Amount Of Volatile Organic Compounds Research Articles

Effect of Volatile Organic Compounds on Pulmonary Functions Among Paint Industry Workers of Unorganized Sectors.

Background Paint industry workers are constantly exposed to paints and organic solvents that contain a substantial quantity of volatile organic compounds (VOCs). Exposure to VOC emissions could result in pulmonary, neurobehavioral, and hematological consequences. Limited studies have been undertaken in India to assess the health consequences of VOCs among paint industry workers in unorganized sectors. Aim To assess the effects of VOCs on pulmonary function in paint industry workers of unorganized sectors. Methodology A hundred and twenty full-time male construction painters and small-scale paint manufacturing workers aged 25-60 were assessed for respiratory symptoms using a questionnaire, and pulmonary functions using Wright's Peak Expiratory Flow Meter (PEFR). Participants were randomly selected forVOC assessment andthe cumulative solvent exposure index was calculated. A pulmonary function test (PFT) was performed on a subset of construction painters (n=30) using a Koko spirometer. Results The concentration of VOCs such as benzene, ethylbenzene, toluene, and xylene (BETX) and dichloromethane levels exceeded American Conference of Governmental Industrial Hygienists (ACGIH)threshold limit values (TLVs) among the paint manufacturing workers. About 52% of paint workers reported respiratory symptoms. Around 22% of the participants showedreduced pulmonary function (PEFR<400 L/min). There was a significant weaknegativecorrelationbetween PEFR andwork experience (r = -0.2, p=0.03). PFT parameters among a subset of construction painters revealed a significant moderate negative correlation with work experience [forced expiratory volume at the onset of the first second (FEV1) (r = -0.6, p=0.001) and forced vital capacity (FVC) (r = -0.53, p=0.005)] and cumulative VOC exposure index [FEV1 (r = -0.53, p = 0.004) and FVC (r = -0.5, p = 0.008)]. Conclusion The concentration of VOCs was higher among paint industry workers of unorganized sectors and they reported respiratory symptoms and diminished pulmonary function. To reduce morbidity, it is critical to enhance awareness about occupational safety and services in these unorganized sectors.

Sprayed Urine Emits a Pungent Odor due to its Increased Adhesion to Vertical Objects via Urinary Proteins Rather Than to Changes in its Volatile Chemical Profile in Domestic Cats.

Spraying urine on vertical objects by raising the tail is a commonly observed functional behavior for chemical communication in Felidae species, including domestic cats (Felis silvestris catus). The sprayed urine is recognized as a chemical signal for territorial ownership of their habitats. Previous studies reported that sprayed urine emits a more pungent odor than urine excreted from a squatting position. However, little is known about how sprayed urine acts as a strong scent mark in the environment. Here, we showed that sprayed urine originates only from bladder urine without any secretions, such as anal sac secretions, but it can effectively emit volatile organic compounds (VOCs) when smeared on vertical objects due to its strong adhesion. Chemical profiles of VOCs and odor qualities were similar between fresh sprayed urine and bladder urine sampled immediately after spraying from the same individuals. Meanwhile, feline-specific proteinuria arising from excretion of a carboxylesterase that produces a precursor of cat-specific odorants resulted in reduced surface tension of the urine and increased adhesion to vertical surfaces, which kept sprayed urine on the surfaces and led to the emission of large amounts of VOCs. In conclusion, proteinuria contributes to the emission of a strong odor through its enhanced adhesion to vertical objects without other secretions containing malodorous substances. These findings improve our understanding of the mechanism of scent marking via the spraying of urine for chemical communication in cats.

Numerical Simulation of Flow Characteristics for Supercritical CO2-Sprayed Polyurethane Resin.

