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This work presents a year-long integral study of air quality parameters in Ciudad Real, a small city in the center of Spain, and its influence on the nearby national park, Las Tablas de Daimiel. The study covers meteorological parameters and criteria pollutants such as O3, NO, NO2, SO2, and PM10. Additionally, for each month, a 1-week campaign was performed sampling air in sorbent tubes with 8-h time resolution to analyze anthropogenic volatile organic compounds and the effects of seasons, daytime, and working-weekend days. During these campaigns, 24-h PM2.5 samples were also collected to measure the load of bacteria and fungi, as well as the trace concentrations of elements. The city and the national park NOx profiles showed that emissions from the town had a non-perceivable effect on the protected area. PM10 levels in Ciudad Real were influenced by Saharan intrusions, as was the national park; however, Ciudad Real had a higher contribution from anthropogenic sources. Ozone levels were lower in the city during the cold season due to the higher concentration of NOx and have not changed significantly in the last decade. The VOCs with higher average concentrations were toluene, m,p-xylene, benzene, methylene chloride, and o-xylene, with traffic being the main source of these pollutants in the city. For benzene and carbon tetrachloride levels, weak carcinogenic risks were estimated. In PM2.5, the most abundant metals were Na, Zn, Mg, Ca, Al, Fe, and K. The carcinogenic and non-carcinogenic risks estimated from the levels of the studied metals were negligible. Bacterial and fungal counts positively correlated with the concentration of PM2.5. Microbial community composition showed seasonal variability, with the dominance of human pathogenic bacteria which correlated with certain pollutants such as SO2. Bacillus and Cutibacterium were the most abundant genera. [ABSTRACT FROM AUTHOR]

Understanding the pollution levels, potential sources, and chemical reactivity of atmospheric volatile organic compounds (VOCs), the key precursors of ozone (O3) and fine particulate matter (PM2.5), is important for emission control and air pollution abatement. This study presents a systematic VOCs analysis in a less studied heavy industrial urban agglomeration located in Northeast China. Using a cruising platform, we conducted real-time monitoring of VOC concentrations and components at Changchun (CC), Jilin (JL), Siping (SP), and Liaoyuan (LY) in Jilin Province. During the observation period, the average VOC concentrations at CC, JL, SP, and LY were 63.38 ± 127.03, 260.39 ± 855.76, 18.06 ± 17.17, and 10.12 ± 17.48 µg/m3, respectively. Halocarbons were predominant with a high percentage of contribution (22.4–31.1%) to the total observed VOCs for all cities. Combined with 2020-based anthropogenic VOCs emission inventory of Jilin Province, we concluded that industrial processes had the largest contribution to VOCs concentration in CC, whereas petrochemical emission was the major source of VOCs in JL. The assessment of atmospheric photochemical reactivity indicates the dominant role of aromatics and alkenes in O3 formation potential (OFP). As the second-most abundant species in CC and JL, aromatics contributed over 50% of the OFPs. Alkenes played a dominant role in O3 formation in SP and LY, accounting for nearly half of the total OFPs. Considering the VOC emission characteristics and OFP results, we suggest that reducing aromatics emissions, particularly benzene, toluene, ethylbenzene, and xylene, should be given higher priority to mitigate O3 pollution and prevent health risks. Moreover, industrial-related, and petrochemical sources are crucial in the evolution of O3 pollution, which should be incorporated into heavy industrial urban air quality management and targeted control of O3 pollution in Northeast China. [ABSTRACT FROM AUTHOR]

The Maptaphut industrial area, one of the largest petrochemical complexes in Thailand, is the major cause of the various air pollutants. The larger concern is that a significant volume of air pollution is emitted and that air quality management needs to be improved. This is in part due to a lack of deeper understanding of how anthropogenic emissions are emitted from different sources in this area— especially volatile organic compounds (VOCs). Moreover, it has complicated relationship results of air pollution, disease mechanisms, and health effects. As a result, its available data can only give a rough indication of them. These factors are often assumed to be associated with economic consequences, but assessing the health-related economic losses caused by air pollution remains limited in many ways. Four targeted VOCs were analyzed, including benzene, 1,3-butadiene, 1,2-dichloroethane, and vinyl chloride from industrial and non-industrial sources, namely stacks, flares, storage tanks, wastewater treatment plants, transportation and marketing, fugitive losses, slurry/open equipment/vessel, and on-road mobile emissions. Source apportionment can be conducted using emissions inventory (EI) to establish pollution source databases, the dispersion model, and then imported on the risk model by determining receptors. The AERMOD dispersion model coupled with the IRAP-h view model was used to predict the spatial distribution of the ground-level concentration and analyze the inhalation health risk covering cancer and non-cancer risks— as well as the prioritization of pollutants. The risk assessment results indicated that the highest risk occurred most from 1,3-butadiene for cancer and chronic non-cancer risks contributed to fugitive sources, about 83% and 94%, and most benzenes for acute non-cancer risk contributed to on-road mobile sources, at about 56%. Consequently, the benzene classified as the most important priority depending on its risk results, comprehensive epidemiological studies, and discharge volumes. With the economic benefits assessment, BenMAP-CE was further utilized to estimate the health impacts and economic value of multiple scenarios to facilitate decision-making for benzene reduction. Overall, the 10% rollback policy for benzene concentration, monetized value of about 13.13 billion US dollars for all mortalities, gave the best practical scenario for the most economically viable option based on the B/C (benefit/cost) ratio results in Maptaphut. Ultimately, policymakers need to take additional measures to improve air quality and reduce health impacts while also considering economic benefits, especially benzene reduction. [ABSTRACT FROM AUTHOR]

This study established a novel infield sensing approach based on detection of the volatile compound markers in skin secretions. This was based on analysis of volatile compounds in axillary sweat samples collected from RT-PCR-proven Coronavirus disease 2019 (COVID-19) positive and negative populations using gas chromatography-mass spectrometry (GC–MS). The analysis proposed the possible markers of the monoaromatic compounds and ethyl hexyl acrylate. A portable photo ionization detector (PID) incorporated with the selective material towards the marker compounds was then developed with the pressurized injection approach. This provided the accuracy of 100% in the research phase (n = 125). The developed approach was then applied for screening of 2207 COVID-19 related cases covering the periods of the Alpha, Beta, Delta and Omicron variants of SARS-CoV-2 infection in Bangkok, Thailand. This offered the sensitivity, specificity and accuracy ranges of 92–99, 93–98 and 95–97%, respectively. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are continuously emitted into the atmosphere from natural and anthropogenic sources and rapidly spread from the atmosphere to different environments. A large group of VOCs has been included in the class of air pollutants; therefore, their determination and monitoring using reliable and sensitive analytical methods represents a key aspect of health risk assessment. In this work, an untargeted approach is proposed for the evaluation of the exposure to volatile organic compounds of workers in an engine manufacturing plant by GC–MS measurements, coupled with solid-phase microextraction (SPME). The analytical procedure was optimized in terms of SPME fiber, adsorption time, desorption time, and temperature gradient of the chromatographic run. For the microextraction of VOCs, the SPME fibers were exposed to the air in two different zones of the manufacturing factory, i.e., in the mixing painting chamber and the engine painting area. Moreover, the sampling was carried out with the painting system active and running (system on) and with the painting system switched off (system off). Overall, 212 compounds were identified, but only 17 were always present in both zones (mixing painting chamber and engine painting area), regardless of system conditions (on or off). Finally, a semi-quantitative evaluation was performed considering the peak area value of the potentially most toxic compounds by multivariate data analyses. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs), play a crucial role as precursors of ozone (O3) and secondary organic aerosols, making them significant air pollutants. Efforts to effectively eliminate ethyl acetate (EA), a typical VOC in many industrial processes, has attracted significant attention worldwide. In this study, a catalyst consisting of MgAl2O4 spinel prepared via the sol-gel method was adopted to support MnOx by incipient wetness impregnation for complete catalytic oxidation of EA. The prepared catalysts were characterized by XRD, SEM, TEM, BET, XPS and H2-TPR. It was found that the calcination temperature of the support is crucial for the catalytic activity. The optimal calcination temperature of the support is found to be 800°C, resulting in a perfect MgAl2O4 spinel phase and a crystalline size of 8.3 nm. The optimized MnOx/MA-800 displayed high catalytic activity (T95 = 240°C) and stability due to its high reduction ability and high atomic ratios of Mn4+/Mn3+ and Oads/O. [ABSTRACT FROM AUTHOR]

