Volatile Exposure Research Articles

Assessing volatile organic compounds exposure and prostate-specific antigen: National Health and Nutrition Examination Survey, 2001-2010.

BackgroundVolatile organic compounds (VOCs) are a large group of chemicals widely used in people's daily routines. Increasing evidence revealed the VOCs' accumulating toxicity. However, the VOCs toxicity in male prostate has not been reported previously. Thus, we comprehensively evaluated the association between VOCs and prostate-specific antigen (PSA).MethodsA total of 2016 subjects were included in our study from the National Health and Nutrition Examination Survey with VOCs, PSA, and other variables among U.S. average population. We constructed XGBoost Algorithm Model, Regression Model, and Generalized linear Model (GAM) to analyze the potential association. Stratified analysis was used to identify high-risk populations.ResultsXGBoost Algorithm model identified blood chloroform as the most critical variable in the PSA concentration. Regression analysis suggested that blood chloroform was a positive association with PSA, which showed that environmental chloroform exposure is an independent risk factor that may cause prostate gland changes [β, (95% CI), P = 0.007, (0.003, 0.011), 0.00019]. GAM observed the linear relationship between blood chloroform and PSA concentration. Meanwhile, blood chloroform linear correlated with water chloroform in the lower dose range, indicating that the absorption of water may be the primary origin of chloroform. Stratified associations analysis identified the high-risk group on the chloroform exposures.ConclusionThis study revealed that blood chloroform was positively and independently associated with total PSA level, suggesting that long-term environmental chloroform exposure may cause changes in the prostate gland.

Tuning the sensing responses towards room-temperature hypersensitive methanol gas sensor using exfoliated graphene-enhanced ZnO quantum dot nanostructures

A suitable and non-invasive methanol sensor workable in ambient temperature conditions with a high response has gained wide interest to prevent detrimental consequences for industrial workers from its low-level intoxication. In this work, we present a tunable and highly responsive ppb-level methanol gas sensor device working at room temperature via a bottom-up synthetic approach using exfoliated graphene sheet (EGs) and ZnO quantum dots (QDs) on an aluminum anodic oxide (AAO) template. It is verified that EGs-supported AAO with a vertical electrode configuration enabled high and fast-responsive methanol sensing. Moreover, the hydroxyl and carboxyl groups of the high surface area EGs and ZnO QDs with a 3.37 eV bandgap efficiently absorbing UV light led to 56 times high response due to the enhanced polarization on the sensor surface compared to non-UV-radiated EGs/AAO at 800 ppb of methanol. The optimal resonance frequency of methanol is determined to be 100 kHz, which could detect methanol with high response of 2.65% at 100 ppm. The limit of detection (LOD) concentration is obtained at 2 ppb level. This study demonstrates the potential of UV-assisted ZnO, EGs, and AAO-based capacitance sensor material for rapidly detecting hazardous gaseous light organic molecules at ambient conditions, and the overall approach can be easily expanded to a novel non-invasive monitoring strategy for light and hazardous volatile organic exposures.

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

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.

Volatile anesthetic agents for life-threatening pediatric asthma: A multicenter retrospective cohort study and narrative review.

Volatile anesthetic agents are described as rescue therapy for children invasively ventilated for critical asthma. Yet, data are currently limited to case series. Using the Virtual Pediatric Systems database, we assessed children admitted to a pediatric intensive care unit invasively ventilated for life-threatening asthma and hypothesized ventilation duration and mortality rates would be lower for subjects exposed to volatile anesthetics compared with those without exposure. We performed a multicenter retrospective cohort study among nine institutions including children 5-17years of age invasively ventilated for asthma from 2013 to 2019 with and without exposure to volatile anesthetics. Primary outcomes were ventilation duration and mortality. Secondary outcomes included patient characteristics, length of stay, and anesthetic-related adverse events. A subgroup analysis was performed evaluating children intubated ≥2days. Of 203 children included in study, there were 29 (14.3%) with and 174 (85.7%) without exposure to volatiles. No differences in odds of mortality (1.1, 95% CI: 0.3-3.9, p>.999) were observed. Subjects receiving volatiles experienced greater median difference in length of stay (4.8, 95% CI: 1.9-7.8days, p<.001), ventilation duration (2.3, 95% CI: 1-3.3days, p<.001), and odds of extracorporeal life support (9.1, 95% CI: 1.9-43.2, p=.009) than those without volatile exposure. For those ventilated ≥2days, no differences were detected in mortality, ventilation duration, length of stay, arrhythmias, or acute renal failure. However, the odds of extracorporeal life support remained greater for those receiving volatiles (7.6, 95% CI: 1.3-44.5, p=.027). No children experienced malignant hyperthermia or hepatic failure after volatile exposure. For intubated children for asthma, no differences in mechanical ventilation duration or mortality between those with and without volatile anesthetic exposure were observed. Although volatiles may represent a viable rescue therapy for severe cases of asthma, definitive, and prospective trials are still needed.

