Volatile Organic Compounds Exposure Research Articles

Evaluating Phenotypic and Transcriptomic Responses Induced by Low-Level VOCs in Zebrafish: Benzene as an Example.

Urban environments are plagued by complex mixtures of anthropogenic volatile organic compounds (VOCs), such as mixtures of benzene, toluene, ethylene, and xylene (BTEX). Sources of BTEX that drive human exposure include vehicle exhaust, industrial emissions, off-gassing of building material, as well as oil spillage and leakage. Among the BTEX mixture, benzene is the most volatile compound and has been linked to numerous adverse health outcomes. However, few studies have focused on the effects of low-level benzene on exposure during early development, which is a susceptible window when hematological, immune, metabolic, and detoxification systems are immature. In this study, we used zebrafish to conduct a VOC exposure model and evaluated phenotypic and transcriptomic responses following 0.1 and 1 ppm benzene exposure during the first five days of embryogenesis (n = 740 per treatment). The benzene body burden was 2 mg/kg in 1 ppm-exposed larval zebrafish pools and under the detection limit in 0.1 ppm-exposed fish. No observable phenotypic changes were found in both larvae except for significant skeletal deformities in 0.1 ppm-exposed fish (p = 0.01) compared with unexposed fish. Based on transcriptomic responses, 1 ppm benzene dysregulated genes that were implicated with the development of hematological system, and the regulation of oxidative stress response, fatty acid metabolism, immune system, and inflammatory response, including apob, nfkbiaa, serpinf1, foxa1, cyp2k6, and cyp2n13 from the cytochrome P450 gene family. Key genes including pik3c2b, pltp, and chia.2 were differentially expressed in both 1 and 0.1 ppm exposures. However, fewer transcriptomic changes were induced by 0.1 ppm compared with 1 ppm. Future studies are needed to determine if these transcriptomic responses during embryogenesis have long-term consequences at levels equal to or lower than 1 ppm.

Handheld two-stroke engines as an important source of personal VOC exposure for olive farm workers.

Personal exposure to volatile organic compounds (VOCs) is mainly associated with indoor exposures; however, elevated short-term exposures may also occur during ambient activities. Handheld two-stroke gasoline-powered engines have widespread use in agriculture, but so far, no studies have been conducted on the potential health risks due to the inhalation of emitted VOCs. A one-week passive sampling has been conducted on olive farm workers during the harvesting season to monitor personal exposure levels to VOCs. The first group of workers was selected to represent the contribution of gasoline-powered shaker to daily personal VOC exposures, and one another group of workers was selected as the control, whose have not been using the device. Higher concentrations of 1-pentene, n-hexane, isopentane, n-pentene, and toluene were observed in personal samples collected from machine operators. Personal exposure concentrations of a total of 45 monitored VOCs varied between 29.2 ± 10.7 and 3733.4 ± 3300.1µgm-3 among 20 volunteer workers. Estimated carcinogenic risks were between the acceptable levels of 10-4 and 10-6 for all workers. All individual chronic HQs and HIs (as the sum of individual HQs) were below the benchmark value of 1 for regular workers in 3 different sampling sites, whereas HI values in both acute (short term) and chronic exposure scenarios were exceeded 1 for shaker machine operators. This represented potential non-carcinogenic health hazards for exposed shaker operators, along with elevated VOCs.

Exposure and health risk assessment of indoor volatile organic compounds in a medical university

