Volatile Exposure Research Articles

Volatile Organic Compound Exposure in Colorado Nail Salons

A pilot study of Volatile Organic Compound (VOC) exposure was conducted in 6 nail salons along Colorado’s front range. Measurements included area concentrations of Total VOCs (TVOCs), Formaldehyde (HCHO), Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX), as well as personal exposure sampling of four additional VOCs and worker health surveys. Preliminary data includes average TVOC levels between 3ppm and 22ppm, average HCHO levels between 12ppb and 405ppb, and BTEX concentrations between 23ppb and 300ppb. All participating salons exceeded the NIOSH standard for 8hr time-weighted HCHO concentration on at least one measurement day, and several salons exceeded other HCHO standards including the ACGIH 8hr Threshold Limit Value (TLV). BTEX concentrations observed were similar to those measured in previous occupational exposure studies of gasoline and diesel station attendants and oil refinery workers. Most (65%) survey respondents reported experiencing at least one health symptom as a result of their employment in the nail salon industry, with the most common symptoms including headaches, skin irritation, eye irritation, and nose irritation. Cancer risk estimates for Benzene and Formaldehyde exposure were calculated using cancer slope factors published by the United States Environmental Protection Agency (US EPA) in their Integrated Risk Information System (IRIS). These estimates are based on a 30-year occupational exposure duration, and incorporate average body weights provided by the Center for Disease Control (CDC), as well as inhalation rates provided by US EPA. The elevated lifetime risk for Squamous Cell Carcinoma (SCC) from formaldehyde exposure ranged from approximately 1 in 100,000 (1.18x10^-5) to over 6 in 10,000 (6.5x10^-4). The elevated lifetime risk for Leukemia from benzene exposure ranged from 5.15x10^-7 to 5.05x10^-5.

Health risk assessment of volatile organic compounds exposure near Daegu dyeing industrial complex in South Korea

BackgroundStudying human health in areas with industrial contamination is a serious and complex issue. In recent years, attention has increasingly focused on the health implications of large industrial complexes. A variety of potential toxic chemicals have been produced during manufacturing processes and activities in industrial complexes in South Korea. A large number of dyeing industries gathered together in Daegu dyeing industrial complex. The residents near the industrial complex could be often exposed to volatile organic compounds. This study aimed to evaluate VOCs levels in the ambient air of DDIC, to assess the impact on human health risks, and to find more convincing evidences to prove these VOCs emitted from DDIC.MethodsAccording to deterministic risk assessment, inhalation was the most important route. Residential indoor, outdoor and personal exposure air VOCs were measured by passive samplers in exposed area and controlled area in different seasons. Satisfaction with ambient environments and self-reported diseases were also obtained by questionnaire survey. The VOCs concentrations in exposed area and controlled area was compared by t-test. The relationships among every VOC were tested by correlation. The values of hazard quotient (HQ) and life cancer risk were estimated.ResultsThe concentrations of measured VOCs were presented, moreover, the variety of concentrations according the distances from the residential settings to the industrial complex site in exposed area. The residential indoor, outdoor, and personal exposure concentrations of toluene, DMF and chloroform in exposed area were significantly higher than the corresponding concentrations in controlled area both in summer and autumn. Toluene, DMF, chloroform and MEK had significantly positive correlations with each other in indoor and outdoor, and even in personal exposure. The HQ for DMF exceeded 1, and the life cancer risk of chloroform was greater than 10− 4 in exposed area. The prevalence of respiratory diseases, anaphylactic diseases and cardiovascular diseases in exposed area were significantly higher than in controlled area.ConclusionsThis study showed that adverse cancer and non-cancer health effects may occur by VOCs emitted from DDIC, and some risk managements are needed. Moreover, this study provides a convenient preliminarily method for pollutants source characteristics.

Personal, Psychosocial and Environmental Factors Related to Sick Building Syndrome in Official Employees of Taiwan.

