Occurrence of and dermal exposure to benzene, toluene and styrene found in hand sanitizers from the United States

Styrene and ethylbenzene exposure and type 2 diabetes mellitus: A longitudinal gene-environment interaction study

Styrene and ethylbenzene (S/EB) are identified as hazardous air contaminants that raise significant concerns. The association between S/EB exposure and the incidence of type 2 diabetes mellitus (T2DM), and the interaction between genes and environment, remains poorly understood. Our study consisted of 2219 Chinese adults who were part of the Wuhan-Zhuhai cohort. A follow-up assessment was conducted after six years. Exposure to S/EB was quantified by determining the concentrations of urinary biomarkers of exposure to S/EB (UBE-S/EB; urinary phenylglyoxylic acid level plus urinary mandelic acid level). Logistic regression models were constructed to investigate the relations of UBE-S/EB and genetic risk score (GRS) with T2DM prevalence and incidence. The interaction effects of UBE-S/EB and GRS on T2DM were investigated on multiplicative and additive scales. UBE-S/EB was dose-dependently and positively related to T2DM prevalence and incidence. Participants with high levels of UBE-S/EB [relative risk (RR) = 1.930, 95% confidence interval (CI): 1.157-3.309] or GRS (1.943, 1.110-3.462) demonstrated the highest risk of incident T2DM, in comparison to those with low levels of UBE-S/EB or GRS. Significant additive interaction between UBE-S/EB and GRS on T2DM incidence was discovered with relative excess risk due to interaction (95% CI) of 0.178 (0.065-0.292). The RR (95% CI) of T2DM incidence was 2.602 (1.238-6.140) for individuals with high UBE-S/EB and high GRS, compared to those with low UBE-S/EB and low GRS. This study presented the initial evidence that S/EB exposure was significantly related to increased risk of T2DM incidence, and the relationship was interactively aggravated by genetic predisposition.

Infants exposure to chemicals in diapers: A review and perspective

Diapers are a staple care product for infants, yet concerns persist regarding the potential risks posed by dermal exposure to chemicals through their usage. This review provides a comprehensive summary of reported chemicals, highlighting the frequent detection of polychlorodibenzo-p-dioxins (PCDDs), phthalates (PAEs), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), bisphenols (BPs), organotins, and heavy metals. Disposable diapers commonly exhibit higher concentrations of VOCs, PAEs, BPs, and heavy metals than other chemicals. Our estimation reveals formaldehyde as posing the highest dermal exposure dose, reaching up to 0.018 mg/kg bw/day. Conversely, perfluorooctanoic acid (PFOA) exhibits lower exposure, but its non-cancer hazard quotient (0.062) is the highest. In most scenarios, the risk of chemical exposure through diapers for infants is deemed acceptable, while the risk is higher under some extreme exposure scenarios. Using the cancer slope factor recently suggested by U.S. EPA, the cancer risk in diapers raised by PFOA is 5.5 × 10-5. It should be noted that our estimation is approximately 1000-10,000 folds lower than some previous estimations. The high uncertainties associated with exposure and risk estimations are primarily raised by unclear parameters related to chemical migration coefficients, absorption factors, concentrations, and toxicity data for skin exposure, which requires research attention in future. Besides that, future research endeavors should prioritize the identification of potential toxic chemicals and the development of hygiene guidelines and standards.

The Potential of Fecal Volatile Organic Compound Analysis for the Early Diagnosis of Late-Onset Sepsis in Preterm Infants: A Narrative Review

Early diagnosis and treatment of late-onset sepsis (LOS) is crucial for survival, but challenging. Intestinal microbiota and metabolome alterations precede the clinical onset of LOS, and the preterm gut is considered an important source of bacterial pathogens. Fecal volatile organic compounds (VOCs), formed by physiologic and pathophysiologic metabolic processes in the preterm gut, reflect a complex interplay between the human host, the environment, and microbiota. Disease-associated fecal VOCs can be detected with an array of devices with various potential for the development of a point-of-care test (POCT) for preclinical LOS detection. While characteristic VOCs for common LOS pathogens have been described, their VOC profiles often overlap with other pathogens due to similarities in metabolic pathways, hampering the construction of species-specific profiles. Clinical studies have, however, successfully discriminated LOS patients from healthy individuals using fecal VOC analysis with the highest predictive value for Gram-negative pathogens. This review discusses the current advancements in the development of a non-invasive fecal VOC-based POCT for early diagnosis of LOS, which may potentially provide opportunities for early intervention and targeted treatment and could improve clinical neonatal outcomes. Identification of confounding variables impacting VOC synthesis, selection of an optimal detection device, and development of standardized sampling protocols will allow for the development of a novel POCT in the near future.