Many volatile organic compounds (VOCs) are used for experiments at universities, and most of them contain benzene, toluene, ethylbenzene, xylene, and an extraction solvent of dichloromethane. This study aimed to investigate the indoor concentrations of these five compounds in different locations on campus and to evaluate possible health risks for faculty members and students in a medical university. We selected 10 locations as sampling sites to conduct 4-h monitoring sessions on weekdays each season during 2019–2020. We used a 6-liter canister to collect air samples and analyzed these five VOCs via gas chromatography with a flame ionization detector. Monte Carlo simulation was performed to evaluate the carcinogenic and noncarcinogenic risks of these five VOCs. We found that dichloromethane was the most highly detected compound (median: 621.07 μg/m3; range: 44.01–8523.91 μg/m3), and the Department of Medicine had the highest concentration of the total of these VOCs among all of the locations (median: 5595.29 μg/m3; range: 1565.67–7398.66 μg/m3). The median carcinogenic risks of dichloromethane and benzene were 6.36 × 10−5 (95% confidence interval [CI]: 6.83 × 10−6−7.37 × 10−4) and 5.47 × 10−6 (95% CI: 4.03 × 10−7−2.42 × 10−5), respectively, for faculty members, and the lower risks of 3.14 × 10−5 (95% CI: 3.39 × 10−6−3.64 × 10−4) and 2.69 × 10−6 (95% CI: 1.97 × 10−7−1.19 × 10−5) were estimated for the students. The chronic noncarcinogenic risks of four VOCs were less than one, except for dichloromethane with a median hazard index of 1.92 (95% CI: 2.11 × 10−1−2.22 × 101). This study observed the spatial variation in the concentrations of the total of five VOCs and dichloromethane. The carcinogenic risks were classified as being at the possible level, and the noncarcinogenic risk of dichloromethane was greater than the acceptable level. Increasing local exhaust ventilation during the experiment and reducing the using amount of dichloromethane are recommended actions to reduce VOCs exposures in the medical university.

1309-P: Central Mechanisms of Pollution-Induced Metabolic Disease

There is growing evidence linking exposure to volatile organic compounds (VOC) in ambient air with metabolic disease in humans. Benzene is a prominent VOC present in water, food, detergents, vehicle exhaust, tobacco smoke, and e-cigarettes. However, a direct link between exposure to VOC and metabolic homeostasis is not yet established. We performed a meta-analysis and found a positive association between exposure to VOC and metabolic impairments. Using a highly controlled mouse exposure system, we have recently demonstrated that chronic exposure of mice to VOC induces neuroinflammation and insulin resistance predisposing to T2D. To establish a timeline for the onset of VOC-triggered metabolic effects, we monitored glucose changes of exposed mice using continuous glucose monitoring (CGM) system. Surprisingly, we detected significant changes in glycemic control of male mice starting at day 4 of exposure. Further, mice exhibited impaired parameters of energy homeostasis within 6h of exposure. This was associated with activation of hypothalamic gliosis via stimulation of the NF-κB signaling and dysregulation of hypothalamic insulin signaling, contributing to blunted responses to glucose stimulation in glucose-sensing neurons. To determine the role of the central inflammatory mechanism in VOC-induced metabolic imbalance, we genetically ablated NF-κB signaling in microglia using Cx3cr1creERΔIKK mice. Selective inhibition of microglial NF-κB signaling completely restored hypothalamic insulin signaling, astrocytes activation, and hypothalamic glucose-sensing, consequently protecting from whole-body metabolic imbalance induced by VOC exposure. Importantly, this effect was mediated via hypothalamic ER stress response. Collectively, our data provide evidence that neuroinflammatory responses precede and mechanistically contribute to whole-body metabolic imbalance and identify air pollution-induced cellular and molecular targets in the hypothalamus that lead to metabolic disease. Disclosure L.K.Debarba: n/a. L.Koshko: None. H.M.Jayarathne: None. Z.Yi: None. U.Klueh: Research Support; Dexcom, Inc. M.Sadagurski: None. Funding American Diabetes Association (1-18-JDF-063)

A study on human perception in aircraft cabins and its association with volatile organic compounds