Chronic thinner inhalation alters olfactory behaviors in adult mice

Volatile solvents exposure can result in various behavioral impairments that have been partly associated to altered adult hippocampal neurogenesis. Despite recent evidence supporting this association, few studies have been devoted to examine the impact on olfactory functioning and olfactory bulb (OB) neurogenesis, although olfactory system is directly in contact with volatile molecules. Thus, this study was designed to evaluate in adult mice the potential modifications of the olfactory functioning after acute (1 day), subchronic (6 weeks) and chronic (12 weeks) exposure to thinner vapor at both behavioral and cellular levels. Firstly, behavioral evaluations showed that chronic thinner exposure impacts on odor detection ability of treated mice but does not affect mice ability to efficiently discriminate between two different odors. Moreover, chronic thinner exposure produces impairment in the olfactory-mediated associative memory. Secondly, analysis of the effects of thinner exposure in the subventricular zone (SVZ) of the lateral ventricle and in the OB revealed that thinner treatments do not induce apoptosis nor glial activation. Thirdly, immunohistochemical quantification of different markers of adult olfactory neurogenesis showed that inhalant treatments do not change the number of proliferating progenitors in the SVZ and the rostral migratory stream (RMS), as well as the number of newborn cells reaching and integrating in the OB circuitry. Altogether, our data highlight that the impaired olfactory performances in chronically-exposed mice are not associated to an alteration of adult neurogenesis in the SVZ-OB system.

Herbivore-induced volatiles influence moth preference by increasing the β-Ocimene emission of neighbouring tea plants.

Herbivore-induced plant volatiles prime neighbouring plants to respond more strongly to subsequent attacks. However, the key volatiles that trigger this state and their priming mechanisms remain largely unknown. The tea geometrid Ectropis obliqua is one of the most devastating leaf-feeding pests of tea plants. Here, plant-plant communication experiments demonstrated that volatiles emitted from tea plants infested by E. obliqua larvae triggered neighbouring plants to release volatiles that repel E. obliqua adult, especially mated females. Volatile analyses revealed that the quantity of eight volatiles increased dramatically when plants were exposed to volatiles emitted by infested tea plants, including (Z)-3-hexenol, linalool, α-farnesene, β-Ocimene and (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT). The results of behavioural bioassays demonstrated that β-Ocimene strongly repelled mated E. obliqua females. Individual volatile compound exposure experiments revealed that (Z)-3-hexenol, linalool, α-farnesene and DMNT triggered the emission of β-Ocimene from tea plants. Chemical inhibition experiments demonstrated that the emission of β-Ocimene induced by (Z)-3-hexenol, linalool, α-farnesene and DMNT were dependent on Ca2+ and JA signalling. These findings help us to understand how E. obliqua moths respond to volatiles emitted from tea plants and provide new insight into volatile-mediated plant-plant interactions. They have potential significance for the development of novel insect and pest control strategies in crops.