Dynamic adsorption is important for evaluating the Volatile Organic Compounds (VOCs) adsorption performance. During adsorption process, the exothermal characteristic could lead to an increase of the column temperature, which might cause bed combustion and is negative to the adsorption efficiency. In present study, we chose graphene oxide(GO) as adsorbent, comparing with hypercrosslinked polymeric adsorbent(HPA), and conducted the dynamic adsorption experiment of ethanol, n-hexane and cyclohexane at 308 K, 318 and 328 K with different adsorbent column height. The results showed that the temperature had linear and negative influence on breakthrough capacity for three VOCs on two adsorbents. And the breakthrough adsorption capacity of ethanol, n-hexane and cyclohexane on two adsorbents were as follows: ethanol > cyclohexane > n-hexane, closely related with physical parameters of VOCs. But the physical properties of ethanol, n-hexane and cyclohexane have little influence on dynamic adsorption rate in this paper. In addition, for n-hexane and cyclohexane, the breakthrough adsorption capacity on HPA were higher than that on GO, but their k values were similarity on HPA and GO. While for ethanol, the breakthrough capacity and k value on GO were higher than HPA. Most important of all, the negative effect of temperature on VOCs adsorption on GO was lower than HPA. Therefore, GO is a good alternative adsorbent for VOCs recovery. Furthermore, with higher column height, the dynamic adsorption capacity was higher but the adsorption rate was lower. While the influence of temperature on dynamic adsorption capacity and rate were relative independent with column height of adsorbent. [ABSTRACT FROM AUTHOR]

Herbivorous insects assess and choose their potential host plants based on traits that may correlate with host suitability or quality. These traits may operate as cues for better resources, noxious chemicals, or fewer competitors and enemies. Interactions between insects and their host plants may also be modulated by the nutritional value of the plant, by plant chemical stimuli, or by physical traits such as trichomes. Differences in chemical or physical cues among plants may convey information about diet suitability. Several studies have addressed the topic of differences in plant traits between host and non-host plants; fewer have addressed these differences among potential host plants. We have studied the effect of chemical and physical plant traits on the feeding and oviposition preferences of the oligophagous herbivore Epilachna paenulata (Coleoptera: Coccinellidae) and two of its host plants, Cucurbita maxima and Cucurbita moschata (Cucurbitaceae). We first typified the volatile and non-volatile chemical profiles and the trichome distribution of the plants. Then, using behavioral assays, we evaluated feeding and oviposition preferences of E. paenulata. Further, to assess a correlation between oviposition preferences and offspring survival, we measured larval performance as indicated by survival, mass, and time to complete each instar. Female longevity in both Cucurbita host plants was also evaluated. Our results show that the congeneric plants bear differences in their chemical profiles, including volatile organic compounds, leaf waxes, and leaf parenchyma metabolites. Trichome abundance was also different, with C. maxima presenting fewer hairs. Epilachna paenulata females laid significantly more eggs in C. maxima, regardless of the plant they were raised as larvae. Female longevity on C. maxima was higher, but larval performance showed no difference between both plants. The proximate causes mediating female oviposition preferences may then involve trichome abundance, oviposition deterrents, toxic substances, or a combination of these factors. [ABSTRACT FROM AUTHOR]

Characteristic volatile organic compounds (VOCs) are anticipated to be used for the identification of lung cancer cells. However, to date, consistent biomarkers of VOCs in lung cancer cells have not been obtained through direct comparison between cancer and healthy groups. In this study, we regulated the glycolysis, a common metabolic process in cancer cells, and employed solid phase microextraction gas chromatography mass spectrometry (SPME–GC–MS) combined with untargeted analysis to identify the characteristic VOCs shared by cancer cells. The VOCs released by three types of lung cancer cells (A549, PC-9, NCI-H460) and one normal lung epithelial cell (BEAS-2B) were detected using SPME–GC–MS, both in their resting state and after treatment with glycolysis inhibitors (2-Deoxy-d-glucose, 2-DG/3-Bromopyruvic acid, 3-BrPA). Untargeted analysis methods were employed to compare the VOC profiles between each type of cancer cell and normal cells before and after glycolysis regulation. Our findings revealed that compared to normal cells, the three types of lung cancer cells exhibited three common differential VOCs in their resting state: ethyl propionate, acetoin, and 3-decen-5-one. Furthermore, under glycolysis control, a single common differential VOC—acetoin was identified. Notably, acetoin levels increased by 2.60–3.29-fold in all three lung cancer cell lines upon the application of glycolysis inhibitors while remaining relatively stable in normal cells. To further elucidate the formation mechanism of acetoin, we investigated its production by blocking glutaminolysis. This interdisciplinary approach combining metabolic biochemistry with MS analysis through interventional synthetic VOCs holds great potential for revolutionizing the identification of lung cancer cells and paving the way for novel cytological examination techniques. [ABSTRACT FROM AUTHOR]

The specific surface area of attapulgite was significantly enhanced (from 128 to 212 m2/g) by its purification with sodium hexametaphosphate and nitric acid. Subsequently, an acid modification method was employed to prepare a coated attapulgite cordierite honeycomb with a specific surface area approximately 39 times larger than that of the bare cordierite honeycomb. SEM images showed that the surface of the cordierite was rough and uneven, with the attapulgite filling the large pores on its surface, forming a "nail-like" interaction between the coating and the carrier. After loading the catalyst, no significant mass loss was observed after 1 h of ultrasonic testing, indicating good adhesion stability of the coating. Furthermore, under test conditions of GHSV (Gas Hourly Space Velocity) = 10 000 h–1 and a toluene concentration of 1500 ppm, the prepared integrated catalyst exhibited excellent activity for the catalytic oxidation of toluene, with T50 and T90 values of 261 and 290°C, respectively, suggesting broad application prospects. [ABSTRACT FROM AUTHOR]

To what extent particular plant defences against herbivorous insects are constitutive or inducible will depend on the costs and benefits in their neighbourhood. Some defensive chemicals in leaves are thought to be costly and hard to produce rapidly, while others, including volatile organic compounds that attract natural enemies, might be cheaper and can be released rapidly. When surrounding tree species are more closely related, trees can face an increased abundance of both specialist herbivores and their parasitoids, potentially increasing the benefits of constitutive and inducible defences. To test if oaks (Quercus robur) respond more to herbivore attacks with volatile emission than with changes in leaf phenolic chemistry and carbon to nitrogen ratio (C: N), and whether oaks respond to the neighbouring tree species, we performed an experiment in a forest in Poland. Oak saplings were placed in neighbourhoods dominated by oak, beech, or pine trees, and half of them were treated with the phytohormone methyl jasmonate (elicitor of anti-herbivore responses). Oaks responded to the treatment by emitting a different volatile blend within 24 h, while leaf phenolic chemistry and C: N remained largely unaffected after 16 days and multiple treatments. Leaf phenolics were subtly affected by the neighbouring trees with elevated flavan-3-ols concentrations in pine-dominated plots. Our results suggest that these oaks rely on phenols as a constitutive defence and when attacked emit volatiles to attract natural enemies. Further studies might determine if the small effect of the neighbourhood on leaf phenolics is a response to different levels of shading, or if oaks use volatile cues to assess the composition of their neighbourhood. [ABSTRACT FROM AUTHOR]

Intercropping faba bean with vegetables provides a possibility to promote pest control and better nutrient cycling in sustainable agriculture. Faba bean produces extrafloral nectar which supports parasitoid wasps that play a role in the biological control of pest insects. However, adult lepidopteran pests also benefit from nectar, increasing their lifespan and the number of offspring they produce. Here, a laboratory-based study was conducted to assess the role of faba bean on the components of a Brassica-based host-parasitoid system. We measured how access to faba bean affected the longevity and fecundity of the brassica pest Plutella xylostella and its parasitoid Cotesia vestalis. It was also studied if odors of flowering faba bean disrupt host finding by C. vestalis in Y-tube bioassays and volatile organic compounds were analyzed to explain the olfaction-based choices made by the parasitoids. The longevity of C. vestalis was 6.6 times longer and the number of pupae produced almost 10 times greater when they had access to faba bean. Meanwhile, the longevity of P. xylostella was 3.6 times longer and it laid 4.6 times more eggs when provided access to faba bean. In Y-tube bioassays, C. vestalis females also oriented toward host-related odors of the damaged cabbage more than intact cabbage when odors of faba bean were mixed with both of them. In conclusion, faba bean provided sustenance to both pest insects and their natural enemies that prolonged their lifespans and their reproductive capacity. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) are a class of ubiquitous substances that are present in outdoor and indoor air. They are emitted by a wide range of sources and can penetrate and accumulate specifically in indoor environments. Concern is growing among the scientific community regarding the potential health impacts of exposure to a high concentration of VOCs in indoor spaces. Due to their still-developing respiratory and immune systems, children may be the most fragile subjects in this regard, and therefore, the study of indoor air quality in schools is of the utmost importance. In this work, the concentrations of total volatile organic compounds (TVOCs) and of 20 specific compounds belonging to this class were determined in a school in Squinzano, a town in the province of Lecce (Apulia region, southern Italy). Sampling was carried out in indoor (classrooms and bathrooms) and outdoor (terrace) areas using passive diffusive samplers for VOCs and photoionization detectors for TVOCs. Average concentrations of both TVOC (303 ± 47 µg m−3) and individual VOCs (< 0.5 µg m−3) were below levels of concern; however, specific indoor sources such as cleaning activities and student occupancy were responsible for peaks in TVOC concentrations above harmless levels for children and school staff. The data were then compared to the ones obtained in a similar study conducted in a school in Galatina, another town of the Apulia region, highlighting the impact of the surrounding outdoor environment on the indoor profile of VOCs. [ABSTRACT FROM AUTHOR]