More than 8 million people fly on commercial aircraft each day with approximately 5% having a pre-existing respiratory disease. Thus it is necessary to provide high air quality in aircraft to protect public health. Volatile organic compounds (VOCs) present in aircraft cabins are suspected to contribute to the reported complaints. We investigated concentrations of VOCs, air temperature, relative humidity, and CO2 concentrations in a total of 46 flights, including 26 Chinese domestic flights and 20 international flights. We focused on the data from the cruising phase without meal serving in which the air supply and air recirculation were steady. A total of 284 passengers (i.e., 101 on international flights and 183 on Chinese domestic flights) were invited to participate in questionnaire surveys in this phase. We performed a linear mixed model analysis by controlling for potential confounders (age, gender, smoke habits, and history of allergy) to study associations between VOCs exposures and passengers' complaints. Xylene was significantly associated with irritations of the eyes, nose, and throat on both international and domestic flights, with antilog beta values from 1.12 to 1.28 (p < 0.05). The association of some aldehydes (i.e., nonanal, decanal, and heptanal), which are potential oxidation products with ozone, with passengers’ sensory irritations was also significant, especially during international flights (antilog beta values: 1.19–1.22). It indicates that VOCs, especially xylene and aldehydes, in aircraft cabins may influence the perceived indoor air quality and complaints among passengers.

Health risk analysis from volatile organic compounds and fine particulate matter in the printing industry.

The association between the printing activity and the pollutant exposure of the workers was investigated in five consecutive working days, during 8 h work shift per day. Exposure concentrations of the total volatile organic compound and fine particulate matter were measured in the four voluntary printing factories in Thailand. Two types of the printing process, offset and digital printing, were compared. The 8 h average of particulate matter 2.5 in the field blank, Offset A, Offset B, Offset C printing and Digital printing D was 7.46, 21.51, 44.26, 77.92, and 42.08 µgm−3, respectively. The highest particulate matter level in the Offset printing C, 77.92 µgm−3 was due to the surrounded paper dust in the area. The 8 h average of total volatile organic compounds in field blank, Offset A, Offset B, Offset C printing and Digital printing D was 0.12, 2.68, 5.02, 21.86, and 0.67 ppm, respectively. The highest total volatile organic compound was 21.86 ppm in the Offset printing C because of the high production rate and the application of organic solvents in the cleanup process. Worker's exposure to total volatile organic compound and particulate matter 2.5 in the offset printings was higher than in the digital laser printing. From the health risk evaluation, the workers in offset printings were at risk from total volatile organic compound exposure, Hazard quotient > 1. However, workers exposed to particulate matter exposures were not at risk, Hazard quotient < 1.Graphic abstract

Exposure to polycyclic aromatic hydrocarbons and volatile organic compounds is associated with a risk of obesity and diabetes mellitus among Korean adults: Korean National Environmental Health Survey (KoNEHS) 2015-2017.

Environmental pollutants have been known to increase the risks of not only respiratory and cardiovascular disease but also metabolic diseases such as obesity and diabetes mellitus (DM). Polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) such as benzene and toluene are major constituents of environmental pollution. In the present study, we employed the population of the Korean National Environmental Health Survey (KoNEHS) Cycle 3 conducted between 2015 and 2017, and assessed the associations of urinary biomarkers for PAHs and VOCs exposure with obesity and DM. A total of 3787 adult participants were included and the urinary concentrations of four PAH metabolites and two VOC metabolites were measured. For correcting urine dilution, a covariate-adjusted standardization method was used. The highest quartiles of urinary 2-hydroxynaphthalene (2-NAP) [OR (95% confidence interval (CI))=1.46 (1.13, 1.87)] and sum of PAH metabolites [OR (95% CI)=1.45 (1.13, 1.87)] concentrations were associated with a higher risk of obesity [body mass index (BMI)≥25kg/m2]. BMI was positively associated with urinary 2-NAP [β (95% CI)=0.25 (0.09, 0.41), p=0.003] and sum of PAH metabolites [β (95% CI)=0.29 (0.08, 0.49), p=0.006] concentrations. The risk of DM was increased with increasing quartile of 2-hydroxyfluorene (2-OHFlu) and trans, trans-muconic acid (t,t-MA) (p for trend<0.05 and<0.001, respectively). The highest quartile of t,t-MA showed a significantly higher risk of DM [OR (95% CI)=2.77 (1.74, 4.42)] and obesity [OR (95% CI)=1.42 (1.06, 1.90)]. Urinary t,t,-MA level was positively associated with BMI [(β (95% CI)=0.51 (0.31, 0.71), p<0.001] and non-alcoholic fatty liver disease index [(β (95% CI)=0.09 (0.06, 0.12), p<0.001]. In conclusion, the benzene metabolites t,t-MA and PAH metabolite 2-OHFlu were associated with an increased risk of DM. Urinary biomarkers for PAHs and VOCs were positively associated with BMI in the Korean adult population. Further studies to validate these observations in other populations are warranted.

