Concentrations Of Volatile Organic Compounds Research Articles

Domestic groundwater wells in Appalachia show evidence of low-dose, complex mixtures of legacy pollutants.

Lack of water quality data for private drinking water sources prevents robust evaluation of exposure risk for communities co-located with historically contaminated sites and ongoing industrial activity. Areas of the Appalachian region of the United States (i.e., Pennsylvania, Ohio and West Virginia) contain extensive hydraulic fracturing activity, as well as other extractive and industrial technologies, in close proximity to communities reliant on private drinking water sources, creating concern over potential groundwater contamination. In this study, we characterized volatile organic compound (VOC) occurrence at 307 private groundwater well sites within Pennsylvania, Ohio, and West Virginia. The majority (97%) of water samples contained at least one VOC, while the average number of VOCs detected at a given site was 5 ± 3. The majority of individual VOC concentrations fell below applicable U.S. Environmental Protection Agency (EPA) Maximum Contamination Levels (MCLs), except for chloroform (MCL of 80 μg L-1; n = 1 at 98 μg L-1), 1,2-dibromoethane (MCL of 0.05 μg L-1; n = 3 ranging from 0.05 to 0.35 μg L-1), and 1,2-dibromo-3-chloropropane (MCL of 0.2 μg L-1; n = 7 ranging from 0.20 to 0.58 μg L-1). To evaluate well susceptibility to VOCs from industrial activity, distance to hydraulic fracturing site was used to assess correlations with contaminant occurrences. Proximity to closest hydraulic fracturing well-site revealed no statistically significant linear relationships with either individual VOC concentrations, or frequency of VOC detections. Evaluation of other known industrial contamination sites (e.g., US EPA Superfund sites) revealed elevated levels of three VOCs (chloroform, toluene, benzene) in groundwaters within 10 km of those Superfund sites in West Virginia and Ohio, illuminating possible point source influence. Lack of correlation between VOC concentrations and proximity to specific point sources indicates complex geochemical processes governing trace VOC contamination of private drinking water sources. While individual concentrations of VOCs fell well below recommended human health levels, the low dose exposure to multiple VOCs occurring in drinking supplies for Appalachian communities was noted, highlighting the importance of groundwater well monitoring.

Identification on Key Volatiles Contributed to Oviposition Preference of Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae) from High and Normal Oleic Varieties of Peanut

The Indian meal moth, Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae), a primary stored peanut insect pest, exhibited a significant difference in oviposition preference among normal-oleic peanuts (NOPs) and high-oleic peanuts (HOPs). Identifying key volatile organic compounds (VOCs) that are attractive or repellent to P. interpunctella is of great significance for the ecological management of pests. The profiles and contents of VOCs among NOP and HOP varieties were measured and compared, and key bioactive VOCs were further confirmed via an electroantennogram (EAG) analysis, as well as behavioral responses in Y-tube olfactometer and wind tunnel bioassays. Females prefer to lay eggs on NOP varieties more than on HOP ones. Acetophenone, nonanal, decanal, dodecane, 2,5-dimethylbenzaldehyde, and 4-ethyl-benzaldehy derived from tested peanuts elicited stronger antennal EAG responses. The results of the Y-tube olfactometer and wind tunnel bioassay showed that the relative high levels of nonanal, dodecane, and unique VOC acetophenone in NOP varieties have a significant attraction to P. interpunctella. Conversely, 4-ethyl-benzaldehyde and the unique VOC 2,5-dimethyl-benzaldehyde commonly found in HOP varieties exhibit notable repellent effects on P. interpunctella. These VOCs could contribute to the development of attractants or repellents derived from special peanut varieties for pest management.