Sick building syndrome (SBS) is a combination of symptoms that can be attributed to exposure to specific building conditions. The present study recruited 389 participants aged 20–65 years from 87 offices of 16 institutions to examine if personal factors, work-related psychosocial stress, and work environments, were associated with five groups of SBS symptoms, including symptoms for eyes, upper respiratory tract, lower respiratory tract, skin, and non-specific systems. Indoor environmental conditions were monitored. Data were analyzed using multivariate logistic regression (MLR) analyses and were reported as adjusted Odds Ratios (aOR). SBS symptoms for eyes were associated with older age, sensitivity to tobacco, and low indoor air flow. Upper respiratory symptoms were related to smoking, low social support, longer work days, and dry air. High indoor air flow was associated with reduced upper respiratory symptoms (aOR = 0.29; 95% confidence interval (CI) = 0.13–0.67). Lower respiratory symptoms were associated with high work pressure, longer work hours, chemical exposure, migraine, and exposure to new interior painting. Recent interior painting exposure was associated with a high estimated relative risk of low respiratory symptoms (aOR = 20.6; 95% CI = 2.96–143). Smoking, longer work days, low indoor air flow, indoor dryness, and volatile organics exposure, were associated with other non-specified symptoms including headache, tiredness, difficulty concentrating, anger, and dizziness. In conclusion, there are various SBS symptoms associated with different personal characteristics, psychosocial, and environmental factors. Psychosocial factors had stronger relationships with lower respiratory symptoms than with other types of SBS symptoms. Good ventilation could reduce risk factors and may relieve SBS symptoms.

Liver volatolomics to reveal poultry exposure to γ-hexabromocyclododecane (HBCD)

Hexabromocyclododecane (HBCD) is a critical emerging brominated flame retardant to which consumers can be exposed at high doses through a single food intake. Based on an animal experiment involving 3 groups of laying hens fed during 70 days with a control diet or γ-HBCD-contaminated diets at 0.1 or 10 μg γ-HBCD g−1 feed, this study aims to use the volatolome of biological samples for revealing markers of livestock exposure to HBCD. Liquid chromatography–tandem mass spectrometry was used to monitor the time-course of HBCD levels in bodily samples. Each liver was analyzed by solid-phase microextraction–gas chromatography–mass spectrometry for volatolome profiling. After 70 days, γ-HBCD concentrations in egg yolk, fat, liver and serum reached 54 ± 4, 85 ± 6, 31 ± 6, and 32 ± 4 ng g−1 lw, respectively, for the low exposure level and 4.6+/5.7, 7.8+/6.5, 3.9+/3.0 and 3.9+/6.1 μg g−1 lw, respectively, for the high exposure level. Isomerization of γ-HBCD into α- and β-HBCD was observed in all tissues, at least for the high exposure level. Volatolome data allowed a significant discrimination between control and exposed animals whatever the feed contamination load, demonstrating a liver metabolic response to γ-HBCD exposure. The relevance of the twenty nine volatile exposure markers tentatively identified was discussed in light of literature data.

Psychosocial Causes Affecting Inhalants Addiction in Children and Adolescents: Case Report

ABSTRACTApart from industrial exposure, volatile agent exposure occurs to a significant extent by abusing these substances with the aim of excitement. In recent years, inhalants addiction has rapidly spread among children and adolescents. Indeed children and adolescents’ use of substance may vary. Inhalants dependence is generally seen at average 14-15 years of age in the patients. When psychological reasons affecting volatile substance dependence are examined, it can be said that factors such as not knowing how to cope with stress in general, desire to get rid of negative and bad emotions, pleasure from matter, pleasure, wanting to belong to a group and feeling strong.When social factors are taken into consideration, it is first and foremost that access to volatile substances is easy and cheap, acceptance within the family, peer influence, positive perspective on the substance in the social environment and encouraging visuals in the social media Here we present a case of psychosocial factors that cause alcohol and cannabis addiction in his family narrative, which begins to use volatile substance (lighter gas) at the age of 12, in addition to inhalants, alcohol and cannabis.Key Words: Inhalants, substance addiction, psychosocial causes

