benzophenone-3 is a putative endocrine disrupting chemical and common ingredient in sunscreens. The potential of endocrine disrupting chemicals to act as agonists or antagonists in critical hormonally regulated processes, such as mammary gland development and mammary tumorigenesis, demands evaluation of its potential in promoting breast cancer. This study identifies the effects of BP-3 on mammary tumorigenesis with high-fat diet during puberty versus adulthood in Trp53-null transplant BALB/c mice. Benzophenone-3 exposure yielded levels in urine similar to humans subjected to heavy topical sunscreen exposure. Benzophenone-3 was protective for epithelial tumorigenesis in mice fed lifelong low-fat diet, while promotional for epithelial tumorigenesis in mice fed adult high-fat diet. Benzophenone-3 increased tumor cell proliferation, decreased tumor cell apoptosis, and increased tumor vascularity dependent on specific dietary regimen and tumor histopathology. Even in instances of an ostensibly protective effect, other parameters suggest greater risk. Although benzophenone-3 seemed protective on low-fat diet, spindle cell tumors arising in these mice showed increased proliferation and decreased apoptosis. This points to a need for further studies of benzophenone-3 in both animal models and humans as a potential breast cancer risk factor, as well as a more general need to evaluate endocrine disrupting chemicals in varying dietary contexts.

The banned sunscreen ingredients and their impact on human health: a systematic review

Recent evidence of high systemic absorption of sunscreen ingredients has raised concerns regarding the safety of sunscreen products. Oxybenzone (BP-3) and octinoxate (OMC), two common sunscreen ingredients, were recently banned in Key West and Hawaii owing to their toxic effects on marine ecosystems. Their impact on human health requires a careful assessment. To summarize the current evidence on the association between the systemic level of BP-3 or OMC and its health impact, a primary literature search was conducted using PubMed database in February 2019. There are 29 studies that address the impact of these ingredients on human health. Studies show that elevated systemic level of BP-3 has no adverse effect on male and female fertility, female reproductive hormone level, adiposity, fetal growth, child's neurodevelopment, and sexual maturation. However, the association of BP-3 level on thyroid hormone, testosterone level, kidney function, and pubertal timing has been reported and prompts further investigations to validate a true association. The systemic absorption of OMC has no reported effect on thyroid and reproductive hormone levels. In conclusion, current evidence is not sufficient to support the causal relationship between the elevated systemic level of BP-3 or OMC and adverse health outcomes. There are either contradictory findings among different studies or an insufficient number of studies to corroborate the observed association. To accurately evaluate the long-term risk of exposure to BP-3 and OMC from sunscreen, a well-designed longitudinal randomized controlled trial needs to be conducted.

Culturing Rat Whole Ovary for UV Filter Benzophenone-3 Treatment

We describe a detailed protocol to establish a newborn rat whole ovary culture, which enables the study of direct effects (independent of hypothalamic-pituitary-gonadal axis) of endocrine disrupting chemicals (EDCs), such as benzophenone-3 (BP-3). This method is useful to understand changes in follicle formation, primordial to primary transition, and expression of regulatory molecules linked to these processes and also provides an alternative to animal models. © 2019 by John Wiley & Sons, Inc. Basic Protocol 1: Rat ovarian surgery Basic Protocol 2: Whole organ/ovarian culture Basic Protocol 3: RNA isolation and quantitative real-time PCR Basic Protocol 4: Histological processing and staining.

Metabolism and disposition of 2-hydroxy-4-methoxybenzophenone, a sunscreen ingredient, in Harlan Sprague Dawley rats and B6C3F1/N mice; a species and route comparison

2-Hydroxy-4-methoxybenzophenone (HMB) is a common ingredient in personal care products and used as an UV stabilizer. In these studies, disposition and metabolism of [¹⁴C]HMB in rats and mice was assessed following single gavage administration (10, 100, or 500 mg/kg), single IV administration (10 mg/kg), or dermal application (0.1, 1, 10, or 15 mg/kg).Following gavage administration, [¹⁴C]HMB was well absorbed and excreted mainly in urine (39-57%) and feces (24-42%) with no apparent difference between doses, species or sexes. Distribution of HMB in tissues was minimal in rats (0.36%) and mice (<0.55%).Distribution of HMB following dermal application was comparable to that following gavage administration; no differences between doses, sexes, or species were observed but absorption varied between dose vehicles. Light paraffin oil had the highest absorption and excretion (98% of the HMB dose absorbed).In rats, HMB slowly appeared in the systemic circulation (T_max ∼2-6 h) and had poor bioavailability (F%<1).Urine metabolites for both species and all routes included HMB, HMB-glucuronide, 2,4-dihydroxybenzophenone (DHB), DHB-glucuronide, and DHB-sulfates, and novel minor dihydroxy metabolites including 2,5-dihydroxy-4-methoxybenzophenone.In vitro hepatic metabolism in mice differed from human and in vivo metabolism especially for phase II conjugates.