Tropospheric ozone precursors: global and regional distributions, trends, and variability

Abstract. Tropospheric ozone results from in situ chemical formation and stratosphere–troposphere exchange (STE), with the latter being more important in the middle and upper troposphere than in the lower troposphere. Ozone photochemical formation is nonlinear and results from the oxidation of methane and non-methane hydrocarbons (NMHCs) in the presence of nitrogen oxide (NOx=NO+NO2). Previous studies showed that O3 short- and long-term trends are nonlinearly controlled by near-surface anthropogenic emissions of carbon monoxide (CO), volatile organic compounds (VOCs), and nitrogen oxides, which may also be impacted by the long-range transport (LRT) of O3 and its precursors. In addition, several studies have demonstrated the important role of STE in enhancing ozone levels, especially in the midlatitudes. In this article, we investigate tropospheric ozone spatial variability and trends from 2005 to 2019 and relate those to ozone precursors on global and regional scales. We also investigate the spatiotemporal characteristics of the ozone formation regime in relation to ozone chemical sources and sinks. Our analysis is based on remote sensing products of the tropospheric column of ozone (TrC-O3) and its precursors, nitrogen dioxide (TrC-NO2), formaldehyde (TrC-HCHO), and total column CO (TC-CO), as well as ozonesonde data and model simulations. Our results indicate a complex relationship between tropospheric ozone column levels, surface ozone levels, and ozone precursors. While the increasing trends of near-surface ozone concentrations can largely be explained by variations in VOC and NOx concentration under different regimes, TrC-O3 may also be affected by other variables such as tropopause height and STE as well as LRT. Decreasing or increasing trends in TrC-NO2 have varying effects on TrC-O3, which is related to the different local chemistry in each region. We also shed light on the contribution of NOx lightning and soil NO and nitrous acid (HONO) emissions to trends of tropospheric ozone on regional and global scales.

Volatile Organic Compound (VOC) Contamination in Hotel Rooms: A Pilot Study to Understand Sources and Health Risks

The COVID-19 pandemic drove the use of cleaning products, causing organic solvent contamination in hospitality environments. This pilot study investigated the presence and concentrations of volatile organic compounds (VOCs) in selected hotels in four different US cities with varying star ratings at the end of the pandemic period. Targeting 139 VOCs, 57 were detected across eight groups: alcohols, halocarbons, aromatics, alkanes, terpenes, carbonyls, ethers, and esters, in the indoor air. Alcohols were the most prevalent, especially in lower-rated hotels, suggesting higher use of cleaning supplies. Elevated levels of aromatics were detected in hotels rated under three stars, with a notable disparity compared to higher-rated hotels. Additionally, alkanes and terpenes such as n-tetradecane and d-limonene were consistently detected. Health risk assessment showed concentrations of all VOCs remained below their health criteria for customers. The cumulative cancer risk was 2.25 × 10−6 for hotel workers from chronic occupational exposure to eight carcinogenic VOCs, representing 1/3 of the lifetime risk from these chemicals in the ambient air. Cancer risks from individual VOCs ranged from 0.001 × 10−6 to 1.07 × 10−6, with chloroform accounting for nearly half of the cumulative risk. The findings underscore the need for careful selection and use of furnishings and cleaning supplies and for effective indoor air pollution control and management in hotel indoor environments.

The effect of Atmospheric Boundary Layer Meteorology in climate-related gases and VOCs concentrations over 3 European cities using an aerial platform

In the frame of the EU Horizon2020 ICARUS project, a N.A.S.A Awarded Light Manned Aircraft equipped with high-tech scientific instrumentation was used to perform an aerial mapping over Athens, Thessaloniki and Ljubljana greater areas. This study aimed to evaluate the effect of Atmospheric Boundary Layer (ABL) on Green House Gases (GHGs) and Volatile Organic Compounds (VOCs) concentrations over urban and rural areas of the above cities. Simultaneous ground-based measurements were performed in the respective regions. Air samples were pressurized with a stainless-steel bellows compressor into electropolished stainless steel canisters and analyzed by the use of a novel gas chromatographic system. The estimation of the mixing height (ΜΗ) of the ABL was based on the synoptic scale atmospheric circulation and the prevailing background wind. It was found that the MH variation, following the prevailing meteorological conditions, results in different concentration profiles in the lower troposphere over the examined regions. The pollutants concentrations were generally decreasing with altitude in the ABL. Under certain meteorological conditions, vertical mixing plus horizontal transport can cause a high pollution level at the top of ABL. The pollutants concentrations were low over less industrialized and upwind regions, suggesting that local emission sources play significant role on the GHGs and VOCs levels over the regions. However, due to the large scale of sampling area that the aircraft covers the above gradients in concentrations are relative low. AQ modelling activities for simulating the cases studied in the current or any relative future work could reduce operating costs and allow projections of potential impacts.