Health risk assessment of volatile organic compounds exposure among nail salon workers in Vietnam

Purpose The objective of this study is to assess the carcinogen and non-carcinogen risks due to exposure to volatile organic compounds including methyl methacrylate (MMA), benzene, toluene, and xylene among Vietnamese nail salon workers, using probabilistic health risk assessment. Methods This study applied the probabilistic health risk assessment framework to assess the health risk due to exposure to four types of volatile organic compounds among nail salon workers. Forty-two passive personal samples of full-shift female nail workers from 15 salons in Da Nang city were monitored and analyzed by GC-FID in the Thammasat laboratory. Exposure parameters were collected by interviewing nail salon workers. Monte Carlo simulation was used to characterize the risk and its uncertainty. Results The mean of concentrations of MMA, benzene, toluene, and xylene were 20.62, 0.21, 2.49, and 0.58 mg m−3, respectively. The 95th percentile hazard quotients calculated for MMA, benzene, toluene, and xylene were 33.14, 7.49, 0.54, and 2.07, respectively. The 95th percentile lifetime cancer risk for benzene was 198 times higher than the EPA recommendation for cancer risk (10−6). Conclusions Non-cancer risks from exposure to MMA, benzene, and xylene were many times higher than the acceptable limit, which indicated a possible risk of adverse health effects among nail salon workers. Nail salon workers may also be at risk of leukemia or cancer of the blood-forming organs because the cancer risk due to exposure to benzene is higher than the recommended level.

The Association between Exposure to Residential Indoor Volatile Organic Compounds and Measures of Central Arterial Stiffness in Healthy Middle-Aged Men and Women.

It is well reported that individuals spend up to 90% of their daily time indoors, with between 60% to 90% of this time being spent in the home. Using a cross-sectional study design in a population of 111 healthy adults (mean age: 52.3 ± 9.9 years; 65% women), we investigated the association between exposure to total volatile organic compounds (VOCs) in indoor residential environments and measures of central arterial stiffness, known to be related to cardiovascular risk. Indoor VOC concentrations were measured along with ambulatory measures of pulse pressure (cPP), augmentation index (cAIx) and cAIx normalized for heart rate (cAIx75), over a continuous 24-h period. Pulse wave velocity (cfPWV) was determined during clinical assessment. Multiple regression analysis was performed to examine the relationship between measures of arterial stiffness and VOCs after adjusting for covariates. Higher 24-h, daytime and night-time cAIx was associated with an interquartile range increase in VOCs. Similar effects were shown with cAIx75. No significant effects were observed between exposure to VOCs and cPP or cfPWV. After stratifying for sex and age (≤50 years; >50 years), effect estimates were observed to be greater and significant for 24-h and daytime cAIx in men, when compared to women. No significant effect differences were seen between age groups with any measure of arterial stiffness. In this study, we demonstrated that residential indoor VOCs exposure was adversely associated with some measures of central arterial stiffness, and effects were different between men and women. Although mechanistic pathways remain unclear, these findings provide a possible link between domestic VOCs exposure and unfavourable impacts on individual-level cardiovascular disease risk.

Recent progress on MOF-based optical sensors for VOC sensing.

The raising apprehension of volatile organic compound (VOC) exposures urges the exploration of advanced monitoring platforms. Metal-organic frameworks (MOFs) provide many attractive features including tailorable porosity, high surface areas, good chemical/thermal stability, and various host-guest interactions, making them appealing candidates for VOC capture and sensing. To comprehensively exploit the potential of MOFs as sensing materials, great efforts have been dedicated to the shaping and patterning of MOFs for next-level device integration. Among different types of sensors (chemiresistive sensors, gravimetric sensors, optical sensors, etc.), MOFs coupled with optical sensors feature distinctive strength. This review summarized the latest advancements in MOF-based optical sensors with a particular focus on VOC sensing. The subject is discussed by different mechanisms: colorimetry, luminescence, and sensors based on optical index modulations. Critical analysis for each system highlighting practical aspects was also deliberated.