Development, Cytotoxicity and Eye Irritation Profile of a New Sunscreen Formulation Based on Benzophenone-3-poly(ε-caprolactone) Nanocapsules

The objective of this work was to characterize the toxicological profile of a newly developed sunscreen formulation based on polymeric nanocapsules (NCs) loading benzophenone-3 (BZP3). NCs composed of poly(ε-caprolactone) carrot oil and Pluronic^® F68 were produced by emulsification-diffusion method. Their mean particle size (Z-Ave) ranged from 280 to 420 nm, polydispersity index (PDI) was below 0.37, while zeta potential (ZP) reached about |+11 mV|. No cytotoxic effects were observed in L929 fibroblast cell line for the blank (i.e., non-loaded) NCs and BZP3-loaded NCs (BZP3-NCs). The semi-solid sunscreen formulation was stable over time (centrifugation testing) and exhibited non-Newtonian pseudoplastic behavior, which is typical of products for topical application onto the skin. The sun protection factor (SPF) value reached 8.84, when incorporating BZP3-NCs (SPF of 8.64) into the semi-solid formulation. A synergistic effect was also observed when combining the formulation ingredients of nanocapsules, i.e., SPF of carrot oil was 6.82, blank NCs was 6.84, and BZP3-loaded NCs was 8.64. From the hen’s egg-chorioallantoic membrane test (HET-CAM) test, the non-irritation profile of the developed formulations could also be confirmed. The obtained results show a promising use of poly(ε-caprolactone) nanocapsules to be loaded with lipophilic sunscreens as benzophenone-3.

UV Resistance of bacteria from the Kenyan Marine cyanobacterium Moorea producens

UV resistance of bacteria isolated from the marine cyanobacterium Moorea producens has not been observed previously, findings which highlight how unsafe germicidal UV irradiation for sterilization of air, food, and water could be. Further, UV resistance of Bacillus licheniformis is being observed for the first time. This study focused on bacteria isolated from the marine cyanobacterium M. producens collected off the Kenyan coast at Shimoni, Wasini, Kilifi, and Mida. UV irradiance of isolates (302 nm, 70 W/m2 , 0-1 hr) established B. licheniformis as the most UV resistant strain, with the following order of taxon resistance: Bacilli> γ proteobacteria > Actinobacteria. UV resistance was independent of pigmentation. The maximum likelihood phylogenetic distance determined for both B. licheniformis and Bacillus aerius relative to M. producens CCAP 1446/4 was 2.0. Survival of B. licheniformis upon UV irradiance followed first-order kinetics (k = 0.035/min, R2  = 0.88). Addition of aqueous extracts (2, 10, 20 and 40 mg/ml) of this B. licheniformis strain on the less resistant Marinobacterium stanieri was not significant, however, the commercial sunscreen benzophenone-3 (BP-3) positive control and the time of irradiance were significant. Detection of bacteria on M. producens filaments stained with acridine orange confirmed its nonaxenic nature. Although the chemistry of UV resistance in cyanobacteria has been studied in depth revealing for example the role of mycosporine like amino acids (MAAs) in UV resistance less is known about how bacteria resist UV irradiation. This is of interest since cyanobacteria live in association with bacteria.

Evaluating the Joint Toxicity of Two Benzophenone-Type UV Filters on the Green Alga Chlamydomonas reinhardtii with Response Surface Methodology

The widespread occurrence of benzophenone-type ultraviolet (UV) filter has raised the public concerns over the ecotoxicological effects of these chemicals. The present study assessed the joint toxicity of two representative benzophenones, benzophenone-1 (BP-1) and benzophenone-3 (BP-3), on the green alga Chlamydomonas reinhardtii using response surface methodologies (RSM). Specific growth rate and photosynthetic pigments were used as endpoints to evaluate the toxic effects. Generally, exposure to the combined BP-1 and BP-3 negatively affected cell growth and pigments production, with higher inhibitions at higher exposure concentrations. The simultaneous reduction in growth rate and pigments contents indicated that BP-1 and BP-3 regulated the growth of the tested alga by affecting the photosynthesis process. Results also showed that second order polynomial regression models fitted well with experimental results for all endpoints. The obtained regression models further indicated that the effects of the combination stemmed significantly from the linear concentration of BP-1 and BP-3. The overall results demonstrated that RSM could be a useful tool in ecotoxicological studies.