Vocs pollution and respiratory exposure in commercial and residential underground parking garages

The indoor air quality in Underground Parking Garages (UPGs) has deteriorated significantly, primarily due to the high concentrations of particulate matter and volatile organic compounds (VOCs) emitted by idling or low-speed motor vehicles. However, the compositional characteristics and respiratory exposure to VOCs in UPGs have not been quantitatively analyzed. To establish a method for investigating the respiratory exposure to VOCs among different populations in UPGs, a three-dimensional dynamic diffusion model of indoor pollutants was developed based on monitoring data from 116 components in various UPGs in a large city in northern China. The results indicated that air pollution in underground spaces poses significant health risks to workers and children. Furthermore, a comprehensive approach is essential for improving ventilation capacity and air quality in underground transportation spaces.

Risk-oriented source apportionment and implications for mitigation strategies of VOCs in industrial parks: Insights from odor pollution and health risks

A typical industrial park in the upper reaches of the Yangtze River Economic Belt, which is 70 km from the Chongqing urban center, was used to investigate the occurrence and exposure of harmful volatile organic compounds (VOCs). An exposure risk method and a risk-oriented source apportionment approach were performed to assess the inhalation risks and apportion VOC sources, respectively. The quantitative relationships between risk factors and pollution sources were established, identifying key pathogenic and odorous VOCs. The quantitative emission reduction strategies were developed based on risk thresholds. Residents within the industrial parks face potential health risks due to pathogenic VOCs and nuisance odors, and workers in specific sectors experience two to six times higher risks than those in residential areas. Six risk sources were identified in the industrial park, ranked according to their contribution to VOC concentrations as follows: industrial sewage treatment (IST) (32.59 %), natural gas chemical industry (NGCI) (27.77 %), diesel vehicle exhaust (DVE) (12.04 %), pharmaceutical manufacturing industry (PMI) (11.14 %), chemical raw materials manufacturing (CRMM) (9.96 %), and iron and steel industry (ISI) (6.5 %). Among these, NGCI, IST, and CRMM were the top contributors to pathogenic risks, with contributions of 32.13 %, 29.71 %, and 21.71 % to non-carcinogenic risks, and 18.15 %, 19.87 %, and 27.99 % to carcinogenic risks, respectively. DVE produced significantly higher odor pollution compared to other sources, with intensities that were 3 to 10 times greater. The key pathogenic and odorous VOCs differ by source, resulting in varying control priorities for different VOC species. Reducing emissions from these six sources for 20 high-risk species (e.g., acrolein, 2-chlorotoluene, 1,2-dibromoethane, dichloromethane, and p-diethylbenzene) will simultaneously lower pathogenic and odor risks, with cumulative reduction rates ranging from 4.11 % to 93.75 %. This study provides quantitative control targets for VOCs from a health risk perspective, offering valuable guidance for developing risk management policies in industrial parks.

