Volatile Organic Compounds In Air Research Articles

Self-wetting triphase photocatalysis for effective and selective removal of hydrophilic volatile organic compounds in air

Photocatalytic air purification is widely regarded as a promising technology, but it calls for more efficient photocatalytic materials and systems. Here we report a strategy to introduce an in-situ water (self-wetting) layer on WO3 by coating hygroscopic periodic acid (PA) to dramatically enhance the photocatalytic removal of hydrophilic volatile organic compounds (VOCs) in air. In ambient air, water vapor is condensed on WO3 to make a unique tri-phasic (air/water/WO3) system. The in-situ formed water layer selectively concentrates hydrophilic VOCs. PA plays the multiple roles as a water-layer inducer, a surface-complexing ligand enhancing visible light absorption, and a strong electron acceptor. Under visible light, the photogenerated electrons are rapidly scavenged by periodate to produce more •OH. PA/WO3 exhibits excellent photocatalytic activity for acetaldehyde degradation with an apparent quantum efficiency of 64.3% at 460 nm, which is the highest value ever reported. Other hydrophilic VOCs like formaldehyde that are readily dissolved into the in-situ water layer on WO3 are also rapidly degraded, whereas hydrophobic VOCs remain intact during photocatalysis due to the “water barrier effect”. PA/WO3 successfully demonstrated an excellent capacity for degrading hydrophilic VOCs selectively in wide-range concentrations (0.5−700 ppmv).

Insight into the environmental monitoring and source apportionment of volatile organic compounds (VOCs) in various functional areas

Atmospheric aerosol contamination has caused widespread concern about human and environmental health. However, research about VOCs as an important precursor of secondary aerosols in ambient air is still limited. In this study, VOCs at sites from three typical functional areas in Hefei, China, were monitored using GC–MS/FID. The VOCs in ambient air from different functional areas showed significantly different characteristics. The highest concentrations and the biggest diurnal difference of VOCs were found in the High-tech Zone (industrial area) with serried emission sources. Additionally, lower VOC concentration was observed in Changjiang West Road, the center area of studied city. The VOC concentration in this area is strongly related to other pollutants. The composition of VOCs at all sampling sites showed certain common characteristics, i.e., alkanes, OVOCs, and halogenated hydrocarbons account for more than 75% of the total VOCs’ quality. The High-tech Zone with the highest concentration of VOCs also has the highest proportion of alkanes. Besides, the positive matrix factorization analysis results revealed that vehicle exhaust, LPG volatilization sources, and chemical solvents were the most important VOC emission sources in Hefei. In terms of the contribution of VOC components to the OFP at the three sites, the olefins and alkynes at the Changjiang West Road site and the Science Island site contribute the most significant proportion. In contrast, the OVOCs at the High-tech Zone site contribute the largest proportion.

Volatile Organic Compounds in the Azteca/Cecropia Ant-Plant Symbiosis and the Role of Black Fungi.

Black fungi of the order Chaetothyriales are grown by many tropical plant-mutualistic ants as small so-called “patches” in their nests, which are located inside hollow structures provided by the host plant (“domatia”). These fungi are introduced and fostered by the ants, indicating that they are important for the colony. As several species of Chaetothyriales tolerate, adsorb, and metabolize toxic volatiles, we investigated the composition of volatile organic compounds (VOCs) of selected domatia in the Azteca/Cecropia ant-plant mutualism. Concentrations of VOCs in ant-inhabited domatia, empty domatia, and background air were compared. In total, 211 compounds belonging to 19 chemical families were identified. Ant-inhabited domatia were dominated by ketones with 2-heptanone, a well-known ant alarm semiochemical, as the most abundant volatile. Empty domatia were characterized by relatively high concentrations of the monoterpenes d-limonene, p-cymene and β-phellandrene, as well as the heterocyclic sulphur-containing compound, benzothiazole. These compounds have biocidal properties and are primarily biosynthesized by plants as a defense mechanism. Interestingly, most of the latter compounds were present at lower concentrations in ant inhabited domatia than in non-colonized ones. We suggest that Chaetothyriales may play a role in reducing the VOCs, underlining that the mutualistic nature of these fungi as VOCs accumulation might be detrimental for the ants, especially the larvae.

