Benzophenone-3: Comprehensive review of the toxicological and human evidence with meta-analysis of human biomonitoring studies

Contaminants of emerging concern in an endangered population of common eiders (Somateria mollissima) in the Baltic Sea

Contaminants of emerging concern (CECs) are ubiquitous in aquatic environments and pose a range of biological effects including endocrine disruption. Yet, knowledge of their occurrence in wildlife including seabirds remains scarce. We investigated the occurrence of selected bisphenols, benzophenones, phthalate metabolites, benzotriazoles, benzothiazoles, parabens, triclosan, and triclocarban in plasma of 18 breeding female common eiders (Somateria mollissima) from an endangered population in the Baltic Sea as most of these CECs have never before been examined in eiders. We sampled blood at the start (T1) and end (T2) of incubation to investigate concentration changes during incubation. As early- and late-breeding eiders tend to differ in how they finance reproduction (local vs stored nutrient reserves), we compared early and late breeders to assess whether CEC concentrations differed by breeding phenology. Of the 58 targeted CECs, 21 were detected in at least one female, with bisphenol A (BPA) and benzophenone-3 (BzP-3) occurring most frequently (T1: 78% and 61%; T2: 61% and 67%, respectively), while mono(2-ethyl-1-hexyl) phthalate (mEHP), BPA, and monoethyl phthalate (mEP) were detected in the highest concentrations (median concentrations 27.1, 12.7, and 11.2 ng/g wet weight, respectively, at T1). No CEC concentrations differed between early and late incubation. Late breeders had significantly higher concentrations of BzP-3, monomethyl phthalate (mMP), and mEP during early incubation (4.55 vs 1.24 ng/g ww, 7.05 vs 3.52, and 11.2 vs < limit of detection (LOD), respectively) and significantly higher concentrations of mMP and mEP during late incubation (6.16 vs  Collapse

Key Words

• Avian
• Blood
• Duck
• Personal care product
• Plasticizer
• UV filter

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MESH Headings

• Animals
• Female
• Water Pollutants, Chemical/analysis
• Endangered Species
• Environmental Monitoring/methods
• Phenols
• Benzhydryl Compounds
• Ducks
• Benzophenones
• Endocrine Disruptors/analysis
• Phthalic Acids

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Affiliation(s)

Amalie V Ask Department of Biology, University of Turku, FI-20014, Turku, Finland.
Veerle L B Jaspers Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Junjie Zhang Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Alexandros G Asimakopoulos Department of Chemistry, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Sunniva H Frøyland Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Juho Jolkkonen Department of Biological and Environmental Science, FI-40014, University of Jyväskylä, Finland
Wasique Z Prian Department of Biology, Norwegian University of Science and Technology (NTNU), NO-7491, Trondheim, Norway
Nora M Wilson Ab Bengtskär Oy, FI-25950, Rosala, Finland; Physics, Faculty of Science and Engineering, Åbo Akademi University, FI-20500, Turku, Finland
Christian Sonne Department of Ecoscience, Aarhus University, Arctic Research Centre (ARC), DK-4000, Roskilde, Denmark
Martin Hansen Department of Environmental Science, Aarhus University, DK-4000, Roskilde, Denmark
Markus Öst Environmental and Marine Biology, Åbo Akademi University, FI-20500, Turku, Finland
Sanna Koivisto Finnish Safety and Chemicals Agency, P.O. Box 66, FI-00521, Helsinki, Finland
Tapio Eeva Department of Biology, University of Turku, FI-20014, Turku, Finland
Farshad S Vakili Department of Biology, University of Turku, FI-20014, Turku, Finland
Céline Arzel Department of Biology, University of Turku, FI-20014, Turku, Finland

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BP-3 exposure at environmentally relevant concentrations induced male developmental reproductive toxicity via ER/CCL27/ROS pathway in mice

BP-3 is the most widely used ultraviolet absorber, but its toxic effects and mechanisms far from being elucidated. This study evaluated the male developmental reproductive toxicities and mechanism of low-doses of BP-3. The results indicated that BP-3 (2.28 and 228 μg/L) led to a decrease in sperm quantity, quality and testosterone level, impaired blood-testis barrier (BTB) integrity and cytoskeleton, accompanied by aggravated oxidative stress in testes of mice on postnatal day 56 (PND 56). Notably, chemokine CCL27, a driver of oxidative stress, was significantly upregulated induced by BP-3. Similar disrupted effects were detected in testes of mice on PND14, which could be antagonized by ICI 182780 (estrogen receptor antagonist). Mechanistically, BP-3 directly interacted with ER, which boosted CCL27 expression, reactive oxygen species (ROS) accumulation, and BTB and cytoskeleton impairment. In vitro, si-CCL27 and/or ROS scavenger treatment significantly antagonized BP-3-induced oxidative stress and the decrease of BTB and cytoskeleton related genes in TM4 cells. These findings demonstrate that prolonged exposure to low-doses of BP-3 resulted in detrimental effects on testicular development through activation of the ER/CCL27/ROS axis. This study provides a novel perspective understanding the male reproductive toxicity risk caused by BPs exposure at low-doses.

Interference Mechanisms of Endocrine System and Other Systems of Endocrine-Disrupting Chemicals in Cosmetics-In Vitro Studies

Endocrine-disrupting chemicals (EDCs), found in various cosmetic products, interfere with the normal functioning of the endocrine system, impacting hormone regulation and posing risks to human health. Common cosmetic EDCs, such as ultraviolet (UV) filters, parabens, and triclosan, can enter the human body through different routes, including skin absorption. Their presence has been linked to adverse effects on reproduction, immune function, and development. High-throughput in vitro assays, using various human cell lines, were employed to assess the effects of common cosmetic EDCs such as ethylhexyl methoxycinnamate (EHMC), benzophenone-3 (BP-3), homosalate, and parabens. Despite ongoing regulatory efforts, gaps persist in understanding their long-term impacts, particularly when they are present as mixtures or degradation products in the environment. This study focuses on recent in vitro research to investigate the mechanisms through which cosmetic-related EDCs disrupt the endocrine system and other physiological systems. The in vitro findings highlight the broader systemic impact of these chemicals, extending beyond the endocrine system to include immune, reproductive, and cardiovascular effects. This research underscores the importance of developing safer cosmetic formulations and enhancing public health protection, emphasizing the need for stricter regulations.

The impact of Benzophenone-3 on osteoarthritis pathogenesis: a network toxicology approach

Background

Arthritis is a degenerative joint disease influenced by various environmental factors, including exposure to Benzophenone-3 (BP3), a common UV filter. This study aims to elucidate the toxicological impact of BP3 on arthritis pathogenesis using network toxicology approaches.

Method

We integrated data from the Comparative Toxicogenomics Database (CTD) and Gene Expression Omnibus (GEO) to identify differentially expressed BP3-related toxicological targets in osteoarthritis (OA). Enrichment analyses were conducted to determine the implicated biological processes, cellular components, and molecular functions. Further, the involvement of the PI3K-Akt signaling pathway was investigated, along with correlations with immune cell infiltration and immune-related pathways. Molecular docking analysis was performed to examine BP3 interactions with key PI3K-Akt pathway proteins.

Results

A total of 74 differentially expressed BP3-related targets were identified. Enrichment analysis revealed significant pathways, including PI3K-Akt, MAPK, and HIF-1 signaling. The PI3K-Akt pathway showed notable dysregulation in OA, with reduced activity and differential expression of key genes such as ANGPT1, ITGA4, and PIK3R1. Correlation analysis indicated significant associations between PI3K-Akt pathway activity and various immune cell types and immune pathways. Molecular docking highlighted strong interactions between BP3 and proteins like AREG, suggesting potential disruptions in signaling processes.

Conclusions

BP3 exposure significantly alters the expression of toxicological targets and disrupts the PI3KAkt signaling pathway, contributing to OA pathogenesis. These findings provide insights into the molecular mechanisms of BP3-induced OA and identify potential therapeutic targets for mitigating its effects.

