Concentrations Of Volatile Organic Compounds Research Articles

Wintertime ozone surges: The critical role of alkene ozonolysis

Ozone (O3) pollution is usually linked to warm weather and strong solar radiation, making it uncommon in cold winters. However, an unusual occurrence of four high O3 episode days (with maximum hourly concentrations exceeding 100 ppbv and peaking at 121 ppbv) was recorded in January 2018 in Lanzhou city, China. During these episodes, the average daytime concentration of total non-methane volatile organic compounds (TVOCs) reached 153.4 ± 19.0 ppbv, with alkenes—largely emitted from the local petrochemical industry—comprising 82.3 ± 13.1 ppbv. Here we show a photochemical box model coupled with a Master Chemical Mechanism to elucidate the mechanisms behind this unusual wintertime O3 pollution. We find that the typically low temperatures (−1.7 ± 1.3 °C) and weak solar radiation (263.6 ± 60.7 W m-2) of those winter episode days had a minimal effect on the reactivity of VOCs with OH radicals. Instead, the ozonolysis of alkenes generated Criegee intermediates, which rapidly decomposed into substantial ROx radicals (OH, HO2, and RO2) without sunlight. This radical production led to the oxidation of VOCs, with alkene ozonolysis ultimately contributing to 89.6 ± 8.7% of the O3 formation during these episodes. This mechanism did not activate at night due to the depletion of O3 by the NO titration effect. Furthermore, the findings indicate that a reduction of alkenes by 28.6% or NOx by 27.7% in the early afternoon could significantly mitigate wintertime O3 pollution. Overall, this study unravels the unique mechanism of alkene-induced winter O3 pollution and offers a reference for winter O3 reduction strategies in the petrochemical industrial regions.

Systematic study of polymer gas sampling bags for offline analysis of exhaled breath

Polymeric bags are a widely applied, simple, and cost-effective method for the storage and offline analysis of gaseous samples. Various materials have been used as sampling bags, all known to contain impurities and differing in their cost, durability, and storage capabilities. Herein, we present a comparative study of several well-known bag materials, Tedlar (PVF), Kynar (PVDF), Teflon (PTFE), and Nalophan (PET), as well as a new material, ethylene vinyl copolymer (EVOH), commonly used for storing food. We investigated the influences of storage conditions, humidity, bag cleaning, and light exposure on volatile organic compound concentration (acetone, acetic acid, isoprene, benzene, limonene, among others) in samples of exhaled human breath stored in bags for up to 48 h. Specifically, we show high losses of short-chain fatty acids (SCFAs) in bags of all materials (for most SCFAs, less than 50% after 8 h of storage). We found that samples in Tedlar, Nalophan, and EVOH bags undergo changes in composition when exposed to UV radiation over a period of 48 h. We report high initial impurity levels in all the bags and their doubling after a period of 48 h. We compare secondary electrospray ionization and proton transfer reaction mass spectrometry in the context of offline analysis after storage in sampling bags. We provide an analytical perspective on the temporal evolution of bag contents by presenting the intensity changes of all significantm/zfeatures. We also present a simple, automated, and cost-effective offline sample introduction system, which enables controlled delivery of collected gaseous samples from polymeric bags into the mass spectrometer. Overall, our findings suggest that sampling bags exhibit high levels of impurities, are sensitive to several environmental factors (e.g. light exposure), and provide low recoveries for some classes of compounds, e.g. SCFAs.

Culinary evolution of cultured Takifugu Flavidus head soup: Nutrient dynamics and flavor profiles across cooking durations

This study aimed to examine the effects of different cooking durations on the nutrient composition and flavor profile of cultured Takifugu Flavidus head soup (CTHS). The dynamic changes of key nutrients and volatile organic compounds (VOCs) in CTHS during a 180-min cooking process were meticulously tracked using chemical analysis and headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results revealed a continuous increase in the content of proteins, lipids, sugars, amino acids (AAs), and fatty acids (FAs) in CTHS with extended cooking time, while the diversity and concentration of VOCs fluctuated. The unique flavor of CTHS was primarily attributed to the presence of key aldehyde compounds, such as (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, and decanal, with their levels declining after 120 min. Correlation analysis and principal component analysis (PCA) revealed a strong correlation between nutrients and VOCs. The increased levels of AAs and FAs exacerbated FA oxidation and Maillard reactions, thereby promoting the formation of key VOCs, especially after 90 min. In summary, controlling cooking duration is essential to establish a balance between nutrition and flavor in traditional cooking methods; the optimal quality CTHS can be achieved by cooking for 120 min. This study provided critical insights for enhancing the culinary quality and health benefits of traditional soups, while offering a scientific reference for gastronomy enthusiasts and the food industry.