Conventional paint spraying processes often use small molecule organic solvents and emit a large amount of volatile organic compounds (VOCs) that are highly toxic, flammable, and explosive. Alternatively, the spraying technology using supercritical CO2 (scCO2) as a solvent has attracted attention because of its ability to reduce VOC emissions, but the flow characteristics of coatings have not been thoroughly studied. Therefore, we numerically simulate the spraying process based on the actual process of scCO2 spraying polyurethane coatings by computational fluid dynamics (CFD). The effects of inlet pressure and volume fraction of scCO2 on the fluid motion parameters inside the nozzle as well as the atomization effect of droplets outside the nozzle are investigated. The simulated results show that a fluid with a large volume fraction of scCO2 will obtain a smaller density, resulting in a larger velocity and a larger distance for the spray to effectively spray. Higher coating content and bigger inlet pressures will result in higher discrete phase model (DPM) concentrations, and thus a bigger inlet pressure should be used to make the droplets more uniform across the 30° spray range. This study can provide theoretical guidance for the process of scCO2-sprayed polyurethane resin.

Absorption of n-butyl acetate from tannery air emissions by waste vegetable oil/water emulsions

Tanning industries emit a huge quantity of Volatile Organic Compounds (VOCs), including hydrophilic and hydrophobic solvents. In this study, vegetable oil/water emulsions with 2 and 5 vol% of corn oil (O) or waste cooking oil (WCO) were prepared. Their potential as absorbents of n-butyl acetate (BA), in place of water, was investigated to increase the efficiency of tannery wet scrubbers. BA was selected as a representative component of hydrophobic VOC emissions derived from leather finishing processes. Static and dynamic absorption tests were performed with a BA concentration of 500 ppmv (2.6 g/m3) and a flowrate of 3.0 L/min to evaluate Henry’s law constant, absorption efficiency, absorption capacity, and saturation time of the various investigated absorbents. The feasibility of the absorbent regeneration was also studied by hot stripping with nitrogen. The results showed that Henry’s constant of BA in oil/surfactant/water or oil/water emulsions (5 vol% oil), regardless of the oil used, were significantly lower than those in water (3.6 versus 15.9 atm), and BA absorption capacity (0.84 g/L) was four times higher than the value in water. The presence of the surfactant (0.2–0.8 vol%) contributed to improving the oil/water emulsions stability without having a significant effect on BA absorption capacity. Almost complete BA desorption from the saturated emulsions was obtained by flowing hot N2 at 80°C, demonstrating the absorbent regeneration's feasibility followed by recovery and reuse. Therefore, the oil/water emulsions containing 5 vol% of WCO are efficient and sustainable absorbents of BA, with potential use in VOC emission treatment systems.

Nicotine in electronic cigarettes

AbstractElectronic cigarettes (ECs) are battery-powered gadgets that heat liquid to produce an aerosol. Nicotine is a primary ingredient in some e-liquids; however, due to a lack of quality control regulations, the nicotine may become tainted, or the measured and labelled values may not correspond. To avoid such issues, it is essential to identify the components that contribute to erroneous nicotine quantification. Herein, the differences between free-base nicotine and nicotine salts are discussed, highlighting the lower volatility of nicotine salts and their longer persistence in the body. Discrepancies were noted in the concentration of nicotine salts in some e-liquid samples, with labelled and measured values of 48 and 68.8 mg/mL, respectively, in one sample, and 24 and 33.1 mg/mL, respectively, in another. Inconsistencies were also observed in e-liquids labelled as nicotine-free: one sample had a nicotine concentration of 21.80 mg/cartridge, while another had a concentration of 23.91 mg/mL. The review also covers differences in the potency, flavour, and storage of nicotine under various conditions. Additionally, the literature suggests that the components in ECs are separated into the liquid and vapour phases; thus, phase selection should be considered to ensure optimal experimental outcomes. For instance, the vapour phase comprises the greatest quantities of volatile organic compounds, even though nicotine has been detected in all phases. Finally, the role of ECs in smoking cessation is discussed. The reviewed findings underscore the need for further research on e-liquids, particularly regarding their long-term clinical effects.