Enhancing accuracy and reproducibility in asphalt VOCs qualitative and quantitative analysis: Insights from laboratory studies on emission characteristics

Asphalt pavement will emit Volatile Organic Compounds (VOCs) during life cycle, posing environmental and health risks. Precise understanding of the emission characteristics of asphalt VOCs will facilitate the formulation of targeted measures for reducing emissions. Simulating the emission characteristics of VOCs from asphalt under laboratory conditions is an effective method for predicting asphalt VOCs pollution and implementing effective control measures. In this study, a quality control method for qualitative and quantitative detection of asphalt VOCs in laboratory settings was established based on sample storage time, asphalt sources, and temperature sensor positions. Furthermore, the study investigated the influence of mixing speed and sampling pump speed during asphalt VOCs generation on the emission characteristics. The results demonstrate that the quality control methods exhibit excellent reproducibility and reliability, making them valuable for future research and emission control strategies. Furthermore, the total concentration of asphalt VOCs increases with higher mixing speeds, but stabilizes when the mixing speed reaches 750–1250 r/min. As mixing speed increases, the proportion of alkane groups significantly decreases, while the proportion of aldehydes markedly increases, with the overall proportion remaining relatively stable. Decreasing sampling pump speed leads to a gradual increase in asphalt VOCs concentration. At lower pump speeds, a nonlinear increase in concentration occurs due to VOCs enrichment effects. Asphalt VOCs concentrations exhibit a proportional increase with sampling pump speeds exceeding 1000 ml/min. Finally, based on the results of the three-level analysis of "total concentration-group-substance" and taking into account the energy consumption, it is recommended that the mixing speed be set at 1000 r/min and the sampling pump speed be set at 1000 ml/min for the generation and collection of asphalt-related VOCs. This study can provide a reliable method for generating and collecting asphalt-related VOCs and offer critical insights for optimizing VOCs emission reduction strategies.

The detection and utilization of volatile metabolomics in Klebsiella pneumoniae by gas chromatography-ion mobility spectrometry

This research aimed to analyze the volatile compounds emitted during the proliferation of Klebsiella pneumoniae (K. pneumoniae) in the laboratory setting using gas chromatography-ion mobility spectrometry (GC-IMS) and to investigate the potential of volatile metabolomics for detecting carbapenemase-producing strains of K. pneumoniae. The volatile metabolomics of K. pneumoniae were comprehensively analyzed using GC-IMS in tryptic soy broth (TSB) as the culture medium. Afterward, the growth stabilization period (T2) served as the primary time point for analysis, with the introduction of imipenem and carbapenemase inhibitors (avibactam sodium or EDTA) during the exponential growth phase (T0) to further investigate alterations in volatile molecules associated with K. pneumoniae. Standard strains were utilized as references, while clinical strains were employed for validation purposes. At T2, a total of 22 volatile organic compounds (VOCs) associated with K. pneumoniae were identified (3 VOCs found in both monomer and dimer forms). Significant differences in VOCs were observed between carbapenemase-negative and carbapenemase-positive strains, both standard and clinical, following the introduction of imipenem. Furthermore, the addition of avibactam sodium led to distinct changes in the VOC content of strains producing class A carbapenemase, while the addition of EDTA resulted in specific alterations in the volatile metabolic profiles of strains producing class B carbapenemase. GC-IMS demonstrated significant promise for analyzing bacterial volatile metabolomics, and its application in evaluating the volatolomics of K. pneumoniae may facilitate the timely detection of carbapenemase-producing strains.

Spatial–Temporal Characteristics, Source Apportionment, and Health Risks of Atmospheric Volatile Organic Compounds in China: A Comprehensive Review