Fume emissions from a low-cost 3-D printer with various filaments

ABSTRACT3-D printing is an additive manufacturing process involving the injection of melted thermoplastic polymers, which are then laid down in layers to achieve a pre-designed shape. The heated deposition process raises concerns of potential aerosol and volatile organic compounds (VOC) emission and exposure. The decreasing cost of desktop 3-D printers has made the use of 3-D printers more acceptable in non-industrial workplaces lacking sufficient ventilation. Meanwhile, little is known about the characteristics of 3-D printing fume emission. The objective of this study was to characterize aerosols and VOC emissions generated from various filaments used with a low-cost 3-D printer in an environmental testing chamber. A pre-designed object was printed in 1.25 hours using eight types of filaments. A scanning mobility particle sizer and an aerodynamic particle sizer were employed to measure the particle size distribution in sub-half-micron fraction (<0.5 µm) and super-half-micron fraction (0.5–20 µm), respectively. VOC concentration was monitored real-time by a photoionization detector and sampled with a tri-sorbent thermal desorption tube, and analyzed by thermal desorption gas chromatography mass spectrometry (TD-GC/MS). Results showed high levels of fume particles emission rate (1.0 × 107 to 1.2 × 1010 #/min) in the sub-half-micron range with mode sizes of 41–83 nm. Particle concentrations peaked during the heat-up and solid layer printing periods. Total VOC concentration in the chamber followed a first-order buildup, with predominant VOC species in the chamber were breakdown and reaction products of the filaments, such as styrene from ABS filaments. These findings and exposure scenario estimation suggest that although the VOC concentrations were much lower than occupational exposure limits, particles with size less than micron might be a concern for users of low-cost 3-D printers due to high respirablity, especially if used in settings without proper guidance and engineering control.

Oxidative Enzyme Response of Watercress (Nasturtium officinale) to Sublethal Fuel Exposure

Biomarkers such as oxidase enzyme activity from flora exposed to chemicals in the water column and sediments have been widely used by ecotoxicologists to assess the quality of an environment. Biomarkers such as oxidase enzymes are especially useful indicators because they represent a direct biological response to environmental toxicity. A luminometer was used to quantify oxidase enzyme production in watercress (Nasturtium officinale) due to toxic chemical exposure of E85 (85% ethanol and 15% gasoline blend), gasoline, and 99% pure ethanol over a 72-h period in aquatic root exposure and volatile leaf exposure experiments. Aquatic exposure to E85 caused an increase in oxidative enzyme production while gasoline and ethanol caused no significant changes in oxidase concentrations. Aquatic root exposure results were compared to volatile leaf exposures where effects of E85, gasoline, and ethanol caused increases in oxidase production. Morphometric measurements were also conducted as plant stress comparisons to oxidative enzyme analyses. Measurements of root length showed increases in root growth at some concentrations of fuels with only the highest concentration of E85 resulting in a decrease in root growth when compared to the control.

Physical and environmental hazards in the prosthetics and orthotics workshop: a pilot study.

Prosthetists and Orthotists (P&O) are exposed to physical hazards within the workshop environment. Concern regarding these exposures has been expressed by P&Os; however, little research has been undertaken. Exposures to noise and volatile organic compounds in amounts larger than statutorily allowed can have adverse short and long term consequences on people’s health. To identify and quantify hazardous noise and chemical exposures in a typical P&O workplace. Noise and volatile organic compound testing was undertaken in 2011 and 2013. Modifications to the workshop occurred between these testing times and the impact of these changes examined. The levels of volatile organic compounds was very low in all areas in 2011 and 2013. Noise levels were high and staff require the use of PPE to prevent exposure beyond levels prescribed in the Australian Standards. Conclusions. Occupational environmental exposures in P&O are of concern to the profession. A pilot study of one facility demonstrated that Occupational Noise exposures are high and may result in hearing loss and other adverse health outcomes. Occupational chemical exposures through volatile organic compound exposures are relatively low. Further, systematic investigation is required to develop evidence-based control strategies.

Volatile organic compounds emitted by Trichoderma species mediate plant growth.

BackgroundMany Trichoderma species are applied as biofungicides and biofertilizers to agricultural soils to enhance crop growth. These filamentous fungi have the ability to reduce plant diseases and promote plant growth and productivity through overlapping modes of action including induced systemic resistance, antibiosis, enhanced nutrient efficiency, and myco-parasitism. Trichoderma species are prolific producers of many small metabolites with antifungal, antibacterial, and anticancer properties. Volatile metabolites of Trichoderma also have the ability to induce resistance to plant pathogens leading to improved plant health. In this study, Arabidopsis plants were exposed to mixtures of volatile organic compounds (VOCs) emitted by growing cultures of Trichoderma from 20 strains, representing 11 different Trichoderma species.ResultsWe identified nine Trichoderma strains that produced plant growth promoting VOCs. Exposure to mixtures of VOCs emitted by these strains increased plant biomass (37.1–41.6 %) and chlorophyll content (82.5–89.3 %). Trichoderma volatile-mediated changes in plant growth were strain- and species-specific. VOCs emitted by T. pseudokoningii (CBS 130756) were associated with the greatest Arabidopsis growth promotion. One strain, T. atroviride (CBS 01-209), in our screen decreased growth (50.5 %) and chlorophyll production (13.1 %). Similarly, tomatoes exposed to VOCs from T. viride (BBA 70239) showed a significant increase in plant biomass (>99 %), larger plant size, and significant development of lateral roots. We also observed that the tomato plant growths were dependent on the duration of the volatile exposure. A GC–MS analysis of VOCs from Trichoderma strains identified more than 141 unique compounds including several unknown sesquiterpenes, diterpenes, and tetraterpenes.ConclusionsPlants grown in the presence of fungal VOCs emitted by different species and strains of Trichoderma exhibited a range of effects. This study demonstrates that the blend of volatiles produced by actively growing fungi and volatile exposure time in plant development both influence the outcome of volatile-mediated interactions. Only some of our growth promoting strains produced microbial VOCs known to enhance plant growth. Compounds such as 6-pentyl-2H-pyran-2-one were not common to all promoting strains. We found that biostimulatory strains tended to have a larger number of complex terpenes which may explain the variation in growth induced by different Trichoderma strains.

