In vitro determination of transdermal permeation of synthetic musks and estimated dermal uptake through usage of personal care products

Occurrence, time trends, and human exposure of siloxanes and synthetic musk compounds in indoor dust from Korean homes

Siloxanes and synthetic musk compounds (SMCs) have been widely used as additives in household and personal care products. Humans are easily exposed to siloxanes and SMCs originating from these products through ingestion and dermal absorption of indoor dust. In the present study, indoor dust samples were analyzed for 19 siloxanes (cyclic and linear) and 12 SMCs (polycyclic, macrocyclic, and nitro musks) to assess their occurrence, time trends over time, source, and health risks. A total of 18 siloxanes and 10 SMCs were detected in all indoor dust samples obtained from 2011⎯2021, indicating widespread and long-term contamination. Higher detection frequencies and concentrations were associated with siloxanes and SMCs with higher use and strong resistance against degradation processes. Indoor dust samples were dominated by linear siloxanes (L11-L13), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-(g)-2-benzopyran (HHCB), musk ketone (MK), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN). The frequent use of household and personal care products is likely an important source of siloxane and SMC contamination in indoor environments. The concentrations of siloxanes and SMCs in indoor dust increased from 2011 to 2021, particularly, those of linear siloxanes, reflecting the impact of regulatory actions addressing cyclic siloxanes. The profiles of siloxanes remained stable throughout the study period, whereas those of SMCs shifted from nitro to polycyclic musks. The estimated daily intakes (EDIs) of siloxanes and SMCs arising from ingestion were greater than from dermal absorption of indoor dust. The EDIs of siloxanes and SMCs associated with indoor dust indicated that children are exposed to these pollutants.

Use of Chemical Hair Straighteners and Fecundability in a North American Preconception Cohort

Chemical hair straighteners ("relaxers") are used by millions of North Americans, particularly women of color. Hair relaxers may contain endocrine-disrupting compounds, which can harm fertility. We evaluated the association between hair relaxer use and fecundability among 11,274 participants from Pregnancy Study Online (PRESTO), a North American preconception cohort study. During 2014-2022, participants completed a baseline questionnaire in which they reported their history of relaxer use and completed follow-up questionnaires every 8 weeks for 12 months or until pregnancy, whichever came first. We used multivariable-adjusted proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs). Relative to never use, fecundability was lower among current (FR = 0.81, 95% CI: 0.64, 1.03) and former (FR = 0.89, 95% CI: 0.81, 0.98) users of hair relaxers. FRs for first use of hair relaxers at ages <10, 10-19, and ≥20 years were 0.73 (95% CI: 0.55, 0.96), 0.93 (95% CI: 0.83, 1.04), and 0.85 (95% CI: 0.74, 0.98), respectively. Fecundability was lowest among those with longer durations of use (≥10 years vs. never: FR = 0.71, 95% CI: 0.54, 0.91) and more frequent use (≥5 times/year vs. never: FR = 0.82, 95% CI: 0.60, 1.11), but associations were nonmonotonic. In this preconception cohort study, use of chemical hair straighteners was associated with slightly reduced fecundability.

Analysis of the contribution of locally derived wastewater to the occurrence of Pharmaceuticals and Personal Care Products in Antarctic coastal waters

Pharmaceuticals and Personal Care Products (PPCPs) are emerging pollutants detected in many locations of the world including Antarctica. The main objective of this review is to discuss the influence of the human population on the concentration, distribution and biological effects of PPCPs across the Antarctic coastal marine ecosystem. We carried out a review of the scientific articles published for PPCPs in Antarctic, supported by the information of the Antarctic stations reported by Council of Managers of National Antarctic Programs (CONMAP), Scientific Committee on Antarctic Research (SCAR) and Secretariat of the Antarctic Treaty (ATS). In addition, spatial data regarding the Antarctic continent was obtained from Quantarctica. Antarctic concentrations of PPCPs were more reflective of the treatment system used by research stations as opposed to the infrastructure built or the annual occupancy by station. The main problem is that most of the research stations lack tertiary treatment, resulting in elevated concentrations of PPCPs in effluents. Furthermore, the geographic distribution of Antarctic field stations in coastal areas allows for the release of PPCPs, directly into the sea, a practice that remains in compliance with the current Protocol. After their release, PPCPs can become incorporated into sea ice, which can then act as a chemical reservoir. In addition, there is no clarity on the effects on the local biota. Finally, we recommend regulating the entry and use of PPCPs in Antarctica given the difficulties of operating, and in some cases the complete absence of appropriate treatment systems. Further studies are needed on the fate, transport and biological effects of PPCPs on the Antarctic biota. It is recommended that research efforts be carried out in areas inhabited by humans to generate mitigation measures relative to potential adverse impacts. Tourism should be also considered in further studies due the temporal release of PPCPs.