One-year monitoring of aromatic volatile organic compounds (VOCs) in urban areas of Malaysia

VOCs have been one of the important limiting factors of O3 photochemical production in the urban tropical region. This study aims to determine the variation and composition of aromatic VOCs as well as their contribution to the O3 formation. The hourly data of benzene, toluene, ethylbenzene and xylenes (BTEX) and ozone (O3) were retrieved from January until December 2019 at three continuous air quality monitoring stations (S1, S2 and S3) operated by the Malaysian Department of Environment (DOE). Aromatic VOCs is detected by using an online gas chromatography analyser (GC 5000BTX). The annual average ΣBTEX concentrations ranged from 14.53 ± 12.43 μg m-3 to 25.04 ± 24.04 μg m-3 during the observation period, with toluene as the most dominant species with an average concentration of 10.65 ± 12.12 μg m-3. The O3 formation potential (OFP) was calculated and the results indicated that toluene is the highest contributor of O3-forming potential, followed by m, p-xylene, o-xylene, ethylbenzene and benzene with the value of 127.8 μg m-3 (40.90 %), 103.0 μg m-3 (32.97 %), 48.66 μg m-3 (15.58 %), 26.17 μg m-3 (8.38 %) and 6.74 μg m-3 (2.15 %), respectively. Since the study of VOCs in Malaysia is quite limited, a more comprehensive study is currently underway to integrate the research on variation of VOCs in ambient air and its impact on the environment and human health.

Volatile organic compounds (VOCs) in indoor air and tap water samples in residences of pregnant women living in an area of unconventional natural gas operations: Findings from the EXPERIVA study

BackgroundNortheastern British Columbia (Canada) is an area of unconventional natural gas (UNG) exploitation by hydraulic fracturing, which can release several contaminants, including volatile organic compounds (VOCs). To evaluate gestational exposure to contaminants in this region, we undertook the Exposures in the Peace River Valley (EXPERIVA) study. ObjectivesWe aimed to: 1) measure VOCs in residential indoor air and tap water from EXPERIVA participants; 2) compare concentrations with those in the general population and explore differences related to sociodemographic and housing characteristics; and 3) determine associations between VOC concentrations and density/proximity to UNG wells. MethodsEighty-five pregnant women participated. Passive air samplers were analyzed for 47 VOCs, and tap water samples were analyzed for 44 VOCs. VOC concentrations were compared with those from the Canadian Health Measure Survey (CHMS). We assessed the association between different metrics of well density/proximity and indoor air and tap water VOC concentrations using multiple linear regression. Results40 VOCs were detected in >50% of air samples, whereas only 4 VOCs were detected in >50% of water samples. We observed indoor air concentrations >95th percentile of CHMS in 10–60% of samples for several compounds (acetone, 2-methyl-2-propanol, chloroform, 1,4-dioxane, hexanal, m/p-xylene, o-xylene, styrene, decamethylcyclopentasiloxane, dodecane and decanal). Indoor air levels of chloroform and tap water levels of total trihalomethanes were higher in Indigenous participants compared to non-Indigenous participants. Indoor air levels of chloroform and acetone, and tap water levels of total trihalomethanes were positively associated with UNG wells density/proximity metrics. Indoor air BTEX (benzene, toluene, ethylbenzene, xylenes) levels were positively correlated with some well density/proximity metrics. ConclusionOur results suggest higher exposure to certain VOCs in pregnant women living in an area of intense unconventional natural gas exploitation compared with the general Canadian population, and that well density/proximity is associated with increased exposure to certain VOCs.

Novel Graphene Wool Gas Adsorbent for Volatile and Semivolatile Organic Compounds.