Extraction of volatile organic compounds liberated upon filament extrusion by 3D pen and its comparison with a desktop 3D printer using solid-phase microextraction fiber and Arrow

Desktop 3D printers that operate by the fused deposition modeling (FDM) mechanism are known to release numerous hazardous volatile organic compounds (VOCs) during printing, including some with potential carcinogenic effects. Operating in a similar manner to FDM 3D printers, 3D pens have gained popularity recently from their ability to allow users to effortlessly draw in the air or create various 3D printed shapes while handling the device like a pen. In contrast to numerous modern 3D printers, 3D pens lack their own ventilation systems and are often used in settings with minimum airflow. Their operation makes users more vulnerable to VOC emissions, as the released VOCs are likely to be in the breathing zone. Consequently, monitoring VOCs released during the use of 3D pens is crucial. In this study, VOCs liberated while extruding acrylonitrile butadiene styrene (ABS) filaments from a 3D pen were measured by solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS). SPME was investigated using the traditional fiber and Arrow geometries with the DVB/Carbon WR/PDMS sorbent while four different brands of ABS filaments—Amazon Basics, Gizmodork, Mynt 3D, and Novamaker—were used with the 3D pen. Heatmap analysis showed differentiation among these brands based on the liberated VOCs. The nozzle temperature and printing speed were found to affect the number and amount of released VOCs. This study goes a step further and presents for the first time a comparison between 3D pen and a desktop 3D printer based on liberated VOCs. Interestingly, the findings reveal that the 3D pen releases a greater number and amount of VOCs compared to the printer. The amounts of liberated VOCs, as indicated by the corresponding chromatographic peak areas, were found to be 1.4 to 62.6 times higher for the 3D pen compared to the 3D printer when using SPME Arrow.

Balancing the "magic triangle" performance of tire rubber nanocomposites with novel low VOC silane coupling agents

Nowadays, coupling agents are still the core technology of the “green tire” industry, which not only effectively weaken the silica network but also enhance the interface interaction between silica and rubber matrix. However, the reaction between the traditional silane coupling agents and the silanol groups on silica surface generates a large amount of volatile organic compounds (VOCs), which can affect the performance of the rubber composites and pollute the environment. In this paper, a series of novel coupling agents with low VOC emission were synthesized by reacting fatty alcohol polyoxyethylene ethers of different polyether lengths (AEOX) with bis-[γ-(triethoxysilyl) propyl]-tetrasulfide TESPT (Si69). The structure of the novel coupling agent was characterized using FT-IR and 1H NMR. Meanwhile, it has been proven through FT-IR, XPS, TGA, and GCMS that the novel coupling agent can react with silica and reduce VOC emissions. Then the novel coupling agent was added into the silica/natural rubber (NR) nanocomposite. The test results of rubber composites showed that the addition of novel coupling agent can significantly enhance the dispersion of silica in the rubber matrix and effectively balance the "magic triangle" performance of tire. As a result, the rolling resistance of the silica/NR composites is reduced by 15.8 %, the wet skid resistance is improved by 14.2 %, and the abrasion resistance is improved by 20.3 %.

In situ construction of epoxy crosslinked Si-Al zeolite-like catalytic structure in wood to achieve high flame retardancy

As green renewable resources, wood and its composites are widely used in the construction field, which puts forward higher requirements for their flame-retardant performance. In this study, a high-temperature hydrothermal crystallization method for in situ constructing an epoxy crosslinked Si–Al zeolite-like structural wood composite (WZLC) was reported. Under the action of amine guiding agents and epoxy resin, the zeolite-like catalytic structure constructed in poplar wood comprised negative electrocatalytic sites, which can efficiently catalyze the formation of the carbon layer and endow WZLC with excellent flame retardant, smoke-suppression, and self-extinguishing properties. Compared with the untreated wood (WN), the thermal stability of the treated wood (WZLC) was greatly improved, and the amount of volatile organic compounds released during the decomposition process was significantly reduced. The heat release rate, total heat release, smoke production rate, and total smoke production of WZLC1 decreased by 50.23%, 44.14%, 45.21%, and 28.46%, respectively. Particularly, CO and CO2 yields of WZLC significantly decreased by 92.26% and 92.02%, respectively, indicating that the Si–Al zeolite-like catalytic structure displayed excellent catalytic flame retardant properties, which can effectively decrease the thermal decomposition rate and combustion risk of the WZLC. This method uses less flame retardants to achieve a good flame retardant and smoke suppression effect, thereby reducing the risk of environmental pollution caused by too many flame retardants.