Urinary Concentrations of Triclosan, Benzophenone-3, and Bisphenol A in Taiwanese Children and Adolescents

The purpose of this study was to determine the levels of urinary triclosan (TCS), benzophenone-3 (BP-3), and bisphenol A (BPA) in 52 children and 71 adolescents. The effects of age and sex on the levels of urinary TCS, BP-3, and BPA were explored, respectively. Results demonstrated the overall detection rates of urinary TCS, BP-3, and BPA were 18.7%, 8.1%, and 49.6%, respectively. The females had higher TCS concentrations than males (p = 0.051). The detection rate of urinary BP-3 in females (12.3%) was higher than that in males (0%) (p = 0.015). Moreover, the detection rate of urinary BP-3 in adolescents (14.1%) was higher than that in children (0%) (p = 0.005). For children, no urinary BP-3 was found. There were no differences in detection rates and concentrations of urinary TCS, BP-3, and BPA between males and females, respectively. For adolescents, urinary BP-3 was only found in the females. Urinary TCS levels in females were higher than those in males (p = 0.047). The present study showed that urinary TCS concentrations in females were significantly higher than those in males, respectively. In addition, BP-3 was only detected in urine samples of female adolescents. Sex and age were the important factors influencing urinary TCS and BP-3 concentrations.

Acute Toxicity and Ecological Risk Assessment of Benzophenone-3 (BP-3) and Benzophenone-4 (BP-4) in Ultraviolet (UV)-Filters

Ultraviolet (UV)-absorbing chemicals (UV filters) are used in personal care products for the protection of human skin and hair from damage by UV radiation. Although these substances are released into the environment in the production and consumption processes, little is known about their ecotoxicology effects. The acute toxicity and potential ecological risk of UV filters benzophenone-3 (BP-3) and benzophenone-4 (BP-4) on Chlorella vulgaris, Daphnia magna, and Brachydanio rerio were analyzed in the present study. The EC₅₀ values (96 h) of BP-3 and BP-4 on C. vulgaris were 2.98 and 201.00 mg/L, respectively. The 48 h-LC₅₀ of BP-3 and BP-4 on D. magna were 1.09 and 47.47 mg/L, respectively. The 96 h-LC₅₀ of BP-3 and BP-4 on B. rerio were 3.89 and 633.00 mg/L, respectively. The toxicity of a mixture of BP-3 and BP-4 on C. vulgaris, D. magna, and B. rerio all showed antagonistic effects. The induced predicted no-effect concentrations of BP-3 and BP-4 by the assessment factor method were 1.80 × 10⁻³ and 0.47 mg/L, respectively, by assessment factor (AF) method, which were both lower than the concentrations detected in the environment at present, verifying that BP-3 and BP-4 remain low-risk chemicals to the aquatic ecosystem.

Presence of UV filters in surface water and the effects of phenylbenzimidazole sulfonic acid on rainbow trout (Oncorhynchus mykiss) following a chronic toxicity test

UV filters belong to a group of compounds that are used by humans and are present in municipal waste-waters, effluents from sewage treatment plants and surface waters. Current information regarding UV filters and their effects on fish is limited. In this study, the occurrence of three commonly used UV filters - 2-phenylbenzimidazole-5-sulfonic acid (PBSA), 2-hydroxy-4-methoxybenzophenone (benzophenone-3, BP-3) and 5-benzoyl-4-hydroxy-2-methoxy-benzenesulfonic acid (benzophenone-4, BP-4) - in South Bohemia (Czech Republic) surface waters is presented. PBSA concentrations (up to 13μgL(-1)) were significantly greater than BP-3 or BP-4 concentrations (up to 620 and 390ngL(-1), respectively). On the basis of these results, PBSA was selected for use in a toxicity test utilizing the common model organism rainbow trout (Oncorhynchus mykiss). Fish were exposed to three concentrations of PBSA (1, 10 and 1000µgL(-1)) for 21 and 42 days. The PBSA concentrations in the fish plasma, liver and kidneys were elevated after 21 and 42 days of exposure. PBSA increased activity of certain P450 cytochromes. Exposure to PBSA also changed various biochemical parameters and enzyme activities in the fish plasma. However, no pathological changes were obvious in the liver or gonads.