Boosting VOCs elimination by coupling different techniques

Volatile Organic Compounds (VOCs) are known to be hazardous and harmful to human health and the environment. In mixtures or during repeated exposures, significant toxicity of these compounds in trace amounts has been revealed. In vitro air-liquid interface approaches underlined the interest in evaluating the impact of repeated VOC exposure and the importance of carrying out a toxicological validation of the techniques in addition to the standard chemical analyses. The difficulties in sampling and measuring VOCs in stationary source emissions are due to both the complexity of the mixture present and the wide range of concentrations. The coupling of VOC treatment techniques results in efficient systems with lower operating energy consumption. Three main couplings are outlined in this review, highlighting their advantages and relevance. First, adsorption-catalysis coupling is particularly valuable by using adsorption and catalytic oxidation regeneration initiated, for example, by selective dielectric heating. Then, several key aspects of the plasma catalysis process, such as the choice of catalysts suitable for the non-thermal plasma (NTP) environment, the simultaneous removal of different VOCs, and the in situ regeneration of the catalyst by NTP exposure, are discussed. The adsorption-photocatalysis coupling technology is also one of the effective and promising methods for VOC removal. The VOC molecules strongly adsorbed on the surface of the photocatalyst can be directly oxidized by the photogenerated hole on the photocatalyst (e.g., TiO2).

Paper-Based Wearable Sensors for Humidity and VOC Detection

Acceptable indoor air quality is a concern for the comfort and health of humans, in which the 40–70% of relative humidity (RH) is comfortable for the human body and the existence of volatile organic compounds (VOCs) may be harmful for our health. Therefore, the development of wearable sensors that can monitor the RH and VOCs in real time is highly desired. In this work, a mixture of conductive carbon black and exfoliated graphene was dip-coated on filter paper to easily fabricate a paper-based flexible sensor, which can detect RH in the range of 33–95% and VOCs including methanol (MeOH), ethanol (EtOH), toluene (PhMe), dichloromethane (DCM), acetone, and petroleum ether (PE) with relatively short response time. The device can be used to monitor the indoor RH and human breath under various conditions. It also can work as a sensitive and quick-response alarm for the VOC exposure. Furthermore, this flexible sensor is disposable by ultrasonic treatment without producing hazardous residues, thus considered as an environment-friendly electronic. This versatile and green flexible electronic device may find applications in wearable air monitoring devices and health care.

Volatile-mediated plant-plant interactions: volatile organic compounds as modulators of receiver plant defence, growth, and reproduction.

It is firmly established that plants respond to biotic and abiotic stimuli by emitting volatile organic compounds (VOCs). These VOCs provide information on the physiological status of the emitter plant and are available for detection by the whole community. In the context of plant-plant interactions, research has focused mostly on the defence-related responses of receiver plants. However, responses may span hormone signalling and both primary and secondary metabolism, and ultimately affect plant fitness. Here we present a synthesis of plant-plant interactions, focusing on the effects of VOC exposure on receiver plants. An overview of the important chemical cues, the uptake and conversion of VOCs, and the adsorption of VOCs to plant surfaces is presented. This is followed by a review of the substantial VOC-induced changes to receiver plants affecting both primary and secondary metabolism and influencing plant growth and reproduction. Further research should consider whole-plant responses for the effective evaluation of the mechanisms and fitness consequences of exposure of the receiver plant to VOCs.