Volatile organic compounds (VOCs) are ubiquitous in the atmosphere, posing significant adverse impacts on air quality and human health. However, current research on atmospheric VOCs mainly focuses on specific regions or industries, without comprehensive national-level analysis. In this study, a total of 99 articles on atmospheric VOCs in China published from 2015 to 2024 were screened, and data on their concentrations, source apportionment, and health risks were extracted and summarized. The results revealed that the annual average concentrations of TVOCs and their groups in China generally increased and then decreased between 2011 and 2022, peaking in 2018–2019. A distinct seasonal pattern was observed, with the highest concentrations occurring in winter, followed by autumn, spring, and summer. TVOC emissions were highly concentrated in northern and eastern China, mainly contributed by alkanes and alkenes. Source apportionment of VOCs indicated that vehicle sources (32.9% ± 14.3%), industrial emissions (18.0% ± 12.8%), and other combustion sources (13.0% ± 13.0%) were the primary sources of VOCs in China. There was a significant positive correlation (p < 0.05) between the annual mean VOC concentration and population size, and a notable negative correlation (p < 0.05) with GDP per capita. Atmospheric VOCs had no non-carcinogenic risk (HI = 0.5) but exhibited a probable carcinogenic risk (7.5 × 10−5), with relatively high values for 1,2-dibromoethane, 1,2-dichloroethane, and naphthalene. The health risk was predominantly driven by halocarbons. These findings are essential for a better understanding of atmospheric VOCs and for developing more targeted VOC control measures.

Long-term emission characteristics of VOCs from building materials

Long-term emission behaviors of volatile organic compounds (VOCs) from indoor buildings materials heavily depend on the value of three key parameters (initial concentration C0, diffusion coefficient Dm, partition coefficient K) that govern emissions over time. We made the first attempt to quantitatively explore the variation of parameters through a long-lasting aging test that simulates natural indoor exposure. Over a span of 431 days, we obtained a substantial dataset consisting of ten thousand data points. The parameters of six VOCs (formaldehyde, benzene, toluene, ethylbenzene, o-xylene, p-m-xylene) from three kinds of wood-based boards with different aging intervals were determined. Our findings demonstrate that C0 decreases exponentially with aging time, while Dm and K merely fluctuate with it. With the obtained correlations, ventilation time for renovated house is proposed to meet the WHO standard. These results lay the groundwork for predicting long-term indoor VOC concentrations, which is crucial for indoor air quality pre-evaluation.

Multi-Domain Environmental Quality of Indoor Mixed-Use Open Spaces and Insights into Healthy Living—A Quarantine Hotel Case Study

In the post-pandemic context, data-driven design interventions that can endow architectural spaces with mixed-use and open characteristics that are adaptable and environmentally resilient are increasingly important. Ubiquitous semi-public architecture, such as hotel buildings, plays a crucial role in public health emergencies. Many hotels adopt mixed-use and open room spatial layouts, integrating diverse daily functions into a single tiny space, fostering flexible utilization and micro-scale space sharing; however, these also introduce potential health risks. This study offers a comprehensive evaluation of the indoor environmental quality (IEQ) of a hotel room space and discusses feasible intervention strategies for healthier renovation and rehabilitation. Taking a hotel in Shenzhen as a case, a multi-domain environmental assessment was conducted during the COVID-19 quarantine period in the summer of 2022. The study examines the health risks inherent in the hotel’s guest room and the varying patterns of IEQ factors across the hotel’s domains, including volatile organic compound concentrations, physical environmental parameters, and heat stress indices. The results illustrate diverse change trends in the chemical, physical, and heat stress factors present in the tested quarantined hotel room space throughout a typical summer day. Although most of the examined environmental factors meet local and global standards, some problems draw attention. In particular, the PM2.5 concentration was generally observed to be above the World Health Organization (WHO) air quality guideline (AQG) standards, and the interior lighting did not meet required standards most of the time. Moreover, correlation and multiple regression analyses uncover significant influence by physical environmental conditions on the concentrations of chemical pollutants in the hotel room. The study preliminarily identifies that higher relative humidity could lead to a lower concentration of CO2 while a higher PM2.5 concentration. Wet bulb globe temperature (WBGT) was observed to positively affect CO2 concentration. Further, the results suggest that even with relatively rigorous initial adjustment and re-renovation, multi-domain environmental quality in air-conditioned quarantine hotel rooms should be monitored and ameliorated from time to time. Overall, this study offers a scientific foundation for healthier upgrades of existing hotel buildings as well as provides insights into achieving environmental resilience in newly constructed hotel buildings for the post-pandemic era.