Antimicrobial resistance in fungal pathogens (both human and plant) is increasing alarmingly, leading to massive economic crises. The existing anti-fungal agents are becoming ineffective, and the situation worsens on a logarithmic scale. Novel antifungals from unique natural sources are highly sought to cope sustainably with the situation. Metabolites from endophytic microbes are the best-fitted alternatives in this case. Endophytes are the untapped sources of 'plants' internal microbial population' and are promising sources of effective bio-therapeutic agents. Fungal endophytes were isolated from Tropaeolum majus and checked for antifungal activity against selected plant and human pathogens. Bioactive metabolites were identified through chromatographic techniques. The mode of action of those metabolites was evaluated through various spectroscopic techniques. The production of antifungal metabolite was optimized also. In particular VOCs (volatile organic compounds) of TML9 were tested in vitro for their anti-phytopathogenic activity. Ethyl acetate (EA) extract of cell-free culture components of Colletotrichum aenigma TML3 exhibited broad-spectrum antifungal activity against four species of Candida and the major constituents reported were 6-pentyl-2H-pyran-2-one, 2-Nonanone, 1 propanol 2-amino. The volatile metabolites, trans-ocimene, geraniol, and 4-terpinyl acetate, produced from Curvularia lunata TML9, inhibited the growth of some selected phyto pathogens. EA extract hampered the biofilm formation, minimised the haemolytic effect, and blocked the transformation of Candida albicans (MTCC 4748) from yeast to hyphal form with a Minimum Fungicidal Concentration (MFC) of 200–600 µg mL−1. Central carbohydrate metabolism, ergosterol synthesis, and membrane permeability were adversely affected and caused the lethal leakage of necessary macromolecules of C. albicans. Volatile metabolites inhibited the growth of phytopathogens i.e., Rhizoctonia solani, Alternaria alternata, Botrytis cinerea, Cercospora beticola, Penicillium digitatum, Aspergillus fumigatus, Ceratocystis ulmi, Pythium ultimum up to 89% with an IC50 value of 21.3–69.6 µL 50 mL−1 and caused leakage of soluble proteins and other intracellular molecules. Citrusy sweet odor volatiles of TML9 cultured in wheat-husk minimised the infections of Penicillium digitatum (green mold), in VOC-exposed sweet oranges (Citrus sinensis). Volatile and non-volatile antifungal metabolites of these two T. majus endophytes hold agricultural and pharmaceutical interests. Metabolites of TML3 have strong anti-Candida activity and require further assessment for therapeutic applications. Also, volatile metabolites of TML9 can be further studied as a source of antifungals. The present investigational outcomes bio-prospects the efficacy of fungal endophytes of Garden Nasturtium. [ABSTRACT FROM AUTHOR]

Kappaphycus alvarezii is one of the most essential edible seaweeds in the global trade of marine products. The product quality will directly influence the flavor, odor, and impact on the human health of this edible seaweed. These functions are associated with volatile organic compound (VOCs) content and are controlled by seaweed cultivation sites. This study investigated VOCs using HS-SPME combined with GC–MS and multivariate analysis to determine the VOCs to be used as key markers for the quality of seaweeds from different cultivation sites. The HS-SPME factors, such as the amount of sample, extraction temperature, and extraction time, were optimized based on Box–Behnken design (BBD) and response surface methodology (RSM) for multi-response optimization (MRO). The precision of the approach varied from 1.17% (alkanes) to 6.30% (carboxylic acids) for repeatability and 3.93% (furans) to 16.64% (sesquiterpenoids) for intermediate precision. This method was applied to samples collected from nine different geographical regions in Indonesia. Principal Component Analysis (PCA) was used to determine data distribution from 48 compounds in K. alvarezii from those different cultivation sites. Based on PCA, four key marker VOCs, including heptadecane, 3-methylbutanoic acid, 2-pentyl furan, and 2-heptanone, were successfully established. [ABSTRACT FROM AUTHOR]

Detection of volatile organic compounds (VOCs) from the breath is becoming a viable route for the early detection of diseases non-invasively. This paper presents a sensor array of 3 component metal oxides that give maximal cross-sensitivity and can successfully use machine learning methods to identify four distinct VOCs in a mixture. The metal oxide sensor array comprises NiO-Au (ohmic), CuO-Au (Schottky), and ZnO–Au (Schottky) sensors made by the DC reactive sputtering method and having a film thickness of 80–100 nm. The NiO and CuO films have ultrafine particle sizes of < 50 nm and rough surface texture, while ZnO films consist of nanoscale platelets. This array was subjected to various VOC concentrations, including ethanol, acetone, toluene, and chloroform, one by one and in a pair/mix of gases. Thus, the response values show severe interference and departure from commonly observed power law behavior. The dataset obtained from individual gases and their mixtures were analyzed using multiple machine learning algorithms, such as Random Forest (RF), K-Nearest Neighbor (KNN), Decision Tree, Linear Regression, Logistic Regression, Naive Bayes, Linear Discriminant Analysis, Artificial Neural Network, and Support Vector Machine. KNN and RF have shown more than 99% accuracy in classifying different varying chemicals in the gas mixtures. In regression analysis, KNN has delivered the best results with an R2 value of more than 0.99 and LOD of 0.012 ppm, 0.015 ppm, 0.014 ppm, and 0.025 ppm for predicting the concentrations of acetone, toluene, ethanol, and chloroform, respectively, in complex mixtures. Therefore, it is demonstrated that the array utilizing the provided algorithms can classify and predict the concentrations of the four gases simultaneously for disease diagnosis and treatment monitoring. [ABSTRACT FROM AUTHOR]

The increasing automobile repair industries (ARIs) with spray facilities have become an important volatile organic compound (VOC) pollution source in China. However, the VOC health risk assessment for long-term exposure in ARIs has not been well characterized. In this study, though sampled VOCs from 51 typical ARIs in Beijing, the relationship between emission patterns, average daily exposure concentrations (EC), and health risks was comprehensively analyzed with the health assessment method. Results showed that concentrations of 117 VOCs from the samples ranged from 68.53 to 19863.32 μg·m−3, while the ARI operator's daily VOC inhalation EC was 11.24–1460.70 μg·m−3. The organic VOC (OVOC) concentration accounted for 73.16 ~ 94.52% in the solvent-based paint workshops, while aromatics were the main VOC component in water-based paint spraying (WPS) workshops, accounting for 70.08%, respectively. And the method of inhalation exposure health risk assessment was firstly used to evaluate carcinogenicity and non-carcinogenicity risk for sprayers in ARIs. The cumulative lifetime carcinogenic risk (LCR) for 24 sampled VOCs were within acceptable ranges, while the mean hazard index (HI) for 1 year with 44 sampled VOCs was over 1. Among them, ethyl alcohol had a high carcinogenic risk in both mixed water-based paint (MP) and solvent-based paint workshops. The mean HI associated with aromatics were 2.88E − 3 and 4.30E − 3 for 1 h in MP and WPS workshops. O-ethyl toluene and acetone are VOC components that need to be paid attention to in future paint raw materials and spraying operations. Our study will provide the important references for the standard of VOC occupational exposure health limits in ARIs. [ABSTRACT FROM AUTHOR]

With the implementation of garbage classification, perishable waste has become increasingly concentrated. This has led to a significant change in the VOC release characteristics at residential garbage collection points, posing a potential risk with unknown characteristics. This study investigated the release characteristics, odor pollution, and health risks of VOCs at garbage collection points under different classification effectiveness, seasons, garbage drop-off periods, and garbage collection point types. The results showed that the average concentration of VOCs released from the garbage sorting collection points (SPs) was 341.43 ± 261.16 μg/m3, and oxygenated compounds (e.g., ethyl acetate and acetone) were the main VOC components. The VOC concentration increased as the community classification effectiveness improved, and it was higher in summer (followed by spring, autumn, and winter). Moreover, the VOC concentrations were higher in the evenings than in the mornings and at centralized garbage collection points (CPs) than at SPs. Further, odor activity value (OAV) assessments indicated that acrolein, styrene, and ethyl acetate were the critical odorous components, with an average OAV of 0.87 ± 0.85, implying marginal odor pollution in some communities. Health risk assessments further revealed that trichloroethylene, benzene, and chlorotoluene were the critical health risk substances, with an average carcinogenic risk (CR) value of 10−6–10−4, and a non-carcinogenic risk (HI) value < 1. These results indicated that HIs were acceptable, but potential CRs existed in the communities. Therefore, VOC pollution prevention and control measures should be urgently strengthened at the garbage collection points in high pollution risk scenarios. [ABSTRACT FROM AUTHOR]