Stability of volatile organic compound metabolites in urine at various storage temperatures and freeze-thaw cycles for 8 months

The urinary concentrations of mercapturic acid metabolites of volatile organic compounds (VOCs) have been used as biomarkers of human exposure to this class of chemicals. However, long-term stability of these VOC metabolites (VOCMs) in urine at various storage conditions such as temperature, duration, and freeze-thaw cycles is not known. In this study, spot urine samples collected from three volunteers, stored at 22 °C (room temperature: RT), 4 °C (refrigerator) and -20 °C (freezer) for up to 240 days were analyzed at weekly to monthly interval for a total of 19 time points. Samples stored at 4 °C and -20 °C underwent 18 freeze-thaw cycles at RT for 30 min at each of the time points. Among 38 VOCMs analyzed, up to 18 metabolites were detected at concentrations above their respective detection limits on Day 0 (baseline concentration), and the concentrations of several VOCMs declined with the storage duration. Eight to ten VOCMs were lost completely within 240 days of storage at RT, compared to between two and five at 4 °C and between one and seven at -20 °C. The loss rate varied depending on the sample, storage temperature, VOCM, and number of freeze-thaw cycles. Storage of urine at RT led to a rapid loss of VOCMs in comparison to that stored at 4 °C or -20 °C. Among VOCMs measured, CEMA, SBMA, GAMA, DHBMA, AMCC, TCVMA, and HPMMA were lost more rapidly than the other metabolites. CMEMA, a major VOCM found in all three urines at baseline, exhibited a rapid loss in those of two volunteers but not of the other volunteer, suggesting sample to sample variation in lose rates. Freeze-thaw cycles considerably affected VOCM concentrations in urines stored at 4 °C or -20 °C. It is recommended that urine samples are analyzed for VOCMs within a couple of months of collection and stored at temperatures below -20 °C, with minimal or no freeze-thaw cycles. This study highlights the need for appropriate storage conditions to maintain the integrity of samples for biomonitoring studies.

Volatile organic compounds: A threat to the environment and health hazards to living organisms - A review

Volatile organic compounds (VOCs) are the organic compounds having a minimum vapor pressure of 0.13 kPa at standard temperature and pressure (293 K, 101 kPa). Being used as a solvent for organic and inorganic compounds, they have a wide range of applications. Most of the VOCs are non-biodegradable and very easily become component of the environment and deplete its purity. It also deteriorates the water quality index of the water bodies, impairs the physiology of living beings, enters the food chain by bio-magnification and degrades, decomposes and manipulates the physiology of living organisms. To unveil the adverse impacts of volatile organic compounds (VOCs) and their rapid eruption and interference in the living world, a review has been designed. This review presents an insight into the currently available VOCs, their sources, applications, sampling methods, analytic procedures, imposition on the health of aquatic and terrestrial communities and their contamination of the environment. Elaboration has been done on representation of toxicological effects of VOCs on vertebrates, invertebrates, and birds. Subsequently, the role of environmental agencies in the protection of environment has also been illustrated.

Chemical, ecotoxicological, cytotoxic, and mutagenic evaluation of gelling agents used in the production of 70% alcohol gel

With COVID-19, there has been an increase in the use of gelling agents for hand sanitizer production, and as a result, the release of this product into wastewater could induce impacts and adverse reactions in living organisms. Thus, ecotoxicological and cytotoxicological assessments of gelling agents with test organisms from different trophic levels are necessary to assess their environmental safety. For this, seven cellulose-based gelling agents and a polyacrylic acid derivative (C940) were selected for tests with Artemia salina. The most toxic agent was tested on Allium cepa to assess cytotoxicity. The volatile compounds of the gelling agents were analyzed. Cellulose-based gelling agents were not considered toxic according to their LC50, but C940 presented moderate toxicity to A. salina and cytotoxicity to Allium cepa, but without mutagenicity. In addition, C940 contained cyclohexane as a volatile compound. Thus, cellulose-based gelling agents are better environmental options than carbomer for 70% alcohol gel sanitizer.