Influence of Germicidal UV (222 nm) Lamps on Ozone, Ultrafine Particles, and Volatile Organic Compounds in Indoor Office Spaces.

Germicidal ultraviolet lamps with a peak emission at 222 nm (GUV222) are gaining prominence as a safe and effective solution to reduce disease transmission in occupied indoor environments. While previous studies have reported O3 production from GUV222, less is known about their impact on other indoor constituents affecting indoor air quality, especially in real occupied environments. In this study, the effects of GUV222 on the levels of ozone (O3), ultrafine particles (UFPs), and volatile organic compounds (VOCs) were investigated across multiple offices with varying occupancies. O3 from the GUV222 operation was observed to increase linearly (∼300 μg h-1 m-1) with a UV light path length from 0 to 3 m beyond which it stabilized. When applied in offices, the O3 production models based on continuous measurements revealed O3 production rates of 1040 ± 87 μg h-1. The resulting increases in steady-state concentrations of 5-21 μg m-3 were highly dependent on the number of office occupants. UFP production occurred during both unoccupied and occupied conditions but predominantly in newly renovated offices. Time-resolved measurements with a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) revealed clear alterations in office VOC concentrations. Unsurprisingly, O3 oxidation chemistry was observed, including monoterpene deprivation and 4-oxopentanal (4-OPA) production. But additionally, significant alterations from unidentified mechanisms occurred, causing increased levels of various PTR-TOF-MS signals including C2H5O2+ and C4H9+ hypothesized to arise from photoinduced formation or off-gassing during the GUV222 lamp operation.

Evaluation of photocatalytic efficiency of TiO2 applied over cement plaster for mitigating urban air pollutant: TVOC

Photocatalysis emerged as a prominent method for mitigating air pollution stemming from emissions of total volatile organic compounds (TVOCs) in both indoor and outdoor environments. Given the slow degradation rate of certain TVOCs, which pose health risks, including carcinogenicity, there is a pressing need for effective air purification strategies, particularly within built environments where individuals spend substantial amounts of time. This study delves into the efficacy of TiO2 photocatalysis in reducing air pollutants when applied to building surfaces. Cement mortar samples, incorporating varied doses of TiO2 ranging from 7.83E-03 g/cm2 to 4.92E-02 g/cm2, were prepared and examined within batch reactors, both under sunlight exposure and in the absence thereof, to gauge their degradation rates towards TVOCs. Furthermore, surface characterization techniques were employed to explicate the microstructural properties of TiO2-coated plastered samples. The results obtained demonstrated the variation in the rate of degradation from 1.09E-04±0.1 % to 3.1E-4 ± 1.13 % min−1cm−2 for various initial concentrations of total volatile organic compounds (TVOCs) in the range of 600 ppm to 2900 ppm over a period of 100 min. The selected approach demonstrated the maximum degradation rate constant of 5.2E-04 min−1cm−2 corresponding to 15 % of TiO2 dose by weight of cement. These findings underscore the promise of TiO2 in purifying polluted air and advocate for its widespread implementation on building surfaces to enhance air quality.

Identification of Volatile Organic Compounds (Distinct Biomarkers) Emitted by Cancer Cells Using Gas Chromatography-mass Spectrometry – A Review

The utilization of Gas Chromatography-Mass Spectrometry (GC-MS) for the detection of Volatile Organic Compounds (VOCs) as potential biomarkers in cancer diagnostics is an evolving and promising field. This review outlines current exploratory and pilot studies that lay a fundamental groundwork for future research. Due to the complexity of the fecal and respiratory volatilome, influenced by a myriad of biological and environmental factors, it is crucial to expand research demographics to enhance data robustness and ensure the applicability of findings across diverse populations. We have also, herein, highlighted the dual capability of VOC analysis to detect cancer and differentiate between its stages, which is vital for customizing patient treatment plans and monitoring therapeutic efficacy. Furthermore, establishing quantifiable thresholds for VOC concentrations is essential for their clinical adoption as reliable indicators of cancer. The integration of GC-MS with machine learning and Artificial Intelligence (AI) could be useful for comprehensive metabolic profiles and facilitating the development of non-invasive and real-time diagnostic tools. The adoption of multi-omics approach promises a deeper understanding of cancer biology, potentially leading to personalized medicine and strategies finely tuned to individual molecular profiles. Hence, the research on VOCs as cancer biomarkers is set to offer transformative advancements in diagnostic technologies, ultimately improving patient outcomes through tailored therapeutic interventions.