Volatile and semivolatile organic compounds in ambient air and occupational settings are of great concern due to their associated adverse human health and environmental impacts. Novel graphene wool samplers have been developed and tested to overcome limitations of commercially available sorbents that can only be used once and typically require solvent extraction. Graphene wool (GW) was synthesized by non-catalytic chemical vapor deposition with optimized conditions, resulting in a novel fibrous graphene wool that is very easy to manage and less rigid than other forms of graphene, lending itself to a wide range of potential applications. Here, the air pollutant sampling capabilities of the GW were of interest. The optimal packing weight of GW inside a glass tube (length 178 mm, i.d. 4 mm, o.d. 6 mm) was investigated by the adsorption of vaporized alkane standards on the GW, using a condensation aerosol generator in a temperature-controlled chamber and subsequent detection using a flame ionization detector. The optimized GW packing density was found to be 0.19 mg mm–3 at a flow rate of 500 mL min–1, which provided a gas collection efficiency of >90% for octane, decane, and hexadecane. The humidity uptake of the sampler is less than 1% (m/m) for ambient humidities <70%. Breakthrough studies showed the favorable adsorption of polar molecules, which is attributed to the defective nature of the graphene and the inhomogeneous coating of the graphene layers on the quartz wool, suggesting that the polar versus non-polar uptake potential of the GW can be tuned by varying the graphene layering on the quartz wool substrate during synthesis. Oxidized domains at the irregular edges of the graphene layers, due to a broken, non-pristine sp2 carbon network, allow for adsorption of polar molecules. The GW was applied and used in a combustion sampling campaign where the samplers proved to be comparable to frequently used polydimethylsiloxane sorbents in terms of sampling and thermal desorption of non-polar semivolatile organic compounds. The total alkane concentrations detected after thermal desorption of GW and PDMS samplers were found to be 17.96 ± 13.27 and 18.30 ± 16.42 μg m–3, respectively; thus, the difference in the alkane sampling concentration between the two sorbent systems was negligible. GW provides a new, exciting possibility for the monitoring of organic air pollutants with numerous advantages, including high sampling efficiencies, simple and cost-effective synthesis of the thermally stable GW, solvent-free and environmentally friendly analysis, and, importantly, the reusability of samplers.

Novel Porous Carbon Material for the Detection of Traces of Volatile Organic Compounds in Indoor Air.

A highly sensitive and selective silicon-based microanalytical prototype was used to identify a few ppb of volatile organic compounds (VOCs) in indoor air. Herein, a new nonactivated tannin-derived carbon synthesized by an environmentally friendly method, DM2C, a MIL-101(Cr) MOF, and a DaY zeolite were selected for the preconcentration of BTEX compounds (i.e., benzene, toluene, ethylbenzene, and xylenes). Integrating a small amount of these nanoporous solids inside a miniaturized preconcentration unit led to excellent preconcentration performance. By taking advantage of the high adsorption-desorption capacities of the DM2C adsorbent, concentrations as low as 23.5, 30.8, 16.7, 25, and 28.8 ppb of benzene, toluene, ethylbenzene, ortho- and para-xylene, respectively, were detected in a short analysis time (∼10 min) even in the presence of 60% relative humidity at 25 °C. The DM2C showed excellent stability over a period of 4 months and more than 500 tests, as well as repeatability, which makes it a very reliable adsorbent for the detection of trace VOCs in indoor air under realistic conditions in the presence of humidity.

Exposure of heat-not-burn tobacco effect on the quality of air and expiratory plume

The increasing interest to avoid the consumption of regular tobacco has lead in the development of several types of devices to decrease the effects of this practice on active and bystanders. In this work, the impact of the use of new heat-not-burn (HnB) devices has been evaluated and compared with that of regular cigarettes and electronic cigarettes (e-cigs). Portable monitoring devices were employed for CO, CO2, particulate matter (PM) and volatile organic compounds (VOCs) to evaluate the quality of indoor air and expiratory plume of both, active and passive, users during these practices. It can be noticed that the levels of VOCs in active HnB smokers expiratory air are five times lower in particular cases than those provided by regular tobacco and three times lower than those obtained for e-cigs, while the contribution of particulate matter to air pollution decreases between 200 and 600 times regarding the values obtained for e-cig vaping and regular tobacco smoking. The level of contaminants as CO decreases significantly in both, active and passive HnB smokers, in comparison with active and passive regular tobacco smokers, due to the absence of organic material combustion.Regarding passive HnB smokers, the exposure to HnB smoke do not increases the level of VOCs in ambient air nor in expiratory plume, remaining at the basal levels, being three times lower than values obtained to an exposure to regular tobacco smoke and two times lower than exposure to e-cigs vapours. On the other hand, the use of HnB devices decreases the concentration of PM in bystanders around thirty five times in relation with values obtained for passive regular tobacco smokers. Concerning the nicotine content delivered by HnB tobacco, data shown that HnB tobacco provides values from 0.5 to 1.7 mg of nicotine to the mainstream, being these values similar to those found in conventional tobacco.