Toxicity of chemical-based hand sanitizers on children and the development of natural alternatives: a computational approach

The unintended exposure of children to hand sanitizers poses a high risk of potentially fatal complications. Skin irritation, dryness, cracking, peeling, hypoglycemia, apnea, and acidosis are examples of unintended consequences of hand sanitizer. The sanitizer reportedly kills normal microbial flora on hands, which usually promotes innate immunity among children under 12. Children are more susceptible to the toxicity associated with the chemical constituents of marketed chemical-based hand sanitizers; however, the studies to develop sanitizer formulations for children are rudimentary. The adverse events limit the use of hand sanitizers specifically in children because of their sensitive and delicate skin. Additionally, it is reported that many chemical-based hand sanitizer formulations, especially alcohol-based ones may also contain contaminants like methanol, acetaldehyde, benzene, isopropanol, and ethyl-acetate. These contaminants are found to be hazardous to human health exhibiting toxicity on ingestion, inhalation, or dermal exposure, especially in children. Therefore, it is important to design novel, innovative, safer sanitizer formulations for children. The study aims to discuss the toxic contaminants in chemical-based sanitizer formulations and propose a design for novel herbal formulations with minimal toxicity and adverse effects, especially for children. The review focuses on ADMET analysis of the common contaminants in hand sanitizers, molecular docking, Lipinski's rule of five analysis, and molecular simulation studies to analyze the efficacy of interaction with the receptor leading to anti-microbial activity and drug-likeness of the compound. The in silico methods can effectively validate the potential efficacy of novel formulations of hand sanitizers designed for children as an efficient alternative to chemical-based sanitizers with greater efficacy and the absence of toxic contaminants.

Adult-Onset Transcriptomic Effects of Developmental Exposure to Benzene in Zebrafish (Danio rerio): Evaluating a Volatile Organic Compound of Concern

Urban environments are afflicted by mixtures of anthropogenic volatile organic compounds (VOCs). VOC sources that drive human exposure include vehicle exhaust, industrial emissions, and oil spillage. The highly volatile VOC benzene has been linked to adverse health outcomes. However, few studies have focused on the later-in-life effects of low-level benzene exposure during the susceptible window of early development. Transcriptomic responses during embryogenesis have potential long-term consequences at levels equal to or lower than 1 ppm, therefore justifying the analysis of adult zebrafish that were exposed during early development. Previously, we identified transcriptomic alteration following controlled VOC exposures to 0.1 or 1 ppm benzene during the first five days of embryogenesis using a zebrafish model. In this study, we evaluated the adult-onset transcriptomic responses to this low-level benzene embryogenesis exposure (n = 20/treatment). We identified key genes, including col1a2 and evi5b, that were differentially expressed in adult zebrafish in both concentrations. Some DEGs overlapped at the larval and adult stages, specifically nfkbiaa, mecr, and reep1. The observed transcriptomic results suggest dose- and sex-dependent changes, with the highest impact of benzene exposure to be on cancer outcomes, endocrine system disorders, reproductive success, neurodevelopment, neurological disease, and associated pathways. Due to molecular pathways being highly conserved between zebrafish and mammals, developmentally exposed adult zebrafish transcriptomics is an important endpoint for providing insight into the long term-effects of VOCs on human health and disease.