Diffusive uptake rates for passive air sampling: Application to volatile organic compound exposure during FIREX-AQ campaign

Passive (diffusive) sampling using sorbents is an economical and versatile method of measuring pollutants in air, including volatile organic compounds (VOCs). Diffusive uptake rates (UTRs) are needed for each analyte to obtain average concentrations during a specific passive sampling time duration. Here, a simultaneous active/diffusive ambient air sampling technique on Tenax®TA was employed to measure 24-hours, 7, 14 and 28-days UTRs of up to 27 VOCs, including benzene, toluene, ethylbenzene, xylenes (BTEX), C6–C12 hydrocarbons, benzenes derivatives, tetrachloroethylene, pinenes and limonene. Samples were analyzed via thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) for desired analytes. Seven-day UTR values ranged from 0.17 to 0.59 mL/min and many compounds exhibited a linear relationship with UTR and time duration up to 14 or 28 days. This may be the most comprehensive UTR tabulation of VOCs on Tenax®TA for time periods of 24 hours –28 days available. These rates were applied to VOC data measured during the 2019 NASA/NOAA Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) campaign, with goals to determine the chemical composition of western US wildfire smoke and to assess human exposure to air toxics. Summer 2019 exposure levels of BTEX at five Northwestern cities were low and the cancer risk due to benzene was assessed during FIREX-AQ to be background or 1 × 10−6. The UTRs derived here can be useful in applications of diffusive sampling, including estimation of sub-chronic to chronic human exposure risk of air toxics and wildfire smoke.

Testosterone is Sufficient to Impart Susceptibility to Isoflurane Neurotoxicity in Female Neonatal Rats.

Volatile anesthetic exposure during development leads to long-term cognitive deficits in rats which are dependent on age and sex. Female rats are protected relative to male rats for the same exposure on postnatal day 7. Here we test our hypothesis that androgens can modulate chloride cotransporter expression to alter the susceptibility to neurotoxicity from GABAergic drugs using female rats with exogenous testosterone exposure. Female rats were injected with testosterone (100 μg/animal) or vehicle on postnatal days 1 to 6. On postnatal day 7, the animals were randomized to either isoflurane exposure or sham. Spatial memory was assessed with the Barnes maze starting on postnatal day 41. Western blots were run from testosterone treated postnatal day 7 animals to measure levels of chloride cotransporters sodium-potassium-chloride symporter (NKCC1) and chloride-potassium symporter 5 (KCC2). Exogenous testosterone modulated isoflurane anesthetic neurotoxicity in female rats based on poor performance in the probe trial of the Barnes Maze. By contrast, females with vehicle and isoflurane exposure were able to differentiate the goal position. These behavioral differences corresponded to differences in the protein levels of NKCC1 and KCC2 after exogenous testosterone exposure, with NKCC1 increasing ( P <0.001) and KCC2 decreasing ( P =0.003) relative to female controls. The expression of chloride cotransporters, NKCC1 and KCC2, is altered by testosterone in female rats and corresponds to a cognitive deficit after isoflurane exposure. This confirms the role of androgens in perinatal anesthetic neurotoxicity and supports our hypothesis that the developing GABAergic system plays a critical role in the underlying mechanism.

Joint effects of ethnic enclave residence and ambient volatile organic compounds exposure on risk of gestational diabetes mellitus among Asian/Pacific Islander women in the United States

BackgroundAsian/Pacific Islander (API) communities in the United States often reside in metropolitan areas with distinct social and environmental attributes. Residence in an ethnic enclave, a socially distinct area, is associated with lower gestational diabetes mellitus (GDM) risk, yet exposure to high levels of air pollution, including volatile organic compounds (VOCS), is associated with increased GDM risk. We examined the joint effects of ethnic enclaves and VOCs to better understand GDM risk among API women, the group with the highest prevalence of GDM.MethodsWe examined 9069 API births in the Consortium on Safe Labor (19 hospitals, 2002–2008). API ethnic enclaves were defined as areas ≥66th percentile for percent API residents, dissimilarity (geographic dispersal of API and White residents), and isolation (degree that API individuals interact with another API individual). High levels of 14 volatile organic compounds (VOC) were defined as ≥75th percentile. Four joint categories were created for each VOC: Low VOC/Enclave (reference group), Low VOC/No Enclave, High VOC/Enclave, High VOC/No Enclave. GDM was reported in medical records. Hierarchical logistic regression estimated odds ratios (OR) and 95% confidence intervals (95%CI) between joint exposures and GDM, adjusted for maternal factors and area-level poverty. Risk was estimated for 3-months preconception and first trimester exposures.ResultsEnclave residence was associated with lower GDM risk regardless of VOC exposure. Preconception benzene exposure was associated with increased risk when women resided outside enclaves [High VOC/No Enclave (OR:3.45, 95%CI:1.77,6.72)], and the effect was somewhat mitigated within enclaves, [High VOC/Enclave (OR:2.07, 95%:1.09,3.94)]. Risks were similar for 12 of 14 VOCs during preconception and 10 of 14 during the first trimester.ConclusionsAPI residence in non-enclave areas is associated with higher GDM risk, regardless of VOC level. Ethnic enclave residence may mitigate effects of VOC exposure, perhaps due to lower stress levels. The potential benefit of ethnic enclaves warrants further study.