Potential antiandrogenic effects of parabens and benzophenone-type UV-filters by inhibition of 3α-hydroxysteroid dehydrogenases

Parabens and UV-filters are frequently used additives in cosmetics and body care products that prolong shelf-life. They are assessed for potential endocrine disrupting properties. Antiandrogenic effects of parabens and benzophenone-type UV-filters by blocking androgen receptor (AR) activity have been reported. Effects on local androgen formation received little attention. Local 5α-dihydrotestosterone (DHT) production with subsequent AR activation is required for male external genitalia formation during embryogenesis. We investigated whether parabens and benzophenone-type UV-filters might cause potential antiandrogenic effects by inhibiting oxidative 3α-hydroxysteroid dehydrogenases (3α-HSDs) involved in the backdoor pathway of DHT formation. Five different 3α-HSDs were assessed for their efficiency to catalyze the 3α-oxidation reaction to form DHT and activate AR. 17β-hydroxysteroid dehydrogenase type 6 (HSD17B6), retinol dehydrogenases type 5 and 16 were further assessed using a radiometric in vitro activity assay to determine the conversion of 5α-androstane-3α-ol-17-one to 5α-androstane-3,17-dione in lysates of overexpressing HEK-293 cells. All parabens tested, except p-hydroxybenzoic acid (a main metabolite) inhibited HSD17B6 activity. Hexyl- and heptylparaben, as well as benzophenone (BP)-1 and BP-2, showed the highest inhibitory potencies, with nanomolar IC50 values. Molecular modeling predicted binding modes for the inhibitory parabens and BPs and provided an explanation for the observed structure-activity-relationship. Our results propose a novel mechanism of antiandrogenic action for commercially used parabens and BP UV-filters by inhibiting HSD17B6 and lowering DHT synthesis. Follow-up studies should assess BP-3 metabolism after topical application and whether the identified inhibitors reach concentrations in liver, testis, or prostate to inhibit HSD17B6, thereby causing antiandrogenic effects.

Sunscreen use associated with elevated prevalence of anti-nuclear antibodies in U.S. adults

BACKGROUND

Antinuclear antibody (ANA) prevalence in the U.S. population increased from 1988 to 2012, especially in white and more educated individuals. In adults ages 20-39 years from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2011-2012, ANA prevalence was previously associated with urinary concentrations of a common sunscreen ingredient, benzophenone 3, measured in winter. Spot urines may not capture relevant chronic exposures, thus we examined whether ANA was related to sunscreen use.

METHODS

In a cross-sectional study of adults ages 20-59 (N = 416 ANA positive, 2656 ANA negative, by Hep-2 immunofluorescence, 1:80 dilution), we examined associations of ANA with reported sunscreen use when in the sun for 1 h or more. Logistic regression was used to calculate covariate-adjusted prevalence odds ratios (POR) and 95 % Confidence Intervals (CI), overall and stratified by demographic factors, season, and vitamin D. We explored associations and joint effects with other sun protective behaviors and sunburn in the past 12 months.

RESULTS

The association of ANA with sunscreen differed by age (interaction p = 0.004): for ages 20-39, we saw an exposure response (POR 2.61, 95 % CI 1.50, 4.24 for using sunscreen always or most of the time, and POR 1.85; 1.12, 3.05 for less frequent versus never-use; trend p < 0.001). These associations were more apparent in females (interaction p = 0.082), non-Hispanic white and black participants (vs. other race/ethnicity, interaction p = 0.023), and those with sufficient serum vitamin D (≥50 vs. <50 nmol/L, interaction p = 0.001). ANA was not associated with other protective behaviors and not confounded or modified by these behaviors or recent sunburn.

CONCLUSIONS

These cross-sectional findings showed frequent sunscreen was associated with ANA in younger adults, supporting the need for replication, and longitudinal studies with detailed exposure histories.

Exposure to bisphenols, parabens, and benzophenones in colostrum breast milk of Panamanian women: A pilot study from the PA-MAMI cohort

BACKGROUND

Breast milk is the optimal source of nutrition for infants but can also expose them to endocrine-disrupting chemicals (EDCs), among other environmental contaminants.

AIM

To determine concentrations of non-persistent phenolic EDCs (three bisphenols, four parabens [PBs], and six benzophenones [BPs]), in colostrum samples from Panamanian mothers and to examine associated reproductive, sociodemographic, and life-style factors.

METHODS

Dispersive liquid-liquid microextraction was used to measure concentrations of bisphenol A (BPA), bisphenol F (BPF), bisphenol S (BPS), methyl- (MeP), ethyl- (EtP), propyl- (n-PrP), and butyl-paraben (n-BuP), and benzophenones BP-1, BP-2, BP-3, BP-6, BP-8, and 4-hydroxy-BP in colostrum milk samples from 36 mothers. An ad hoc questionnaire was used to collect data on potential influentially variables, and multiple linear and logistic regression analyses were conducted.

RESULTS

Two or more tested EDCs were detected in 36 colostrum samples (100 %), at least four in 14 samples (38.9 %), and at least six in 4 samples (11.1 %). The most frequently detected compounds were BPA (91.7 %), BP-8 (63.9 %), MeP (47.2 %), and BPF (41.7 %). The median concentration was 3.45 ng/mL for BP-8 and 1.37 ng/mL for BPA. No concentrations of n-PrP, BP-1, BP-6, or 4-hydroxy-BP were detected. Associations were observed between phenolic EDC concentrations and maternal place of residence, consumption frequency of poultry, fish, fresh cheese, fruit, yogurt and chocolate, intake of nutritional supplements, and application of some personal care products.

CONCLUSIONS

Bisphenols, parabens, and benzophenones were widely present in colostrum milk samples from Panamanian women. Preventive measures are needed to maximize the benefits of breastfeeding.

Understudied and underestimated impacts of organic UV filters on terrestrial ecosystems

Organic UV filters (OUVFs) are vital components in various personal care products (PCPs) and commercial goods, with the annual consumption estimated at 10,000 tons. Consequently, the unavoidable use of OUVFs in PCPs and other unregulated commercial applications could present a considerable risk to human and environmental health. These chemical entities enter terrestrial ecosystems through wastewater discharge, agriculture, atmospheric deposition, and recreational activities. Compared to aqueous ecosystems, the effects of OUVFs on terrestrial environments should be more studied and potentially underestimated. The present review addresses the abovementioned gap by summarizing 189 studies conducted between 2006 and 2024, focusing on the analytical measures, occurrence, and ecotoxicological effects of OUVFs on terrestrial ecosystems. These studies underscore the harmful effects of certain OUVFs on the development, reproduction, and endocrine systems of terrestrial organisms, highlighting the necessity for comprehensive toxicological assessments to understand their impacts on non-target species in terrestrial ecosystems. Besides, by underscoring the ecological effects of OUVFs, this review aims to guide future research and inform regulatory measures to mitigate the risks posed by these widespread contaminants. Meanwhile, interdisciplinary research is essential, integrating environmental science, toxicology, ecology, and chemistry to tackle OUVF challenges in terrestrial ecosystems.

The Potential of Natural Compounds in UV Protection Products

Overexposure to ultraviolet radiation mainly leads to skin disorders (erythema, burns, immunosuppression), skin aging, and skin cancer as the most serious side effect. It has been widely accepted that using sunscreen products is an important way to protect against the harmful effects of UV rays. Although commercial sunscreens have constantly changed and improved over time, there are emerging concerns about the safety of conventional, organic, UV filters due to adverse effects on humans (such as photoallergic dermatitis, contact sensitivity, endocrine-disrupting effects, etc.) as well as accumulation in the environment and aquatic organisms. This is why natural compounds are increasingly being investigated and used in cosmetic and pharmaceutical sunscreens. Some of these compounds are widely available, non-toxic, safer for use, and have considerable UV protective properties and less side effects. Plant-based compounds such as flavonoids can absorb UVA and UVB rays and possess antioxidant, anticarcinogenic, and anti-inflammatory effects that contribute to photoprotection. Apart from flavonoids, other natural products such as certain vegetable oils, carotenoids, stilbenes, and ferulic acid also have UV-absorbing properties. Some vitamins might also be beneficial for skin protection due to their antioxidant activity. Therefore, the aim of this research was to gain insight into the potential of natural compounds to replace or reduce the amount of conventional UV filters, based on recent research.