Emission Characteristics and Environmental Impact of VOCs from Wooden Furniture-manufacturing Industry in China

Volatile organic compounds （VOCs） from the wooden furniture-manufacturing industry are an important emission source. To study the emission characteristics of VOCs from the wooden furniture-manufacturing industry and associated environmental impacts, nine typical wooden furniture manufacturers in China were selected to carry out sample collection and VOCs detection. The maximum incremental reactivity （MIR） method and secondary organic aerosol （SOA） formation potential method were used to quantify the corresponding contributions to the generation of O3 and SOA. The results showed that： ① The concentrations of VOCs emitted from different types of coating exhaust gas were different. The emission concentration of VOCs in solvent-based coating exhaust gas was significantly higher than that in water-based coating exhaust gas and ultra-violet （UV） coating exhaust gas, and the VOCs emission concentrations ranged between 2.82 - 155.37, 1.13 - 104.45, and 0.57 - 1.15 mg·m-3, respectively. ② The main organic group in solvent-based coating exhaust gas was esters, accounting for 45.88%, and butyl acetate （31.07%） was the main VOCs species. The main organic group in water-based coating exhaust gas and UV coating exhaust gas was alcohols, and the main VOCs species in water-based coating exhaust gas and UV coating exhaust gas were both ethanol, accounting for 46.63% and 34.32%, respectively. ③ The OFP of VOCs emitted by solvent-based coating, water-based coating, and UV coating were 149.23, 50.90, and 1.87 mg·m-3, respectively, and the primary contributing components of OFP of different types of coating were m/p-xylene （26.61%）, ethanol （36.35%）, and ethanol （23.98%）, respectively. ④ The SOA of VOCs emitted by solvent-based coating, water-based coating, and UV coating were 0.76, 0.25, and 0.01 mg·m-3, respectively. The SOA generation of various types of coating was dominated by aromatics（96.35%-98.96%）, and the main active compounds were toluene, ethylbenzene, and xylene. ⑤ Comparing the environmental impact of exhaust gas from solvent-based coating, water-based coating, and UV coating, it was found that the OFP and SOA generated by the VOCs emitted from solvent-based coating were much higher than those for water-based coating and UV coating. Therefore, the implementation of water-based coating and UV coating substitution strategy from the source could effectively reduce VOCs emissions and abate OFP and SOA productions.

Sensitivity Analysis of Atmospheric Ozone and Source Apportionment of Volatile Organic Compounds in Yinchuan City

Based on the observation data of O3 concentration in Yinchuan in 2022, the monthly variation characteristics of O3 concentrations were analyzed. Further, based on the observation data of meteorological elements, conventional pollutants, and volatile organic compounds （VOCs） concentrations at an urban site in Yinchuan from May to July, the difference in meteorological elements and precursor concentrations between the polluted days and the non-polluted days were compared. Then, the O3 sensitivity and the VOCs sources were discussed using the Framework for 0-D Atmospheric Modeling （F0AM） and positive matrix factorization （PMF） model, respectively. The results showed that： ① The O3 pollution occurred from May to July in 2022, and the concentrations of O3-8h-90per were 156 μg·m-3, 170 μg·m-3, and 174 μg·m-3, respectively, with exceeding standard rates of 9.7%, 26.7%, and 29.0%, respectively. ② Compared with those on the non-polluted days, the hourly mean values of temperature, total solar radiation, and concentrations of various precursors on the O3-polluted days increased, including the volume concentrations of propane, isobutane, ethane, n-butane, and dichloromethane, which increased significantly by 33.1%, 29.1%, 25.0%, 22.7%, and 21.3%, respectively. The results showed that the combined increase in pollutant emissions and adverse meteorological conditions contributed to the formation of O3. ③ From May to July 2022, the top five VOCs species in terms of ozone formation potential （OFP） value on whole, non-polluted, and polluted days were the same. They were acetaldehyde, m/p-xylene, ethylene, isoprene, and toluene, mainly from solvent use sources, natural sources, and chemical industry emissions. ④ The local O3 production was mostly controlled by VOCs, and the relative incremental reactivity （RIR） results revealed that O3 production showed strong positive sensitivity to alkene and aromatic hydrocarbon but showed negative sensitivity to NOx on both polluted and non-polluted days. The relative contributions of active species such as acetone, ethylene, and isobutane to O3 production were high, and the implementation of an emission reduction scheme with the ratio of VOCs to NOx emission reduction much greater than 1 could effectively reduce the local O3 concentration. ⑤ The main sources of atmospheric VOCs in Yinchuan were motor vehicle emission sources （32.3%）, process sources （20.7%）, combustion sources （19.2%）, solvent use sources （12.7%）, gasoline volatile sources （9.1%）, and natural sources （6%）, and the contribution rate of motor vehicle emission sources on polluted days increased by 4.6% compared with that on non-polluted days, indicating that the motor vehicle emission source was an important object of summer VOCs control in Yinchuan.