Association Between Anesthetic Dose and Technique and Oncologic Outcomes After Surgical Resection of Non-Small Cell Lung Cancer

Because of the biologic effects of volatile anesthetics on the immune system and cancer cells, it has been hypothesized that their use during non-small cell lung cancer (NSCLC) surgery may negatively affect cancer outcomes compared with total intravenous anesthesia (TIVA) with propofol. The present study evaluated the relationship between anesthetic technique and dose and oncologic outcome in NSCLC surgery. Retrospective cohort study. Surgical records collated from a single, tertiary care hospital and combined with the Scottish Cancer Registry and continuously recorded electronic anesthetic data. Patients undergoing elective lung resection for NSCLC between January 2010 and December 2014. The cohort was divided into patients receiving TIVA only and patients exposed to volatile anesthetics. Final analysis included 746 patients (342 received TIVA and 404 volatile anesthetic). Kaplan-Meier survival curves with log-rank testing were drawn for cancer-specific and overall survival. No significant differences were demonstrated for either cancer-specific (p = 0.802) or overall survival (p = 0.736). Factors influencing survival were analyzed using Cox proportional hazards modeling. Anesthetic type was not a significant predictor for cancer-specific or overall survival in univariate or multivariate Cox analysis. Volatile anesthetic exposure was quantified using area under the end-tidal expired anesthetic agent versus time curves. This was not significantly associated with cancer-specific survival on univariate (p = 0.357) or multivariate (p = 0.673) modeling. No significant relationship was demonstrated between anesthetic technique and NSCLC survival. Whether a causal relationship exists between anesthetic technique during NSCLC surgery and oncologic outcome warrants definitive investigation in a prospective, randomized trial.

Exposure of Helicoverpa armigera Larvae to Plant Volatile Organic Compounds Induces Cytochrome P450 Monooxygenases and Enhances Larval Tolerance to the Insecticide Methomyl.

Simple SummaryUpon insect herbivory plants release herbivore-induced plant volatiles (HIPVs) to elicit either direct antiherbivore defenses by intoxicating the herbivore or indirect defenses by attracting natural enemies. Insect herbivores use sophisticated detoxification systems, including cytochrome P450 monooxygenases (P450s), to cope with plant defensive chemicals and insecticides. Many behaviors of insects are manipulated to a large extent by olfaction. However, few studies concern the role of olfaction in insect adaptation to xenobiotics. In this study we show that olfactory exposure of Helicoverpa armigera, a devastating pest of many important crop plants that has developed high levels of resistance to various insecticides, to four plant volatile compounds limonene, nerolidol, 2-heptanone and cis-3-hexenyl acetate dramatically increases larval tolerance to carbamate insecticide methomyl. Inhibition of P450s by piperonyl butoxide (PBO), a well-known P450 inhibitor, compromises the effects of volatile exposure. Exposure to the four volatiles upregulates multiple detoxification systems, including cytochrome P450s. Our findings indicate that induction of insecticide-detoxifying P450s by plant volatiles prior to actually inflicting plant damage may confer insect larvae more time to pre-activate insect detoxification systems prior to the ingestion or contact of insecticides, leading to increased larval tolerance to insecticides.Plants release an array of volatile chemicals into the air to communicate with other organisms in the environment. Insect attack triggers emission of herbivore-induced plant volatiles (HIPVs). How insect herbivores use these odors to plan their detoxification systems is vital for insect adaptation to environmental xenobiotics. Here we show that the larvae of Helicoverpa armigera (Hübner), a broadly polyphagous lepidopteran herbivore, have the capacity to use plant volatiles as cues to upregulate multiple detoxification systems, including cytochrome P450 monooxygenases (P450s), for detoxification of insecticides. Olfactory exposure of the fifth instars to two terpene volatiles limonene and nerolidol, and two green-leaf volatiles 2-heptanone and cis-3-hexenyl acetate significantly reduced larval susceptibility to the insecticide methomyl. However, larval pretreatment with piperonyl butoxide (PBO), a known P450 inhibitor, neutralized the effects of volatile exposure. Furthermore, larval exposure to the four plant volatiles enhanced activities of P450 enzymes in midguts and fatbodies, and upregulated expression of CYP6B2, CYP6B6 and CYP6B7, P450s involved in detoxification of the insecticide. Larval exposure to 2-heptanone and limonene volatiles also enhanced activities of glutathione-s-transferase and carboxylesterase. Our findings suggest that olfactory exposure to HIPVs enhances larval insecticide tolerance via induction of detoxification P450s.