ChlorTox scale assessment, greenness, and whiteness evaluation of selective spectrophotometric analysis of dimenhydrinate and cinnarizine

Nausea and vomiting are considered common series side effects induced by chemotherapy treatment in cancer patients. This annoying side effect can impair the patient's compliance to cancer treatment and affect their quality of life. Dimenhydrinate and cinnarizine in combined pharmaceutical dosage form is used to control chemotherapy induced nausea and vomiting in cancer patients. For safety, selective spectrophotometric methods based on novel dual resolution strategies were introduced to estimate dimenhydrinate and cinnarizine in presence of their harmful impurities namely benzophenone and 1- (diphenylmethyl)piperazine, respectively. These methods namely, dual ratio difference (DRD), dual ratio extraction (DRE) and dual absorbance extraction coupled with dual ratio extraction (DAE-DRE) were successfully performed to simultaneously analyze the drug of interests dimenhydrinate and cinnarizine in their pure form, synthetic mixtures and in market dosage form. Linearity ranges were 6.0-60.0 μg/mL and 3.0-30.0 μg/mL for dimenhydrinate and cinnarizine, respectively with good recovery% of Mean ± SD for all the proposed methods 99.82 ± 0.48, 99.79 ± 0.40, 100.14 ± 0.82, 100.03 ± 0.69, respectively. ICH guidelines were adhered in accordance with confirming validation of the proposed methods where fulfilling results were accomplished. Various unified greenness and whiteness assessment tools, such as the chlorTox scale, greenness index via spider chart, AGREE (The Analytical Greenness Metric), green certificate, and the RGB12 algorithm were employed in this research to assess the greenness and sustainability of the introduced UV-spectrophotometric methods in comparison to the reported HPLC method. As a result, these methods hold significant potential for utilization in the quality control department of pharmaceutical companies, contributing to enhanced pharmaceutical product analysis and overall sustainability practices.

Benzophenone-3 exposure induced apoptosis via impairing mitochondrial function in human chondrocytes

Osteoarthritis (OA) is a chronic joint disease affecting millions of adults worldwide, characterized by degeneration of articular cartilage. Many environmental risk factors contribute to OA development. Benzophenone-3 (BP-3), a commonly used ultraviolet filter in personal care products, has been positively associated with OA risk. However, it remains unclear whether and how BP-3 induces toxic effects on articular chondrocytes and promote OA development. This study aims to investigate the damage of BP-3 at environmentally relevant concentrations to human chondrocytes, as well as potential mechanisms linking BP-3 with injury of chondrocytes. Notably, BP-3 significantly inhibited cell viability, induced apoptosis, and up-regulated matrix metalloproteinase (MMP) 1 and 13 which mediated cartilage degradation in C28/I2 human normal chondrocytes. Moreover, the function of mitochondria was impaired and oxidative stress occurred in BP-3 exposure groups, evidenced by elevation of reactive oxygen species (ROS) generation, reduction of mitochondrial membrane potential, decrease of ATP production and inhibition of mitochondrial respiratory chain complex I, II, III and IV. Meanwhile, BP-3 caused mitochondrial cristae vague and formation of autophagosomes. PTEN induced putative kinase 1/E3 ubiquitin protein ligase (PINK1/Parkin) pathway was also activated by BP-3. Addition of autophagy inhibitor, 3-Methyladenine (3-MA), suppressed PINK1/Parkin-mediated mitophagy, but increased BP-3-induced expression of MMP1 and 13, as well as exacerbated BP-3-induced apoptosis, suggesting mitophagy may exert a chondroprotective effect and partially alleviate apoptosis induced by this compound. In brief, BP-3 exposure may increase OA risk via inducing apoptosis and increasing breakdown of extracellular matrix in chondrocytes, and mitochondrial dysfunction and mitophagy may play a crucial role in the mechanisms of BP-3-induced toxicity to articular chondrocytes.

Degradation kinetics and disinfection by-products formation of benzophenone-4 during UV/persulfate process

The degradation kinetics, reaction pathways, and disinfection by-products formation of an organic UV filter, benzophenone-4 (BP4) during UV/persulfate oxidation were investigated. BP4 can hardly be degraded by UV alone, but can be effectively decomposed by UV/persulfate following pseudo-first order kinetics. BP4 degradation rate was enhanced with increasing persulfate dosage and decreasing pH from 8 to 5. However, the degradation rate of BP4 at pH 9 was higher than that at pH 8 because of the presence of phenolic group in BP4 structure. and SO 4 - ⋅ were confirmed as the major contributors to BP4 decomposition in radical scavenging experiments, and the second-order rate constants between HO ⋅ and BP4 as well as those between SO 4 - ⋅ and BP4 were estimated by establishing and solving a kinetic model. The presence of B r - and humic acid inhibited the decomposition of BP4, while N O 3 - promoted it. The mineralisation of BP4 was only 9.1% at the persulfate concentration of 50 μM. Six degradation intermediates were identified for the promulgation of the reaction pathways of BP4 during UV/persulfate oxidation were proposed as a result. In addition, the formation of DBP in the sequential chlorination was evaluated at different persulfate dosages, pH values, and water matrix. The results of this study can provide essential knowledge for the effective control of DBP formation with reducing potential hazard to provide safe drinking water to the public.

Investigating the metabolomic pathways in female reproductive endocrine disorders: a Mendelian randomization study

Introduction

Reproductive endocrine disorders (RED), including polycystic ovary syndrome (PCOS), endometriosis (EMs), and female infertility (FI), significantly affect women's health globally, with varying prevalence across different regions. These conditions can be addressed through medication, surgical interventions, and lifestyle modifications. However, the limited understanding of RED's etiology and the substantial economic burden of its treatment highlight the importance of investigating its pathogenesis. Metabolites play a critical role in metabolic processes and are potentially linked to the development of RED. Despite existing studies suggesting correlations between metabolites and RED, conclusive evidence remains scarce, primarily due to the observational nature of these studies, which are prone to confounding factors.

Methods

This study utilized Mendelian Randomization (MR) to explore the causal relationship between metabolites and RED, leveraging genetic variants associated with metabolite levels as instrumental variables to minimize confounding and reverse causality. Data were obtained from the Metabolomics GWAS Server and the IEU OpenGWAS project. Instrumental variables were selected based on their association with the human gut microbiota composition, and the GWAS summary statistics for metabolites, PCOS, EMs, and FI were analyzed. The MR-Egger regression and random-effects inverse-variance weighted (IVW) methods were employed to validate the causal relationship. Cochran's Q test was employed to evaluate heterogeneity, sensitivity analysis was performed using leave-one-out analysis, and for pleiotropy analysis, the intercept term of MR-Egger's method was investigated.

Results

The MR analysis revealed significant associations between various metabolites and RED conditions. For instance, a positive association was found between 1-palmitoylglycerophosphocholine and PCOS, while a negative association was noted between phenylacetate and FI. The study identified several metabolites associated with an increased risk and others with protective effects against PCOS, EMs, and FI. These findings highlight the complex interplay between metabolites and RED, suggesting potential pathways through which these conditions could be influenced or treated.

Conclusion

This MR study provides valuable insights into the causal relationship between metabolites and female reproductive endocrine disorders, suggesting that metabolic alterations play a significant role in the pathogenesis of PCOS, EMs, and FI, and offering a foundation for future research and therapeutic development.

Personal care products use during SARS-CoV-2 pandemic: Environmental and public health impact assessment using wastewater-based epidemiology

The recent SARS-CoV-2 pandemic had profound consequences on people's wellbeing, societies and economy worldwide. This manuscript discusses public exposure to chemicals of concern in personal care products (parabens and benzophenones) during SARS-CoV-2 pandemic. These were monitored for two years in four catchments (two cities and two towns) in South West England accounting for >1 million people. Results showed slightly higher usage of personal care products in small towns than big cities. Major changes in usage of parabens (p values < 0.05) were observed during national lockdowns (NLs). This is likely due to increased awareness towards personal hygiene. In contrast, benzophenones showed seasonal trends; there were higher correlations with sunshine prevalence and temperature rather than NLs reflecting their usage in sunscreen products. Estimation of per capita intake of parabens and benzophenones using WBE revealed lower intake than the Acceptable Daily Intake (ADI) established by the EFSA; however, the metabolism factor used was considered putative due to the lack of pharmacokinetic studies. Prediction of environmental exposure revealed peaks of higher impact during NLs and first year of pandemic, nevertheless the overall predicted values were below Predicted No Effect Concentrations (PNEC).

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

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

Body dissatisfaction widens the racial disparities of Benzophenone-3, a chemical biomarker of personal care and consumer product usage

Background

Body dissatisfaction can drive individuals to use personal care products, exposing themselves to Benzophenone-3 (BP3). Yet, no study has examined the link between body dissatisfaction and elevated chemical exposures.

Objectives

Our study examines how body dissatisfaction impacts the racial differences in BP3 exposures.

Methods

Using NHANES 2003-2016 data for 3,072 women, we ascertained body dissatisfaction with a questionnaire on weight perception. We ran two generalized linear models with log10-transformed urinary concentrations of BP3 as the outcome variable and the following main predictors: one with race/ethnicity and another combining race/ethnicity and body dissatisfaction. We also conducted stratified analyses by race/ethnicity. We adjusted for poverty income ratio, BMI, urinary creatinine, and sunscreen usage.