Logistic regression analysis on risk factors of autism spectrum disorders

Objective To explore the possible risk factors for autism spectrum disorders (ASD), and to provide a basis for exploring the etiology of the disease. Methods This case-control study included 68 patients diagnosed as ASD for a first lifetime(according to the fourth edition of the American Diagnostic and Statistical Manual of Mental Disorders for ASD diagnosis) from May 2014 to January 2015, and 77 non-ASD controls (normal children, matched on gender) in Jiangxi Children's Hospital were selected to undergo the risk factor survey for ASD.The survey content included 10 categories: general status, birth, feeding, the past history, mother's pregnancy and her health condition during pregnancy and environmental exposure, parents' occupational exposure, family history and relevant test results.Logistic regression analysis was performed to analyze the results of the survey. Results The possible risk factors for ASD increased if mother had virus infection 2 years before pregnant (OR=7.97, 95%CI: 2.42-26.31), had occupational exposure (OR=3.99, 95%CI: 1.27-12.52), volatile organic compounds exposure during pregnancy (OR=22.21, 95%CI: 2.28-216.09), as well as living closely to transport passage ways during pregnancy (OR=0.59, 95%CI: 0.38-0.93) or having a family heredity history (OR=58.50, 95%CI: 5.81-589.57). Breastfeeding (OR=0.81, 95%CI: 0.66-0.98) might be a protective factor in ASD. Conclusions In addition to genetic factors, the ute-rine environment from conception to birth and growth environment play an important role in the pathogenesis of ASD. Key words: Autism spectrum disorder; Risk factor; Logistic regression analysis

Excess Lifetime Cancer Risk Assessment of Volatile Organic Compounds Emitted from a Petrochemical Industrial Complex

ABSTRACTA health risk assessment for the Lin-Yuan Petrochemical Industrial Complex (LYPIC) in southern Taiwan was conducted in this study. The main aims of the study were to develop an emission inventory for the 21 processing plants in the LYPIC, conduct hazard identification based on the emission inventory, perform an exposure assessment by applying air dispersion modeling to obtain the annual average concentration of hazardous air pollutants near the LYPIC, and estimate the lifetime risk of cancer associated with volatile organic compound exposure for residents living in the vicinity of the LYPIC. Comparing with the reported monitoring data from several petrochemical and refinery plants in the world, the estimated exposure concentrations in this study were within reasonable range. The results of cancer risk assessment showed that the cumulative excess lifetime cancer risk (ELCR) at four representative residential sites surrounding the LYPIC were in the range of 9.3 × 10–5 to 1.7 × 10–4. From a risk management perspective, in order to protect human health, greater emphasis on the reduction of emissions of benzene, 1,3-butadiene, acrylonitrile, and vinyl chloride is recommended. This study provides a feasible risk assessment procedure to identify the key carcinogenic chemicals emitted from a petrochemical industrial complex.

Associations of Cognitive Function Scores with Carbon Dioxide, Ventilation, and Volatile Organic Compound Exposures in Office Workers: A Controlled Exposure Study of Green and Conventional Office Environments.