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

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

Microplastic properties and their interaction with hydrophobic organic contaminants: a review

Microplastics (MPs) have been defined as particles of size < 5 mm and are characterized by hydrophobicity and large surface areas. MPs interact with co-occurring hydrophobic organic contaminants (HOCs) via sorption-desorption processes in aquatic and terrestrial environments. Ingestion of MPs by living organisms may increase exposure to HOC levels. The key mechanisms for the sorption of HOCs onto MPs are hydrophobic interaction, electrostatic interaction, π-π interactions, hydrogen bonding, and Van der Waals forces (vdW). Polymer type, UV-light-induced surface modifications, and the formation of oxygen-containing functional groups have a greater influence on electrostatic and hydrogen bonding interactions. In contrast, the formation of oxygen-containing functional groups negatively influences hydrophobic interaction. MP characteristics such as crystallinity, weathering, and surface morphology affect sorption capacity. Matrix properties such as pH, ionic strength, and dissolved organic matter (DOM) also influence sorption capacity by exerting synergistic/antagonistic effects. We reviewed the mechanisms of HOC sorption onto MPs and the polymer and matrix properties that influence the HOC sorption. Knowledge gaps and future research directions are outlined.

Levels of parabens and bisphenols in personal care products and urinary concentrations in Indian young adult women: Implications for human exposure and health risk assessment

Limited information is available about the levels of exposure of paraben and bisphenols emerging from personal care products (PCPs) use in Indian women and the risk associated with it. In this study, liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to determine the concentrations of six parabens (methyl-, ethyl-, propyl-, butyl, benzyl-, and heptyl-parabens) and 8 bisphenols (Bisphenol A, B, F, P, S, Z, AP, and AF) in PCPs samples (n = 114) obtained from Indian market and in the urine samples of young adult females (n = 52). The concentrations measured in PCPs and urine samples were used to determine the estimated daily intake. The mean concentrations of 6 parabens and 8 bisphenols in PCPs ranged from 38.3 to 2.38 × 10⁵ ng/g and 2.71-148 ng/g, respectively. In urine samples analysed, the mean concentrations of 6 parabens and 8 bisphenols ranged from 0.007 to 293 ng/mL and 0.10-10.8 ng/mL, respectively. There was no significant correlation of EDCs with age, BMI and waist-to-hip ratio (WHR), but significant correlations (p < 0.05) were observed between urinary paraben and bisphenol concentrations. A statistically significant difference (p < 0.05) exists between the BMI and WHR groups by bisphenol concentrations. Estimated daily intake and exposure risks for parabens and bisphenols revealed no possible concerns for Indian young adult females. Hitherto, this is the first study to show that Indian young adult females were exposed to parabens and bisphenols. This study provides evidence on PCPs usage contribute to the urinary concentrations of EDCs.

Dermal exposure to synthetic musks: Human health risk assessment, mechanism, and control strategy

Synthetic musks (SMs) have been widely used as odor additives in personal care products (PCPs). Dermal exposure to SMs is the main pathway of the accumulation of these chemicals in human kerateins and poses potential health risks. In this study, in silico methods were established to reduce the human health risk of SMs from dermal exposure by investigating the risk mechanisms, designing lower bioaccumulation ability SMs and suggesting proper PCP ingredients using molecular docking, molecular dynamics simulation, and quantitative structure-activity relationship (QSAR) models. The binding energy, a parameter reflecting the binding ability of SMs and human keratin protein (4ZRY), was used as the indicator to assess the human health risk of SMs. According to the mechanism analysis, total energy was found as the most influential molecular structural feature influencing the bioaccumulation ability of a SM, and as one of the main factors influencing the function (i.e., odor sensitivity) of an SM. The 3D-QSAR models were constructed to control the human health risk of SMs by designing lower-risk SMs derivatives. The phantolide (PHAN)- 58 was determined to be the optimum SM derivative with lower bioaccumulation ability (reduced 17.25%) and improved odor sensitivity (increased 7.91%). A further reduction of bioaccumulation ability of PHAN-58 was found when adding proper body wash ingredients (i.e., alkyl ethoxylate sulfate (AES), dimethyloldimethyl (DMDM), EDTA-Na4, ethylene glycol distearate (EGDS), hydroxyethyl cellulose (HEC), lemon yellow and octyl glucose), leading to a significant reduction of the bioaccumulation ability (42.27%) compared with that of PHAN. Results demonstrated that the proposed theoretical mechanism and control strategies could effectively reduce the human health risk of SMs from dermal exposure.