Occurrence of and dermal exposure to benzene, toluene and styrene in sunscreen products marketed in the United States

Occurrence of volatile organic compounds (VOCs) such as benzene in personal care products is a topic of public health concern. Sunscreen products are extensively used to protect skin and hair from UV radiation from sun light. Nevertheless, little is known about exposure doses and risks of VOCs present in sunscreens. In this study, we determined the concentrations of and exposure to three VOCs, namely benzene, toluene and styrene, in 50 sunscreen products marketed in the United States. Benzene, toluene and styrene were found in 80 %, 92 % and 58 %, respectively, of the samples analyzed at mean concentrations of 45.8 ng/g (range: 0.007-862), 89.0 ng/g (range: 0.006-470) and 161 ng/g (range: 0.006-1650), respectively. The mean dermal exposure doses (DEDs) to benzene, toluene and styrene of children/teenagers were 68.3, 133 and 441 ng/kg-bw/d, respectively, whereas those of adults were 48.7, 94.6 and 171 ng/kg-bw/d, respectively. The lifetime cancer risk from benzene concentrations present in 22 sunscreen products (44 % of the samples) for children/teenagers and 19 sunscreen products (38 %) for adults, exceeded the acceptable benchmark risk level (1.0 × 10-6). This is the first study to comprehensively assess the concentrations of and risks to benzene, toluene and styrene present in sunscreen products.

Urinary metabolites of multiple volatile organic compounds among pregnant women across pregnancy: Variability, exposure characteristics, and associations with selected oxidative stress biomarkers

Volatile organic compounds (VOCs) are a group of pollutants pervasive in daily life with identified adverse health effects. However, no study has investigated the variability in VOC metabolites during pregnancy and their relationships with oxidative stress biomarkers in pregnant women. In the present study, the variability of 21 selected VOC metabolites was examined and their relationships with three selected oxidative stress biomarkers measured in spot urine samples at three trimesters of 1094 pregnant women were analyzed. Nineteen VOC metabolites were ubiquitous in the urine samples with detection rates ranging from 75.9% to 100%. Monohydroxybutenyl mercapturic acid (MHBMA) and s-phenyl mercapturic acid (PMA) had detection rates lower than 1.00%. Intraclass correlation coefficients (ICCs) of the detected analytes at three trimesters ranged 0.07-0.24, and the concentrations were highest in the first trimester. Higher concentrations of some VOC metabolites were related with participant characteristics including higher pre-pregnancy body mass index (BMI), lower education level, unemployment during pregnancy, multiparity, and sampling season of summer or winter. In repeated cross-sectional analyses, interquartile range (IQR) increases in the 19 detected VOC metabolites were positively related with 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), and 4-hydroxy nonenal mercapturic acid (HNEMA) with the estimates ranging from 9.00% to 204%. The mixture effect of the VOC metabolites on the oxidative stress biomarkers was further assessed using weighted quantile sum regression (WQS) models and the results showed that the WQS index of VOC metabolite mixture was significantly associated with 8-OHdG (β: 0.37, 0,32, and 0.39 at the 1st, 2nd, and 3rd trimester, respectively), 8-OHG (0.38, 0.32, and 0.39) and HNEMA (1.21, 1.08, and 1.10). Glycidamide mercapturic acid (GAMA), and trans,trans-muconic acid (MU) were the strongest contributors of the mixture effect on 8-OHdG, 8-OHG, and HNEMA, respectively. Overall, urinary concentrations of the VOC metabolites during pregnancy were strongly associated with the oxidative stress biomarkers.

Occurrence, effects, and ecological risks of chemicals in sanitizers and disinfectants: A review

In response to the novel coronavirus referred to as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) – a virus that causes COVID-19 disease has led to wide use of sanitizers and disinfectants. This, in turn, triggered concerns on their potential deleterious effects to human health and the environment due to numerous chemicals incorporated in both product categories. Here, the current state of science regarding the occurrence and ecological effects of different classes of chemicals in these products (e.g., ultraviolent filters, fragrances, etc.) are summarized in different natural (e.g., rivers) and engineered (e.g., wastewater treatment plants) systems. Data collected in the literature suggests chemicals incorporated in sanitizers and disinfectants are present in the environment, and a large portion are toxic to fish, algae, and daphnia. Using the risk quotient approach based on occurrence data, we found eight chemicals that posed the highest risk to aquatic organisms in freshwater systems were benzalkonium chloride, 4-chloro-m-cresol, sodium ortho phenyl phenate, hydrogen peroxide, 1, 2-propanediol, 4-Methyl-benzilidine-camphor, ethylhexyl methoxy cinnamate, and octocrylene. Considering limited occurrence and effects information for most chemicals, further studies on environmental monitoring and potential consequences of long-term exposure in aquatic ecosystems are recommended.

