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Rapid detection of indoor airborne viruses is critical to prevent the spread of respiratory diseases. Herein, we present sensitive, highly rapid electrochemical measurement of airborne coronaviruses through condensation-based direct impaction onto antibody-immobilized, carbon nanotube-coated porous paper working electrodes (PWEs). Carboxylated carbon nanotubes are drop-cast on paper fibers to make three-dimensional (3D) porous PWEs. These PWEs have higher active surface area-to-volume ratios and electron transfer characteristics than conventional screen-printed electrodes. The limit of detection and detection time of the PWEs for liquid-borne coronaviruses OC43 are 65.7 plaque-forming units (PFU)/mL and 2 min, respectively. The PWEs showed sensitive and rapid detection of whole coronaviruses, which can be ascribed to the 3D porous electrode structure of the PWEs. Moreover, water molecules condense on airborne virus particles during air sampling, and these water-encapsulated virus particles (<4 µm) are impacted on the PWE for direct measurement without virus lysis and elution. The whole detection takes ∼10 min, including air sampling, at virus concentrations of 1.8 and 11.5 PFU/L of air, which can be due to the highly enriching and minimally damaging virus capture on a soft and porous PWE, demonstrating the potential for the rapid and low-cost airborne virus monitoring system. [Display omitted] • Paper working electrodes (PWEs) are used to detect whole coronaviruses in liquids and in air. • Carbon nanotubes are deposited on a fibrous paper to make porous PWEs. • The detection time of PWEs for liquid-borne coronaviruses is 2 min. • Airborne coronaviruses are water-encapsulated and impacted on PWEs for direct measurement without virus lysis and elution. • Detection of airborne coronaviruses takes ∼10 min including air sampling at 1–10 PFU/L of air. [ABSTRACT FROM AUTHOR]

Heritage guidelines recognize odors as a value associated with a place. This study aims to clarify the connection between heritage and volatile organic compounds at the molecular level. At variance with previous studies, usually focused only on book‐related compounds from accelerated degradation tests, the whole air of one of the most significant historical libraries in Italy was studied. A sampling of the volatiles off‐gassing from the two most iconic rooms, respectively open and forbidden to visitors, was performed via a non‐invasive, nondestructive green method, solid‐phase‐micro‐extraction. The gas‐chromatographic analyses resulted in the appraisal of olfactory contributions from books, storage environment, and, for the first time, anthropic activities and pollution.Concerning the paper decay process, for the very first time, the presence of 2‐ethyl‐1‐hexanol in the chromatographic signature of the library air is rationalized according to the Guerbet reaction. The presence of all other compounds is explained by the paper decay process, anthropic sources, and pollution. Indoor air comprises analytes related to paper decay, identified by previous studies, and additional compounds never found before.Most volatile compounds are aliphatic and aromatic hydrocarbons, aldehydes, alcohols, terpenes, and terpenoids. Odor contributions from a selected number of analytes were pinpointed. Alkanes dominate the volatiles chromatographic signature, and impart a slight hydrocarbon smell. Aromatics supplement their characteristic aromatic odor. Aldehydes' very low odor threshold makes them strongly contribute to both fruity and fatty descriptors. Benzaldehyde, furfural, vanillin, and camphor add, respectively, an hint of almond, bread, vanilla, and camphor. Alcohols such as 2‐ethyl hexanol have a floral scent. Wood‐related terpenes and terpenoids contribute to the woody smell of the library.The digital molecular fingerprint of the "scent of knowledge" enables documentation, conservation, and future chemical reproduction of the historical library odor. [ABSTRACT FROM AUTHOR]

Maintaining regular physical exercise is essential for maintaining good health. In China, fitness centres are thriving, and the cleanliness of the exercise environment has become increasingly important. This study investigated the thermal response and indoor air environment of fitness personnel in various areas of a fitness centre using subjective evaluation and on-site air environment measurements. The findings revealed that the indoor air environment in different exercise areas of the fitness centre varied spatially, which can lead to discomfort amongst fitness personnel during exercise. Overall, the thermal sensation in different areas of the fitness centre was found consistently too hot. Temperature and humidity have the greatest impact on the thermal sensation of individuals in different areas, while indoor air pollutants have a minimal effect. The intensity and duration of exercise can also influence the body's heat sensation and pollutant inhalation dose. The body's heat balance mechanism can affect subjective evaluations. This study proposes three strategies for optimizing the indoor environment of fitness centres through principal component analysis. This paper provides data and a methodological framework for the development of specifications supporting the design, operation and management of the environment in fitness centres. [ABSTRACT FROM AUTHOR]