Results

BP3 levels in Mexican American, Other Hispanic, Other Race, non-Hispanic White, and non-Hispanic Asian women were on average 59%, 56%, 33%, 16%, and 9% higher, respectively, compared to non-Hispanic Black women. Racial differences in BP3 levels are accentuated with body dissatisfaction. For example, Other Hispanic women perceiving themselves as overweight had 69% higher BP3 levels than non-Hispanic Black women (p-value = 0.01), while those perceiving themselves as at the right weight had 32% higher levels (p-value = 0.31). Moreover, minority women perceiving themselves as overweight tended to have higher BP3 levels than those who do not. For example, BP3 levels in Other Hispanic women perceiving themselves as overweight are significantly higher compared to those who do not (73%, p-value = 0.03). In contrast, such differences in the non-Hispanic White women are minimal (-0.5%, p-value = 0. 98).

Discussion

Minority women with body dissatisfaction show elevated BP3 exposure independent of sunscreen usage, implying that their elevated exposures may stem from using other personal care and consumer products. Further research is needed to determine if increases of exposure to potential toxicants occur among minority women with body dissatisfaction.

Relationship between the use of hair products and urine benzophenone-3: the Korean National Environmental Health Survey (KoNEHS) cycle 4

Background

Benzophenone-3 is a type of ketone with 2 benzene rings attached to a carbonyl group (C=O) and one benzene ring attached to a hydroxyl group (-OH). As an endocrine-disrupting chemical, benzophenone-3 is known to be associated with reproductive, developmental, thyroid, and endocrine toxicities. Benzophenone-3 is commonly used in hair products, cosmetics, and ultraviolet (UV) filters because of its characteristic property to absorb UV light. This study aims to investigate the association between the use of hair products and urine benzophenone-3 using the data from the Korean National Environmental Health Survey (KoNEHS) cycle 4 (2018-2020), which represents the Korean population.

Methods

Using the KoNEHS cycle 4 survey, the data of 3,796 adults aged ≥ 19 years were analyzed. Based on the 75th percentile concentration of urine benzophenone-3, the participants were divided into the low- and high-concentration groups. Chi-square test was conducted to analyze the association of urine benzophenone-3 with distribution of general characteristics, use of personal care products, consumption of marine foods, and use of plastic products as the variable. Logistic regression analysis was conducted to calculate odds ratios (ORs) for the high-concentration group of urine benzophenone-3 based on the use of hair products.

Results

Women with < 6 times or ≥ 6 times of hair product usage had significantly higher adjusted ORs compared to those who did not use hair products. The calculated ORs were 1.24 (95% confidence interval [CI]: 1.12-1.38) for women with < 6 times of usage and 1.54 (95% CI: 1.33-1.79) for women with ≥ 6 times of usage.

Conclusions

This study revealed the association between the use of hair products and the concentration of urine benzophenone-3 in the general Korean population.

Prenatal exposure to environmental phenols and fetal growth across pregnancy in the LIFECODES fetal growth study

INTRODUCTION

Environmental phenols are endocrine disrupting chemicals hypothesized to affect early life development. Previous research examining the effects of phenols on fetal growth has focused primarily on associations with measures of size at delivery. Few have included ultrasound measures to examine growth across pregnancy.

OBJECTIVE

Investigate associations between prenatal exposure to phenols and ultrasound and delivery measures of fetal growth.

METHODS

Using the LIFECODES Fetal Growth Study (n = 900), a case-cohort including 248 small-for-gestational-age, 240 large-for-gestational age, and 412 appropriate-for-gestational-age births, we estimated prenatal exposure to 12 phenols using three urine samples collected during pregnancy (median 10, 24, and 35 weeks gestation). We abstracted ultrasound and delivery measures of fetal growth from medical records. We estimated associations between pregnancy-average phenol biomarker concentrations and repeated ultrasound measures of fetal growth using linear mixed effects models and associations with birthweight using linear regression models. We also used logistic regression models to estimate associations with having a small- or large-for-gestational birth.

RESULTS

We observed positive associations between 2,4-dichlorophenol, benzophenone-3, and triclosan (TCS) and multiple ultrasound measures of fetal growth. For example, TCS was associated with a 0.09 (95 % CI: 0.01, 0.18) higher estimated fetal weight z-score longitudinally across pregnancy. This effect size corresponds to a 21 g increase in estimated fetal weight at 30 weeks gestation. Associations with delivery measures of growth were attenuated, but TCS remained positively associated with birthweight z-scores (mean difference: 0.13, 95 % CI: 0.02, 0.25). Conversely, methylparaben was associated with higher odds of a small-for-gestational age birth (odds ratio: 1.45, 95 % CI: 1.06, 1.98).

DISCUSSION

We observed associations between some biomarkers of phenol exposure and ultrasound measures of fetal growth, though associations at the time of delivery were attenuated. These findings are consistent with hypotheses that phenols have the potential to affect growth during the prenatal period.

Hazard identification of endocrine-disrupting carcinogens (EDCs) in relation to cancers in humans

Endocrine disrupting chemicals or carcinogens have been known for decades for their endocrine signal disruption. Endocrine disrupting chemicals are a serious concern and they have been included in the top priority toxicants and persistent organic pollutants. Therefore, researchers have been working for a long time to understand their mechanisms of interaction in different human organs. Several reports are available about the carcinogen potential of these chemicals. The presented review is an endeavor to understand the hazard identification associated with endocrine disrupting carcinogens in relation to the human body. The paper discusses the major endocrine disrupting carcinogens and their potency for carcinogenesis. It discusses human exposure, route of entry, carcinogenicity and mechanisms. In addition, the paper discusses the research gaps and bottlenecks associated with the research. Moreover, it discusses the limitations associated with the analytical techniques for detection of endocrine disrupting carcinogens.

Synthesis, Characterization, and Evaluation of a Hindered Phenol-Linked Benzophenone Hybrid Compound as a Potential Polymer Anti-Aging Agent

Hindered phenol antioxidants and benzophenone UV absorbers are common polymer additives and often used in combination applications to enhance the anti-aging performance of polymer materials. This study primarily aims to incorporate hindered phenol and benzophenone structures into a single molecule to develop a multifunctional polymer additive with good anti-aging performance. Thus, a novel potential polymer anti-aging agent, namely 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid 3-(4-benzoyl-3-hydroxyphenoxy)propyl ester (3C), was synthesized using 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 3-bromo-1-propanol, and 2,4-dihydroxybenzophenone as raw materials by two-step procedure. The structure of compound 3C was characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray single crystal diffraction. Its thermal stability and UV resistance were assessed using thermogravimetric analysis (TGA) and UV absorption spectroscopy (UV). The compound 3C as an additive was incorporated into the preparation of polyolefin elastomer (POE) films. The anti-aging performance of POE films was evaluated by measuring parameters such as oxidation induction time, melt flow index, transmittance, and infrared spectra of the artificially aged POE films. The results indicate that the compound 3C exhibits a promising anti-aging performance in both thermo-oxidative aging and ultraviolet aging tests of POE films and is a potential polymer anti-aging agent.

Hydrophobic eutectic solvents for surface water treatment with a focus on benzophenone type UV filters

Effective removal of organic UV filters from aquatic environmental compartments and swimming waters is very important because these substances are hazardous to humans and wildlife at low concentrations and act as endocrine disruptors. Therefore, the aim of the present article is to determine the extraction efficiencies of hydrophobic deep eutectic solvents (HDES) for the selected UV filters based on benzophenone structure (benzophenone, 2,4-dihydroxybenzophenone, 2,2´,4,4´-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2´-dihydroxy-4-methoxybenzophenone, 4-methacryloxy-2-hydroxybenzophenone) from aqueous matrices. For this purpose, six HDESs based on dl-menthol in combination with caprylic, decanoic and lauric acid are prepared and compared with referent terpene solvents such as terpineol and linalool. The effect of various parameters such as HDES composition, volume ratio, frequency and shaking time are studied. The highest extraction efficiency is shown by HDES of menthol:caprylic acid (1:1) composition at the aqueous:organic phase volume ratio of 1:1, shaking frequency of 1500 rpm and shaking time of 15 min. The achieved extraction efficiencies are higher than 99.6 % for all benzophenones studied in the purification of stagnant pond water, swimming pool water and river water samples. After a simple and fast sample treatment, the residual levels of benzophenones in the waters are controlled by a newly developed sensitive HPLC-MS/MS method with LOQs in the range of 0.7 - 5.0 ng/mL.

Maternal concentrations of environmental phenols during early pregnancy and behavioral problems in children aged 4 years from the Shanghai Birth Cohort

BACKGROUND

Prenatal exposure to environmental phenols such as bisphenol (BPs), paraben (PBs), benzophenone (BzPs), and triclosan (TCS) is ubiquitous and occurs in mixtures. Although some of them have been suspected to impact child behavioral development, evidence is still insufficient, and their mixed effects remain unclear.