Tailor-made fermentation of sourdough reduces the acrylamide content in rye crispbread and improves its sensory and nutritional characteristics

Thirty strains of lactic acid bacteria (LAB) and Saccharomyces cerevisiae E8.9 (wild type) were used to formulate fifteen combinations of starters by mixing two or three LAB with the yeast (ratio LAB: yeast, 10: 1). Such combinations were used to prepare rye sourdough and their performance in term of acidification and biochemical characteristics during fermentation at two temperatures (30 and 37 °C) and duration (4 and 8 h) were screened. The best thirteen sourdough formulations were selected and used for rye crispbread making. The analysis of acrylamide concentration demonstrated that 11 out 13 formulations resulted in significant decreases of concentration compared to the baker's yeast (control), with reductions up to 79.6 %. The rye sourdough crispbreads showed also higher amount of volatile organic compounds (VOCs) compared to the baker's yeast control. Two rye sourdough crispbreads, selected to represent the opposite extremes within the thirteen formulations in term of VOC profiles and fermentation performances, demonstrated better sensory and nutritional features, such as phytic acid reduction (up to 47.3 %), and enhanced total free amino acid compared to the control. These evidences suggest the potential of tailored sourdough fermentations as alternative and suitable biotechnological strategy for lowering acrylamide levels in rye crispbread.

Obtaining accurate non-methane hydrocarbon data for ambient air in urban areas: comparison of non-methane hydrocarbon data between indirect and direct methods

Abstract. Since non-methane hydrocarbons (NMHCs) include numerous species of volatile organic compounds (VOCs), they are the only indicators that can characterize the total amount of VOCs in ambient air. More than 90 % of NMHC instruments in the market use the indirect method for NMHC determination, utilizing a gas chromatograph to determine the concentrations of total hydrocarbons (THCs) and methane in air. However, we found indirect NMHC measurements incorrectly characterized the low NMHC concentrations in the urban air. These measurements were hindered by the uncertain changes in the errors associated with low THC concentrations, humidity and macroscopic substances (oxygen) in the atmosphere. In this study, we conducted intercomparisons between 10 instruments in the market using different operation principles; among these, two used the direct method, and eight used the indirect method. For the indirect method, experiments showed that when the NMHC concentration was 50 ppb C, the errors in the measurement results were 32 % (CH4) and 98 % (THC) when compared to theoretical values. The oxygen content in the sample gas directly affected the response of the THC. The effect of increased oxygen content on the analysis of oxygen-containing substances was more significant than that of the increase in hydrocarbon substances. The response of dry zero was blank, and the response value increased non-linearly with relative humidity (RH). RH had a great impact on low NMHC concentrations of nearly 50 %. For the direct method, although various flow designs were applied for different instruments, the results indicated that they generally showed lower interference and higher accuracy for the ambient NMHC measurements. With the online direct methods, we obtained more reliable data and characteristics for low-concentration NMHCs in downtown Shanghai. The median of hourly data was 163.1 ppb C, and the highest ratio of the maximum and minimum concentrations of NMHCs reached 9.56 in a single day.

Ozone containment through selective mitigation measures on precursors of volatile organic compounds

Abatement of volatile organic compounds (VOCs) ozone reduction is usually carried out by reducing the total amount of VOCs without considering reactivity between different species. This study incorporates the concept of maximum incremental reactivity (MIR) and speciation profiles into the industrial emission inventory of Taiwan to target organic species from industrial sources with the greatest ozone formation potentials (OFPs). These high OFP sources/species are then mitigated to assess the O3 reduction amount (ΔO3) with Community Multiscale Air Quality (CMAQ) modeling under VOC-limited conditions. The objective is to minimize the number of target sources/species and their tonnage while achieving maximum O3 reduction. This approach is referred to as the Selective Precursor Mitigation (SPM).A case study of a high ozone episode (September 4–10, 2020) was chosen for illustration, during which a relatively stagnant atmospheric condition with minimal transboundary ozone occurred. A series of scenarios to target the highest OFP chemicals/industries for mitigation are compared for the achievable max. ΔO3, areas affected (area coverage), and reduction efficiency. For instance, by reducing the ten leading industry classes with the island's highest OFPs (OFPind), up to 19 % of max. 1-h ΔO3 can be expected. If, however, the same tonnage of VOCs as that of OFPind is distributed to all industries without considering the reactivity, called the overall mitigation (OM), comparable results to those of OFPind were found, but the number of sources needed to be managed with OM would increase by nearly three times (29,662 for OM vs. 11,981 for OFPind). Further reducing the management scale by only zooming in the ten highest OFP chemicals within the ten leading OFP industries (OFPsp) would result in relatively limited area coverage. Still, major ozone hot spots could be alleviated.Although the domain is set on the island of Taiwan, the SPM approach is universally applicable to other regions worldwide to gain the maximum ozone reduction effect at a minimized societal cost.