Potential health concerns from cooking with natural gas appliances include short-term exposure to nitrogen dioxide (NO2). Published, one-hour concentrations measured in a few kitchens during simulated cooking events have been cited as justification for moving to electric alternatives by certain advocates. These estimates, however, are not believed to adequately represent typical potential exposure concentrations. In this paper, the various challenges in evaluating potential exposures based on measured indoor air concentrations of NO2 associated with cooking are identified and discussed. These include the lack of standards for indoor air in the U.S., the relatively short duration of cooking activities, and the likelihood of bias in indoor NO2 measurements due to the instrument response to other nitrogen-containing compounds. Correction factors for making more meaningful comparisons are suggested, including correction for duration of cooking time and correction for presence of nitrous acid (HONO). [ABSTRACT FROM AUTHOR]

An intensive field campaign was conducted to monitor indoor air formaldehyde in two French elementary schools for 5 weeks, where the experimental conditions were modified every week. Formaldehyde concentration was monitored using two portable laboratory prototypes with a detection limit of 1 μg m−3 and a temporal resolution of 2 s. Carbon dioxide concentration, temperature (T), and relative humidity (RH) were also recorded over the whole field campaign. To take advantage of continuous measurement of formaldehyde for post-data analysis, these 2-s raw formaldehyde concentrations were then used to recalculate the average values for several time steps, i.e., 1 min, 10 min, 1 h, and 1 day. This paper highlights that a time resolution of 10 min is sufficient and well adapted to monitor most of the variations of formaldehyde concentrations observed in these two classrooms. The weekly mean formaldehyde concentrations calculated were in the ranges of 25.6–33.8 μg m−3 and 14.7–26.8 μg m−3 for schools 1 (S1) and 2 (S2), respectively, once excluded an unwanted painting event in S1. The results obtained were in excellent agreement with those determined by using the reference method based on DNPH derivatization. The results also revealed that building materials and furniture were two significant formaldehyde emission sources. Unlike most of the studies found in the literature in which formaldehyde is monitored using passive sampling, continuous measurements allowed us to estimate real children's exposure. When considering only the children's occupation time, a significant decrease in average formaldehyde concentration ranging between 20 and 34 % was observed for weeks 4 and 5 when the occupants followed specific strategies for natural ventilation. Opening the windows as soon as the CO2 exceeds the thresholds appears to be the most efficient way to limit exposure to formaldehyde in the two investigated schools. The findings of this paper demonstrate the importance of continuous and accurate formaldehyde measurements with at least 10-min time resolution which could serve as a roadmap for future developments of formaldehyde low-cost sensors. [ABSTRACT FROM AUTHOR]

Exposure to potentially toxic elements (PTEs) bound to PM2.5 can cause various health effects, including cardiovascular disease, allergies, and other related diseases. There have been several studies on the concentration of PTEs, including zinc (Zn), iron (Fe), and manganese (Mn) bound PM2.5 in the indoor air of urban schools. In this study, the concentration of Zn, Fe, and Mn in the indoor air of schools bound PM2.5 were meta-analyzed. PubMed and Scopus were used to retrieve papers related to the concentration of PTEs bound PM2.5 in the indoor air of urban schools from January 1, 2000 to March 10, 2020. The concentration of PTEs in PM2.5 was meta-analyzed based on the country subgroup in the random-effects model (REM). Thirty papers with 25 data reports were included in the study. The rank order of PTEs bound PM2.5 was Zn (17.32 ng/m3) > Fe (14.49 ng/m3) > Mn (7.40 ng/m3). The rank order of countries based on the concentration of Fe-bound PM2.5 in the indoor air of urban schools was China > Poland > Italy > Spain > Taiwan > Turkey > Iran) > Chile; Zn, Poland > Iran > Taiwan > Turkey > Spain > Italy > Chile; and for Mn, Poland > China > Iran > Taiwan > Spain > Italy > Chile. The pooled concentration of PTEs (Fe, Mn, and Zn) bound PM2.5 in the indoor air of urban schools in Poland and China was higher than in other countries, hence, therefore, it is recommended to carry out a PM2.5 concentration reduction program in the indoor air of schools in these countries. [ABSTRACT FROM AUTHOR]