Advancing Breathomics through Accurate Discrimination of Endogenous from Exogenous Volatiles in Breath.

Breathomics, a growing field in exposure monitoring and clinical diagnostics, has faced accuracy challenges due to unclear contributing factors. This study aims to enhance the potential of breathomics in various frontiers by categorizing exhaled volatile organic compounds (VOCs) as endogenous or exogenous. Analyzing ambient air and breath samples from 271 volunteers via TD-GC × GC-TOF MS/FID, we identify and quantify 50 common VOCs in exhaled breath. Advanced quantitative structure-property relationships and compartment models are employed to obtain VOCs kinetic parameters. This in-depth approach allows us to accurately determine the alveolar concentration of VOCs and further discern their origins, facilitating personalized application of breathomics in exposure assessment and disease diagnosis. Our findings demonstrate that prolonged external exposure turns humans into secondary pollutant sources. Analysis of endogenous VOCs reveals that internal exposure poses more significant health risks than external. Moreover, by correcting environmental backgrounds, we improve the accuracy of gastrointestinal disease diagnostic models by 15-25%. This advancement in identifying VOC origins via compartmental models promises to elevate the clinical relevance of breathomics, marking a leap forward in exposure assessment and precision medicine.

Analysis of Volatile Organic Compound Emissions in 3D Printing: Implications for Indoor Air Quality

This study provides a comprehensive analysis of volatile organic compound (VOC) emissions in the context of 3D printing, a rapidly advancing technology that is transforming manufacturing processes. As the adoption of 3D printing grows, concerns regarding its potential impact on indoor air quality have emerged. This research addresses these concerns by investigating the risks associated with VOC emissions and proposing effective mitigation strategies. Using a robust methodology, filament and resin-based 3D printers were employed alongside VOC sampling equipment (Tenax tubes and personal pumps) to assess emissions. A detailed analysis of 49 VOCs revealed variable concentrations across different printing materials, with ethyl acetate being the dominant compound in resin printing and decanal in filament printing. While individual VOC levels were below 1% of occupational exposure limits, total VOC concentrations frequently exceeded the recommended indoor threshold of 200 µg/m3, particularly in resin-based processes. This raises concerns about the combined effects of multiple VOCs, some of which are known carcinogens. These findings underscore the need for further investigation into the cumulative health impacts of prolonged exposure to multiple VOCs. The study also emphasises the importance of accounting for both facility-specific conditions and material emissions to fully understand the environmental and health consequences of 3D printing. Preventative measures, such as enclosing 3D printers and equipping them with extraction systems, are recommended to safeguard user health.

Indoor Environmental Quality in Portuguese Office Buildings: Influencing Factors and Impact of an Intervention Study

Office workers spend a considerable part of their day at the workplace, making it vital to ensure proper indoor environmental quality (IEQ) conditions in office buildings. This work aimed to identify significant factors influencing IEQ and assess the effectiveness of an environmental intervention program, which included the introduction of indoor plants, carbon dioxide (CO2) sensors, ventilation, and printer relocation (source control), in six modern office buildings in improving IEQ. Thirty office spaces in Porto, Portugal, were randomly divided into intervention and control groups. Indoor air quality, thermal comfort, illuminance, and noise were monitored before and after a 14-day intervention implementation. Occupancy, natural ventilation, floor type, and cleaning time significantly influenced IEQ levels. Biophilic interventions appeared to decrease volatile organic compound concentrations by 30%. Installing CO2 sensors and optimizing ventilation strategies in an office that mainly relies on natural ventilation effectively improved air renewal and resulted in a 28% decrease in CO2 levels. The implementation of a source control intervention led to a decrease in ultrafine particle and ozone concentrations by 14% and 85%, respectively. However, an unexpected increase in airborne particle levels was detected. Overall, for a sample of offices that presented acceptable IEQ levels, the intervention program had only minor or inconsistent impacts. Offices with declared IEQ problems are prime candidates for further research to fully understand the potential of environmental interventions.