Association of uterine activity and maternal volatile anesthetic exposure during open fetal surgery for spina bifida: a retrospective analysis

BackgroundRecent warnings postulate a possible damaging effect of volatile anesthetics on the fetus. In our archive of fetal surgeries, we found wide variation in dosing of volatile anesthetics during spina bifida surgeries. We hypothesized that there was an association between volatile anesthetic exposure and uterine activity. MethodsSixty anesthesia records from spina bifida operations were assessed. We analyzed the course of the administered volatile anesthetic during surgery and calculated from each patient’s anesthesia record the volatile anesthetic exposure expressed in vol%h. We divided the records into two post hoc groups of the 20 lowest exposure (Group L) versus the 20 highest exposure (Group H), and compared them for uterine activity and fetal heart rate. ResultsThe number of contractions per hour was significantly greater in Group H (mean 1.3, SD ± 1.2) compared with Group L (mean 0.5, SD ± 0.6, P=0.049). There was no difference between the groups for the administration of the tocolytic drug atosiban (P=0.29). The course of the mean arterial pressure did not significantly differ but group H needed significantly more vasoactive medication (P <0.05). ConclusionsWe found that a lower intra-operative volatile anesthetic exposure than recommended in the MOMS-trial (i.e. <2.0 minimum alveolar concentration [MAC]) was not associated with an increase in intra-operative uterine activity. This is an indication that during spina bifida surgery, 2.0 MAC may not be necessary to avoid potentially harmful uterine activity.

Head, Shoulders, Knees, and Toes: Placement of Wearable Passive Samplers Alters Exposure Profiles Observed.

Chemical exposures are a major risk factor for many diseases. Comprehensive characterization of personal exposures is necessary to highlight chemicals of concern and factors that influence these chemical exposure dynamics. For this purpose, wearable passive samplers can be applied to assess longitudinal personal exposures to airborne contaminants. Questions remain regarding the impact of sampler placement at different locations of the body on the exposure profiles observed and how these placements affect the monitoring of seasonal dynamics in exposures. This study assessed personal air contaminant exposure using passive samplers worn in parallel across 32 participant's wrists, chest, and shoes over 24 h. Samplers were analyzed by thermal desorption gas chromatography high-resolution mass spectrometry. Personal exposure profiles were similar for about one-third of the 275 identified chemicals, irrespective of sampler placement. Signals of certain semivolatile organic compounds (SVOCs) were enhanced in shoes and, to a lesser extent, wrist samplers, as compared to those in chest samplers. Signals of volatile organic compounds were less impacted by sampler placement. Results showed that chest samplers predominantly captured more volatile exposures, as compared to those of particle-bound exposures, which may indicate predominant monitoring of chemicals via the inhalation route of exposure for chest samplers. In contrast, shoe samplers were more sensitive to particle-bound SVOCs. Seventy-one chemicals changed across participants between winter and summer in the same manner for two or more different sampler placements on the body, whereas 122 chemicals were observed to have seasonal differences in only one placement. Hence, the placement in certain cases significantly impacts exposure dynamics observed. This work shows that it is essential in epidemiological studies undertaking exposure assessment to consider the consequence of the placement of exposure monitors.