Background:The indoor built environment plays a critical role in our overall well-being because of both the amount of time we spend indoors (~90%) and the ability of buildings to positively or negatively influence our health. The advent of sustainable design or green building strategies reinvigorated questions regarding the specific factors in buildings that lead to optimized conditions for health and productivity.Objective:We simulated indoor environmental quality (IEQ) conditions in “Green” and “Conventional” buildings and evaluated the impacts on an objective measure of human performance: higher-order cognitive function.Methods:Twenty-four participants spent 6 full work days (0900–1700 hours) in an environmentally controlled office space, blinded to test conditions. On different days, they were exposed to IEQ conditions representative of Conventional [high concentrations of volatile organic compounds (VOCs)] and Green (low concentrations of VOCs) office buildings in the United States. Additional conditions simulated a Green building with a high outdoor air ventilation rate (labeled Green+) and artificially elevated carbon dioxide (CO2) levels independent of ventilation.Results:On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001). VOCs and CO2 were independently associated with cognitive scores.Conclusions:Cognitive function scores were significantly better under Green+ building conditions than in the Conventional building conditions for all nine functional domains. These findings have wide-ranging implications because this study was designed to reflect conditions that are commonly encountered every day in many indoor environments.Citation:Allen JG, MacNaughton P, Satish U, Santanam S, Vallarino J, Spengler JD. 2016. Associations of cognitive function scores with carbon dioxide, ventilation, and volatile organic compound exposures in office workers: a controlled exposure study of green and conventional office environments. Environ Health Perspect 124:805–812; http://dx.doi.org/10.1289/ehp.1510037

Investigation of volatile organic compounds exposure inside vehicle cabins in China

This study assessed the concentrations of specific volatile organic compounds (VOCs) inside vehicle cabins under different practical vehicle driving conditions in China. The mean concentrations of the VOCs, including benzene, toluene, xylene, ethylbenzene, styrene, formaldehyde, acetaldehyde, acetone, and acrolein, were 16.73 μg/m3, 66.02 μg/m3, 14.20 μg/m3, 6.78 μg/m3, 28.09 μg/m3, 16.43 μg/m3, 12.47 μg/m3, and 20.65 μg/m3 (the sum of acetone and acrolein), respectively. All the specified VOCs inside vehicle cabins were not exceeded the limits of the national standard. The in-cabin VOCs concentrations were investigated for 16 private vehicles under three ventilation conditions: (i) fan off and recirculation (RC) off, (ii) fan on and RC off, and (iii) fan on and RC on. The VOCs concentrations increased 50.46% (mean of the measured VOCs) when the ventilation condition changed from (ii) to (i), and increased 51.38% (mean of the measured VOCs) when ventilation condition changed from (ii) to (iii). Two vehicle models (vehicle model A and vehicle model B) were tested in the study to investigate the influence on in-cabin VOCs concentrations of two typical interior trims (leather, fabric). The VOCs concentrations inside B vehicles (leather interiors) were averagely 1.42 times larger than the concentrations in A vehicles (fabric interiors). For new vehicles, the concentrations of benzene, toluene, xylene, ethylbenzene, formaldehyde, acetaldehyde, acetone and acrolein were larger than the concentrations inside old vehicles by 12.89%, 103.54%, 123.14%, 104.20%, 6.26%, 6.31%, and 10.67%, respectively. The VOCs concentrations significantly increased as the raise of ambient temperature. Toluene, styrene, ethylbenzene, and xylene were the most sensitive VOCs to temperature, which increased 513.6%, 544.8%, 767.0%, and 597.7% as the temperature increased from 11 °C to 25 °C.

In-situ Real-Time Monitoring of Volatile Organic Compound Exposure and Heart Rate Variability for Patients with Multiple Chemical Sensitivity.

In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health 2010, 7, 4127–4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

Social Networks of Educated Nematodes.

Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments.

Case report: proximal tubule impairment following volatile anesthetic exposure.

The safety of contemporary volatile anesthetic agents with respect to kidney function is well established, and growing evidence suggests that volatile anesthetics even protect against ischemic nephropathy. However, studies examining effects of volatile anesthetics on kidney function frequently demonstrate transient proteinuria and glycosuria following exposure to these agents, although the cause of these findings has not been thoroughly examined. We describe the case of a patient who underwent a neurosurgical procedure, then experienced glycosuria without hyperglycemia that resolved within days. Following a second neurosurgical procedure, the patient again developed glycosuria, now associated with ketonuria. Further examination demonstrated nonalbuminuric proteinuria in conjunction with urinary wasting of phosphate and potassium, indicative of proximal tubule impairment. We suggest that transient proximal tubule impairment may play a role in the proteinuria and glycosuria described following volatile anesthetic exposure and discuss the relationship between these observations and the ability of these agents to protect against ischemic nephropathy.