Sensors and sensor systems for monitoring fine particles with aerodynamic diameters smaller than 2.5 µm can provide real-time feedback on indoor air quality and thus can help guide actions to manage indoor air pollutant concentrations. Standardized verification of the performance and accuracy of sensors and sensor systems is crucial for predicting the efficacy of such monitoring. A new ASTM International standard test method (ASTM D8405) was created for this need and is the most exacting laboratory protocol published to date for evaluating indoor air quality sensors and sensor systems measuring particles smaller than 2.5 µm in diameter. ASTM D8405 subjects sensors and sensor systems to five test phases: (1) an initial particle concentration ramp; (2) exposure to various temperature and humidity conditions; (3) exposure to interfering particles; (4) temperature cycling; and (5) a final particle concentration ramp to assess drift. This paper discusses the development of the standard test method, key aspects of the testing process, example evaluation results, and a comparison of this standard test method against peer evaluation protocols. [ABSTRACT FROM AUTHOR]

Sansevieria trifasciata plant is one of the most popular indoor plant around the world. Its potential for toluene removal in intramural conditions is well known. S. trifasciata potted plants also degrade toluene through their phyllosphere, rhizosphere, endophytes, and soil-associated microbial activities. Since the phyllosphere is a transient habitat, this study focused on the other microbial habitats associated with the S. trifasciata potted plant. Hence, the soil and endophytic bacterial isolates were selected after three successive enrichments with 1% toluene. The redox indicator 2.6-dichloro phenol indophenol (DCPIP) activity was used to rank this bacteria's ability to degrade toluene. The two most active isolates were chosen and subjected to molecular identification and quantitative analysis to measure toluene degradation. The headspace initial toluene concentration was 41,385 ± 404 mg/m3 ~ 104 ppm, after 28 days, bacterial isolates Priestia aryabhattai TE2 and Metabacillus halosaccharovorans 3S1 were found to have reduced toluene by 17.34% and 40.53%, respectively, while the survival rates were revealed as 96.8 ± 14.6% and 1863 ± 143%, respectively. M. halosaccharovorans 3S1 has good growth over the time while degrading toluene.Highlights: Investigate the ability of bioremediation to remove toluene from the air using a potted plant system, a hybrid of phytoremediation and bioremediation. A particularly large number of plant species have been studied worldwide, but no complete study has been conducted. In this paper, the studies on the plant and associated microflora are summarised in one framework. Microbial remediation of airborne pollutant removal. Few research studies have investigated microbial removal of toluene, but no complete identification of microorganisms has been carried out, as in this paper. The microbial ability to remove toluene in the atmosphere was [ABSTRACT FROM AUTHOR]

Reducing the heat transfer temperature difference via reasonable indoor temperature determination and air conditioning system design is a confirmed building energy-saving approach for space cooling and heating. However, the energy-saving mechanism cannot be explained scientifically and comprehensively while maintaining the cognitive level of the heat transfer law. In this paper, based on the same climatic conditions and decreasing range of indoor and outdoor temperature difference, the yearly and monthly absolute energy-saving amount (ESA) and relative energy-saving ratio (ESR) are investigated and compared for cooling and heating, respectively, to reveal the energy-saving mechanism for cooling and heating from the microscopic perspective. Two new concepts, including ESA by temperature difference and behavioral ESA by measure itself, are defined. The yearly ESA for cooling or heating caused by the decreasing of temperature difference is composed of those two factors. For cooling, the contribution rate of the behavioral ESA at those moments within the decreasing range of the temperature difference can be up to 78%, while for heating is only 7%. This work can provide theoretical support for building energy system design optimization and method reference for energy-saving analysis of building air conditioning systems with temperature difference considerations for cooling and heating, respectively. [ABSTRACT FROM AUTHOR]

In recent decades, indoor air pollution has become a major concern due to its adverse health effects on the inhabitants. The presence of fine particles (PM2.5) and hazardous volatile organic compounds (VOCs), such as formaldehyde and benzene, in indoor air and their proven carcinogenic effects, has raised the attention of health authorities. Their very difficult and expensive removal by chemical and mechanical methods has led researchers to seek an economical and environmentally friendly technique. The use of plants in different ways such as potted plants or green walls is considered as a potential green solution for the improvement of indoor air quality and the health level of its inhabitants. A review of the literature cited in this paper suggests that plants absorb some of the pollutants, such as particles directly and remove some pollutants such as VOCs indirectly through biological transfer or by using microorganisms. This review paper discusses the types of plants that have been used for the phytoremediation of airborne pollutants and the routes and mechanisms for removing the pollutants. Removal pathways of the pollutants by aerial parts of the plants, the growth media along with the roots and their microorganisms in the rhizosphere part were also discussed. Sensitive analysis of extracted data from the literature outlined the most useful types of plants and the appropriate substrate for phytoremediation. Also, it showed that factors affecting the removal efficiency such as light intensity and ambient temperature, behave differently depending on pollutants and plants types. [ABSTRACT FROM AUTHOR]