Pollution Characteristics and Source Apportionment of Atmospheric VOCs During Ozone Pollution Period in the Main Urban Area of Chongqing

In late August 2020, a period of O3 pollution occurred in the main urban area of Chongqing and lasted for approximately 2 weeks (till early September). Ambient air samples, collected using Summa Canisters and DNPH sampling columns at three observation sites in the main urban area, were used to study the composition, photochemical reaction activity, and source apportionment of volatile organic compounds (VOCs) during the period of O3 pollution. The results showed that the mean volume fraction of TVOCs in the main urban area of Chongqing during the observation period was 45.08×10-9, and the components were ranked by volume fraction in the following order:OVOCs, alkanes, halohydrocarbons, alkenes, aromatics, and alkynes. Formaldehyde, ethylene, and acetone made up the higher volume fraction of VOCs, together accounting for more than 30% of TVOCs. OVOCs and alkenes contributed more to · OH loss rate (Li·OH) and ozone formation potential (OFP) and were the key VOCs components for ozone generation. The main active species in the OVOCs component were formaldehyde, acetaldehyde, and acrolein; the main active species in the alkene component were isoprene, ethylene, and n-butene. The ratio of xylene to ethylbenzene in VOCs was low, and they showed a significant correlation, indicating that the VOCs air mass in the main urban area was highly aging and affected by long-distance transmission from other areas. The source apportionment results of the PMF model showed five main sources of VOCs, namely secondary generation (27.67%), vehicle exhaust (26.56%), industrial emission (17.86%), plant (14.51%), and fossil fuel combustion (13.4%).

P–733 In infertile patients, risk factors for environmental reprotoxic exposure are widespread, limited in number and modifiable

Abstract Study question What are the risk factors for environmental reprotoxic exposure in infertile patients? Summary answer The most represented categories of reprotoxic risk factors (RRF) were dietary exposures (86% of patients), overweight (46%), psychoactive substances (38%) and male occupational exposures (63%). What is known already Numerous studies have reported the deleterious effects of environmental reprotoxic exposures on male or female fertility. These studies most often focus on the impact of a limited number of reprotoxic risk factors (body mass index (BMI), dietary habits, tobacco or alcohol consumption) or a limited number of chemical or physical reprotoxic exposures: phthalates, occupational exposures, or pesticides. Despite the call of several reproductive health professional societies and public health agencies for taking environmental health into account in women of childbearing age, this approach remains little realized in current practice. Study design, size, duration We conducted a prospective, monocentric study between June 2018 and February 2020 in women and men visiting the fertility unit of our University Hospital for assisted reproduction technique (ART) treatment. Participants/materials, setting, methods Patients completed a self-questionnaire to collect information about i) the various types of exposure to RRF, and ii) frequency and intensity of exposures (qualitative and semi-quantitative approach). We performed a literature search in order to define the environmental factors and the exposure level thresholds associated with a “recognized” or “suspected” RRF and we analyzed their nature and number in patients. Main results and the role of chance During the inclusion period, we received 545 couples in consultation, and 405 were included in this study (810 patients/1090, participation rate: 74%). 65% of women and 68% of men self-reported at least one “recognized” RRF. In men, they were from exposure to solvents, heat, psychoactive substances and a BMI&amp;gt;25; in women, from exposure to poor indoor air quality, psychoactive substances and a BMI&amp;gt;25. A limited number of recognized risk factors were recorded in the majority of patients (one, two or three risk factors in 65% of patients). Men were more often exposed than women to occupational risk factors (63% of men versus 28% of women) such as solvents and ambient heat, and women were more often exposed than men to poor indoor air quality and volatile organic compounds (49% of women versus 30% of men). We note that the majority of the risk factors for reprotoxic exposure found were modifiable, specifically dietary, occupational, overweight and psychoactive substance exposures. Limitations, reasons for caution One limitation is the collection of data via a self-administered questionnaire, which makes it possible to estimate the risk factors for reprotoxic exposure, but not to detect them in a measurable way, for example, through exposure biomarkers. In addition, no data is available about all RRF in the general population. Wider implications of the findings: We suggest that if the individual screening of each infertile patient’s RRF was done before ART, most patients could act on a limited number of modifiable RRF, in the aim of increasing their chances of natural pregnancy and improving ART outcomes. Trial registration number N° 2018–13–06–004 (Ethics Committee of the University of Aix Marseille) and N° 2020–27 (Assistance Publique - Hôpitaux de Marseille General Regulation on Data Protection).