Temporal variability in urinary excretion of bisphenol A and seven other phenols in spot, morning, and 24-h urine samples

Human exposure to modern non-persistent chemicals is difficult to ascertain in epidemiological studies as exposure patterns and excretion rates may show temporal and diurnal variations. The aim of this study was to assess the temporal variability in repeated measurements of urinary excretion of bisphenol A (BPA) and seven other phenols. All analytes were determined using TurboFlow-LC-MS/MS. Two spot, three first morning and three 24-h urine samples were collected from 33 young Danish men over a three months period. Temporal variability was estimated by means of intraclass correlation coefficients (ICCs). More than 70% of the urine samples had detectable levels of BPA, triclosan (TCS), benzophenone-3 (BP-3) and sum of 2,4-dichlorophenol and 2,5-dichlorophenol (ΣDCP). We found low to moderate ICCs for BPA (0.10-0.42) and ΣDCP (0.39-0.72), whereas the ICCs for BP-3 (0.69-0.80) and TCS (0.55-0.90) were higher. The ICCs were highest for the two spot urine samples, which were collected approximately 4 days apart, compared with the 24-h urine samples and the first morning urine samples, which were collected approximately 40 days apart. A consequence of the considerable variability in urinary excretion of BPA may be misclassification of individual BPA exposure level in epidemiological studies, which may lead to attenuation of the association between BPA and outcomes. Our data do not support that collection of 24-h samples will improve individual exposure assessment for any of the analysed phenols.

Parental phenols exposure and spontaneous abortion in Chinese population residing in the middle and lower reaches of the Yangtze River

Widespread use of phenols has led to ubiquitous exposure to phenols. In experimental animals, phenols increased resorptions, reduced live litter size and fetal body weights. However, there are limited epidemiological evidences of the relationships between exposure to phenols and pregnancy outcomes. We evaluated the associations between parental urinary levels of various phenols and spontaneous abortion in a Chinese population residing in the middle and lower reaches of the Yangtze River. A case-control study was conducted that included 70 case couples with medically unexplained spontaneous abortion and 180 control couples who did not have a history of spontaneous abortion and had at least one living child. Both parental urinary phenols were measured by ultra-high performance liquid chromatography-tandem mass spectrometry including bisphenol A (BPA), benzophenone-3 (BP-3), 2,3,4-trichlorophenol (2,3,4-TCP), pentachlorophenol (PCP), 4-n-octylphenol (4-n-OP) and 4-n-nonylphenol (4-n-NP). Compared with the low exposure group, there was an increased risk of spontaneous abortion with high paternal urinary PCP concentration [odds ratio (OR)=2.09, 95% Confidence Interval (CI), 1.05-4.14], and maternal exposure to 4-n-OP and alkylphenol(s) also significantly increased the risk of spontaneous abortion (OR=2.21, 95% CI, 1.02-4.80; OR=2.81, 95% CI, 1.39-5.65, respectively). Our study firstly provides the evidence that paternal PCP exposure, maternal 4-n-OP and alkylphenol(s) exposure are associated with spontaneous abortion in humans.

Urinary excretion of phthalate metabolites, phenols and parabens in rural and urban Danish mother-child pairs

Some phthalates, parabens and phenols have shown adverse endocrine disrupting effects in animal studies and are also suspected to be involved in human reproductive problems. However, knowledge about exposure sources and biomonitoring data in different subsets of populations are still scarce. Thus, in this study first morning urine samples were collected from 6 to 11 years Danish children and their mothers. The content of seven parabens, nine phenols and metabolites of eight different phthalates were analysed by LC-MS/MS. Two parabens, six phenols and metabolites from six phthalate diesters were measurable in more than 50%, 75% and 90% of the participants, respectively. Thus the children and their mothers were generally exposed simultaneously to a range of phthalates, phenols and parabens. In general, the levels were low but for several of the compounds extreme creatinine adjusted concentrations 100-500-fold higher than the median level were seen in some participants. Children were significantly higher exposed to bisphenol A (BPA) and some of the phthalates (DiBP, DnBP, BBzP, DEHP and DiNP) than their mothers, whereas mothers were higher exposed to compounds related to cosmetics and personal care products such as parabens (MeP, EtP and n-PrP), benzophenone-3, triclosan and diethyl phthalate. However, a very high correlation between mothers and their children was observed for all chemicals. A high individual exposure to one chemical was often associated with a high exposure to other of the chemicals and the possibility of combination effects of multiple simultaneous exposures cannot be excluded.

Potential external contamination with bisphenol A and other ubiquitous organic environmental chemicals during biomonitoring analysis: an elusive laboratory challenge

BACKGROUND

Biomonitoring studies are conducted to assess internal dose (i.e., body burden) to environmental chemicals. However, because of the ubiquitous presence in the environment of some of these chemicals, such as bisphenol A (BPA), external contamination during handling and analysis of the biospecimens collected for biomonitoring evaluations could compromise the reported concentrations of such chemicals.