Assessment of exposure to volatile organic compounds through urinary concentrations of their metabolites in pet dogs and cats from the United States

Volatile organic compounds (VOCs) are ubiquitous environmental pollutants, exposure to which is associated with birth defects, neurocognitive and reproductive impairments, and cancer. Little is known, however, about VOC exposure in pet dogs and cats, which represent sentinels for human exposure as well as having value as companion animals. In this study, we determined 38 VOC metabolites (VOCMs) in urine samples collected from 47 dogs and 42 cats from the Albany area of New York State. Seventeen (in cats) to twenty (in dogs) VOCMs were found at detection frequencies (DFs) above 60%. The creatinine-adjusted geometric mean (GM) concentrations of individual VOCMs ranged from 5.43 (EMA) to 761 μg/g (3HPMA) in dog urine and 0.824 (SBMA) to 278 μg/g (ATCA) in cat urine. The ∑20 VOCM concentration in dog urine was 2280 μg/g (geometric mean) and the ∑17 VOCM concentration in cat urine was 847 μg/g. Eight individual VOCMs were significantly more abundant in dog than in cat urine, and the urinary concentrations of several VOCMs in dogs were comparable to those reported for human tobacco smokers. Metabolites of acrolein accounted for 43% of ∑20 VOCM concentration in dogs, whereas those of cyanide and benzene accounted for 60% of ∑17 VOCM concentration in cats. Based on acrylamide exposure doses, calculated hazard quotients were above 1 in 77% of dogs and 50% of cats studied, and cancer risk values (using a benchmark of 10^-6) from exposure to acrylamide exceeded 1 for all dogs and cats. This is the first study to report VOCM concentrations in urine collected from pet dogs and cats and highlights the need to identify sources and health implications of VOCs exposure in these animals.

Evaluation of the Safety and Efficacy of Hand Sanitizer Products Marketed to Children Available during the COVID-19 Pandemic

Hand sanitizer use in the United States (U.S.) increased after the SARS-CoV-2 outbreak. The U.S. Food and Drug Administration (FDA) released temporary manufacturer guidance, changing impurity level limits for alcohol-based hand sanitizers (ABHSs). Since the guidance took effect, the FDA has recommended against using these hand sanitizers due to concerns over safety, efficacy, and/or risk of incidental ingestion. To address current gaps in exposure characterization, this study describes a survey of ABHSs marketed to children available in the U.S., as defined by several inclusion criteria. A subset of ABHSs (n = 31) were evaluated for ethanol and organic impurities using a modified FDA method. Products with detectable impurity levels were compared to the FDA's established interim limits. Seven children's products had impurity levels exceeding the FDA's recommended interim limits, including benzene (up to 9.14 ppm), acetaldehyde (up to 134.12 ppm), and acetal (up to 75.60 ppm). The total measured alcohol content ranged from 52% to 98% in all hand sanitizers tested, ranging from 39% below, and up to 31% above, the labeled concentration. Future studies should confirm impurity contamination sources. A risk assessment could determine whether dermal application or incidental ingestion of impurity-containing hand sanitizers pose any consumer risk.

Relationship between styrene exposure and prolactin secretion in human and animal studies: A systematic review

Styrene is widely used in industrial applications. Inhalation exposure occurs in the industry. Some studies indicated that serum prolactin concentrations increased after exposure to styrene, while other studies found no change. In this systematic review, the search was done with the keywords styrene and prolactin in the PubMed, Science Direct, Web of Science and Scopus databases, regardless of the publication period. 118 studies were obtained and only seven articles were finally selected according to exclusion and inclusion criteria. The effect of styrene on prolactin secretion was selected in both human and animal studies. The increased response was seen in inhalation exposures. Subcutaneous exposure has no significant effect on prolactin levels. The observed responses were both dose-dependent and gender-dependent. Changes in serum prolactin were more frequent in women compared to exposed men. Dopamine depletion was not observed in all studies, so more tests on laboratory animals are necessary to clarify the possible mechanism.