Technical and environmental performance assessment of VOCs inhibited asphalt binders and mixtures

Asphalt materials will emit a large amount of volatile organic compounds (VOCs) under high temperature conditions, to address the environmental impact of asphalt pavement construction, this study selected different proportions of activated carbon (AC) and expanded graphite (EG) as composite inhibitors of asphalt VOCs, the road performance and environmental performance of asphalt mixtures are explored. Furthermore, the study proposed the VOCs resistance index (VRI) and VOCs environment-technique index (ETI) to evaluate the environmental and environmental-technical performance of asphalt mixture incorporating composite VOCs inhibitors. The results show that the VOCs inhibited asphalt mixtures with 5% AC-3% EG composite inhibitors has the best comprehensive environmental performance (80.15%), and its environmental technical performance (27.59%) is also the best, which is far higher than the other three VOCs inhibited asphalt mixtures. This study provides a reference and evaluation standard for the future development of efficient asphalt VOCs inhibitors.

Polymeric Fiber based Composite Coatings

Abstract: Environmental friendly products are becoming popular and acceptable in industries due to the global limitation to the amount of volatile organic compounds (VOCs) released into the atmosphere. Low VOC compounds and technologies are also becoming a choice in the coatings and paint industry. Coatings can be made from water or solvent. In coatings from water, we use water as the solvent, therefore coating called waterbased coating and in the case of solvent-borne coatings, we used organic or inorganic compounds as solvents, therefore this coating called as solvent borne coating. Among all different types of solvents water is the greatest choice among these low VOC technologies for usage as a solvent to manufacture chemical compounds and Paints and coatings. because water is often recognized as a low-cost, safe, non-toxic, easily availabl sand ecologically friendly solvent. Also nanomaterials is new field in research and development of material science field. Materials can be one dimensional such as small paricles, materilas can be two dimensional such as fibers. Therefore in two-dimensional materials such as fibers ( micro and nanofibers) use in many different applications such as medical, composites, aerospace, Bulding constructions etc. Nanofiber has the advantage of high surface area to volume ratio hence to decrease the coating defects. micro and nanofibers should be incorporated inside the coating matrix. This way one can improve the properties of waterbased coatings. Hence low VOC solvent water with high surface area fiber is becoming a trend in composite coating and nanotechnology in fibers. This review provides information on Composite coatings, distinct fibers used in coatings and their applications, effects of different sizes of fibers such as micro and nanofibers on coatings

Plasma Polymerization of Precipitated Silica for Tire Application.

Pre-treated silica with a plasma-deposited (PD) layer of polymerized precursors was tested concerning its compatibility with Natural Rubber (NR) and its influence on the processing of silica-silane compounds. The modification was performed in a tailor-made plasma reactor. The degree of deposition of the plasma-coated samples was analyzed by ThermoGravimetric Analysis (TGA). In addition, Diffuse Reflectance Infrared Fourier Transform spectroscopy (DRIFTs), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) were performed to identify the morphology of the deposited plasma polymer layer on the silica surface. PD silica samples were incorporated into a NR/silica model compound. NR compounds containing untreated silica and in-situ silane-modified silica were taken as references. The silane coupling agent used for the reference compounds was bis-(3-triethoxysilyl-propyl)disulfide (TESPD), and reference compounds with untreated silica having the full amount and 50% of silane were prepared. In addition, 50% of the silane was added to the PD silica-filled compounds in order to verify the hypothesis that additional silane coupling agents can react with silanol groups stemming from the breakdown of the silica clusters during mixing. The acetylene PD silica with 50% reduced silane-filled compounds presented comparable properties to the in-situ silane-modified reference compound containing 100% TESPD. This facilitates processing as lower amounts of volatile organic compounds, such as ethanol, are generated compared to the conventional silica-silane filler systems.