OBJECTIVES

To explore the association of prenatal exposure to multiple phenols with child behavioral problems.

METHOD

In a sample of 600 mother-child pairs from the Shanghai Birth Cohort, we quantified 18 phenols (6 PBs, 7 BPs, 4 BzPs, and TCS) in urine samples collected during early pregnancy. Parent-reported Strengths and Difficulties Questionnaires were utilized to evaluate child behavioral difficulties across four subscales, namely conduct, hyperactivity/inattention, emotion, and peer relationship problems, at 4 years of age. Multivariable linear regression was conducted to estimate the relationships between single phenolic compounds and behavioral problems. Additionally, weighted quantile sum (WQS) regression was employed to examine the overall effects of the phenol mixture. Sex-stratified analyses were also performed.

RESULTS

Our population was extensively exposed to 10 phenols (direction rates >50 %), with low median concentrations (1.00 × 10-3-6.89 ng/mL). Among them, single chemical analyses revealed that 2,4-dihydroxy benzophenone (BP1), TCS, and methyl 4-hydroxybenzoate (MeP) were associated with increased behavior problems, including hyperactivity/inattention (BP1: β = 0.16; 95 % confidence interval [CI]: 0.04, 0.30), emotional problems (BP1: β = 0.11; 95 % CI: 0.02, 0.20; TCS: β = 0.08; 95 % CI: 0.02, 0.14), and peer problems (MeP: β = 0.10; 95 % CI: 0.02, 0.18); however, we did not identify any significant association with conduct problems. Further phenol mixture analyses in the WQS model yielded similar results. Stratification for child sex showed stronger positive associations in boys.

CONCLUSION

Our findings indicated that maternal phenol levels during early pregnancy, specifically BP1, TCS, and MeP, are associated with high behavioral problem scores in 4-year-old children.

Prenatal exposure to benzophenone-type UV filters and the associations with neonatal birth outcomes and maternal health in south China

Benzophenone (BP)-type UV filters are commonly added to sunscreens and cosmetics to protect against UV radiation for human skin and hair. As a result, BPs are ubiquitous in the environment and human body, and their endocrine-disrupting characteristics have been a hot topic of discussion. However, our knowledge regarding the detrimental effects of prenatal exposure to BPs on pregnant women and their offspring remains limited. To fill this gap, we determined five BP derivatives in 600 serum samples obtained from pregnant women. All the target analytes, except 2,4-dihydroxybenzophenone (BP-1), have achieved a 100 % detection rate. The most prevalent compound was 2-hydroxy-4-methoxybenzophenone (BP-3), with a median concentration of 0.545 ng/mL. Significant and positive correlations were observed among BP derivatives, indicating both endogenous metabolism and common external sources. Utilizing Bayesian kernel machine regression (BKMR) and quantile-based g-computation (QGC) models, we found relationships between BP exposure and reduced neonatal birth weight (BW) and birth chest circumference (BC) during the third trimester. Notably, the adverse effect of BPs on birth size was sex-specific. Moreover, triglyceride (TG) was identified as a potential mediator of the effect of BPs on blood pressure, and co-exposure to BPs was linked to disruptions in thyroid hormone levels and glucose regulation. Further research is warranted to unravel the toxicity of BPs and their detrimental effects on pregnant women and fetuses.

Female offspring of mice perinatally exposed to benzophenone-3 showed early subfertility linked to a poor oocyte stockpile

Previously, we found that the ultraviolet filter benzophenone-3 (BP3) causes fetal growth restriction in mice when is applied when implantation occurs (first week of gestation). However, whether BP3 can affect gestation and fertility after implantation period is unknown. We aimed to study the effects on reproductive physiology of the offspring caused by perinatal exposure to BP3. C57BL/6 pregnant mice were dermally exposed to 50 mg BP3/kg bw.day or olive oil (vehicle) from gestation day 9 (gd9) to postnatal day 21 (pnd1). We observed no differences in mother's weights, duration of gestation, number of pups per mother, onset of puberty or sex ratio. The weights of the pups exposed to benzophenone-3 were transiently lower than those of the control. Estrous cycle was not affected by perinatal exposure to BP3. Besides, we performed a fertility assessment by continuous breeding protocol: at 10 weeks of age, one F1 female and one F1 male mouse from each group was randomly chosen from each litter and housed together for a period of 6 months. We noticed a reduction in the number of deliveries per mother among dams exposed to BP3 during the perinatal period. To see if this decreased fertility could be associated to an early onset of oocytes depletion, we estimated the ovarian reserve of germ cells. We found reduced number of oocytes and primordial follicles in BP3. In conclusion, perinatal exposure to BP3 leads to a decline in the reproductive capacity of female mice in a continuous breeding protocol linked to oocyte depletion.

An evaluation of dogs' exposure to benzophenones through hair sample analysis

Introduction

Benzophenones (BPs) are used in various branches of industry as ultraviolet radiation filters, but they pollute the natural environment, penetrate living organisms, and disrupt endocrine balance. Knowledge of the exposure of domestic animals to these substances is extremely scant. The aim of the study was to investigate long-term exposure of companion dogs to BPs and relate this to environmental factors.

Material and Methods

Hair samples taken from 50 dogs and 50 bitches from under 2 to over 10 years old were analysed for BP content with liquid chromatography-tandem mass spectrometry.

Results

The results revealed that dogs are most often exposed to 2-hydroxy-4-methoxybenzophenone (BP-3) and 4-dihydroxybenzophenone (BP-1). Concentration levels of BP-3 above the method quantification limit (MQL) were noted in 100% of the samples and fluctuated from 4.75 ng/g to 1,765 ng/g. In turn, concentration levels of BP-1 above the MQL were noted in 37% of the samples and ranged from <0.50 ng/g to 666 ng/g. Various factors (such as the use of hygiene and care products and the dog's diet) were found to affect BP concentration levels. Higher levels of BP-3 were observed in castrated/spayed animals and in animals that required veterinary intervention more often.

Conclusion

The results obtained show that the analysis of hair samples may be a useful matrix for biomonitoring BPs in dogs, and that these substances may be toxic to them.

In vitro blastocyst implantation and trophoblast migration are disrupted by the UV filter benzophenone-3 (BP3)

Benzophenone-3 (BP3) is a common ingredient in personal care products (PCPs) due to its well-established effectiveness in absorbing UV radiation. Sunscreen products are among the most widely used PCPs-containing BP3 applied to the skin, resulting in significant human exposure to BP3 primarily through a dermal application. In the present work, we have tested the action of three environmentally relevant concentrations of BP3 (2, 20 and 200 μg/L) on an in vitro model of implantation of murine blastocysts and on migration ability of the human trophoblast cell line Swan 71. We showed that BP3 caused a significant reduction of blastocyst expansion and a delayed hatching in a non-monotonic way. Besides, embryos displayed a delayed attachment in the three BP3 groups, resulting in a smaller implantation area on the 6th day of culture: BP3(2) (0.32 ± 0.07 mm2); BP3(20) (0.30 ± 0.08 mm2) and BP3(200) (0.25 ± 0.06 mm2) in comparison to the control (0.42 ± 0.07 mm2). We also found a reduced migration capacity of the human first-trimester trophoblast cell line Swan 71 in a scratch assay when exposed to BP3: the lowest dose displayed a higher uncovered area (UA) at 6h when compared to the control, whereas a higher UA of the wound was observed for the three BP3 concentrations at 18 and 24 h of exposure. The changes in UA provoked by BP3 restored to normal values in the presence of flutamide, an androgen receptor (AR) inhibitor. These results indicate that a direct impairment on early embryo implantation and a defective migration of extravillous trophoblast cells through the androgen receptor pathway can be postulated as mechanisms of BP3-action on early gestation with potential impact on fetal growth.