Chemical exposures from upholstered furniture with various flame retardant technologies

Upholstered furniture is often manufactured with polyurethane foam (PUF) containing flame retardants (FRs) to prevent the risk of a fire and/or to meet flammability regulations, however, exposure to certain FRs and other chemicals have been linked to adverse health effects. This study developed a new methodology for evaluating volatile organic compound (VOC) and FR exposures to users of upholstered furniture by simulating use of a chair in a controlled exposure chamber and assessing the health significance of measured chemical exposure. Chairs with different fire‐resistant technologies were evaluated for VOC and FR exposures via inhalation, ingestion, and dermal contact exposure routes. Data show that VOC exposure levels are lower than threshold levels defined by the US and global indoor air criteria. Brominated FRs were not detected from the studied chairs. The organophosphate FRs added to PUF were released into the surrounding air (0.4 ng/m3) and as dust (16 ng/m2). Exposure modeling showed that adults are exposed to FRs released from upholstered furniture mostly by dermal contact and children are exposed via dermal and ingestion exposure. Children are most susceptible to FR exposure/dose (2 times higher average daily dose than adults) due to their frequent hand to mouth contact.

Indoor volatile organic compounds exposures and risk of childhood acute leukemia: a case-control study in shanghai

A case-control study was conducted to investigate the relationship between indoor air pollution and childhood acute leukemia (AL) in Shanghai. 97 cases and 148 gender-, age-, and residence-matched controls were included. Indoor air pollution was evaluated by questionnaires and quantitative measurement including 14 volatile organic compounds (VOCs) and nitrogen dioxide (NO2) in the homes of the two groups. The levels of individual VOCs, VOC families, TVOC (sum of the concentrations of the individual VOCs) and NO2 were compared between the two groups. Exposure to styrene and butyl alcohol were associated with an increased risk of childhood AL (styrene: odds ratio (OR)=2.33, 95% confidence interval (CI): 1.07-5.07; butyl alcohol: OR = 2.51, 95%CI: 1.19-5.28); 4th quartile of chlorinated hydrocarbons (OR = 2.52, 95%CI: 1.02-6.26) and 3rd quartile of TVOC (OR = 4.03, 95%CI: 1.06-6.81) had significant higher ORs for childhood AL compared with that in the lowest quartiles. Elevated levels of individual VOCs, VOC families and TVOC were also associated with self-reported risk factors. Our findings suggest that VOCs exposure was associated with an elevated risk of childhood AL, underscore that more attention should be paid to indoor air pollution as a risk factor of childhood AL.

Behavior and Regional Cortical BOLD Signal Fluctuations Are Altered in Adult Rabbits After Neonatal Volatile Anesthetic Exposure.

Neonatal and infant exposure to volatile anesthetics has been associated with long-term learning, memory, and behavioral deficits. Although early anesthesia exposure has been linked to a number of underlying structural abnormalities, functional changes associated with these impairments remain poorly understood. To investigate the relationship between functional alteration in neuronal circuits and learning deficiency, resting state functional MRI (rsfMRI) connectivity was examined in adolescent rabbits exposed to general anesthesia as neonates (1 MAC isoflurane for 2 h on postnatal days P8, P11, and P14) and unanesthetized controls before and after training with a trace eyeblink classical conditioning (ECC) paradigm. Long-range connectivity was measured between several key regions of interest (ROIs), including primary and secondary somatosensory cortices, thalamus, hippocampus, and cingulate. In addition, metrics of regional BOLD fluctuation amplitudes and coherence, amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) were calculated. Our results showed that the trace ECC learning rate was significantly lower in the anesthesia-exposed group. No anesthesia-related changes in long-range connectivity, fALFF, or ReHo were found between any ROIs. However, ALFF was significantly higher in anesthesia-exposed rabbits in the primary and secondary somatosensory cortices, and ALFF in those areas was a significant predictor of the learning performance for trace ECC. The absence of anesthesia-related changes in long-range thalamocortical connectivity indicates that functional thalamocortical input is not affected. Higher ALFF in the somatosensory cortex may indicate the developmental disruption of cortical neuronal circuits after neonatal anesthesia exposure, including excessive neuronal synchronization that may underlie the observed cognitive deficits.