Exploitation of Selected Sourdough Saccharomyces cerevisiae Strains for the Production of a Craft Raspberry Fruit Beer.

Recent interest in the special beer category has encouraged the search for novel brewing materials, including new ingredients and novel yeast strains, in order to differentiate the finished products. The aim of this work was to select non-brewing S. cerevisiae strains for the production of a fruit beer with raspberry. The in vitro tests and the wort fermentations allowed the selection of two sourdough S. cerevisiae strains, showing high maltose and maltotriose consumption, high ethanol production, and high viability. Fruit beers (FB) and control beers (CB) without raspberries were prepared. Fruit addition accelerated sugar consumption (7 days compared to 13 days) and increased ethanol and glycerol production by yeasts. Raspberry addition and the inoculated yeast strongly affected the aroma profile of beers. FB samples showed a higher amount of volatile organic compounds (VOCs); the most represented classes were alcohols, followed by esters and acids. FB inoculated by the selected S. cerevisiae SD12 showed the highest VOCs concentration (507.33 mg/L). Results highlighted the possible application of sourdough yeast strains for the brewing process, which, combined with raspberry addition, can be exploited for the production of beers with enhanced aromatic features and suitable chemical properties.

VOCs emission from a final landfill cover system induced by ground surface air temperature and barometric pressure fluctuation

Volatile organic compounds (VOCs) emission flux and their concentration profiles were measured at a final municipal solid waste (MSW) landfill cover in Hangzhou, China. The influencing parameters, especially ground surface air temperature and pressure were monitored concomitantly. Furthermore, a numerical model incorporating coupled thermo-hydro-chemical interaction to assess VOCs emission from this final landfill cover (LFC) system was developed and validated with the field test results. The tested total VOC emission flux from the final cover is 0.0124 μg/m2/s, which indicates that the total amount of VOCs emitted into the atmosphere is 391 mg/m2 annually. Among these, dichloromethane (DCM) dominated VOCs emission flux during May, comprising 51.8% of the total emission flux. The numerical simulation results indicated that the diffusive emission flux of VOCs varied consistently with the fluctuation of atmospheric temperature. Whereas, the advective flux varied inversely with the fluctuation of barometric pressure. The highest difference in diffusive emission flux induced by temperature variation is 183 μg/m2/day and occurred in spring. Moreover, the results demonstrated that the impact of atmospheric temperature and pressure fluctuation on the emission of VOC from final covers is non-negligible when reasonably assessing the risks of landfill and landfill gas emission budget.

Emission factors and source profiles of VOCs emitted from coke production in Shanxi, China

Coking plants in China generate a substantial amount of volatile organic compounds (VOCs). The emission factors (EFs) of VOCs from coking plants are not well known, and thus, this study characterized the VOCs in the emissions from four coking plants in Shanxi, China. The EFs of VOCs from different stages of the coking process were calculated, and coal charging exhibited the highest EFs of VOCs, followed by the flue gases from combustion of coke oven gas, wastewater treatment, coke pushing and chemical byproduct recycling. The VOCs in emissions differed by coking process. Alkanes, aromatics and alkenes were the main VOCs emitted during the coking, wastewater treatment and chemical byproduct recycling processes, respectively. To effectively control the contribution of VOCs from coking processes to secondary organic aerosols and ozone formation, attention should be given to wastewater treatment and coal loading processes. The mean annual weight of VOCs emitted from coking plants in China from 2019 to 2021 was estimated to be 32.91 Gg with coking, chemical byproduct recycling, and wastewater treatment processes accounting for 91.34%, 7.85%, and 0.80% of total VOCs, respectively. An uneven spatial distribution of VOCs emissions in China was identified, with Shanxi, Shaanxi, Hebei, Inner Mongolia and Shandong being the largest contributors.