The triple exposure nexus of microplastic particles, plastic-associated chemicals, and environmental pollutants from a human health perspective

The presence of microplastics (MPs) is increasing at a dramatic rate globally, posing risks for exposure and subsequent potential adverse effects on human health. Apart from being physical objects, MP particles contain thousands of plastic-associated chemicals (i.e., monomers, chemical additives, and non-intentionally added substances) captured within the polymer matrix. These chemicals are often migrating from MPs and can be found in various environmental matrices and human food chains; increasing the risks for exposure and health effects. In addition to the physical and chemical attributes of MPs, plastic surfaces effectively bind exogenous chemicals, including environmental pollutants (e.g., heavy metals, persistent organic pollutants). Therefore, MPs can act as vectors of environmental pollution across air, drinking water, and food, further amplifying health risks posed by MP exposure. Critically, fragmentation of plastics in the environment increases the risk for interactions with cells, increases the presence of available surfaces to leach plastic-associated chemicals, and adsorb and transfer environmental pollutants. Hence, this review proposes the so-called triple exposure nexus approach to comprehensively map existing knowledge on interconnected health effects of MP particles, plastic-associated chemicals, and environmental pollutants. Based on the available data, there is a large knowledge gap in regard to the interactions and cumulative health effects of the triple exposure nexus. Each component of the triple nexus is known to induce genotoxicity, inflammation, and endocrine disruption, but knowledge about long-term and inter-individual health effects is lacking. Furthermore, MPs are not readily excreted from organisms after ingestion and they have been found accumulated in human blood, cardiac tissue, placenta, etc. Even though the number of studies on MPs-associated health impacts is increasing rapidly, this review underscores that there is a pressing necessity to achieve an integrated assessment of MPs' effects on human health in order to address existing and future knowledge gaps.

Temporal trends in exposure to parabens, benzophenones, triclosan, and triclocarban in adult females in Kyoto, Japan, from 1993 to 2016

Products used in daily life can contain chemicals such as parabens, benzophenones, triclosan, and triclocarban that have potential endocrine-disrupting effects. Little is known about the temporal trends of exposure levels to some of these chemicals in Japan. Our study assessed the intake and risk associated with exposure to commonly used chemicals. We measured the concentrations of five parabens, four benzophenones, and triclosan and triclocarban in 133 single spot urine samples. The urine samples were collected in 1993, 2000, 2003, 2009, 2011, and 2016 from healthy female residents in Kyoto, Japan. With the exception of methylparaben, ethylparaben, and butylparaben, there were no significant fluctuations in the concentrations of target chemicals over the study period; however, methylparaben, ethylparaben, and butylparaben showed temporal changes in concentrations. Methylparaben concentrations peaked in 2003 with a median value of 309 μg/g creatinine, ethylparaben concentrations peaked in 1993 with a median value of 17.3 μg/g creatinine, and butylparaben showed a decline, with the median values becoming non-detectable in 2009 and 2016. We calculated estimated daily intakes and hazard quotients for each chemical. In the analysis of total samples, 2.3% (3 samples) for butylparaben and 0.8% (1 sample) for propylparaben were found to surpass a hazard quotient of 1. Overall, 3% (n = 4) of the study participants exceeded a hazard index of 1. The potential health risks associated with exposure to butylparaben and propylparaben emphasize the need for further monitoring and research.

Sunscreen compound benzophenone-3 and its relationship with white blood cell counts

BACKGROUND

Evidence from animal models suggests a role for the organic ultraviolet filter benzophenone-3's (BP-3) on white blood cells (WBCs). However, BP-3's effect on WBCs in humans is unknown.

MATERIALS AND METHODS

We used National Health and Nutrition Examination Survey data from 2003 to 2016. We included participants >6 years with data on urinary BP-3, urinary creatinine, and WBC count. Quintiles of urinary creatinine-normalized BP-3 (CnBP-3) levels were used in linear regression models adjusting for age, gender, race, body mass index (BMI), smoking status, education level, family income to poverty threshold ratio, survey cycle, and season.

RESULTS

Of the 16 959 participants, 8564 (50.5%) were females, 6602 (38.9%) were White, and 3870 (22.8%) were Black. The mean (standard deviation) age was 37.6 (22.7) years, BMI was 26.8 (7.40) kg/m2, WBC count was 7.22 (2.53) × 109/L, neutrophil count was 4.15 (1.86) × 109/L, and lymphocyte count was 2.25 (1.33) × 109/L and median (interquartile range) of CnBP-3 was 12.1 (44.9) µg/gm. The highest quintile of CnBP-3 was associated with significantly lower WBC and neutrophil counts compared to the lowest quintile of CnBP-3 (Δ quintiles = -137 × 106/L, 95% CI: -249 to -24, p = 0.02 and = -177 × 106/L, 95% CI: -323 to -30, p = 0.02, respectively). In contrast, we did not observe a difference in lymphocyte count between the lowest and highest quintiles of CnBP-3 in unadjusted or adjusted analyses.

CONCLUSION

We found an inverse relationship between BP-3 levels and WBC and neutrophil counts, and not with lymphocyte count. Further research is needed to confirm our findings.

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

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

Single and combined exposures to bisphenol A and benzophenone-3 during early mouse pregnancy have differential effects on fetal and placental development

Endocrine disrupting chemicals (EDCs) possess the capability to interfere with the endocrine system by binding to hormone receptors, for example on immune cells. Specific effects have already been described for individual substances, but the impact of exposure to chemical mixtures during pregnancy on maternal immune regulation, placentation and fetal development is not known. In this study, we aimed to investigate the combined effects of two widespread EDCs, bisphenol A (BPA) and benzophenone-3 (BP-3), at allowed concentrations on crucial pregnancy processes such as implantation, placentation, uterine immune cell populations and fetal growth. From gestation day (gd) 0 to gd10, female mice were exposed to 4 μg/kg/d BPA, 50 mg/kg/d BP-3 or a BPA/BP-3 mixture. High frequency ultrasound and Doppler measurements were used to determine intrauterine fetal development and hemodynamic parameters. Furthermore, uterine spiral artery remodeling and placental mRNA expression were studied via histology and CHIP-RT-PCR, respectively. Effects of EDC exposure on multiple uterine immune cell populations were investigated using flow cytometry. We found that exposure to BP-3 caused intrauterine growth restriction in offspring at gd14, while BPA and BPA/BP-3 mixture caused varying effects. Moreover, placental morphology at gd12 and placental efficiency at gd14 were altered upon BP-3 exposure. Placental gene transcription was altered particularly in female offspring after in utero exposure to BP-3. Flow cytometry analyses revealed an increase in uterine T cells and NK cells in BPA and BPA/BP-3-treated dams at gd14. Doppler measurements revealed no effect on uterine hemodynamic parameters and spiral artery remodeling was not affected following EDC exposure. Our results provide evidence that exposure to BPA and BP-3 during early gestation affects fetal development in a sex-dependent manner, placental function and immune cell frequencies at the feto-maternal interface. These results call for inclusion of studies addressing pregnancy in the risk assessment of environmental chemicals.

Interference with SPARC inhibits Benzophenone-3 induced ferroptosis in osteoarthritis: Evidence from bioinformatics analyses and biological experimentation

The aim of this study is to conduct a thorough evaluation of the association between Benzophenone-3 (BP-3) exposure and OA, offering critical insights into the underlying mechanisms involved. The National Health and Nutrition Examination Survey (NHANES) database was utilized to investigate the correlation between BP-3 and osteoarthritis. Proteomic sequencing from clinical sample and the PharmMapper online tool were employed to predict the biological target of BP-3. Cellular molecular assays and transfection studies were performed to verify the prediction from bioinformatics analyses. Through cross-sectional analysis of the NHANES database, we identified BP-3 as a risk factor for OA development. The results of proteomic sequencing showed that Secreted Protein Acidic and Rich in Cysteine (SPARC) was significantly elevated in the area of damage compared to the undamaged area. SPARC was also among the potential biological targets of BP-3 predicted by the online program. Through in vitro cell experiments, we further determined that the toxicological effects of BP-3 may be due to SPARC, which elevates intracellular GPX4 levels, activates the glutathione system, and promotes lipid peroxidation to mitigate ferroptosis. Inhibiting SPARC expression has been shown to reduce inflammation and ferroptosis in OA contexts. This research provides an expansive understanding of BP-3's influence on osteoarthritis development. We have identified SPARC as a potent target for combating chondrocyte ferroptosis in BP-3-associated osteoarthritis.