Tuning the Sensitivity of Photonic Sensors Toward Alkanes Through the Textural Properties of Hybrid Xerogel Coatings

AbstractThis work exemplifies how incorporating organosilane modifiers into silica matrices allows for tuning the optical response of reflection photonic sensors through customizing the textural properties of hybrid xerogel sensing films. Xerogels with propyl molar percentages 0, 5, and 10% are used to construct photonic probes (OFS0pTEOS, OFS5pTEOS and OFS10pTEOS, respectively) by dip‐coating upon optimizing film deposition parameters. The time response of these probes toward a battery of volatile organic compounds (VOCs) comprising species with different functionality, size‐shape, and polarity is systematically analyzed through ON/OFF experiments, revealing that a low propyl content makes the poor‐responding OFS0pTEOS film highly sensitive toward non‐aromatic, large molecules with low‐polar or non‐polar character in OFS5pTEOS. This sensor is particularly sensitive toward alkanes, with globular cyclohexane (cyHex) outperforming elongated n‐hexane. Variable‐temperature calibration curves obtained from step‐by‐step experiments and adsorption–desorption cycles corroborate these observations and allow hysteresis to be quantified. The response to cyHex closely follows VOC concentration changes with the most stable signal among analytes, leading to well‐defined curves with low‐to‐negligible hysteresis. The isosteric enthalpies of cyHex adsorption are obtained for both the bulk material and the sensor, demonstrating labile adsorbate‐adsorbent interactions ruling the sensor response and becoming more exothermic for larger VOC concentrations.

Construction of PTFE/PI-PI/PANI-PA composite nanofibrous membrane for efficient photothermal membrane distillation and VOCs interception

Water-soluble volatile organic compounds (VOCs) are one of the difficult substances in seawater and industrial wastewater treatment. Photothermal membrane distillation (PMD) technology has great advantages in solving the problems of low energy conversion efficiency and serious pollution of traditional membrane distillation (MD) technology, but it still faces the challenge that VOCs cannot be effectively removed.To solve this problem, we prepared photothermal Polytetrafluoroethylene/Polyimide-Polyimide/Polyaniline-Polyamide (PTFE/PI-PI/PANI-PA) composite membranes with VOCs interception. The composite membrane was fabricated by applying the previously studied PTFE/PI-PI/PANI/PANI membrane by interfacially polymerising an ultrathin PA layer with controllable pore sizes. Among them, the PTFE/PI-PI/PANI base membrane in the composite membrane not only provides strong support and durability as a backbone structure, but the PANI photothermal layer also provides photothermal conversion for effective PMD operation. In addition, the ultra-thin PA layer acts as a molecular sieve separator to effectively intercept VOCs in the feed solution. When the feed solution was 35 g⋅L−1 NaCl, the average permeate flux of the #M-PA-0.1 membrane was 1.44 ± 0.02 L⋅m−2⋅h−1 with a salt interception rate of 99.99 % or more after 80 h of PMD testing. Meanwhile, when 50 mg⋅L−1 of VOCs was added to the feed solution, the VOCs retention rate >99.35 %, and the concentration of VOCs on the permeate side was much lower than the corresponding concentration in the drinking water standards recommended by the World Health Organisation (WHO) and the US Environmental Protection Agency (EPA). This study effectively combines the molecular sieve effect with the solar-powered evaporation process, which provides a research basis for the preparation of high-performance PMD membranes that can effectively remove volatile organic compounds.