Pollution Characteristics and Source Apportionment of VOCs in Urban Areas of Shijiazhuang in Spring

Samples of ambient volatile organic compounds （VOCs） were collected using SUMMA canisters at three Country Control Sites in Shijiazhuang during the spring of 2019, 2021, and 2022, which were detected using gas chromatography/mass spectrometry （GC/MS）. To investigate the characteristics and temporal variations of VOCs mass concentration levels, the online monitoring data of ozone （O3） and PM2.5 at the same site were also collected. Subsequently, the ozone formation potential （OFP） and secondary organic aerosol formation potential （SOAFP） were utilized to assess the chemical activity of VOCs. Additionally, the potential source areas of VOCs in spring in Shijiazhuang were further identified using the potential source contribution factor （PSCF） method and concentration weight trajectory analysis （CWT）. Hence, the major VOCs sources were evaluated with the VOCs initial mixing ratio. The results demonstrated that the averaged concentration of VOCs during the polluted period and clean period of spring in Shijiazhuang were 191.17 μg·m-3 and 122.18 μg·m-3, respectively. Meanwhile, the OFP was 361.23 μg·m-3 during the polluted period and 266.96 μg·m-3 during the clean period, whereas the SOAFP was 1.98 μg·m-3 and 1.61 μg·m-3, respectively. Therefore, effective control of benzene, toluene, ethylbenzene, and xylene （BTEX） is crucial for reducing PM2.5 and O3 pollution. Based on the results obtained from weight PSCF and CWT, the potential source areas of VOCs were further identified to be primarily located in the eastern Yuhua District, the high-tech district, and the northern Luancheng District of Shijiazhuang. These areas were influenced not only by local emissions but also by transport from neighboring regions, in which consistency between the CWT and PSCF results further supported these findings. Furthermore, the results obtained from the benzene/toluene/ethylbenzene （B/T/E） and xylene/benzene （X/B） ratios indicated that the main sources of VOCs in Shijiazhuang in spring were vehicle exhaust sources and burning sources, leading to a more serious air mass aging phenomenon. Hence, controlling vehicle emissions and implementing regional cooperative measures are the effective strategies for optimizing the air quality of Shijiazhuang.

Short-term temporal variability of volatile contaminant concentrations in soil gas related to soil-atmosphere interface dynamics: Two case studies in the Veneto region (Italy).

The study of the variability of soil gas concentrations is crucial for defining effective monitoring and remediation strategies and for the risk assessment related to the emission of vapors from the subsurface. The traditional soil gas monitoring strategy consists of seasonal surveys based on short-time-averaged sampling. Soil gas monitoring results are often used to assess the risk associated with the emission of volatile contaminants from the subsurface, using models mainly based on molecular diffusion and therefore assuming continuous emission from the soil. At two contaminated sites located in the Veneto region (Italy), continuous monitoring using a photoionization detector, pressure gauges, and an ultrasonic anemometer was used to relate soil gas variability to surface and subsurface physical parameters. At both sites a cyclic diurnal variation of volatile organic compounds concentration in soil gas was observed, correlated with the variation of several meteorological parameters and in particular with the variation of the differential pressure between soil and atmosphere and the buoyancy vertical flux. These findings question the reliability of the conventional methodology employed in the collection and assessment of soil gas data. Integr Environ Assess Manag 2024;20:2023-2032. © 2024 SETAC.