Evaluation of the anti-androgenic and cytotoxic effects of benzophenone-3 in male Sprague-Dawley rats

Benzophenone-3 (BP-3, 2-hydroxy-4-methoxybenzophenone, oxybenzone) is one of the most widely used types of benzophenone organic sunscreen. However, this compound is a potentially harmful toxicant. The aim of this study was 2-fold to: (1) utilize a Hershberger bioassay in vivo in castrated male Sprague-Dawley rats to investigate the anti-androgenic activities of BP-3, and (2) use in vitro a methyl tetrazolium assay to compare the toxicity between Leydig cells (TM3 cells) and mouse fibroblast (NIH-3T3) cell lines. In the Hershberger assay, rats were divided into 6 groups (each of n = 7): a vehicle control, negative control, positive control, PB-3 low (40 mg/kg), BP-3 intermediate (200 mg/kg), and BP-3 high (1000 mg/kg)-dose. The weight of the ventral prostate was significantly decreased at BP-3 doses of 200 or 1,000 mg/kg/day. In addition, the levator anibulbocavernosus muscle weights were also significantly reduced at BP-3 doses of 40, 200, or 1,000 mg/kg/day. In the MTT assay, the viability of NIH-3T3 mouse fibroblast cells was within the normal range. However, the TM3 mouse testis Leydig cell viability was significantly lowered in a concentration-dependent manner. Therefore, data indicate that BP-3 might exert in vivo anti-androgenic and in vitro cytotoxic effects in cells associated with the male reproductive system compared to normal non-reproductive cells.Abbreviation: BP-3: benzophenone-3; CG: Cowper's gland; DMEM: Dulbecco's modified Eagle's medium; DMSO: dimethyl sulfoxide; GP: glans penis; LABC: levator anibulbocavernosus muscle; MTT: methyl tetrazolium; NC: negative control; PC: positive control; SV: seminal vesicle; TP: testosterone propionate; VC: vehicle control; VP: ventral prostate.

Branching morphogenesis of the mouse mammary gland after exposure to benzophenone-3

Pubertal mammary branching morphogenesis is a hormone-regulated process susceptible to exposure to chemicals with endocrine disruptive capacity, such as the UV-filter benzophenone-3 (BP3). Our aim was to assess whether intrauterine or in vitro exposure to BP3 modified the branching morphogenesis of the female mouse mammary gland. For this, pregnant mice were dermally exposed to BP3 (0.15 or 50 mg/kg/day) from gestation day (GD) 8.5 to GD18.5. Sesame oil treatment served as control. Changes of the mammary glands of the offspring were studied on postnatal day 45. Further, mammary organoids from untreated mice were cultured under branching induction conditions and exposed for 9 days to BP3 (1 × 10-6 M, 1 × 10-9 M, or 1 × 10-12 M with 0.01% ethanol as control) to evaluate the branching progression. Mice that were exposed to BP3 in utero showed decreased mRNA levels of progesterone receptor (PR) and WNT4. However, estradiol and progesterone serum levels, mammary histomorphology, proliferation, and protein expression of estrogen receptor alpha (ESR1) and PR were not significantly altered. Interestingly, direct exposure to BP3 in vitro also decreased the mRNA levels of PR, RANKL, and amphiregulin without affecting the branching progression. Most effects were found after exposure to 50 mg/kg/day or 1 × 10-6 M of BP3, both related to sunscreen application in humans. In conclusion, exposure to BP3 does not impair mammary branching morphogenesis in our models. However, BP3 affects PR transcriptional expression and its downstream mediators, suggesting that exposure to BP3 might affect other developmental stages of the mammary gland.

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.

Deep eutectic solvents with solid supports used in microextraction processes applied for endocrine-disrupting chemicals

The determination of endocrine-disrupting chemicals (EDCs) has become one of the biggest challenges in Analytical Chemistry. Due to the low concentration of these compounds in different kinds of samples, it becomes necessary to employ efficient sample preparation methods and sensitive measurement techniques to achieve low limits of detection. This issue becomes even more struggling when the principles of the Green Analytical Chemistry are added to the equation, since finding an efficient sample preparation method with low damaging properties for health and environment may become laborious. Recently, deep eutectic solvents (DESs) have been proposed as the most promising green kind of solvents, but also with excellent analytical properties due to the possibility of custom preparation with different components to modify their polarity, viscosity or aromaticity among others. However, conventional extraction techniques using DESs as extraction solvents may not be enough to overcome challenges in analysing trace levels of EDCs. In this sense, combination of DESs with solid supports could be seen as a potential solution to this issue allowing, in different ways, to determine lower concentrations of EDCs. In that aim, the main purpose of this review is the study of the different strategies with solid supports used along with DESs to perform the determination of EDCs, comparing their advantages and drawbacks against conventional DES-based extraction methods.

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

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

Mechanistic toxicity and growth abnormalities mediated by subacute exposure to environmentally relevant levels of benzophenone-3 in clown anemonefish (Amphiprion ocellaris)

Benzophenone-3 (BP-3) is a UV filter that is ubiquitously present in the environment due to its photostability and degradation resistance and has wide applications in personal care products. BP-3 will eventually be discharged into the ocean. Studies shows BP-3 interferes with endocrine system of aquatic organisms, especially fish. However, the toxicity and mechanisms of subacute exposure of the coral reef fish to BP-3 remain elusive. Here, we exposed the one-month-old clown anemonefish to BP-3 at 1 and 10 μg/L for 14 and 28 days, respectively. After chronic exposure, the effects of BP-3 on the growth of clown anemonefish were investigated in terms of growth-related hormones, immune enzyme activity, digestive enzyme activity, transcriptional profiling of feeding- and obesity-related genes and digital RNA sequencing. The body weight in the BP-3 groups were abnormally increased (1 μg/L group in 14 days treatment and all groups in 28 days treatment), altered insulin content (28 days exposure), immune-related and digestive-related enzymatic activities. At the molecular level, BP-3 interferes with the expression of feeding- and obesity-related genes. Digital RNA sequencing analysis showed that BP-3 interferes with Kyoto encyclopedia of genes and genomes (KEGG) pathways related to growth, social behavior (learning behavior), Mitogen-Activated Protein Kinase (MAPK) signaling pathway, PI3K-Akt signaling pathway, and insulin secretion. Notably, in the insulin secretion, BP-3 induced Ca2+ up-regulation that may damage β cells. Growth abnormalities and social behavior (learning behavior) KEGG pathway disturbances may have potential impacts on populations of clown anemonefish. Our results reveal the toxicological effects of subacute exposure to BP-3, and provides insight into the effects and mechanisms of BP-3 on clown anemonefish growth.

Occurrence and ecological risk assessment of organic UV filters in coastal waters of the Iberian Peninsula

This study aimed to assess the presence of 21 UVFs and metabolites in coastal regions of the Iberian Peninsula, to evaluate their environmental risk, and identify possible influential factors affecting their measured concentrations. Sampling was carried out in spring and summer to assess possible seasonal variations. UVFs were detected in 43 of the 46 sampling sites. Only 5 were found above LOD: BP4, OC, BP3 and metabolites BP1 and BP8. Samples collected in Mar Menor had the greatest variety of compounds per sample and the highest cumulative concentrations. The risk was characterized using Risk Quotients (RQ). BP1 showed a Low environmental Risk in 2 sites while for OC the RQ indicated a Moderate Risk in 22 points. The variables that contribute most to the variation are population density, sampling season, whether it was an open bay or not, and level of urbanization. The presence of WWTPs had a lower influence.

Comparison between endocrine activity assessed using ToxCast/Tox21 database and human plasma concentration of sunscreen active ingredients/UV filters

Sunscreen products are composed of ultraviolet (UV) filters and formulated to reduce exposure to sunlight thereby lessening skin damage. Concerns have been raised regarding the toxicity and potential endocrine disrupting (ED) effects of UV filters. The ToxCast/Tox21 program, that is, CompTox, is a high-throughput in vitro screening database of chemicals that identify adverse outcome pathways, key events, and ED potential of chemicals. Using the ToxCast/Tox21 database, octisalate, homosalate, octocrylene, oxybenzone, octinoxate, and avobenzone, 6 commonly used organic UV filters, were found to have been evaluated. These UV filters showed low potency in these bioassays with most activity detected above the range of the cytotoxic burst. The pathways that were most affected were the cell cycle and the nuclear receptor pathways. Most activity was observed in liver and kidney-based bioassays. These organic filters and their metabolites showed relatively weak ED activity when tested in bioassays measuring estrogen receptor (ER), androgen receptor (AR), thyroid receptor, and steroidogenesis activity. Except for oxybenzone, all activity in the endocrine assays occurred at concentrations greater than the cytotoxic burst. Moreover, except for oxybenzone, plasma concentrations (Cmax) measured in humans were at least 100× lower than bioactive (AC50/ACC) concentrations that produced a response in ToxCast/Tox21 assays. These data are consistent with in vivo animal/human studies showing weak or negligible endocrine activity. In sum, when considered as part of a weight-of-evidence assessment and compared with measured plasma concentrations, the results show these organic UV filters have low intrinsic biological activity and risk of toxicity including endocrine disruption in humans.