Indoor air quality (IAQ) has attracted a lot of attention due to its complexity and direct effect on human health. Indoor settings in libraries entail various volatile organic compounds (VOCs) linked to the aging and degradation of print material. The effect of the storage environment on paper life expectancy was investigated by targeting the VOC emissions of old and new books using headspace solid phase micro extraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) analysis. "Sniffing" of book degradation markers showed both ubiquitously and infrequently occurring VOCs. Old book "degradomics" revealed mostly alcohols (57%) and ethers (12%), whereas new books resulted mainly to ketones (40%) and aldehydes (21%). Chemometric processing of the results with principal component analysis (PCA) corroborated our initial observations and was able to discriminate the books by age into three groups: very old books (from the 1600 s to mid-1700), old books (from the 1800s to the early 1900s), and modern books (from the mid-twentieth century onwards) based on their gaseous markers. The measured mean concentrations of selected VOCs (acetic acid, furfural, benzene, and toluene) were below the respective guidelines set for similar places (i.e. museums). The applied non-invasive, green analytical methodology (HS-SPME-GC/MS) can assist librarians, stakeholders, and researchers to evaluate the IAQ, as well as the degree of degradation, and take the appropriate measures for book restoration and monitoring protocols. [ABSTRACT FROM AUTHOR]

To develop a rice wine with the fragrance and medicinal ingredients of lilies, aroma-producing yeasts (Saccharomyces cerevisiae H1, Hansenula sp. H3, and Pichia kudriavzevii H6) were used for the production of lily rice wine. When the amount of lily added was 1.5 g per 10 g glutinous rice, the content of flavonoids and polyphenols reached 55.54 and 67.68 mg/L, respectively. The sensory evaluation suggested that lily rice wine had the highest score for "malty", "sweety", and "fruity" when the amount of lily added was 0.5 g per 10 g glutinous rice. The result of temperature-programmed headspace gas chromatography ion mobility spectroscopy (TP-HS-GC-IMS) and headspace solid-phase microextraction gas chromatography–olfactometry-mass spectroscopy (HS-SPME-GC-O-MS) clearly showed that linalool and 3-methyl butanal, the unique aromatic compounds of lily, were only detected in fermented lily rice wine to provide flower fragrance. GC-O and odor activity values (OAVs) showed that 11 compounds including ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol, 2-methyl-1-butanol, 3-methylbutyl acetate, ethyl caprate, phenylethyl alcohol, ethyl caprylate, phenethyl acetate, 2-methoxy-4-vinylphenol and γ-nonanoic lactone were indicated to be the major aroma contributors. Based on the aroma recombination experiments, they were further revealed to be the key aroma-active compounds in lily rice wine. At the same time, multivariate data analysis further revealed the correlation between sensory attributes and volatile organic compounds (VOCs) in lily rice wine. This work provides a lily rice wine with a stronger fruit aroma and higher polyphenol content. [ABSTRACT FROM AUTHOR]

In this work, Cu-Mn oxide catalysts supported on ZSM-5 zeolite (Cu7Mn3Ox/ZSM‑5) were modified by low-cost method of acid leaching and employed for the catalytic oxidation of toluene. For investigating the effect of acid modification on catalysts deeply, the prepared materials were characterized by N2 adsorption–desorption, XRD, SEM, H2-TPR, XPS, NH3-TPD, Py-IR and TG. In the decomposition of toluene, the citric acid modified Cu7Mn3Ox/ZSM‑5 exhibited excellent performance of toluene conversion and adsorption compared to Cu7Mn3Ox/ZSM‑5. The preferable performance was associated with the improved pore structure and surface area, along with the more Mn4+ and Cu2+ species formed after citric acid modification. Significantly, citric acid modified Cu7Mn3Ox/ZSM‑5 exhibited satisfied hydrothermal stability and good regeneration ability as well, which would offer an economical strategy to prepare effective catalysts for VOCs treatment. [ABSTRACT FROM AUTHOR]

The protective efficacies of current licensed vaccines against COVID-19 have significantly reduced as a result of SARS-CoV-2 variants of concern (VOCs) which carried multiple mutations in the Spike (S) protein. Considering that these vaccines were developed based on the S protein of the original SARS-CoV-2 Wuhan strain, we designed a recombinant plasmid DNA vaccine based on highly conserved and immunogenic B and T cell epitopes against SARS-CoV-2 Wuhan strain and the Omicron VOC. Literature mining and bioinformatics were used to identify 6 immunogenic peptides from conserved regions of the SARS-CoV-2 S and membrane (M) proteins. Nucleotide sequences encoding these peptides representing highly conserved B and T cell epitopes were cloned into a pVAX1 vector to form the pVAX1/S2-6EHGFP recombinant DNA plasmid vaccine. The DNA vaccine was intranasally or intramuscularly administered to BALB/c mice and evaluations of humoral and cellular immune responses were performed. The intramuscular administration of pVAX1/S2-6EHGFP was associated with a significantly higher percentage of CD8+ T cells expressing IFN-γ when compared with the empty vector and PBS controls. Intramuscular or intranasal administrations of pVAX1/S2-6EHGFP resulted in robust IgG antibody responses. Sera from mice intramuscularly immunized with pVAX1/S2-6EHGFP were found to elicit neutralizing antibodies capable of SARS-CoV-2 Omicron variant with the ACE2 cell surface receptor. This study demonstrated that the DNA vaccine construct encoding highly conserved immunogenic B and T cell epitopes was capable of eliciting potent humoral and cellular immune responses in mice. [ABSTRACT FROM AUTHOR]

Lygus hesperus Knight is a polyphagous pest of major concern to numerous cropping systems across western North America. Lygus hesperus exhibits well-documented host preferences which may be used to develop behavioral management strategies for this pest. This study sought to identify plant volatiles that mediate L. hesperus host preferences and assess the potential of those compounds to improve monitoring and management of this pest. Gas chromatography with electroantennographic detection was applied to identify antennally active compounds in headspace extracts from four host plants of varying attractiveness. Y-tube olfactometer assays were then conducted to determine L. hesperus responses to each of these 17 antennally active compounds individually. Six compounds attracted female L. hesperus, and subsequent tests revealed that females were attracted to an equal-parts blend of these six attractive compounds versus clean air, and that this blend was as attractive as flowering Medicago sativa. We then examined L. hesperus attraction to attractive compounds individually and an equal-parts blend of five attractive compounds in the field. An equal-parts blend of five attractive compounds was tested in strawberry, whereas the blend and each individual component were tested in alfalfa. In both field settings, neither the individual compounds nor the blend increased L. hesperus capture rates compared to unbaited control traps. Low attraction in the field could result from a masking effect of background volatiles or the failure to include important compounds in tested blends. It remains important to assess whether the compounds tested in this study may facilitate L. hesperus management in other cropping systems. [ABSTRACT FROM AUTHOR]