Interference Effect of Tree Spacing on Natural Volatile Organic Compound Concentrations Measured Using Passive Samplers

Research highlights: The increasing rates of mental health disorders during the COVID-19 pandemic have popularized the notion of access to natural environments as a solution, leading to a surge in demand for urban green spaces. The concentration of natural volatile organic compounds (NVOCs) in forests, resulting from plant metabolism, plays a crucial role in forest-based healing and ecosystem health. Background and objectives: This study aimed to investigate how tree spacing influences NVOC concentrations within forest ecosystems using passive samplers, thereby enhancing the understanding of optimal forest management practices to promote human health benefits. Methods: We employed passive samplers to investigate tree spacing effects on NVOC concentrations. We placed passive samplers among trees in the study area to measure NVOC concentrations in individual trees and analyzed the relationship between NVOC concentration and tree spacing and structure. Results: A multiple regression analysis using distance decay models showed that a tree spacing of 2.7–3 m had a significant impact on NVOC concentrations. These findings provide a better understanding of how tree structure, tree spacing, and microclimate within the forest influence NVOC concentration. Conclusion: These findings have important implications for forest management and the design of forest landscapes to promote human health and well-being by considering the spatial distribution of NVOC concentrations.

A sprinkler- water cycle PEC-MFC system with bimetallic monatomic Co-Fe/g-C3N4/ACF cathode achieves efficient removal of gas trimethylamine

Volatile organic compounds (VOCs) air pollutants are the precursors of ozone and PM2.5, all harmful to human health. To reduce the equipment volume further and improve the treatment capacity at room temperature, a novel microbial fuel cell (MFC) system, with a sprinkler and water recycle module, was designed to integrate bio-electricity generation from biodegradation and photocatalytic oxidation of VOCs over cathodic diatomic Co-Fe/g-C3N4 doped activated carbon felt (Co-Fe/g-C3N4/ACF). The removal of trimethylamine in both the gas and liquid phase was proved (VOCs concentration in air ≈ 0.93 g m−3, the removal capacity reached ≥ 119.97 mg gcat-1h−1). Through the sprinkler-water cycle, the trimethylamine molecules in air transferred and diffused to the liquid phase, then acted as the only carbon source for the electrogenic bacteria, that supplied the electricity to drive photoelectric catalysis under light illumination. The high efficiency (>2086 mg gcat-1h−1) and low energy consumption in the new system at room temperature means broad application prospect in VOCs treatment.

Hydrogen Gas-Grilling in Meat: Impact on Odor Profile and Contents of Polycyclic Aromatic Hydrocarbons and Volatile Organic Compounds.

The effect of fuel (hydrogen vs. butane) on the formation of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) was evaluated for grilled horse meat (very low-fat and low-fat) cooking vertically. Gas chromatography-mass spectrometry was used to analyze PAHs and VOCs. An electronic nose was used to evaluate the odor profile. Total high-molecular-weight PAHs ranged from 19.59 to 28.65 µg/kg with butane and from 1.83 to 1.61 µg/kg with hydrogen. Conversely, total low-molecular-weight PAHs went from 184.41 to 286.03 µg/kg with butane and from 36.88 to 41.63 µg/kg with hydrogen. Aldehydes and alkanes were the predominant family in a total of 59 VOCs. Hydrogen gas-grilling reduced significantly (p < 0.05) the generation of VOCs related to lipid oxidation. The odor profile was not modified significantly despite the change of PAHs and VOCs. The findings indicate that hydrogen is a viable alternative to butane for grilling horse meat. Hydrogen gas-grilling may be regarded as a safe cooking procedure of meat from a PAH contamination point and perhaps sustainable environmentally compared to a conventional technique. The present study provides the basis for the use of hydrogen gas in grilled meat.

Mapping air quality variations in industrial and agricultural zones: Understanding spatial and temporal patterns of selected air pollutants