Lymnaea stagnalis and Ophryotrocha diadema as Model Organisms for Studying Genotoxicological and Physiological Effects of Benzophenone-3

Benzophenone-3 (BP-3) is a lipophilic organic compound that occurs naturally in flower pigments. Since it adsorbs ultraviolet (UV) radiation in the UVA and UVB regions, it is one of the most common UV filters found in sunscreen and cosmetic products. We explored by in vivo micronuclei (MNi) assay the genotoxic effects of BP-3 on hemocytes from the freshwater gastropod Lymnaea stagnalis. We also studied its possible toxic effects on life-history traits: body growth in L. stagnalis and egg production of both L. stagnalis and the marine polychaete worm Ophryotrocha diadema. Adult individuals were exposed to increasing concentrations of BP-3 (0.025, 0.050, 0.100, and 0.200 mg/L) once a week for 4 weeks. In L. stagnalis, exposure to BP-3 at concentrations of both 0.2 and 0.1 mg/L produced genotoxic effects on the micronuclei frequencies, but only concentrations of 0.2 mg/L affected the NBUDs frequencies. Similarly, negative effects on body growth were observed at the concentrations of 0.2 and 0.1 mg/L and a significant reduction of egg production at 0.2 mg/L. In O. diadema, a negative correlation between egg production and increasing BP-3 concentrations was observed. Our findings suggest the need for more stringent measures to reduce the presence of BP-3 in the environment.

Benzophenones-natural metabolites with great Hopes in drug discovery: structures, occurrence, bioactivities, and biosynthesis

Fungi have protruded with enormous development in the repository of drug discovery, making them some of the most attractive sources for the synthesis of bio-significant and structural novel metabolites. Benzophenones are structurally unique metabolites with phenol/carbonyl/phenol frameworks, that are separated from microbial and plant sources. They have drawn considerable interest from researchers due to their versatile building blocks and diversified bio-activities. The current work aimed to highlight the reported data on fungal benzophenones, including their structures, occurrence, and bioactivities in the period from 1963 to April 2023. Overall, 147 benzophenones derived from fungal source were listed in this work. Structure activity relationships of the benzophenones derivatives have been discussed. Also, in this review, a brief insight into their biosynthetic routes was presented. This work could shed light on the future research of benzophenones.

Benzophenone-type ultraviolet filters inhibit human and rat placental 3β-hydroxysteroid dehydrogenases: structure-activity relationship and in silico docking analysis

Benzophenones (BPs) are a class of chemicals found in various personal care and cosmetic products, such as sunscreens and lotions. Their usage is known to cause reproductive and hormonal health risks, but the exact mechanism of action remains unknown. In this study, we investigated the effect of BPs on human and rat placental 3β-hydroxysteroid dehydrogenases (3β-HSDs), which play a crucial role in the biosynthesis of steroid hormones, particularly progesterone. We tested inhibitory effects of 12 BPs, and performed structure-activity relationship (SAR) and in silico docking analysis. The potency of BPs to inhibit human 3β-HSD1 (h3β-HSD1) is BP-1 (IC₅₀, 8.37 μM)>BP-2 (9.06 μM)>BP-12 (94.24 μM)>BP-7 (1160 μM) >BP-6 (1257 μM) >BP-6 (1410 μM) > other BPs (ineffective at 100 μM). The potency of BPs on rat r3β-HSD4 is BP-1 (IC₅₀, 4.31 μM)>BP-2 (117.3 μM)>BP-6 (669 μM) >BP-3 (820 μM)>other BPs (ineffective at 100 μM). BP-1, BP-2, and BP-12 are mixed h3β-HSD1 inhibitors and BP-1 is a mixed r3β-HSD4 inhibitor. LogP, lowest binding energy, and molecular weight were positively associated with IC₅₀ for h3β-HSD1, while LogS was negatively associated with IC₅₀. The 4-OH substitution in the benzene ring play a key role in enhancing the effectiveness of inhibiting h3β-HSD1 and r3β-HSD4, possibly through increasing water solubility and decreasing lipophilicity by forming hydrogen bonds. BP-1 and BP-2 inhibited progesterone production in human JAr cells. Docking analysis shows that 2-OH of BP-1 forms hydrogen bond with catalytic residue Ser125 of h3β-HSD1 and Thr125 of r3β-HSD4. In conclusion, this study demonstrates that BP-1 and BP-2 are moderate inhibitors of h3β-HSD1 and BP-1 is moderate inhibitor of r3β-HSD4. There is a significant SAR difference for 3β-HSD homologues between BPs and distinct species-dependent inhibition of placental 3β-HSDs.

Implementation of effect biomarkers in human biomonitoring studies: A systematic approach synergizing toxicological and epidemiological knowledge

Human biomonitoring (HBM) studies have highlighted widespread daily exposure to environmental chemicals. Some of these are suspected to contribute to adverse health outcomes such as reproductive, neurological, and metabolic disorders, among other developmental and chronic impairments. One of the objectives of the H2020 European Human Biomonitoring Initiative (HBM4EU) was the development of informative effect biomarkers for application in a more systematic and harmonized way in large-scale European HBM studies. The inclusion of effect biomarkers would complement exposure data with mechanistically-based information on early and late adverse effects. For this purpose, a stepwise strategy was developed to identify and implement a panel of validated effect biomarkers in European HBM studies. This work offers an overview of the complete procedure followed, from comprehensive literature search strategies, selection of criteria for effect biomarkers and their classification and prioritization, based on toxicological data and adverse outcomes, to pilot studies for their analytical, physiological, and epidemiological validation. We present the example of one study that demonstrated the mediating role of the effect biomarker status of brain-derived neurotrophic factor BDNF in the longitudinal association between infant bisphenol A (BPA) exposure and behavioral function in adolescence. A panel of effect biomarkers has been implemented in the HBM4EU Aligned Studies as main outcomes, including traditional oxidative stress, reproductive, and thyroid hormone biomarkers. Novel biomarkers of effect, such as DNA methylation status of BDNF and kisspeptin (KISS) genes were also evaluated as molecular markers of neurological and reproductive health, respectively. A panel of effect biomarkers has also been applied in HBM4EU occupational studies, such as micronucleus analysis in lymphocytes and reticulocytes, whole blood comet assay, and malondialdehyde, 8-oxo-2'-deoxyguanosine and untargeted metabolomic profile in urine, to investigate, for example, biological changes in response to hexavalent chromium Cr(VI) exposure. The use of effect biomarkers in HBM4EU has demonstrated their ability to detect early biological effects of chemical exposure and to identify subgroups that are at higher risk. The roadmap developed in HBM4EU confirms the utility of effect biomarkers, and support one of the main objectives of HBM research, which is to link exposure biomarkers to mechanistically validated effect and susceptibility biomarkers in order to better understand the public health implications of human exposure to environmental chemicals.

Human risk associated with exposure to mixtures of antiandrogenic chemicals evaluated using in vitro hazard and human biomonitoring data

BACKGROUND

Scientific evidence for underestimated toxicity from unintentional exposure to chemical mixtures is mounting. Yet, harmonized approaches on how to assess the actual risk of mixtures is lacking. As part of the European Joint programme 'Human Biomonitoring for Europe' we explored a novel methodology for mixture risk assessment of chemicals affecting male reproductive function.

METHODOLOGY

We explored a methodology for chemical mixture risk assessment based on human in vitro data combined with human exposure data, thereby circumventing the drawbacks of using hazard data from rodents and estimated exposure intake levels. Human androgen receptor (hAR) antagonism was selected as the most important molecular initiating event linked to adverse outcomes on male reproductive health.

RESULTS

Our work identified 231 chemicals able to interfere with hAR activity. Among these were 61 finally identified as having both reliable hAR antagonist and human biomonitoring data. Calculation of risk quotients indicated that PCBs (118, 138, 157), phthalates (BBP, DBP, DIBP), benzophenone-3, PFOS, methylparaben, triclosan, some pesticides (i.e cypermethrin, β-endosulfan, methylparathion, p,p-DDE), and a PAH metabolite (1-hydroxypyrene) contributed to the mixture effect. The major chemical mixture drivers were PCB 118, BBP, PFOS, DBP, and the UV filter benzophenone-3, together contributing with 75% of the total mixture effect that was primarily driven by high exposure values.

CONCLUSIONS

This viable way forward for mixture risk assessment of chemicals has the advantages of (1) being a more comprehensive mixture risk assessment also covering data-poor chemicals, and (2) including human data only. However, the approach is subjected to uncertainties in terms of in vitro to in vivo extrapolation, it is not ready for decision making, and needs further development. Still, the results indicate a concern for adverse effects on reproductive function in highly exposed boys, especially when considering additional exposure to data-poor chemicals and chemicals acting by other mechanisms of action.