OBJECTIVES

We examined the contamination with the target analytes during analysis of biological specimens in biomonitoring laboratories equipped with state-of-the-art analytical instrumentation.

DISCUSSIONS

We present several case studies using the quantitative determination of BPA and other organic chemicals (i.e., benzophenone-3, triclosan, parabens) in human urine, milk, and serum to identify potential contamination sources when the biomarkers measured are ubiquitous environmental contaminants.

CONCLUSIONS

Contamination with target analytes during biomonitoring analysis could result from solvents and reagents, the experimental apparatus used, the laboratory environment, and/or even the analyst. For biomonotoring data to be valid-even when obtained from high-quality analytical methods and good laboratory practices-the following practices must be followed to identify and track unintended contamination with the target analytes during analysis of the biological specimens: strict quality control measures including use of laboratory blanks; replicate analyses; engineering controls (e.g., clean rooms, biosafety cabinets) as needed; and homogeneous matrix-based quality control materials within the expected concentration ranges of the study samples.

Concentrations of the sunscreen agent benzophenone-3 in residents of the United States: National Health and Nutrition Examination Survey 2003--2004

BACKGROUND

The capability of benzophenone-3 (BP-3) to absorb and dissipate ultraviolet radiation facilitates its use as a sunscreen agent. BP-3 has other uses in many consumer products (e.g., as fragrance and flavor enhancer, photoinitiator, ultraviolet curing agent, polymerization inhibitor).

OBJECTIVES

Our goal was to assess exposure to BP-3 in a representative sample of the U.S. general population > or = 6 years of age.

METHODS

Using automated solid-phase extraction coupled to high-performance liquid chromatography-tandem mass spectrometry, we analyzed 2,517 urine samples collected as part of the 2003--2004 National Health and Nutrition Examination Survey.

RESULTS

We detected BP-3 in 96.8% of the samples. The geometric mean and 95th percentile concentrations were 22.9 microg/L (22.2 microg/g creatinine) and 1,040 microg/L (1,070 microg/g creatinine), respectively. Least-square geometric mean (LSGM) concentrations were significantly higher (p < or = 0.04) for females than for males, regardless of age. LSGM concentrations were significantly higher for non-Hispanic whites than for non-Hispanic blacks (p < or = 0.01), regardless of age. Females were more likely than males [adjusted odds ratio (OR) = 3.5; 95% confidence interval (95% CI), 1.9-6.5], and non-Hispanic whites were more likely than non-Hispanic blacks (adjusted OR = 6.8; 95% CI, 2.9-16.2) to have concentrations above the 95th percentile.

CONCLUSIONS

Exposure to BP-3 was prevalent in the general U.S. population during 2003--2004. Differences by sex and race/ethnicity probably reflect differences in use of personal care products containing BP-3.

Solid-phase extraction and reverse-phase HPLC: application to study the urinary excretion pattern of benzophenone-3 and its metabolite 2,4-dihydroxybenzophenone in human urine

BACKGROUND

Benzophenone-3 (BZ-3) is a common ultraviolet (UV) absorbing compound in sunscreens. It is the most bioavailable species of all UV-absorbing compounds after topical application and can be found in plasma and urine.

OBJECTIVES

The aim of this study was to develop a reverse-phase high performance liquid chromatography (HPLC) method for determining the amounts BZ-3 and its metabolite 2,4-dihydroxybenzophenone (DHB) in human urine. The method had to be suitable for handling a large number of samples. It also had to be rapid and simple, but still sensitive, accurate and reproducible. The assay was applied to study the urinary excretion pattern after repeated whole-body applications of a commercial sunscreen, containing 4% BZ-3, to 25 healthy volunteers.

METHODS

Each sample was analyzed with regard to both conjugated/non-conjugated BZ-3 and conjugated/non-conjugated DHB, since both BZ-3 and DHB are extensively conjugated in the body. Solid-phase extraction (SPE) with C8 columns was followed by reverse-phase HPLC. For separation a Genesis C18 column was used with an acethonitrile-water mobile phase and the UV-detector was set at 287 nm.

RESULTS

The assay was linear r(2) > 0.99, with detection limits for BZ-3 and DHB of 0.01 micromol L(-1) and 0.16 micromol L(-1) respectively. Relative standard deviation (RSD) was less than 10% for BZ-3 and less than 13% for DHB. The excretion pattern varied among the human volunteers; we discerned different patterns among the individuals.

CONCLUSIONS

The reverse-phase HPLC assay and extraction procedures developed are suitable for use when a large number of samples need to be analyzed and the method fulfilled our objectives. The differences in excretion pattern may be due to differences in enzyme activity but further studies, especially about genetic polymorphism, need to be performed to verify this finding.