A Review of Potential Use of Amazonian Oils in the Synthesis of Organogels for Cosmetic Application

New strategies for the delivery of bioactives in the deeper layers of the skin have been studied in recent years, using mainly natural ingredients. Among the strategies are organogels as a promising tool to load bioactives with different physicochemical characteristics, using vegetable oils. Studies have shown satisfactory skin permeation, good physicochemical stability mainly due to its three-dimensional structure, and controlled release using vegetable oils and low-molecular-weight organogelators. Within the universe of natural ingredients, vegetable oils, especially those from the Amazon, have a series of benefits and characteristics that make them unique compared to conventional oils. Several studies have shown that the use of Amazonian oils brings a series of benefits to the skin, among which are an emollient, moisturizing, and nourishing effect. This work shows a compilation of the main Amazonian oils and their nutraceutical and physicochemical characteristics together with the minority polar components, related to health benefits, and their possible effects on the synthesis of organogels for cosmetic purposes.

Prolonged sub-lethal exposure to galaxolide (HHCB) and tonalide (AHTN) promotes the metastatic potential of glioblastoma tumor spheroids

Galaxolide and tonalide are well-known polycyclic musks whose intensive use without limitations in numerous cleaning, hygiene, and personal care products has resulted in widespread direct human exposure via absorption, inhalation, and oral ingestion. Latest data shows that long-term, low-dose exposure to toxic chemicals can induce unpredictable harmful effects in a variety of living systems, however, interactions between synthetic musks and brain tumours remain largely unexplored. Glioblastoma (GB) accounts for nearly half of all tumours of the central nervous system and is characterized by very poor prognosis. The aims of this study were (1) to investigate the potential effect of long-term (20-generation) single and combined application of galaxolide and tonalide at sub-lethal doses (5-2.5 u M) on the angiogenesis, invasion, and migration of human U87 cells or tumour spheroids, and (2) to explore the underlying molecular mechanisms. Random amplified polymorphic DNA assays revealed significant DNA damage and increased total mutation load in galaxolide- and/or tonalide-treated U87 cells. In those same groups, we also detected remarkable tumour spheroid invasion and up-regulation of both HIF1-α/VEGF/MMP9 and IL6/JAK2/STAT3 signals, known to have important roles in hypoxia-related angiogenesis and/or proliferation. Prolonged musk treatment further altered angio-miRNA expression in a manner consistent with poor prognosis in GB. We also detected significant over-expression of the genes Slug, Snail, ZEB1, and Vimentin, which are biomarkers of epithelial to mesenchymal transition. In addition, matrigel, transwell, and wound healing assays clearly showed that long-term sub-lethal exposure to galaxolide and/or tonalide induced invasion and migration proposing a high metastatic potential. Our results suggest that assessing expression of HIF-1a, VEGF, STAT3, and the miR-17-92 cluster in biopsy samples of GB patients who have a history of possible long-term exposure to galaxolide or tonalide could be beneficial for deciding a therapy regime. Additionally, we recommend that extensively-used hygiene and cleaning materials be selected from synthetic musk-free products, especially when used in palliative care processes for GB patients.

Functional modification of HHCB: Strategy for obtaining environmentally friendly derivatives

Galaxolide (HHCB), one of the most widely used synthetic musks in personal care products (PCPs), has been recognized as an emerging contaminant with potential human health concerns. To overcome such adverse effects, a systematic molecular design, screening and performance evaluation approach was developed to generate functionally improved and environmentally friendly HHCB derivatives. Among the 90 designed HHCB derivatives, 15 were screened with improved functional properties (i.e., odor stability and intensity) and less environmental impacts (i.e., lower bio-toxicity, bio-accumulation ability, and mobility) using 3D-QSAR models and density functional theory methods. Their human health risks were then assessed by toxicokinetic analysis, which narrowed the candidates to four. Derivative 7, the designed molecule with the least dermal adsorption potential, was evaluated for its interaction with other PCPs additives (i.e., anti-photosensitivity materials and moisturizer) and such impacts on human health risks using molecular docking and molecular dynamic simulation. The environmental fate of Derivative 7 after transformation (i.e., photodegradation, biotransformation, and chlorination) was also discussed. Biotransformation and chlorination were recognized as optimum options for Derivative 7 mitigation. This study provided the theoretical basis for the design of functionally improved and environmentally friendly HHCB alternatives and advanced the understanding of their environmental behaviors and health risks.