Multi-pollutant removal (MPR) of NO and VOCs simultaneously is efficient of flue gas treatment in coal-fired power plants. But reducing the competition for active sites between NH3, NO, C6H6, and C7H8 remains challenging. Herein, Cr, Mn, and Fe were respectively doped to MoWTi catalyst via wet impregnation. The Fe3+ + Mo5+ ↔ Fe2+ + Mo6+ redox cycle led to an increased proportion of low valence ions (Mo5+ and W5+) and facilitated the creation of active oxygen vacancies with several active sites. It also possessed plentiful mild to strong acid sites with ideal ratio. These factors enhanced catalytic activity of Fe-MoWTi. Remarkable MPR efficiencies of NO, C6H6, and C7H8 were achieved under industrial SCR condition, characterized by low oxygen but high SO2 levels at 340 °C, with removal rates reaching 89.85%, 97.57%, and 86.30% respectively. Theory calculations further revealed that Fe-MoWTi favor NH3 and O2 adsorptions. NO elimination was found to follow both Eley–Rideal (E-R) and Langmuir–Hinshelwood (L–H) processes, supported by in situ DRIFTS analysis. The reactions involving NO/NO2/nitrite/nitrate occurred with NH3(ads)/ NH4+(ads)/NH2 (ads). C6H6 and C7H8 underwent gradual oxidation, formatting alcohols, aldehydes, acids, and maleic acids, before eventually being mineralized to gaseous CO2 and H2O. Findings hold significant potential for application, providing guidance for the development of catalysts with improved resistance against SO2 poisoning and enhanced MPR capabilities. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) have grown due to their crucial role in transitioning from invasive to noninvasive cancer diagnostic methods. This study aimed to assess the feasibility of the metal oxide biosensor platform using urine VOCs for detecting genitourinary cancers. Five different commercially available semiconductor sensors were chosen to detect specific VOCs (methane, iso-butane, hydrogen, ethanol, hydrogen sulfide, ammonia, toluene, butane, propane, trimethylamine, and methyl-mercaptan). Changes in electrical resistance due to temperature variations from the voltage heater were examined to characterize VOC metabolism. Logistic regression and ROC analysis were employed to evaluate potential urine VOCs for genitourinary cancer determination. This study involved 64 participants which were categorized into a cancer and a non-cancer group. The genitourinary cancer (confirmed by tissue pathology) comprised 32 patients, including renal cell carcinoma (3.1%), transitional cell carcinoma (46.9%), and prostate cancer (50%). The non-cancer comprised 32 patients, with 9 healthy subjects and 23 individuals with other genitourinary diseases. Results indicated that VOC sensors for methane, iso-butane, hydrogen, and ethanol, at a voltage heater of 2000 mV, demonstrated a significant predictive capability for genitourinary cancer with P = 0.013. The ROC of these biomarkers also indicated statistical significance in predicting the occurrence of the disease (P < 0.05). This report suggested that methane, iso-butane, hydrogen, and ethanol VOCs exhibited potential for diagnosing genitourinary cancer. Developing gas metal oxide sensors tailored to these compounds, and monitoring changes in electrical resistance, could serve as an innovative tool for identifying this specific type of cancer. [ABSTRACT FROM AUTHOR]

Many workers can be exposed simultaneously to heat and volatile chemicals. In a controlled human exposure study, it was observed that an increase in ambient temperature was associated with increased blood concentrations for acetone and toluene. Based on the expected changes in physiological parameters that occur with an increase in ambient temperature, we aimed to develop a PBPK model for acetone and toluene that could account for the impact of temperature on the kinetics of these solvents. Changes in temperature-dependent physiological parameters (i.e. blood flows, cardiac output, alveolar ventilation) based on recent measurements in volunteers were introduced in the PBPK models to simulate observed blood concentrations for different temperature exposure conditions. Because initial simulations did not adequately predict solvent kinetics at any temperature, the most sensitive parameter (alveolar ventilation; Qp) was, therefore, optimized on experimental acetone blood concentrations to obtain a relationship with temperature. The new temperature-dependent Qp relationship gave Qp values consistent with the literature and estimated a mean increase of 19% at 30 °C (wet bulb globe temperature) compared to 21 °C. The integration of a new temperature-dependent Qp relationship in the PBPK toluene model yielded adequate simulations of the experimental data for toluene in blood, exhaled air and urine. With further validation with other solvents, the temperature-dependant PBPK model could be a useful tool to better assess the risks of simultaneous exposure to volatile chemicals and heat stress and interpret biomonitoring data in workers as well as in the general population. TRN: NCT02659410, Registration date: January 15, 2016. [ABSTRACT FROM AUTHOR]

Magnetic fields (MF) have been proven efficient in bioaugmentation, and the internal MFs have become competitive because they require no configuration, despite their application in waste gas treatment remaining largely unexplored. In this study, we firstly developed an intensity-regulable bioaugmentation with internal MF for gaseous chlorobenzene (CB) treatment with modified packing in batch bioreactors, and the elimination capacity increased by up to 26%, surpassing that of the external MF. Additionally, the microbial affinity to CB and the packing surface was enhanced, which was correlated with the ninefold increased secreted ratio of proteins/polysaccharides, 43% promoted cell surface hydrophobicity, and half reduced zeta potential. Furthermore, the dehydrogenase content was promoted over 3 times, and CB removal steadily increased with the rising intensity indicating enhanced biofilm activity and reduced CB bioimpedance; this was further supported by kinetic analysis, which resulted in improved cell adhesive ability and biological utilisation of CB. The results introduced a novel concept of adjustable magnetic bioaugmentation and provided technical support for industrial waste gas treatments. Key points: • Regulable magnetic bioaugmentation was developed to promote 26% chlorobenzene removal • Chlorobenzene mineralisation was enhanced under the magnetic field • Microbial adhesion was promoted through weakening repulsive forces [ABSTRACT FROM AUTHOR]

Replacing NH3 in NH3-SCR with VOCs provides a new idea for the simultaneous removal of VOCs and NOx, but the technology still has urgent problems such as high cost of catalyst preparation and unsatisfactory catalytic effect in the low-temperature region. In this study, biochar obtained from sewage sludge calcined at different temperatures was used as a carrier, and different Co and Mn injection ratios were selected. Then, a series of sludge-based biochar (SBC) catalysts were prepared by a one-step hydrothermal synthesis method for the simultaneous removal of acetone and NO in a low-temperature photothermal co-catalytic system with acetone replacing NH3. The characterization results show that heat is the main driving force of the reaction system, and the abundance of Co and Mn atoms in high valence states, surface-adsorbed oxygen, and oxygen lattice defects in the catalyst are the most important factors affecting the performance of the catalyst. The performance test results showed that the optimal pyrolysis temperature of sludge was 400 °C, the optimal dosing ratio of Co and Mn was 4:1, and the catalyst achieved 42.98% and 52.41% conversion of acetone and NO, respectively, at 240 °C with UV irradiation. Compared with the pure SBC without catalytic effect, the SBC loaded with Co and Mn gained the ability of simultaneous removal of acetone and NO through the combined effect of multiple factors. The key reaction steps for the catalytic conversion of acetone and NO on the catalyst surface were investigated according to the Mars-van Krevelen (MvK) mechanism, and a possible mechanism was proposed. This study provides a new strategy for the resource utilization of sewage sludge and the preparation of photothermal catalysts for the simultaneous removal of acetone and NO at low cost. [ABSTRACT FROM AUTHOR]

Studies related to effluent produced by structure and vegetation fires often focus on gas phase or solid condensed phase, with limited treatment of liquid condensate generated as smoke cools to ambient. Recent post-fire human health concerns related to systemic human exposures to fire smoke and contamination of water distribution systems after wildland urban interface fires can be informed by understanding the chemical composition of liquid condensate resulting from large-scale fire experiments. In this pilot study, fire effluent (smoke) samples were continuously drawn from five different full-scale room-and-contents fire experiments, from which condensate was collected as the effluent cooled. Elevated concentrations of several volatile organic compounds (VOCs), including benzene, toluene, xylenes, styrene, naphthalene, and acetone along with several anions were detected in the acidic effluent. Many of these same VOCs have been identified in the air during firefighter safety experiments and in post-fire water distribution systems at levels that raise concern for human health. Benzene and naphthalene concentrations in the condensate were orders of magnitude above typical water quality standards and thus may directly contaminate large volumes of water. Peak benzene concentrations were similar to highest values reported from contaminated water distribution systems after wildfire events, though additional study is needed to understand the mechanisms by which this condensate may contribute to systemic contamination. Improved understanding of liquid condensate from fire effluent may be important to other areas of human and environmental health study, and some considerations are provided for future research. [ABSTRACT FROM AUTHOR]

Toxic volatile organic compounds (VOCs) in the atmosphere are considered as hazardous substances that can pose risks to human health and the environment. There is a pressing need to develop efficient processes for reducing their emissions. Among the well-established destruction technologies such as adsorption and biological degradation, oxidation has been reported to be a promising method for VOCs disposal due to its simplicity, high efficiency, and environmental friendliness. For large-scale implementations of catalytic combustion, stable and efficient catalysts are required. In this review, some recent advances in the catalytic oxidation of several representative VOC molecules are discussed and summarized. The discussion is partitioned into two basic categories on the basis of different kinds of active components in catalysts: noble metal-based catalysts and non-noble metal-based catalysts. We generalize typical metals widely used as catalysts for VOCs catalytic oxidation and discuss the effects of some key influential factors (kind of catalyst support, catalyst preparation, metal particle size, metal ratio, reaction atmosphere, electronic structure of active metal) on the VOCs removal performance. Specific catalytic oxidation mechanisms are also summarized. Finally, we bring forward future research directions for rationally designing catalysts for VOCs catalytic oxidation removal in industrial applications. [ABSTRACT FROM AUTHOR]