Diurnal variability in urinary volatile organic compound metabolites and its association with oxidative stress biomarkers

Volatile organic compounds (VOCs) are ubiquitous environmental pollutants that are associated with birth defects, leukemia, neurocognitive deficits, reproductive impairment and cancer in humans exposed to these compounds. Exposure to VOCs can be assessed by measuring their metabolites in urine. Little is known, however, about the temporal variability in urinary VOC metabolite (VOCM) concentrations within- and between-individuals. In this study, we determined the variability in the concentrations of 38 VOCMs in urine samples collected from 19 healthy individuals across a period of 44 days. We also measured seven biomarkers of oxidative stress (lipid, protein and DNA damage) in urine to assess the relationship of VOC exposure to oxidative stress. Seventeen VOCMs had detection frequencies (DFs) of >60% in urine, and we limited further data analysis to those compounds. The creatinine-adjusted geometric mean concentrations of VOCMs ranged from 2.70 μg/g to 327 μg/g in spot and 2.60 μg/g to 551 μg/g in first morning void (FMV) urine samples. Calculation of the intra-class correlation coefficients (ICCs) for 17 VOCM concentrations to assess their predictability and repeatability in urinary measurements showed ranges of 0.080–0.425 in spot and 0.050–0.749 in FMV urine samples, revealing notable within-individual variability. Our results suggest that taking only single measurements of VOCM concentrations in urine in epidemiological investigations may lead to exposure misclassification. In addition, VOCM concentrations were significantly and positively correlated with oxidative stress biomarkers. This study thus provides important information for formulating sampling strategies in the biomonitoring of VOC exposure in human populations.

Occupational exposure to hazards and volatile organic compounds in small-scale plastic recycling plants in Thailand by integrating risk and life cycle assessment concepts

Plastic waste recycling is gaining momentum as a means to promote a sustainable measure and circular economy. Most developing countries are facing significant challenges associated with recycling practices. In Thailand, 90% of the plastic recycling businesses are categorized as small-scale enterprises. There is still a dearth of research on health risk assessments associated with indoor exposure in small-scale waste recycling. This research aims to apply a holistic approach of integrated health risk and life cycle assessment concepts in investigating occupational exposure to all potential hazards in small-scale polyethylene (PE) and polypropylene (PP) recycling plants in Thailand. The results indicated that all exposure levels of heat stress in wet bulb globe temperature in the melting/extrusion stage exceeded the Thai and global Occupational safety and health (OSH) threshold limits for workers with heavy workloads. For workers’ exposure to volatile organic compounds (VOCs), the average total VOCs concentrations emitted from PP and PE recycling were 1625 μg/m3 and 1190 μg/m3, respectively. Hexane and toluene were remarkably found in the extrusion process. The non-cancer hazard quotients (HQs) and hazard indices (HIs) were higher in PP than in PE. The adverse non-cancer risks were concerned in plants that recycle only PP wastes at full capacity (100%) loaded operation (HQs and HIs >1). Recycling facility concentrating more on PE recycling tends to reduce risk to workers. By integrating the revised one box model into the life cycle impact assessment, the results demonstrate that the health impact from indoor VOCs exposure due to the production of 1 kg of recycled PP or PE resin was significantly greatest. Workers in the extrusion process were considered at higher risk of exposure to VOCs and heat. This research makes important contributions to the literature by providing insights into environmental health management and implications for cleaner production in plastic waste recycling. The promotion of effective engineering controls and development of collaborative circular business models in plastic waste recycling sector were highly recommended to increase resource efficiency and promote sustainable production patterns.

Associations Between Residential Exposure to Volatile Organic Compounds and Liver Injury Markers.