With the escalating threat of air pollution on the biota, the need for research on pollutants has become imperative in industrial, urbanized and heavily populated cities. This study aimed to determine the level of major outdoor atmospheric pollutants (PM10, PM2.5, TVOCs, and HCHO) in specific locations including industrial and agricultural zones. Field measurements for this research, spanning 52 locations, were collected in the spring season using a portable instrument, and spatial variation maps were developed using ArcGIS software. The study measured PM10 concentrations ranging from 31 μg/m3 to 267 μg/m3 and PM2.5 concentrations ranging from 27 μg/m3 to 253 μg/m3. PM2.5 levels at most sites exceeded USEPA, WHO, and PEQS standards, while PM10 levels generally met these standards. The highest values of coarse and fine particulate matter were observed in areas dominated by emissions from the textile industry. Furthermore, particulate matter concentrations showed spatial variations, increasing towards the North and East directions. The Total Volatile Organic Compounds (TVOCs) concentrations, ranging from 0 mg/m3 to 4.019 mg/m3, exceeded Hong Kong SAR standards at five locations, thereby elevating health risks for residents in these areas. Similarly, formaldehyde levels, ranging from 0 mg/m3 to 0.754 mg/m3, surpassed the Hong Kong SAR standard at seven locations, indicating a substantial threat of exposure for the local population. In general, air quality at most field sampling sites was registered as UNQUALIFIED but was also observed to be FRESH at a few locations. This research is significant for understanding the levels of major pollutants so that the concerned authorities can take appropriate measures to tackle air pollution by introducing pollution control technologies in industries, switching to renewable energy options, and managing road dust.

Effect of Alkylresorcinols Isolated from Wheat Bran on the Oxidative Stability of Minced-Meat Models as Related to Storage.

Due to their antioxidant activity, alkylresorcinols (ARs) extracted from by-products could represent promising natural and innovative antioxidants for the food industry. This study tested the ability of ARs isolated from wheat bran to increase the shelf-life of minced-meat models stored at 4 °C for 9 days. Fifteen alk(en)ylresorcinols (C17-C25) were recognized by GC/MS, showing good radical-scavenging (200.70 ± 1.33 μmolTE/g extract) and metal-chelating (1.38 ± 0.30 mgEDTAE/g extract) activities. Two ARs concentrations (0.01% and 0.02%) were compared to sodium ascorbate (0.01% and 0.10%) on color (CIELAB values L*, a*, b*, chroma, and hue) and oxidative stability (lipid hydroperoxides, thiobarbituric acid reactive substances (TBARS), and volatile organic compounds (VOCs)) of minced-beef samples. ARs-treated samples were oxidatively more stable than those formulated with sodium ascorbate and the negative control, with significantly lower contents of hydroperoxides and VOCs (hexanal, 1-hexanol, and 1-octen-3-ol) throughout the experiment (p < 0.001). However, no effect on color stability was observed (p > 0.05). Since 0.01% of ARs was equally or more effective than 0.10% sodium ascorbate, those results carry important implications for the food industry, which could reduce antioxidant amounts by ten times and replace synthetic antioxidants with natural ones.

Polyphenylene oxide based lossy mode resonance fiber sensor for the detection of volatile organic and inorganic compounds

This study presents the fabrication and characterization of a fiber optic gas sensor based on Lossy Mode Resonances (LMR). For the first time to our knowledge, a nanosized coating of polyphenylene oxide (PPO) is deposited on a cladding removed multimode silica fiber, serving both as the LMR supporting coating and sensitive overlay. The device exhibits a notable sensitivity of 2500 nm/RIU when immersed in glycerol-water based solutions. For gas detection, the PPO-based LMR device is exposed to varying concentrations of different volatile organic and inorganic compounds, including two alcohols (methanol and ethanol) and ammonia. The sensor demonstrates similar responses to methanol and ethanol gases with a sensitivity of about 0.56 nm/ppm and sensitivity of 0.25 nm/ppm to ammonia in the concentration range of 2.5–37.5 ppm, achieving limits of detection of a few ppm. To comprehensively evaluate the sensor performance, the investigation is also focused on the repeatability, reversibility, response times, as well as cross sensitivity to temperature and relative humidity.

Characteristics and Source Apportionment of Volatile Organic Compounds in a Coastal Industrial Area: A Case Study in the Yangtze River Delta of China.

In recent years, the coastal area in East China has experienced elevated volatile organic compounds (VOCs) levels during specific periods. VOCs have become one of the major atmospheric pollutants in these areas. In this study, 64 compounds including alkanes, alkenes, halohydrocarbons, aromatics, and oxygenated VOCs (OVOCs) were obtained by the TO-15 method through a 12-month campaign in industrial, urban and suburban areas in the Yangtze River Delta of China. The overall trends of total VOC (TVOC) concentrations at eight sampling sites were as follows: winter > autumn > spring > summer. The proportion of VOC categories was various at industrial sites, while OVOCs and halohydrocarbons had high proportions at urban sites and suburban sites, respectively. Coating, vehicle emission, petrochemical source, industrial source, and gasoline volatilization were identified as the major VOC emission sources by the positive matrix factorization model. Petrochemical and coating sources were the prime VOC sources at industrial sites. Aromatics contributed the most ozone formation potential at industrial sites, while OVOCs provided the main contributions at both urban and suburban sites during four seasons. According to the health risk assessment, a high probability of non-carcinogenic risk existed at three industrial sites. Special attention should be given to certain VOCs, such as acrolein and 1,2-dibromoethane in industrial areas.