Plant-herbivore interactions have been extensively studied in tomato plants and their most common pests. Tomato plant chemical defenses, both constitutive and inducible, play a role in mediating these interactions. Damaged tomato plants alter their volatile profiles, affecting herbivore preferences between undamaged and damaged plants. However, previous studies on tomato volatiles and herbivore preferences have yielded conflicting results, both in the volatile chemistry itself as well as in the attraction/repellent herbivore response. This study revisits the volatile-mediated interactions between tomato plants and two of their main herbivores: the leafminer Tuta absoluta and the whitefly Trialeurodes vaporariorum. Tomato plant volatiles were analyzed before and after damage by each of these herbivores, and the preference for oviposition (T. absoluta) and settling (T. vaporariorum) on undamaged and damaged plants was assessed both after conspecific and heterospecific damage. We found that both insects consistently preferred damaged plants over undamaged plants. The emission of herbivore-induced plant volatiles (HIPVs) increased after T. absoluta damage but decreased after T. vaporariorum damage. While some of our findings are in line with previous reports, T. absoluta preferred to oviposit on plants damaged by conspecifics, which differs from earlier studies. A comparison of HIPVs emitted after damage by T. absoluta and T. vaporariorum revealed differences in up- or down-regulation, as well as significant variations in specific compounds (12 for T. absoluta and 26 for T. vaporariorum damaged-plants). Only two compounds, β-caryophyllene and tetradecane, significantly varied because of damage by either herbivore, in line with the overall variation of the HIPV blend. Differences in HIPVs and herbivore preferences may be attributed to the distinct feeding habits of both herbivores, which activate different defensive pathways in plants. The plant's challenge in simultaneously activating both defensive pathways may explain the preference for heterospecific damaged plants found in this study, which are also in line with our own observations in greenhouses. [ABSTRACT FROM AUTHOR]

The capacity for indoor plants including green wall systems to remove specific volatile organic compounds (VOCs) is well documented in the literature; however under realistic settings, indoor occupants are exposed to a complex mixture of harmful compounds sourced from various emission sources. Gasoline vapour is one of the key sources of these emissions, with several studies demonstrating that indoor occupants in areas surrounding gasoline stations or with residentially attached garages are exposed to far higher concentrations of harmful VOCs. Here we assess the potential of a commercial small passive green wall system, commercially named the 'LivePicture Go' from Ambius P/L, Australia, to drawdown VOCs that comprise gasoline vapour, including total VOC (TVOC) removal and specific removal of individual speciated VOCs over time. An 8-h TVOC removal efficiency of 42.45% was achieved, along with the complete removal of eicosane, 1,2,3-trimethyl-benzene, and hexadecane. Further, the green wall also effectively reduced concentrations of a range of harmful benzene derivatives and other VOCs. These results demonstrate the potential of botanical systems to simultaneously remove a wide variety of VOCs, although future research is needed to improve upon and ensure efficiency of these systems over time and within practical applications. [ABSTRACT FROM AUTHOR]

Detection of human-generated volatile organic compounds (VOCs) is a new pathway for assessing health. Herein, a polyvinylidene fluoride (PVDF)-based colorimetric sensor array was designed for detecting disease-related VOCs (DVOCs) within 15 min, using a complex of Cu metal–organic framework, graphene aerogel, and dyes as response materials. Fingermaps derived from 28 DVOCs were obtained for further data processing. Pattern recognition was successfully employed in the correct discrimination of 28 DVOCs in low (10 μM), medium (100 μM), and high (300 μM) concentrations. Importantly, the sensor array also presented excellent discrimination ability and application potential when detecting VOCs produced by human cancer and normal cells. In general, VOC acquisition is noninvasive and harmless, and the PVDF-based sensor arrays are simple and visual. Such advantages expand their further application potential. [ABSTRACT FROM AUTHOR]

Kitchen waste (KW) generates odors comprising complex volatile organic compounds (VOCs). We used gas chromatography–mass spectrometry to analyze VOCs, and 16S gene sequencing was used to analyze the microbial community composition and microbial metabolic mechanism. The results showed that the major odor-causing VOCs were hydrogen sulfide, methanethiol, methyl sulfide, dimethyl disulfide, and ethyl acetate. As the temperature increased, the VOCs and microbial community composition became more complex, and the microbial community related to VOC production included Leuconostoc, Pediococcus, Acetobacter, and Weissella. Based on PICRUSt2 analysis, the possibility of typical VOC interconversion by microbial metabolism was low. It was more likely that precursor substances were catalyzed by enzymes to generate the corresponding VOCs. Attention should be given to trichloromethane and 1,2-dichloroethane, which may cause adverse health effects through long-term inhalation. The study results provide guidance for controlling VOCs from KW. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) emission from electronic manufacturing industries poses severe air pollution and damage to human health; a cost-effective control strategy is urgently needed. Herein, biotrickling filters (BTF) packed with the polyhedron hollow polypropylene balls were employed to remove VOCs emitted from an electronic manufacturing industry. Response surface methodology with Box-Behnken design (RSM-BBD) and backpropagation artificial neural network coupled genetic algorithm model (GA-BPANN) was proposed to simulate and predict BTF performance on VOCs removal at different inlet VOCs concentrations, empty bed retention times (EBRT), and trickling liquid velocity (TLV). The results revealed that the fast start-up time of about 10 days for VOCs removal was achieved in a BTF by using microbial intensive culture and synchronous acclimation. Moreover, under steady-state conditions, the removal efficiency (RE) of VOCs reached above 90.0% at the inlet VOC concentration of 150 mg/m3, EBRT of 45 s, and TLV of 1.5 m/h, corresponding to the elimination capacity (EC) of around 11.0 g m−3 h−1. Furthermore, both RSM-BBD and GA-BPANN models have the good ability to accurately simulate and predict the RE of VOCs under different experimental conditions. In addition, the kinetic behavior of VOCs biodegradation in BTFs conformed to zero-order model with diffusion limitation. The findings herein provide an efficient route for optimizing the parameters design of BFT, which facilitates the application of BTF in VOCs control for electronic manufactory industries. [ABSTRACT FROM AUTHOR]

This investigation explored the association between indoor environmental factors and childhood asthma in Yancheng, China. Asthma case (201 children with recurrent asthma) and control cohorts (242 healthy subjects) were recruited from a Traditional Chinese Medical (TCM) Hospital in Yancheng city, based on the results of an ISAAC questionnaire. Questionnaires regarding environmental risk factors were completed by the child's primary caregivers. To compare data on environmental VOCs and formaldehyde contents between asthma and control cohorts, we passively conducted a 10-day indoor and outdoor sampling. Breastfeeding was a major protective indoor environmental factor for recurrent asthma (adjusted odds ratio [aOR]: 0.368, 95% confidence interval [CI]: 0.216–0.627). Our analysis revealed that childhood recurrent asthma was intricately linked to a family history of asthma. Recurrent asthma was also associated with passive smoking [aOR2.115 (95%-CI 1.275–3.508)]. Analogous correlations were observed between household renovation or new furniture introduction and recurrent asthma [aOR3.129(95%-CI1.542–6.347)]. Benzene and formaldehyde were present in all examined homes. Enhanced benzene and formaldehyde concentrations were strongly evident among asthma versus control cohorts, and they were strongly correlated with augmented recurrent asthma risk. Home environment heavily regulates incidences of childhood recurrent asthma. Hence, actions against the indoor environmental risk factors described in this study may assist in the prevention of recurrent asthma among children. [ABSTRACT FROM AUTHOR]

In this work, Ce was used as the A-site element and three-dimensional ordered macroporous (3DOM) materials as the template to obtain 3DOM CeCo0.7Mn0.3O3 catalyst via excessive impregnation method. The catalyst was subjected to acid/alkali treatment with dilute nitric acid and sodium hydroxide solutions. The results revealed that the catalysts subjected to acid/alkali treatment exhibited better structural and catalytic activity characteristics than the bulk catalyst. Specifically, the specific surface area of the catalyst treated with acid increased from 34.86 to 60.67 m2·g-1, and the relative contents of Oads and Mn4+ species increased. Moreover, the T90% further decreased to 174 °C. As for the catalyst treated with alkali, it exhibited a rougher surface and a wider pore size distribution, producing more lattice defects which were favorable for reaction progress. The T90% was 183 °C, indicating that acid/alkali treatment both had a positive effect on the catalytic oxidation of toluene. [ABSTRACT FROM AUTHOR]

ZSM-5 zeolite has been considered a promising adsorbent for capturing VOCs. However, its hydrophilicity and narrow micropore structure limit their practical application especially under humid atmospheres. In this study, the pure silica mesoporous molecular sieve MCM-41 was assembled on ZSM-5 zeolite with different SiO2/Al2O3 ratios (SARs) via a surfactant-mediated recrystallization method. Then, its adsorption-desorption behaviors were investigated using n-hexane, toluene, and ethyl acetate as VOC model molecules. The results showed that the hydrophobicity of ZSM-5/MCM-41 composites and their VOC diffusion behaviors were significantly improved. Furthermore, the SARs of the ZSM-5 precursors had a remarkable influence on the adsorption performance of ZSM-5/MCM-41 composites. ZSM-5/MCM-41(130) was the optimum option, and its dynamic adsorption capacity for ethyl acetate (111.30 mg·g−1) was higher than that of the corresponding ZSM-5 zeolites even under statured humidity. Meanwhile, the ratios of dynamic adsorption capacities at humid and dry atmospheres (qs,wet/qs,dry) of ZSM-5/MCM-41(130) for n-hexane, toluene, and ethyl acetate were 84.89%, 61.46%, and 73.81% respectively. The results will provide guidelines for the preparation of hydrophobic adsorbents. [ABSTRACT FROM AUTHOR]