Occupational exposures to volatile organic compounds (VOCs) have been associated with numerous health complications including steatohepatitis and liver cancer. However, the potential impact of environmental/residential VOC exposures on liver health and function is largely unknown. To address this knowledge gap, the objective of this cross-sectional study is to investigate associations between VOCs and liver injury biomarkers in community residents. Subjects were recruited from six Louisville neighborhoods, and informed consent was obtained. Exposure biomarkers included 16 creatinine-adjusted urinary metabolites corresponding to 12 parent VOCs. Serological disease biomarkers measured included cytokertain-18 (K18 M65 and M30), liver enzymes, and direct bilirubin. Associations between exposure and disease biomarkers were assessed using generalized linear models. Smoking status was confirmed through urinary cotinine levels. The population comprised of approximately 60% females and 40% males; White persons accounted 78% of the population; with more nonsmokers (n = 413) than smokers (n = 250). When compared with nonsmokers, males (45%) and Black persons (26%) were more likely to be smokers. In the overall population, metabolites of acrolein, acrylonitrile, acrylamide, 1,3-butadiene, crotonaldehyde, styrene, and xylene were positively associated with alkaline phosphatase. These associations persisted in smokers, with the exception of crotonaldehyde, and addition of N,N-dimethylformamide and propylene oxide metabolites. Although no positive associations were observed for K18 M30, the benzene metabolite was positively associated with bilirubin, irrespective of smoking status. Taken together, the results demonstrated that selected VOCs were positively associated with liver injury biomarkers. These findings will enable better risk assessment and identification of populations vulnerable to liver disease.

Volatile organic compounds from second-hand smoke may increase susceptibility of children through oxidative stress damage

Although humans are generally exposed to second-hand smoke (SHS), volatile organic compounds (VOCs) exposure derived from SHS and its health hazard to non-smokers are rarely investigated. Thus, we examined the effects of SHS on VOCs exposure and oxidative stress damage via a passive smoking simulation experiment in 6 children and 7 adults. To further validate the studied urinary VOC metabolites as biomarkers for passive smoking, 259 children were recruited. The levels of 8-hydroxy-2′-deoxyguanosine (8-OHdG), malonaldehyde (MDA), trans-3′-hydroxycotinine (OH-Cot) and 31 VOC metabolites in urine were determined. The results showed that the geomean concentrations of 17 VOC metabolites in urine of children were 26.5%–138% higher than those of adults after passive smoking. The levels of urinary 8-OHdG, MDA and OH-Cot increased by 24.6%, 18.8% and 600% in children, but only 1.25%, 10.3% and 116% in adults, respectively. Therefore, children are more vulnerable to SHS than adults. After exposure to SHS, the levels of 8 urinary VOC metabolites of benzene, acrylonitrile, 1-bromopropane, propylene oxide, toluene, methyl methacrylate and cyanide increased by 60.9%–538% within 23 h. These 8 VOC metabolites were also significantly associated with 8-OHdG or MDA in urine (p < 0.01). Therefore, exposure to VOCs caused by SHS increases body oxidative stress damage. OH-Cot level higher than 2.00 μg/g Cr can be used as a threshold of passive smoking. The levels of urinary s-benzylmercapturic acid (BMA) and s-phenylmercapturic acid (PMA) in children increased by 494% and 728% within 6 h after passive smoking, respectively. Population validation study indicated that BMA and PMA levels were significantly elevated in children exposed to SHS. Therefore, in addition to OH-Cot, urinary BMA and PMA are potentially useful short-term biomarkers of passive smoking. Future studies should focus on the differences in VOC metabolism and detoxification mechanisms between children and adults.

Eight‐carbon volatiles are more toxic to wild‐type Drosophila melanogaster than to flies with blocked immune system mutations

AbstractPrevious work using a Drosophila melanogaster Meigen (Diptera: Drosophilidae) bioassay suggested that the innate immune response of the fly might contribute to the toxicity of certain fungal volatile organic compounds (VOCs). Here, we exposed wild‐type or immune‐deficient strains (NOS, Imd, and Toll) of Drosophila male adults to two concentrations (0.02 and 0.1 µmol ml‐1) of volatilized chemical standards of 1‐octen‐3‐ol, 3‐octanone, and 3‐octanol, and their viability was monitored for 24 h. All fly strains were killed within 2 h when exposed to 1‐octen‐3‐ol at 0.1 µmol ml‐1. The wild‐type, red‐eyed (OregonR) strain was more resistant to all three compounds at both concentrations than the white‐eyed strain (w1118) with wild‐type immune genes. Of the three compounds tested, 3‐octanol at 0.02 µmol ml‐1 was the least toxic to all Drosophila strains. Of the white‐eyed fly mutants, the NOS mutant was more resistant to VOC exposure than the white‐eyed strains carrying no defects in the immune system. The white‐eyed RelE20 (Imd) mutant flies were more susceptible to 0.02 µmol ml‐1 of 1‐octen‐3‐ol than the red‐eyed spz6 (Toll) mutants. Unexpectedly, the most resistant to the eight‐carbon (8‐C) volatiles was displayed by double mutant flies carrying blocked immune system mutations in both the Imd and Toll pathways (RelE20spz6). These data suggest that components of the wild‐type innate immune system of Drosophila are responsible for causing death in flies exposed to 8‐C volatiles.