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Space heating accounts for a large part of building energy consumption. Lowering the heating temperature set-point (Tsp) is expected to be a feasible approach for energy efficiency. In this paper, eight globally typical cities are selected, and the energy-saving mechanism and variation trends of lowering heating Tsp are investigated under different working conditions (climate conditions, construction completion year and inner heat sources). The results show that significant energy-saving effects even appear in the relatively warm-winter cities. The energy-saving mechanism is dominated by two different categories of heating hours including the temperature-difference saving (TDS) hours and the behavioral saving (BS) hours. The contribution of TDS and BS to the whole annual heating energy saving amount (HSA) depends on the reducing level of heating hours. The HSA of lowing Tsp is mainly affected by TDS influence. After coupling the consideration of different factors, with the decreasing annual HSA of buildings, the dominance of the TDS influence mechanism shrinks gradually while the annual heating energy saving ratio (HSR) increases. This work provides the analysis method for building heating energy saving potential evaluation and reference for the establishment of standards and residents' behavioral energy saving in different climatic zones. [ABSTRACT FROM AUTHOR]

Cutting-edge building energy management systems (BEMS) interact with heating, ventilation, air conditioning (HVAC) systems, which generally account for much of the energy consumption. Major attention is focused on the BEMS themselves, barring on-field equipment. In HVAC equipment, sub-optimal controller settings may lead to energy losses and user discomfort, for instance, due to oscillations of air temperature and fan speeds. The way to solve this problem could be to replace classical PID controllers with an alternative concept that does not require tuning and works optimally for a wide range of parameters. This paper compares a fuzzy logic controller (FLC) with a standard PID for a model-based simulation of an HVAC system in Simulink for different conditions using real building measurement data. The end result is the implementation of the developed methods in a newly designed universal control board for air handling units (AHU). The proposed FLC achieves better integral control quality indicators (IAE, ISE, ITAE, ITSE) by at least 27.4%, and smaller supply air temperature variation; the daily mean square error (MSE) was reduced by an average of 36%, which leads immediately to better occupant comfort and a presumed reduction in energy consumption. Compared to the untuned PID, energy consumption was 12.7% lower; this will ensure improved economy from the lowest level, and paves the way for interoperability with high-level energy management schemes. [ABSTRACT FROM AUTHOR]

Although several non-thermal plasmas (NTPs) technologies have been widely investigated in air treatment, very few studies have focused on the inactivation mechanism of viruses by NTPs. Due to its efficiency and environmental compatibility, non-thermal plasma could be considered a promising virus-inactivation technology. Plasma is a partly or fully ionized gas including some species (i.e., electrons, free radicals, ions, and neutral molecules) to oxidize pollutants or inactivate harmful organisms. Non-thermal plasmas are made using less energy and have an active electron at a much higher temperature than bulk gas molecules. This review describes NTPs for virus inactivation in indoor air. The different application processes of plasma for microorganism inactivation at both laboratory and pilot-scale was also reviewed This paper reports on recent advances in this exciting area of viral inactivation identifying applications and mechanisms of inactivation, and summarizing the results of the latest experiments in the literature. Moreover, special attention was paid to the mechanism of virus inactivation. Finally, the paper suggests research directions in the field of airborne virus inactivation using non-thermal plasma. [ABSTRACT FROM AUTHOR]

Invasive fungal infection is an important cause of mortality and morbidity in neonates, especially in low-birthweight neonates. The contribution of fungi in the indoor air to the incidence of mucocutaneous colonization and to the risk of invasive fungal infection in this population is uncertain. This review aimed to identify and to summarize the best available evidence on the fungal contamination in the indoor air of critical hospital areas with an emphasis on pediatric/neonatal ICUs. Publications from 2005 to 2019 were searched in the databases Scientific Electronic Library Online (SciELO), US National Library of Medicine National Institutes of Health Search (PubMed), and Latin American Caribbean Health Sciences (LILACS). Descriptors in Health Sciences (DeCS) were used. Research papers published in Portuguese, English, and Spanish were included. Twenty-nine papers on all continents except Australia were selected. The results showed that the air mycobiota contained several fungal species, notably Aspergillus, Penicillium, Cladosporium, Fusarium, and yeast (Candida) species. The selected papers point out the risks that fungi pose to neonates, who have immature immune system, and describe simultaneous external factors (air humidity, seasonality, air and people flow, use of particulate filters, and health professionals' hand hygiene) that contribute to indoor air contamination with fungi. Improving communication among health professionals is a great concern because this can prevent major health complications in neonates, especially in low-birthweight neonates. The results reinforced the need to monitor environmental fungi more frequently and efficiently in hospitals, especially in neonatal ICUs. [ABSTRACT FROM AUTHOR]