Benzaldehyde, A New Absorption Promoter, Accelerating Absorption on Low Bioavailability Drugs Through Membrane Permeability

Styrax, one of the most famous folk medicines, is a necessary medicine in formulas to help other drugs reach the focal zone and maximize the effectiveness, the mechanism that promotes absorption is not clear yet. This study was carried out to investigate the absorption-promoting effects and the mechanism of benzaldehyde, a key active compound of styrax, on the diffusion rates of drugs with different oral bioavailability. Caco-2 transport experiments were used to investigate the transport rate. Molecular Dynamics Simulation analysis and fluorescence-anisotropy measurements were used to explore the underlying mechanism of absorption-promoting. Validation test in vivo was carried out to reveal the absorption-promoting effects of benzaldehyde on high hydrophilicity drugs. Our data indicated that benzaldehyde(50 μM) elevated the cumulative quantity of passively diffusion drugs with high hydrophilicity such as acyclovir and hydrochlorothiazide. MD and membrane fluidity data explained that benzaldehyde can loosen the structure of the lipid bilayer. The validation tests showed that benzaldehyde (140 mg/kg) remarkably increased the C_max and AUC0-6 of acyclovir and hydrochlorothiazide in vivo. These present studies suggested that benzaldehyde can promote the absorption of drugs with a lower oral bioavailability through disturbing the integrity of lipid bilayer enhanced membrane permeability.

Bioaccessibilities of metal(loid)s and organic contaminants in particulates measured in simulated human lung fluids: A critical review

Particle-bound pollutants can pose a health risk to humans. Inhalation exposure evaluated by total contaminant concentrations significantly overestimates the potential risk. To assess the risk more accurately, bioavailability, which is the fraction that enters into the systemic circulation, should be considered. Researchers have replaced bioavailability by bioaccessibility due to the rapid and cost-efficient measurement for the latter, especially for assessment by oral ingestion. However, contaminants in particulates have different behavior when inhaled than when orally ingested. Some of the contaminants are exhaled along with exhalation, and others are deposited in the lung with the particulates. In addition, a fraction of the contaminants is released into the lung fluid and absorbed by the lung, and another fraction enters systemic circulation under the action of cell phagocytosis on particulates. Even if the release fraction, i.e., release bioaccessibility, is considered, the measurement faces many challenges. The present study highlights the factors influencing release bioaccessibility and the incorporation of inhalation bioaccessibility into the risk assessment of inhaled contaminants. Currently, there are three types of extraction techniques for simulated human lung fluids, including simple chemical solutions, sequential extraction techniques, and physiologically based techniques. The last technique generally uses three kinds of solution: Gamble's solution, Hatch's solution, and artificial lysosomal fluid, which are the most widely used physiologically based simulated human lung fluids. External factors such as simulated lung fluid composition, pH, extraction time, and sorption sinks can affect release bioaccessibility, whereas particle size and contaminant properties are important internal factors. Overall, release bioaccessibility is less used than bioaccessibility considering the deposition fraction when assessing the risk of contaminants in inhaled particulates. The release bioaccessibility measurement poses two main challenges: developing a unified, accurate, stable, simple, and systematic biologically based method, and validating the method through in-vivo assays.

Predicting Transdermal Uptake of Phthalates and a Paraben from Cosmetic Cream Using the Measured Fugacity

Transdermal uptake models compliment in vitro and in vivo experiments in assessing risk of environmental exposures to semivolatile organic compounds (SVOCs). A key parameter for mechanistic models is the chemical driving force for mass transfer from environmental media to human skin. In this research, we measure this driving force in the form of fugacity for chemicals in cosmetic cream and use it to model uptake from cosmetics as a surrogate for condensed environmental media. A simple cosmetic cream, containing no target analytes, was mixed with diethyl phthalate (DEP), di-n-butyl phthalate (DnBP), and butyl paraben (BP) and diluted to make creams with concentrations ranging from 0.025% to 6%. The fugacity, relative to the pure compound, was measured using solid-phase micro extraction (SPME). We found that the relationship between the concentration and fugacity is highly nonlinear. The relative fugacity of the chemicals for a 2% w/w formulation was used in a diffusion-based model to predict transdermal uptake of each chemical and was compared with excretion data from a prior human subject study with the same formulation. Dynamic simulations of excretion are generally consistent with the results of the human subject experiment but sensitive to the input parameters, especially the time between cream application and showering.