Feminine Hygiene Products and Volatile Organic Compounds in Reproductive-Aged Women Across the Menstrual Cycle: A Longitudinal Pilot Study.

Background: Volatile organic compounds (VOCs) have been detected in feminine hygiene products (FHPs), especially in tampons and sanitary pads. However, little is known about whether menstrual products can contribute to VOC exposure in women. Our objectives were to: (1) examine the variations of urinary VOC concentrations during menstrual cycles; (2) evaluate the relationships between the use of menstrual products and urinary VOC concentrations; and (3) link urinary VOC concentrations to those measured in menstrual products. Methods: We measured urinary concentrations of 98 target VOCs in 25 reproductive-aged women with 100 repeated measures collected between October 2018 and February 2019. First-morning-void urine samples were collected four times for each woman during one menstrual cycle. Urinary VOC concentrations were measured using gas chromatography-mass spectroscopy. Results: Of 98 target VOCs measured in the urine samples, 36 VOCs were detected. We did not see statistically significant variations in VOC concentrations across the menstrual cycle. After multivariable adjustment, tampon users had significantly higher concentrations of 2-butanone (β = 1.58 log ng/g, 95% confidence interval [CI]: 0.16-3.00, p = 0.03) and methyl isobutyl ketone (β = 0.63 log ng/g, 95% CI: 0.03-1.22, p = 0.04), compared with pad users. Higher n-nonane, benzene, and toluene estimated from menstrual products were associated with higher urinary concentrations in women. Conclusion: The use of FHPs during menses might be a potential source of VOCs. A larger cohort study is warranted to confirm our results and evaluate clinical implications.

Effects of architecture structure on volatile organic compound and polycyclic aromatic hydrocarbon diffusion in Singapore's Integrated Transport Hubs

Millions of passengers wait for buses at Integrated Transport Hubs (ITH) daily in metropolitan cities. Environmental exposure and associated risk for passengers is of great public concern. In this study, eight volatile organic compounds (VOCs) and the 16 EPA priority polycyclic aromatic hydrocarbons (PAHs) were analyzed in airborne samples collected from indoor waiting areas (Indoor) and bus parks of nine Singapore ITH, which comprises of two types of architectural structure (i.e., fully sheltered and open/partially enclosed). The median concentrations of total VOCs (TVOCs), total gaseous PAHs (TgPAHs) and total airborne particles-adsorbed PAH (TpPAHs) concentrations in Indoor were 30.42 μg/m3, 18.99 ng/m3 and 1.38 ng/m3; respectively. A strong correlation (r ≥ 0.75, p < 0.001) was observed between Indoor and bus parks air compounds. The “Indoor” to bus park pollutant concentration ratio (I/B ratio) showed lower values in the bus interchanges with fully sheltered bus parks (TVOCs: 0.98; TgPAHs: 0.76; TpPAHs: 0.71) than those with open/partially enclosed ones (TVOCs: 1.28; TgPAHs: 1.31; TpPAHs: 0.90). This result suggests that fully sheltered structure may cause the accumulation of air pollutants. The daily VOC and PAH exposure for commuters were further estimated by considering inhalation and dermal doses using Monte Carlo simulation (n = 100,000). Overall, the result showed that the risk is still within international guideline values. In sum, the effect of architecture structure on the migration of air pollutants should be taken into consideration in future transport hub design to reduce pollutant exposure to commuters.