Study of synergistic effect of diatomite and modified attapulgite on reducing asphalt volatile organic compounds emission

The irritating flue gas generated during the heating process of asphalt is a serious emission pollution, causing both health risks and environmental hazards. In this work, a hybrid modified asphalt was prepared to reduce the volatile organic compounds (VOCs) emissions by using diatomite as the primary adsorption material and modified attapulgite as the flame retardant. The physical and rheological property tests showed that the compound of diatomite and modified attapulgite can improve the elevated temperature capability of the binder while slightly reducing the fatigue resistance. The results of the gas chromatography-mass spectrometer test (GC–MS) indicated that the total amount of VOCs released by the compound modifier modified asphalt was reduced by 81.5% compared with that of virgin asphalt (VA), the type of aliphatic hydrocarbons (ALHs) and hydrocarbon derivatives (HYDs) was also reduced by 77% and 92%, respectively. Scanning electron microscopy (SEM), simultaneous thermal (TG), and brunaurer emmett teller (BET) analysis showed that the mechanism of VOCs concentration reduction by the compound modifier might be chelation of dilution (water)-adsorption (hole)-blocking (insulating layer). This study provides a clean asphalt production method to reduce VOCs emission.

Volatile organic compounds and ionic substances contamination in cell processing facilities during rest period; a preliminary assessment of exposure to cell processing operators

IntroductionCell processing operators (CPOs) use a variety of disinfectants that vaporize in the workspace environment. These disinfectants can induce allergic reactions in CPOs, due to their long working hours at cell processing facilities (CPFs). Ionic substances such as CH3COO− generated from peracetic acid, nitrogen oxides (NOx) and sulfur oxides (SOx) from outdoor environment are also known to pollute air. Therefore, our objective was to assess the air quality in CPFs and detect volatile organic compounds (VOCs) from disinfectants and building materials, and airborne ionic substances from outdoor air. MethodsSampling was conducted at three CPFs: two located in medical institutions and one located at a different institution. Air samples were collected using a flow pump. Ion chromatographic analysis of the anionic and cationic compounds was performed. For VOC analysis, a thermal desorption analyzer coupled with capillary gas chromatograph and flame ionization detector was used. ResultsAnalysis of the ionic substances showed that Cl−, NOx, and SOx, which were detected in large amounts in the outdoor air, were relatively less in the CPFs. Ethanol was detected as the main component in the VOC analysis. Toluene was detected at all sampling points. As compared to the other environments, air in the incubator contained larger amounts of VOCs, that included siloxane, tetradecane, and aromatics. ConclusionsNo VOCs or ionic substances of immediate concern to the health of the CPOs were detected during the non-operating period. However, new clinical trials of cell products are currently underway in Japan, and a variety of new cell products are expected to be approved. With an increase in cell processing, health risks to CPOs that have not been considered previously, may become apparent. We should continue to prepare for the future expansion of the industry using a scientific approach to collect various pieces of information and make it publicly available to build a database.

Qualitative and Quantitative Recognition of Volatile Organic Compounds in Their Liquid Phase Based on Terahertz Microfluidic EIT Meta-Sensors

Volatile organic compounds (VOCs) are directly associated with human health concerns and environment safety. Therefore, it is urgent to achieve an accurate detection of VOCs both qualitatively and quantitatively. In this work, the qualitative detection of ethyl benzene (EB), isopropyl alcohol (IPA), ethyl acetate (EA) – three pure VOCs in liquid phase were discussed using terahertz (THz) microfluidic Electromagnetic Induced Transparency (EIT) meta-sensor. The THz response illustrated that with an increase in VOCs’ volumes (1~6μL), resonant frequencies of dual transmission dips (0.855, 1.724 THz) and the EIT peak (1.213THz) exhibited red shift. The limit of detections for pure IPA, EA, EB can achieve 5.45μg, 13.46μg, 4.35μg, respectively. The multivariate fusion (MF) model based on the EIT responses to VOCs was utilized to improve the accuracy of trace detection and classification of VOCs. Furthermore, the above method combined with principal component analysis with Gaussian mixture model (PCA-GMM) and the neural network classification algorithm support vector machine (SVM) was applied to the recognition of VOCs. In addition, the THz method is not feasible to detect trace amounts of VOCs (typically 0.3mg/L) in waste water because water is highly absorbable in THz band and VOCs will evaporate if water is removed. Here, IPA, EA, EB in soil were detected and classified by PCA-GMM combined with MF. Our results provide a new terahertz meta-sensor platform to trace detection of VOCs in liquid phase and in soil and may be used to identify hazardous wastes in illegal dumping.