Factor Exposure Variation and Mutual Fund Performance

We investigated the relationship between a mutual fund’s variation in factor exposures and its future performance. Using a dynamic state-space version of the Carhart (1997) four-factor model to capture factor variations, we found that funds with volatile factor exposures underperform funds with stable factor exposures by 147 bps a year. This underperformance is explained neither by volatile factor loadings of a fund’s equity holdings nor by a fund’s forced trading through investor flows. We conclude that fund managers voluntarily attempt to time factors but are unsuccessful at doing so.

Fungal volatiles influence plant defence against above‐ground and below‐ground herbivory

Abstract Plants have evolved resistance traits that negatively affect attackers, and tolerance traits that sustain plant growth despite herbivore damage. These mechanisms often co‐occur in a mixed‐defence strategy, balancing resistance and tolerance. These plant defences can be enhanced upon interaction with soil micro‐organisms. Here we investigated the effects of volatiles emitted by soil‐borne fungi on plant defence to insect herbivory, and on plant phenology. We exposed roots of Brassica rapa plants to volatiles emitted by four soil‐borne fungi. As a proxy of plant resistance, we assessed the performance of Pieris brassicae, a caterpillar feeding on leaves and inflorescences, and of Delia radicum, an insect root herbivore. As a proxy of plant tolerance, we compared growth of volatile‐exposed plants challenged with or without insects. Additionally, we assessed the effects on plant phenology by recording bolting time and by counting the number of buds and flowers. Plant exposure to fungal volatiles differentially affected plant resistance to above‐ and below‐ground herbivory. Performance of P. brassicae caterpillars differed between the fungal volatile‐exposed plants but was variable between experimental batches. In contrast, the effects of fungal volatiles on D. radicum performance were predominantly negative, indicating an increased plant resistance. Despite root consumption by D. radicum, root dry weight remained unchanged in infested plants compared with uninfested ones, irrespectively of the volatile exposure, suggesting compensation for the tissue loss, sometimes at the cost of undamaged above‐ground tissues. When B. rapa plants were attacked by P. brassicae caterpillars, only exposure to volatiles of some fungi led to compensation for the loss of above‐ground tissues consumed by the caterpillars, which differed between leaves and inflorescences. Furthermore, bolting was accelerated in response to volatiles of some fungi, resulting in more buds and flowers, which suggests a potential enhancement of plant fitness. Our data show that fungal volatiles can modulate the mixed‐defence strategies of B. rapa plants, balancing plant resistance and tolerance to above‐ and below‐ground herbivory. These effects may be variable and were fungus specific. Ultimately, plant fitness may be enhanced upon root exposure to fungal volatiles. A free Plain Language Summary can be found within the Supporting Information of this article.

Fragranced laundry products and emissions from dryer vents: implications for air quality and health

Fragranced laundry products emit numerous volatile organic compounds (VOCs), including terpenes such as limonene. Fragrance emissions have been associated with adverse health effects such as asthma attacks and breathing difficulties. Further, fragrance terpenes are primary indoor air pollutants that can react with other compounds and contribute to both indoor and outdoor air pollution. This paper examines volatile emissions and exposures from fragranced laundry products, and the implications for air quality and health. The paper synthesizes and analyzes data from studies conducted across the United States (US) and Australia (AU), providing results in three main themes: adverse health effects associated with exposure to fragranced laundry products, volatile emissions from fragranced and fragrance-free laundry products, and reductions in VOC emissions by switching from fragranced to fragrance-free products. Across the US and AU, 12.5% and 6.1% of the general population and 28.9% and 12.1% of asthmatics report health problems (respectively) when exposed to scented laundry products coming from a dryer vent. Among the volatile emissions from products, terpenes were the most prevalent VOCs detected in all fragranced laundry products; however, terpenes were absent in all fragrance-free products. By switching from fragranced to fragrance-free laundry products, dryer vent emissions of limonene can be reduced up to 99.7%. As context for significance, switching from fragranced to fragrance-free laundry detergent could reduce limonene emissions from dryer vents per household by an estimated 1.68 g/year. For the study area of metropolitan Melbourne, this represents a reduction in limonene emissions by an estimated 1.58 tons/year. Results from these analyses point to a promising way to reduce emissions and exposures to volatile compounds, and create potential improvements for air quality and health.