The controllable preparation of efficient non-crystalline solid solution catalysts is a great challenge in the catalytic oxidation of volatile organic compounds. In this work, series non-crystalline solid solution structured Ce-Mn co-oxide nanofibers were creatively prepared by adjusting Ce/Mn molar ratios using electrospinning. 0.20CeMnOx (the ratio of Ce to Mn was 0.2) displayed an outstanding low-temperature toluene oxidation activity (T90 = 233 °C). The formation of the amorphous solid solution and the unique nanofiber structure both contributed to a large specific surface area (S = 173 m2 g-1) and high adsorbed oxygen content (Oads/O = 41.3%), which enhanced the number of active oxygen vacancies. The synergies between non-crystalline structure and active oxygen species markedly improved oxygen migration rate as well as redox ability of the catalysts. Additionally, in situ diffuse reflectance infrared Fourier transform spectra showed that the absorbed toluene could be completely oxidized to CO2 and H2O with benzyl alcohol, benzaldehyde, benzoic acid, and maleic anhydride as intermediates. In summary, this study provided an alternative route for the synthesis of non-crystalline metal co-oxide nanofibers. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) such as formaldehyde and benzene are among the key contributors to indoor air pollution. The current situation of environmental pollution is alarming, especially indoor air pollution is becoming a challenge as affecting plants and humans. VOCs are known to adversely affect indoor plants by causing necrosis and chlorosis. In order to withstand these organic pollutants, plants are naturally equipped with an antioxidative defense system. The current research study aimed to evaluate the combined effect of formaldehyde and benzene on the antioxidative response of selected indoor C3 plants including Chlorophytum comosum, Dracaena mysore, and Ficus longifolia. After the combined application of different levels (0, 0; 2, 2; 2, 4; 4, 2; and 4, 4 ppm) of benzene and formaldehyde respectively, in an airtight glass chamber, the enzymatic and non-enzymatic antioxidants were analyzed. Analysis of total phenolics showed a significant increase (10.72 mg GAE/g) in F. longifolia; C. comosum (9.20 mg GAE/g); and D. mysore (8.74 mg GAE/g) compared to their respective controls as 3.76, 5.39, and 6.07 mg GAE/g. Total flavonoids (724 µg/g) were reported in control plants of F. longifolia which were increased to 1545.72 µg/g from 724 µg/g (in control) followed by 322.66 µg/g in D. mysore (control having 167.11 µg/g). Total carotenoid content also increased in D. mysore (0.67 mg/g) followed by C. comosum (0.63 mg/g) in response to increasing the combined dose compared to their control plants having 0.62 and 0.24 mg/g content. The highest proline content was exhibited by D. mysore (3.66 μg/g) as compared to its respective control plant (1.54 μg/g) under a 4 ppm dose of benzene and formaldehyde. A significant increase in enzymatic antioxidants including total antioxidants (87.89%), catalase (59.21 U/mg of protein), and guaiacol peroxidase (52.16 U/mg of protein) was observed in the D. mysore plant under a combined dose of benzene (2 ppm) and formaldehyde (4 ppm) with respect to their controls. Although experimental indoor plants have been reported to metabolize indoor pollutants, the current findings indicate that the combined application of benzene and formaldehyde is also affecting the physiology of indoor plants as well. [ABSTRACT FROM AUTHOR]

Two new binuclear CuI cluster complexes based on mono-phosphine ligands, namely Cu2I2(p-Tol)3P3 (1) and Cu2I2(m-Tol)3P3 (2) (p-Tol = 4-methylphenyl, m-Tol = 3-methylphenyl), have been synthesized by the mechanochemical reaction of CuI with (p-Tol)3P (1) and (m-Tol)3P (2) in molar ratio 2:3. Two complexes were characterized by elemental analysis, X-ray diffraction and UV–Vis spectroscopic analysis. Single-crystal X-ray diffraction revealed that complexes 1 and 2 are binuclear cluster structures with two kinds of cuprous ions in tri- and tetra-coordination modes. They also show different supramolecular structures and different degrees of Cu‧‧‧Cu interaction. Based on TD-DFT calculation and analysis, the luminescence of these two clusters should be originate from the hybrid [(X + M)LCT] excited states. These two clusters show the sensing response modes of fluorescence enhancement and vapochromic fluorescence (including enhancement), respectively. The fluorescence sensing mechanism should be derived from the coordination reaction of pyridine vapor to tri-coordinated Cu of the clusters. [ABSTRACT FROM AUTHOR]

In fungi, little is known about connections between volatile organic compound (VOC) formation and developmental stages that are amongst others triggered by fruiting-related genes (FRGs). We analysed the volatilomes of Schizophyllum commune during different developmental stages in a variety of FRG-deletion strains and wild-type strains. The deletion strains Δtea1Δtea1, Δwc-2Δwc-2 and Δhom2Δhom2 were unable to develop fruiting bodies, and Δfst4Δfst4 formed only rudimentary fruiting body structures. Early developmental stages of these strains were dominated by esters, including methyl 2-methylbutanoate, ethyl 2-methylbutanoate, isobutyl 2-methylpropionate, and 2-methylbutyl acetate, of which the last three were not found in the headspace (HS) of the wild-type samples. Compared to the wild type, in the HS of hom2con samples, that are able to form fruiting bodies, methyl 2-methylbutanoate was the most abundant substance at early stages (68–81% of the total peak area). In contrast to fruiting body forming strains, Δtea1Δtea1, Δwc-2Δwc-2, Δhom2Δhom2 and Δfst4Δfst4 showed less sesquiterpenes in the HS. However, the sesquiterpenes found in the HS of FRG-deletion strains, namely, (E)-nerolidol, δ-cadinene, L-calamenene, α-bisabolol and β-bisabolene, were not present in hom2con or wild-type strains that mainly formed fruiting bodies and barely mycelium. Several sesquiterpenes, including α-guaiene, chamigrene and γ-gurjunene, were only found in presence of fruiting bodies. Our results show remarkable connections between FRGs, fruiting body development and VOC production in S. commune, especially counting for sesquiterpenes. Future studies are needed to reveal whether FRGs directly regulates VOC formation or indirectly by changing the phenotype. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) released along with soil disturbance during the remediation of abandoned industrial sites have attracted great attention due to their possible toxicity and odour. However, the real-time emission characteristics of these VOCs and their subsequent effects on health and olfaction are less understood. In this study, the gaseous VOCs released from soil disturbance by excavators and drilling rigs at an abandoned chemical pesticide plant were monitored online with a laboratory-built single photoionization time-of-flight mass spectrometer (SPI-TOFMS). Twelve main VOCs with total mean concentrations ranging from 2350 to 3410 μg m−3 were observed, with dichloromethane (DCM) having a significant contribution. The total concentrations of the remaining 11 VOCs increased substantially during soil disturbance, with the total mean concentrations increasing from 18.65–39.05 to 37.95–297.94 μg m−3 and those of peak concentrations increasing from 28.46–58.97 to 88.38–839.13 μg m−3. This increase in VOC concentrations during soil disturbance leads to an enhanced heath risk for on-site workers. The distinctive difference between the mean and peak concentrations of VOCs indicates the importance of using mean and peak concentrations, respectively, for risk and olfactory evaluation due to the rapid response of the human nose to odours. As a result, the cumulative noncarcinogenic risk at the relatively high pollutant plot was higher than the occupational safety limit, while the total carcinogenic risks at all monitored scenarios exceeded the acceptable limit. Among the VOCs investigated, DCM and trichloroethylene (TCE) were determined to be crucial pollutants for both noncarcinogenic and carcinogenic risks of VOCs. With regard to olfactory effects, organic sulphides, including dimethyl disulphide (DMDS), dimethyl sulphide (DMS), and dimethyl trisulphide (DMTS) were identified as dominant odour contributors (78.28–92.11%) during soil disturbance. [ABSTRACT FROM AUTHOR]