Development of an expanded polytetrafluorethylene dosimeter for the passive sampling of volatile organic compounds in air

A passive sampler composed of a porous, hydrophobic, and gas-permeable expanded polytetrafluoroethylene (ePTFE) tube was developed to effectively concentrate volatile organic compounds (VOCs) in the air. The ePTFE dosimeter has larger sorbent mass normalized sampling rates (L h−1) compared with literature. This result suggests that ePTFE dosimeter can effectively detect low level VOCs in less contaminated air, including indoors. The air boundary layer thickness can be neglected when the mass accumulated in sorbent is converted to gas phase VOCs concentrations. The vapor pressure dependent desorption of VOCs from the sorbent was observed and modeling results suggested that this could lead to the underestimation of VOCs concentrations in air. However, the determination of the appropriate sampling time and the consideration of desorption could overcome the underestimation. A proton transfer reaction quadrupole mass spectrometer and passive samplers were deployed simultaneously in a chamber under fluctuating VOCs concentrations in air. The time-weighted average concentrations of ethylbenzene were 0.016, 0.015, and 0.017 g m−3 for 23, 46, and 69 min experimental period, respectively. The average concentration of the real-time analysis was 0.015 g m−3 for 69 min. The results show the ePTFE dosimeter can be used to estimate time weighted VOCs concentrations in air.

Heating events drive the seasonal patterns of volatile organic compounds in a typical semi-arid city

The emission characteristics, source apportionment and chemical behavior of volatile organic compounds (VOCs) are important for strategy-making on ozone (O3) and fine particulate matter (PM2.5) control. Based on the continuous observation during four seasons, the seasonal characteristics, chemical reactivity and source apportionment of 116 VOCs species were studied in a typical semi-arid city with no relevant research. The results showed that the annual average concentrations of total volatile organic compounds (TVOCs) in Hohhot was 44.67 ± 46.59 ppbv with the predominant of alkanes and oxygenated volatile organic compounds (OVOCs). The sharp increment of TVOCs were explained by the elevating OVOCs and alkanes in autumn, while alkanes and alkenes in winter. The levels of alkenes presented negative and positive correlations with solar radiation and PM10, respectively. The mixing ratios accounted for 30% (alkanes) and 23% (alkenes and aromatics) of the TVOCs, respectively; while their ozone formation potential (OFP) ~15% and nearly 50% (even 75% in winter), respectively, indicating that the OFP of different VOCs species depends not only on their concentrations but more importantly on their chemical activity in atmosphere. According to the seasonal source apportionment, both the high levels of short-chain alkanes, alkenes and aromatics and the increasing coal sales volume suggested that the combustion sources were the predominant in heating seasons, while solvent uses was extracted as the most predominant during non-heating seasons. In non-heating seasons, the biogenic emission sources, ranking as the second contributor, were significantly higher than heating seasons. Isoprene was the most active biogenic VOCs species, bagging test results showed that deciduous trees were the predominant contributors for isoprene (~99%), while coniferous trees and shrub for monoterpenes (>95%). It will be helpful for understanding the characteristics of VOCs in Chinese national key development areas and informing policy to control semi-arid regional VOCs air pollution.

Observation of Conditions Preceding Peak Indoor Air Volatile Org Compound Concentrations in Vapor Intrusion Studies.

Temporal and spatial variability of indoor air volatile organic compound (VOC) concentrations can complicate vapor intrusion (VI) assessment and decision-making. Indicators and tracers (I&T) of VI, such as differential temperature, differential pressure, and indoor radon concentration, are low-cost lines of evidence to support sampling scheduling and interpretation of indoor air VOC sampling results. This study compares peak indoor air chlorinated VOC concentrations and I&T conditions before and during those peak events at five VI sites. The sites differ geographically and in their VI conceptual site models (CSM). Relative to site-specific baseline values, the results show that cold or falling outdoor temperatures, rising cross slab differential pressures, and increasing indoor radon concentrations can predict peak VOC concentrations. However, cold outdoor air temperature was not useful at one site where elevated shallow soil temperature was a better predictor. Correlations of peak VOC concentrations to elevated or rising barometric pressure and low wind speed were also observed with some exceptions. This study shows how the independent variables that control or predict peak indoor air VOC concentrations are specific to building types, climates, and VI CSMs. More I&T measurements at VI sites are needed to identify scenario-specific baseline and peak related I&T conditions to improve decision-making.

Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

An Assessment of Indoor Air Quality in the Arrivals Hall of Beirut–Rafic Hariri International Airport: Monitoring of VOCs and NO2

In Beirut–Rafic Hariri International Airport (RHIA), airport employees stay at least 12 h inside the airport’s buildings and suffer from respiratory symptoms. Additionally, direct openings exist between the apron and the arrivals hall providing a pathway for contaminated air to enter the buildings. Hence, we study the impact of Beirut–RHIA’s activities on the indoor air of the arrivals hall (impact on employees and passengers) during June, November, and October 2014. Due to their impacts on air quality and human health, assessing of the concentrations of nitrogen dioxide (NO2) and Volatile Organic Compounds (VOCs) was the target of our study by using gas chromatographic techniques (GC-MS and GC-FID) for VOCs and calorimetric methods for NO2 concentrations. NO2 levels indicated a probable hazard to the health of passengers and employees, while measured VOC levels did not present any risks except for acrolein. This is the first study to assess the speciation of a large number of VOCs (46 VOCs) for airport indoor air while revealing a very interesting correlation between aircraft number and the concentrations of VOC groups (namely heavy alkanes, aldehydes and ketones, and monoaromatics). Moreover, this is the first study in Lebanon to assess the speciation of a large number of VOCs in indoor air.

The Measurement and Control Research of Non-metal Material Volatile Organic Compound in Civil Aircraft

The paper expounds the source of volatile compounds in the air of civil cabin. By measuring the air quality in civil cabin and Volatile organic compound (VOC) content of typical non-metal material, in addition, comparing domestic control laws and standards of VOC in civil airplane cabin air with which in overseas, the paper attend to offer recommendations to control civil airport non-metal material VOC and provide a reference for control of non-metal material in civil airplane cabin to related enterprises. The research is aimed to create a foundation to produce a new representation of green and safe domestical civil airplanes. It is very meaningful to motivate domestical civil airplane industry and the international progress of enormous industrial chain that influences.

Life Cycle Assessment and Indoor Environmental Quality of Wooden Family Houses

This article analyzes in detail the impact of wooden houses on the environment using the life cycle assessment (LCA) methodology and at the same time evaluates the indoor environmental quality (IEQ) in these houses. The investigated detached family houses had a wooden structure. The first one had a bearing system made of a wooden frame; other materials were conventional. The second house was built entirely of log wood. Given the high risk of greenhouse gas emissions, the concentration of which in the atmosphere is causing global climate change, the global warming potential (GWP) indicator is crucial. According to results, the family house built entirely of wood and with a biomass boiler significantly reduces CO2 emissions and is therefore considered from the LCA point of view as a more suitable alternative compared to a house with a wooden frame structure. The building materials with the highest share involved in the creation of GWP include concrete structures (38–48%), ceramic roof tiles (33%) and plasterboard (15%). Plasterboard cladding (55%), concrete structures (17–19%), oriented strand board OSB (9–22%), impregnated wooden structures (31–52%) and plastic windows (9%) are the most involved in acidification potential (AP) and eutrophication potential (EP). Plasterboard structures (21%), impregnated wood materials (47.4%), reinforced concrete structures (12%) and mineral wool and roof tiles significantly contribute to the creation of photochemical ozone creation potential (POCP) and ozone depletion potential (ODP). The indoor environmental quality was evaluated through short-term measurements of basic physico-chemical parameters. Since both houses have different characteristics, the aim of this monitoring was to evaluate the actual state of IEQ in selected wooden houses under real conditions. Based on the recorded results, it can be stated that neither presented wooden house, in terms of thermal-humidity microclimate, concentration of CO2 and particulate matter, represents an environment with a negative impact on their occupants. With regards to volatile organic compounds (VOCs), the increased concentrations of xylenes and tetrachlorethylene in the log house were probably caused by the application of impregnation and protective coatings six months before monitoring. In this case, the concentration of tetrachloroethene, which is considered a potential carcinogen, was six times higher than the legislative limit. For VOCs, such as limonene, isobutylene and n-butylacetate, which were found in the wooden frame house, no limits are set. The legislative limits for xylenes and tetrachlorethylene in this house have not been exceeded, and therefore the IEQ cannot yet be considered harmful for health. The presence of all the mentioned VOCs in the interior air of the wooden frame house is more related to the activities of occupants, as this house has been inhabited for several years.