A study of 9 common breath VOCs in 504 healthy subjects using PTR-TOF-MS.

This study employs Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) to analyze exhaled breath profiles of 504 healthy adults, focusing on nine common volatile organic compounds (VOCs): acetone, acetaldehyde, acetonitrile, ethanol, isoprene, methanol, propanol, phenol, and toluene. PTR-MS offers real-time VOC measurement, crucial for understanding breath biomarkers and their applications in health assessment. The study aims to investigate how demographic factors-gender, age, and smoking history-affect VOC concentrations in exhaled breath. The objective is to enhance our understanding of breath biomarkers and their potential for health monitoring and clinical diagnosis. Exhaled breath samples were collected using PTR-MS, measuring concentrations of nine VOCs. The data were analyzed to discern distribution patterns across demographic groups. Males showed higher average VOC levels for certain compounds. Propanol and methanol concentrations significantly increased with age. Smoking history influenced VOC levels, with differences among non-smokers, current smokers, and ex-smokers. This research provides valuable insights into demographic influences on exhaled VOC profiles, emphasizing the potential of breath analysis for health assessment. PTR-MS's real-time measurement capabilities are crucial for capturing dynamic VOC changes, offering advantages over conventional methods. These findings lay a foundation for advancements in non-invasive disease detection, highlighting the importance of considering demographics in breath biomarker research.

An original device to assess the respiratory impact of indoor air VOCs mixture using an in vitro approach

Exposure to indoor air pollution, particularly volatile organic compounds (VOCs), has been recognized as a risk factor in the development of respiratory and allergic diseases. VOCs are mainly emitted continuously at low concentrations from construction furniture and decoration products. Measurement campaigns carried out in new dwellings in France have shown that aldehydes predominate with a tendency to decrease formaldehyde concentrations and to increase those in hexanal. As the main route of VOCs exposure is inhalation, this project assessed the impact of a mixture of 17 VOCs representative of indoor air (in quality and quantity) on respiratory health using an in vitro approach. This original work was based on the set-up of an experimental device, combining a gas generation and dilution bench and exposure to the air-liquid interface (ALI) adapted to the reconstructed human airway epithelium model. The VOC mixture was enriched with formaldehyde or hexanal in different proportions (from 20 to 240 µg.m−3) to study the biological impact of these aldehydes after repeated exposures of airway epithelium. After examination of the stability of the VOC concentrations in generated mixtures and the found of the optimal operating conditions for the dynamic gas generating system, the gaseous mixtures were distributed to the epithelium using the ALI exposure system providing direct contact between the epithelium and the tested mixtures. Our device lead to reproduce real conditions of human exposure. The results showed that the inflammatory response, assessed by the production of four cytokines, varied according to the nature of the aldehyde present in the VOC mixture (formaldehyde or hexanal), its concentration, and the duration and number of exposures applied. The most original and innovative results concern those obtained with hexanal, pollutant under-researched. Our results showed that this aldehyde could pose risks to respiratory health.

Expose to volatile organic compounds is associated with increased risk of depression: A cross-sectional study

With increasing prevalence rate of depression by years, more attention has been paid to the influence of environmental pollutants on depression, but relationship between exposure to volatile organic compounds (VOCs) and depression is rarely studied. Therefore, this cross-sectional study use the National Center for Health Statistics (NHANES) database (2013–2016 years) to explore association between exposure to multiple VOCs and depression in general population. Multiple linear and logistic regression models were used to analyze the association between urinary VOC metabolism (mVOCs) and depression. To further analyze effect of multiple mVOCs mixed exposure, Bayesian kernel machine regression (BKMR) models were performed. A total of 3240 participants and 16 mVOCs were included in the analysis. Results showed that 10 mVOCs exposure were positively correlated with depression by multiple linear and logistic regression models, especially CYMA and MHBMA3, which also showed significant positive association with depression in BKMR model. Mixed exposure of multiple mVOCs was significantly positively correlated with depression. Gender differences were existed in effects of some VOCs concentrations on depression. AAMA, CYMA and MA had significant positive correlations with depression by women, and DHBMA had significant positive correlations with depression by men. Hence, this study showed that exposing to VOCs might have negative impacts on depression, and impact of CYMA and MHBMA3 on depression may be more evident, which provide new ideas for prevention and control of depression. But further research and exploration are needed to clarify the mechanism and influence factors of this relationship, to demonstrate the reliability of these relationship.