As an industrial solid waste produced by alumina industry, red mud was modified as support of Pd catalysts for toluene catalytic oxidation in this paper. The xPd/MRM catalysts had high activity for toluene catalytic oxidation, and the 0.3Pd/MRM catalyst showed the best catalytic performance (T50 = 175 °C and T100 = 200 °C). The results indicated that the prepared 0.3Pd/MRM catalyst had more ratio of surface-adsorbed oxygen and Fe3+, rather than MRM and RM, which benefitted to the toluene oxidation. The excessive Pd species and the growth of the PdO nanoparticles negatively affected the catalytic efficiency of toluene. 0.4Pd/MRM activity decreased because of PdO aggregation in the catalyst, which could be confirmed by TEM analysis. The results of XPS, H2-TPR, FT-IR, O2-TPD, and Raman examination revealed that the formation of Pd-O-Fe under the interaction between Fe in MRM and Pd (Pd2+ + Fe 2+ → Pd0 + Fe3+) increased the electron transfer and raised the mobility of surface-adsorbed oxygen. Furthermore, in situ DRIFTS and GC-MS were used to detect intermediate products of catalytic reactions, and the reaction mechanism of catalysts was also studied. The catalytic oxidation of toluene on 0.3Pd/MRM catalyst might have two reaction paths simultaneously. The first reaction path would be toluene → species benzyl → benzaldehyde → benzoic acid → long-chain aldehydes or carboxylic acids → CO2 and H2O. The second reaction path would be toluene → benzene → phenol → long-chain aldehydes or carboxylic acids → CO2 and H2O. [ABSTRACT FROM AUTHOR]

Real-time online monitoring of volatile organic compounds (VOCs) in ambient air is crucial for timely and effective human health protection. Here, we developed an innovative, automated two-staged adsorption/thermal desorption gas chromatography/mass spectrometry (GC/MS) system for real-time online monitoring of 117 regulated volatile organic compounds (VOCs). This system comprised a sampling unit, water management trap, two-staged adsorption/thermal desorption unit, thermoelectric coolers (TECs), and a commercial GC/MS system. By implementing a micro-purge-and-trap (MP & T) step and a two-staged adsorption/thermal desorption unit, the presence of interfering substances was effectively minimized. The utilization of a heart-cutting GC, combined with a single MS detector, facilitated the precise separation and detection of 117 C2–C12 VOCs, while circumventing the identification and coelution challenges commonly associated with traditional GC-FID or GC-FID/MS methods. The performance of our newly developed online system was meticulously optimized and evaluated using standard gas mixtures. Under optimal conditions, we achieved impressive results, with R2 values ≥ 0.9946 for the standard linear curves of all 117 VOCs, demonstrating a precision (RSD) ranging from 0.2% to 6.4%. When applied in the field monitoring, the concentration drifts for 10 ppbv standard gas mixtures were 0.01–5.64% within 24 h. Our study developed a system for online monitoring of 117 atmospheric VOCs with relatively high accuracy and robustness. [ABSTRACT FROM AUTHOR]

Owing to their facile reactants migration channels, large surface area, maximized exposure of reaction sites and efficient light utilization, three-dimensionally ordered macroporous (3DOM) materials have been extensively adopted in environmental fields such as pollutants removal, environmental detection as well as bacterial disinfection. In this review, the up-to-date 3DOM materials, the corresponding synthesis protocols and the related environmental applications involving photo electrocatalytic pollutants decomposition, thermocatalytic volatile organic compounds (VOCs) elimination, hazardous substances sensing and bacteria inactivation are completely presented. Simultaneously, the inherent advantages and mechanisms of 3DOM materials in different environmental utilization are thoroughly demonstrated and summarized. Furthermore, the improved performance of environmental applications and the methods of fabricating 3DOM materials are correlated in depth, being favorable for readers to obtain the fundamental knowledge and to motivate some innovative thoughts for modifying 3DOM materials with further elevated environmental remediation capability. Finally, the current difficulties and prospects of 3DOM materials for large-scale and commercial applications are outlooked. This critical review is anticipated to promote the optimization of 3DOM materials and to ripen the related environmental remediation techniques. [ABSTRACT FROM AUTHOR]

Plant–plant interactions via volatile organic compounds (VOCs) have received much attention, but how abiotic stresses affect these interactions is poorly understood. We tested the effect of VOCs exposure from damaged conspecifics on the production of extra-floral nectar (EFN) in wild cotton plants (Gossypium hirsutum), a coastal species in northern Yucatan (Mexico), and whether soil salinization affected these responses. We placed plants in mesh cages, and within each cage assigned plants as emitters or receivers. We exposed emitters to either ambient or augmented soil salinity to simulate a salinity shock, and within each group subjected half of the emitters to no damage or artificial leaf damage with caterpillar regurgitant. Damage increased the emission of sesquiterpenes and aromatic compounds under ambient but not under augmented salinity. Correspondingly, exposure to VOCs from damaged emitters had effect on receiver EFN induction, but this effect was contingent on salinization. Receivers produced more EFN in response to damage after being exposed to VOCs from damaged emitters when the latter were grown under ambient salinity, but not when they were subjected to salinization. These results suggest complex effects of abiotic factors on VOC-mediated plant interactions. [ABSTRACT FROM AUTHOR]

Biological control may benefit from the behavioral manipulation of natural enemies using volatile organic compounds (VOCs). Among these, herbivore-induced plant volatiles (HIPVs) provide potential tools for attracting or retaining predators and parasitoids of insect pests. This work aimed to characterize the VOCs emitted by pear plants in response to attack by Cacopsylla bidens (Hemiptera: Psyllidae), a major pest in pear orchards, to compare these with VOCs induced by a leaf chewing insect, Argyrotaenia sphaleropa (Lepidoptera: Tortricidae), and to evaluate the behavioral response of Chrysoperla externa (Neuroptera: Chrysopidae) to HIPVs from pear plants damaged by either herbivore. The results demonstrated that plants damaged by the pear psylla emitted VOC blends with increased amounts of aliphatic aldehydes. Leafroller damage resulted in increased amounts of benzeneacetonitrile, (E)-4,8-dimethylnona-1,3,7-triene, β-ocimene and caryophyllene. In olfactometer bioassays, larvae of C. externa were attracted to herbivore-damaged plants when contrasted with undamaged plants. When plant odors from psylla-damaged were contrasted with those of leafroller-damaged plants, C.externa preferred the former, also showing shorter response lag-times and higher response rates when psylla-damaged plants were present. Our results suggest that pear plants respond to herbivory by modifying their volatile profile, and that psylla-induced volatiles may be used as prey-specific chemical cues by chrysopid larvae. Our study is the first to report HIPVs in pear plants attacked by C. bidens, as well as the attraction of C. externa to psyllid-induced volatiles. [ABSTRACT FROM AUTHOR]

Vaccination clearly decreases coronavirus disease 2019 (COVID-19) mortality; however, they also impose selection pressure on the virus, which promotes the evolution of immune escape variants. For example, despite the high vaccination level in especially Western countries, the Omicron variant caused millions of breakthrough infections, suggesting that the highly mutated spike protein in the Omicron variant can escape antibody immunity much more efficiently than the other variants of concern (VOCs). In this study, we investigated the resistance/susceptibility of T helper cell responses that are necessary for generating efficient long-lasting antibody immunity, in several VOCs. By predicting T helper cell epitopes on the spike protein for most common HLA-DRB1 alleles worldwide, we found that although most of high frequency HLA-DRB1 alleles have several potential T helper cell epitopes, few alleles like HLA-DRB1 13:01 and 11:01 are not predicted to have any significant T helper cell responses after vaccination. Using these predictions, a population based on realistic human leukocyte antigen-II (HLA-II) frequencies were simulated to visualize the T helper cell immunity on the population level. While a small fraction of this population had alarmingly little predicted CD4 T cell epitopes, the majority had several epitopes that should be enough to generate efficient B cell responses. Moreover, we show that VOC spike mutations hardly affect T helper epitopes and mainly occur in other residues of the spike protein. These results suggest that lack of long-lasting antibody responses is not likely due to loss of T helper cell epitopes in new VOCs. [ABSTRACT FROM AUTHOR]

This study aims the development of a novel chemical method for toluene estimation. In this account, pure toluene was oxidized by KMnO4 in a basic medium that converts into potassium benzoate, which is analyzed by UV Spectrophotometer, and the % age conversion is determined. Different concentrations of potassium benzoate obtained by applying reaction to varying amounts of toluene; are analyzed that give wavelength maxima at 223.5 nm same as that of pure potassium benzoate, and the exact amount of toluene in the sample can be quantified. This method's detection limit is 0.1 ml (87 mg) of toluene. This method provides high sensitivity and accuracy that would be ideal for the estimation of toluene. This paper is also confined to the impurity of benzene in toluene. The amount fraction of benzene was quantified using a Janovsky reaction that leads to the dye formation. Colorimetric measurement of formed dye quantifies the benzene amount fraction in pure toluene, i.e., 0.045 ± 0.002 ml of benzene in 5 ml of pure toluene. [ABSTRACT FROM AUTHOR]