Seasonal profiles of atmospheric PAHs in an e-waste dismantling area and their associated health risk considering bioaccessible PAHs in the human lung

Due to the development of the economy, electronic waste (e-waste) has become a new global problem and e-waste dismantling processes are an important source of air pollution. Among the pollutants emitted, polycyclic aromatic hydrocarbons (PAHs) are a severe concern because of their carcinogenic and mutagenic properties. However, few studies have investigated the atmospheric PAHs generated by e-waste dismantling in a specific region, especially the PAH levels throughout the year. Thus, we assessed the effects of PAHs on the local air quality by sampling the total suspended particulates (TSP), PM₁₀, PM_2.5, and gaseous phase from an e-waste dismantling area and a control site during four seasons. The TSP, PM₁₀, and PM_2.5 concentrations were measured as 84.8-414, 70.7-302, and 57.1-204 μg m^-3, respectively, in this area, and those of three types of particulate bound-PAHs and gaseous phase PAHs were 2.6-16.1, 2.2-15.1, 1.9-14.6, and 20.1-72.8 ng m^-3, respectively. The pollutant levels were higher in the spring and winter than those in the summer and autumn. The PAH sources were identified by diagnostic ratio approaches and principal component analysis. E-waste dismantling was identified as the major source of PAH pollution within this area, where approximately 82.4% of the PAHs was attributed to e-waste dismantling at an industrial park (EP site). Among the sites sampled, the pollutant levels and cancer risk were highest at the EP site, and they could pose a cancer risk for humans, although only the bioaccessible PAHs in human lungs were considered. In particular, infants had a higher health risk than adults, thereby suggesting that air pollution with PAHs is a concern in this area. This study provides clear evidence of the requirement for control measurements of e-waste dismantling processes.

Effect of layered application on the skin permeation of a cosmetic active component, rhododendrol

Cosmetics containing rhododendrol (RD) were voluntarily recalled after incidents of leukoderma related to their use. Users reported using up to five different RD-containing products by layered application. In this study, we investigated the effects of layered application, formulations, and their components on the skin permeation of cosmetics containing RD. Experiments were designed to simulate actual in-use conditions, such as varying application volumes, physical mixing of formulations, sequence of cosmetics application and time interval between applications, to establish their effect on the skin permeation of RD. Milk and lotion RD-containing cosmetics (2%), 1% aqueous RD, and preparations of formulation components were applied as the first or second layers as finite doses of 10 or 20 µL/cm². Permeation experiments were performed through excised porcine ear skin using Franz diffusion cells with an effective diffusion area of 1.77 cm². Cosmetics applied by layered application exhibited lower skin permeation of RD compared with a single application despite having the same application dose. High initial volume (20 µL at 0 or 5 sec) did not exhibit any significant reduction in the permeation of RD. Formulations and their components caused varying reductions in RD permeation, probably due to changes in thermodynamic activity of the active component. Layered application, formulation components, application volume, time interval and sequence of application had significant influences on the skin permeation of the active component. Moreover, this study established a method of investigating the influence of formulations and their components on the skin permeation of actives after layered application.

Synthetic Musks: A Class of Commercial Fragrance Additives in Personal Care Products (PCPs) Causing Concern as Emerging Contaminants

Synthetic musks (SMs) are promising fragrance additives used in personal care products (PCPs). The widespread presence of SMs in environmental media remains a serious risk because of their harmful effects. Recently, the environmental hazards of SMs have been widely reported in various environmental samples including those from coastal and marine regions. This paper provides a systematic review of SMs, including their classification, synthetic routes, analysis and occurrence in environmental samples, fate and toxicity in the environment, as well as the associated risk assessment and pollution control. Research gaps and future opportunities were also identified with the hope of raising interest in this topic.