Updating Real-World Profiles of Volatile Organic Compounds and Their Reactivity Estimation in Tunnels of Mexico City

The main objective of this work was to bring to date the exhaust and evaporative volatile organic compound (VOC) profiles from light-duty gasoline vehicles, carrying out a sampling and analysis campaign in two tunnels of Mexico City. The abundance of exhaust-emission VOC profiles was the same in 2018 as in 1998 (alkanes &gt; aromatics &gt; olefins &gt; acetylene), albeit exhibiting large differences (67%, 17%, 12%, and 4% for 2018, and 50%, 26%, 16%, and 8% for 1998, respectively). An important reduction of 69% and 77% in VOC concentrations was registered inside and outside of the tunnel, respectively, in comparison with 1998. In the ambient air, alkanes accounted for 77%, since high concentrations of liquefied petroleum (LP) gas species are still present. Ethylene, propylene, 1-butene, and toluene from tunnel emissions contributed prominently to ozone formation, while the most reactive gasoline vapors were pentenes, pentanes, and butenes, although the ozone formation potential due to VOCs in tunnel emissions and ambient air also had a significant reduction. These results demonstrate that strategies carried out in the last 20 years were successful in achieving a better air quality, although the aromatic and olefin content in gasolines needs to be further reduced to lower the concentrations of toxic and reactive species.

Elevated Levels of Biogenic Nonmethane Hydrocarbons in the Marine Boundary Layer of the Arabian Sea During the Intermonsoon

AbstractThe Arabian Sea is one of the most biologically productive ocean regimes and hence possesses a perennially intense oxygen minimum zone. High productive oceans can potentially modify the production and sea‐to‐air exchange of trace gases including volatile organic compounds (VOCs). We measured nonmethane hydrocarbons (NMHCs) such as ethane, ethene, propane, propene, 1‐butene, cis‐2‐butene, and 1‐pentene in the marine air and characterized phytoplankton species in seawater of the Arabian Sea during the premonsoon season of the year 2017. The light alkenes namely ethene and propene were the dominant VOCs in the marine air with average mixing ratios of 8.92 ± 3.50 and 3.38 ± 1.30 ppbv, respectively. Daytime enhancements of ethene, propene, 1‐butene, cis‐2‐butene, and 1‐pentene were 20–40% higher than their nighttime values. The high levels of alkenes were associated with the higher abundances of Trichodesmium and Thalassiosira species. The Δethene/Δpropene (2.63 ppb ppb−1) was comparable to those reported for other oceanic regions. Estimated emission fluxes of ethene (2.0–6.9 × 109 molecules cm−2 s−1) were higher than those reported for several other oceanic regions. Such high emission rates of NMHCs in remote regions can significantly affect the regional tropospheric oxidation chemistry leading to the formation of ozone and secondary organic aerosols. Our observations highlight the need to evaluate the biogeochemical processes controlling the oceanic emissions of NMHCs over the northern Indian Ocean.

Volatile Organic Compounds (VOCs) from Wood and Wood-Based Panels: Methods for Evaluation, Potential Health Risks, and Mitigation.

Volatile organic compounds (VOCs) are contained in various construction materials and interior equipment. Their higher concentrations in the indoor air are associated with negative effects on human health and are disputed in terms of health risk, since people spend a considerable part of their lifetime indoors. Therefore, the presence of VOCs in indoor air is a case of concern regarding sick building syndrome (SBS). From a historical point of view, wood and wood-based panels represent a widely used material. Nevertheless, wood appears to be nowadays a product and a material of a sustainable future. Depending on wood extractives’ composition and an abundance of diverse wood species, different profiles of volatiles are emitted. In case of wood-based panels, the impact of adhesives and additives that are essentially applied aiming to adjust the panels’ properties is even enriching this cocktail of chemicals. This paper comprises the issue of VOCs emitted from wood and wood-based panels. The most abundant VOCs were summarized. The options of VOCs for analytical determination from these matrixes are described with their benefits and limitations.