Male Sexual Behavior and Pheromone Emission Is Enhanced by Exposure to Guava Fruit Volatiles in Anastrepha fraterculus.

BackgroundPlant chemicals can affect reproductive strategies of tephritid fruit flies by influencing sex pheromone communication and increasing male mating competitiveness.Objective and MethodologyWe explored whether exposure of Anastrepha fraterculus males to guava fruit volatiles and to a synthetic blend of volatile compounds released by this fruit affects the sexual performance of wild and laboratory flies. By means of bioassays and pheromone collection we investigated the mechanism underlying this phenomenon.ResultsGuava volatile exposure enhanced male mating success and positively affected male calling behavior and pheromone release in laboratory and wild males. Changes in male behavior appear to be particularly important during the initial phase of the sexual activity period, when most of the mating pairs are formed. Exposure of laboratory males to a subset of guava fruit volatiles enhanced mating success, showing that the response to the fruit might be mimicked artificially.ConclusionsVolatiles of guava seem to influence male mating success through an enhancement of chemical and physical signals related to the communication between sexes. This finding has important implications for the management of this pest species through the Sterile Insect Technique. We discuss the possibility of using artificial blends to improve the sexual competitiveness of sterile males.

Age matters: the effects of volatile organic compounds emitted by Trichoderma atroviride on plant growth.

Studying the effects of microbial volatile organic compounds (VOCs) on plant growth is challenging because the production of volatiles depends on many environmental factors. Adding to this complexity, the method of volatile exposure itself can lead to different responses in plants and may account for some of the contrasting results. In this work, we present an improved experimental design, a plate-within-a-plate method, to study the effects of VOCs produced by filamentous fungi. We demonstrate that the plant growth response to VOCs is dependent on the age of the plant and fungal cultures. Plants exposed to volatiles emitted by 5-day-old Trichoderma atroviride for 14 days exhibited inhibition, while plants exposed to other exposure conditions had growth promotion or no significant change. Using GC-MS, we compared fungal volatile emission of 5-day-old and 14-day-old T. atroviride. As the fungi aged, a few compounds were no longer detected, but 24 new compounds were discovered.

From Natural Resource Boom to Sustainable Economic Growth: Lessons for Mongolia

Some resource-rich developing countries are in the process of harnessing immense mining resources towards inclusive growth and prosperity. Nevertheless, tapping into natural resources could be challenging given the large front-loaded investment, volatile capital flows and exposure to global commodity markets. Public investment is needed to remove the often-large infrastructure gap and unlock the economic potential. However, too rapid fiscal outlays could push the economy to its limit of absorptive capacity and increase macro-financial vulnerabilities. This paper utilizes a structural model-based approach to analyze macroeconomic impacts of different public investment strategies on key fiscal and non-fiscal variables such as debt, consumption, sovereign wealth fund, and real exchange rates. We apply the model to Mongolia and draw policy recommendations from the analysis. We find that fiscal policy adjustment, particularly moderating infrastructure investment and optimizing investment efficiency is needed to maintain macroeconomic and external stability, as well as to boost the long-term sustainable growth for Mongolia.

Volatiles emitted by leaf rust infected wheat induce a defence response in exposed uninfected wheat seedlings

Volatile organic compounds emitted from plant tissues have been implicated to play many roles. Interplant signalling is an experimentally proven phenomenon whereby volatiles produced under stress conditions may diffuse to neighbouring plants to induce a response. The current project was undertaken to investigate a putative signalling event between leaf rust (Puccinia triticina Erikss.) infected and uninfected wheat (Triticum aestivum L.) using a continual air-flow system. Exposure to volatiles emitted by either infected resistant or susceptible plants decreased the percentage leaf area infected and pustule size in recipient plants after a subsequent infection with leaf rust, but in the case of infected resistant plants, the decrease in percentage leaf area infected was significant. The activation of a defence response was confirmed through a significant induction of β-1,3-glucanase activity at 8 h post volatile exposure in exposed resistant and susceptible seedlings, depending on the source of the volatiles. Increased PR1 gene expression supported the activation of the defence response. Emitted volatiles were captured by solid phase micro-extraction and identified by GC-MS. Based on their detection and the literature, ocimene from infected resistant seedlings and green leaf volatiles from infected susceptible seedlings are suggested as likely candidates for the inter-plant communication.