Benzophenone-UV filters in personal care products and urine of schoolchildren from Shenzhen, China: Exposure assessment and possible source

The use of benzophenone (BP)-type UV filters in personal care products (PCPs) has rapidly increased in China over the past decade, leading to growing concerns on the potential adverse effects associated with the usage. Urine analysis is an ideal non-invasive approach for human biomonitoring of xenobiotics that are excreted mainly through urinary system. To investigate human exposure of PCPs to children from South China, we determined BP-type UV filters in a total of 156 commercial PCP goods covering 11 categories, as well as 280 urine samples collected from elementary school students in Shenzhen, China. Five BP analogues (i.e., BP1, BP2, BP3, BP8, and 4HB) were frequently detected in both PCPs and urine, among which BP3 was the dominant analogue, accounting for 96.3% of the total BPs in PCPs and 53.2% in urine, respectively. Sunscreens contained the highest BP concentrations (mean: 2.15 × 10⁴ ng g^-1) among all PCP goods. Girls exhibited higher urinary BP concentrations than boys, and body mass index positively influenced BP concentrations. However, no regional difference in urinary BP concentration was observed. The estimated dermal uptake of BPs from PCPs after considering the percutaneous absorption rates was much lower than the estimated dermal intake. The total daily excretion doses estimated from urinary BPs were 74.4 and 47.4 ng·kg^-1_bw day^-1 for girls and boys, respectively. The higher usage of body lotions, hand lotions, and sunscreens by girls than boys (1.49 vs. 1.03 times week^-1) might play an important role.

Estimation of intake and uptake of bisphenols and triclosan from personal care products by dermal contact

Increasing concern has been raised in respect of exposure to bisphenols and triclosan (TCS) due to their widespread use. However, little is known about their occurrence in personal care products (PCPs) or, particularly, their dermal uptake following daily application. It is therefore necessary to evaluate the human health risk of bisphenols and TCS via dermal absorption. In this study, 150 PCPs, covering 11 different categories, were collected in China. The concentrations of seven bisphenol analogues and TCS were measured, and the associated human health risks by dermal contact were estimated. High detection frequencies of TCS (46.7%) and bisphenol AF (38.7%) were found in the PCPs. The highest mean concentration of Σ₇BPs (sum concentration of all seven bisphenols) was 77.8ngg^-1 found in masks, and the highest mean concentration of TCS was 86.7ngg^-1 in hand sanitizers. The bisphenol composition profiles varied among different categories. Bisphenol A and bisphenol F generally showed higher concentrations. Combining the concentrations of the target substances with the daily usage quantities of PCPs and other parameters, the total estimated dermal intakes and uptakes of Σ₇BPs and TCS were calculated. The results showed that the former (12.1 and 1.06ng·kg^-1_bwday^-1) were markedly higher than the latter (1.21 and 9.58×10^-2ng·kg^-1_bwday^-1), which included dermal absorption rates of the chemicals in the estimation. Although diet is the main source, and oral ingestion is the main route, for human BPA exposure, the results of the estimated dermal uptakes of BPA in the present study combined with those from a European study show that dermal contact is the main route with thermal paper being the main contributor when both unconjugated and conjugated BPA in the human body are considered. The present study also showed that exposure to BPA in PCPs following dermal contact should not be ignored.

Indoor residential exposure to semivolatile organic compounds in France

Multiple chemicals are emitted in residential accommodation. Aggregate Daily Doses (ADD) (ng/kg-bw/d) were estimated for 32 semivolatile organic compounds (SVOCs) of different chemical families that are frequently detected in French dwellings in both air and settled dust. Daily doses were determined using steady-state models for the population, categorized into 11 age groups covering birth to age 30. Three routes of exposure were taken into account: dust ingestion, inhalation (gaseous and particulate phases) and dermal contact with the gaseous phase of air. Contamination levels were preferentially retrieved from large, nationwide representative datasets. A two-dimensional probabilistic approach was used to assess parametric uncertainty and identify the most influential factors. For children aged 2 to 3years, ADD estimates spanned orders of magnitude, with median values ranging from 8.7pg/kg-bw/d for 2,2',3,4,4'-pentabromodiphenylether (BDE 85) to 1.3μg/kg-bw/d for di-isobutyl phthalate (DiBP). Inhalation, ingestion and dermal pathway contributed at varying levels, and depending on compound, air was the dominant medium for 28 of the 32 compounds (either by inhalation or dermal contact). Indoor exposure estimate variance was mainly driven by indoor contamination variability, and secondarily by uncertainty in physical and chemical parameters. These findings lend support to the call for cumulative risk assessment of indoor SVOCs.