Assessing VOC emissions from different gas stations: impacts, variations, and modeling fluctuations of air pollutants

Gas stations distributed around densely populated areas are responsible for toxic pollutant emissions such as volatile organic compounds (VOCs). This study aims to measure VOCs emission from three different kinds of gas stations to determine the extent of pollution from the gas stations and the most frequent type of VOC compound emitted. The concentrations of ambient VOCs at three refueling stations with a different type of fuels in Mashhad were monitored. The result of this study showed that CNG fuel stations are less polluting than petrol stations. In all the studied sites, the highest concentrations were related to xylene isomers, irrespective of the fuel type. Total VOCs at the supply of both compressed natural gas (CNG) and gasoline stations was 482.36 ± 563.45 µg m−3. At a CNG station and a gasoline station, total VOC concentrations were 1363.4 ± 1975 µg m−3 and 410.29 ± 483.37 µg m−3, respectively. The differences in concentrations of toluene and m,p-xylene between the fuel stations can be related to the quality and type of fuel, vapor recovery technology, fuel reserves, dripless nozzles, traffic density in these stations, meteorological conditions and the location of sampling sites. The combination of a sine function and a quadratic function could model the fluctuation behavior of air pollutants like m,p-xylene. In all the sites, the highest concentrations were related to xylene isomers, irrespective of the type of fuel. The changing rate of m,p-xylene pollutant in each station was also modeled in this study.

Transcriptomic and Physiological Analysis Reveals the Possible Mechanism of Inhibiting Strawberry Aroma Changes by Ultrasound after Harvest.

The volatile compounds in strawberries play a significant role in the formation of strawberry aroma. However, these compounds undergo continual changes during storage, resulting in a decline in quality. In this study, a total of 67 volatile organic compounds (VOCs) were identified in strawberries through quantitative analysis. At the end of the storage period, the VOC content in the ultrasonic group was 119.02 µg/kg higher than that in the control group. The results demonstrated that the ultrasonic treatment increased the contents of terpenes and esters at the end of storage. Among these, linalool increased from 67.09 to 91.41 µg/kg, while ethyl cinnamate increased from 92.22 to 106.79 µg/kg. Additionally, the expression of the key metabolic genes closely related to these substances was significantly up-regulated. The expression of the FaNES gene, related to terpene metabolism, was up-regulated by 2.8 times in the second day, while the expression of the FaAAT gene, related to ester metabolism, was up-regulated by 1.5 times. In summary, this study provides a theoretical basis for exploring the mechanism of ultrasonic effect on strawberry flavor and quality after harvest.

GIS-Based Analysis of Volatile Organic Compounds in Bucheon, Korea, Using Mobile Laboratory and Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry Methods.

Recently, volatile organic compounds (VOCs) have been shown to act as precursors of secondary organic particles that react with ultraviolet rays in the atmosphere and contribute to photochemical smog, global warming, odor, and human health risks, highlighting the importance of VOC management. In this study, we measured VOC concentrations in various contexts including industrial and residential areas of Bucheon, Korea, through mobile laboratory and proton-transfer-reaction time-of-flight mass spectrometry methods to determine winter VOC concentrations and visualized the data based on spatial information. Regional characteristics, temperature/humidity, atmospheric conditions, wind speed, traffic volume, etc., during the measurement period of the study site were comprehensively reviewed. For this purpose, global information system (GIS)-based air quality data and various environmental variables were comprehensively reviewed to assess spatial and temporal concentrations in three dimensions rather than in tables and graphs. Among VOCs, the levels of toluene, methanol, and n + i-butene were relatively high, with average concentrations of 48.3 ± 67.2, 34.4 ± 102.7, and 32.6 ± 57.7 ppb, respectively, at the end of the working day. The highest concentrations occurred near the Ojeong Industrial Complex. Mobile pollution sources are also a major driver of VOCs, highlighting the necessity of comprehensively reviewing traffic variables such as road level, estimated traffic volume, and average speed when identifying hotspots of air pollution. GIS-based visualization analysis techniques will improve the efficiency of air quality management.