The recycling and utilization of lithium-ion batteries has received a lot of attention. The use of recycled waste lithium-manganese batteries to degrade formaldehyde contaminated gas by adsorption is certainly killing two birds with one stone. In this paper, efficient catalysts capable of degrading formaldehyde were obtained using lithium-manganese button batteries being discharged to different levels and then recovering the cathode material by a simple method and labelled as LixMnO2 (x = 0.00; 0.25; 0.50; 0.75; 1.00). The fully discharged cathode material Li1.00-MnO2 degraded formaldehyde at nearly 100% (less than 0.1 ppm) within 24 h at room temperature, which is twice the degradation rate of the undischarged cathode material. The high degradation efficiency is attributed to the continuous doping of Li+ as the discharge proceeds and the conversion of Mn(IV) to Mn(III), so the lattice gap, defects, surface oxygen species and specific surface area of the catalyst increase. And the surface oxygen involved in the degradation of formaldehyde increases. The catalytic activity of the catalyst for formaldehyde gradually increased with the discharge, promoting the catalytic degradation effect. The degradation rate of formaldehyde at low concentrations was close to 100% within 24 h. This study provides an attractive approach for converting lithium battery electrode materials into formaldehyde degradation catalysts to improve the indoor environment. [ABSTRACT FROM AUTHOR]

Volatile methyl siloxanes (VMS) are ubiquitous in indoor environments due to their use in personal care products. This paper builds on previous work identifying sources of VMS by synthesizing time-resolved proton-transfer reaction time-of-flight mass spectrometer VMS concentration measurements from four multiweek indoor air campaigns to elucidate emission sources and removal processes. Temporal patterns of VMS emissions display both continuous and episodic behavior, with the relative importance varying among species. We find that the cyclic siloxane D5 is consistently the most abundant VMS species, mainly attributable to personal care product use. Two other cyclic siloxanes, D3 and D4, are emitted from oven and personal care product use, with continuous sources also apparent. Two linear siloxanes, L4 and L5, are also emitted from personal care product use, with apparent additional continuous sources. We report measurements for three other organosilicon compounds found in personal care products. The primary air removal pathway of the species examined in this paper is ventilation to the outdoors, which has implications for atmospheric chemistry. The net removal rate is slower for linear siloxanes, which persist for days indoors after episodic release events. This work highlights the diversity in sources of organosilicon species and their persistence indoors.

This paper describes how an extreme Saharan dust event that took place in March 2022 affected the Iberian Peninsula and was noticed not only by the outdoor air quality monitoring stations measuring PM2.5 and PM10 but also by indoor air monitoring systems in Fatima, central Portugal. The observed particulate matter concentrations clearly show the influence that such an event has on the indoor air quality inside buildings and that the magnitude of that influence is also dependent on the specific characteristics of the buildings, mainly the ventilation conditions, as should be expected. Therefore, this study alerts us to the necessity of integrating indoor and outdoor air quality monitoring systems to achieve automated air conditioning systems capable of efficiently controlling both temperature and air cleanliness. [ABSTRACT FROM AUTHOR]

Effective identification of pollution sources is particularly important for indoor air quality. Accurate estimation of source strength is the basis for source effective identification. This paper proposes an optimization method for the deconvolution process in the source strength inverse calculation. In the scheme, the concept of time resolution was defined, and combined with different filtering positions and filtering algorithms. The measures to reduce effects of measurement noise were quantitatively analyzed. Additionally, the performances of nine deconvolution inverse algorithms under experimental and simulated conditions were evaluated and scored. The hybrid algorithms were proposed and compared with single algorithms including Tikhonov regularization and iterative methods. Results showed that for the filtering position and algorithm, Butterworth filtering performed better, and different filtering positions had little effect on the inverse calculation. For the calculation time step, the optimal Tr (time resolution) was 0.667% and 1.33% in the simulation and experiment, respectively. The hybrid algorithms were found to not perform better than the single algorithms, and the SART (simultaneous algebraic reconstruction technique) algorithm from CAT (computer assisted tomography) yielded better performances in the accuracy and stability of source strength identification. The relative errors of the inverse calculation for source strength were typically below 25% using the optimization scheme. [ABSTRACT FROM AUTHOR]

Providing comfortable indoor air quality control in residential construction is an exceedingly important issue. This is due to the structure of the fast response controller of air quality. The presented work shows the breakdown and creation of a mathematical model for an interactive, nonlinear system for the required comfortable air quality. Furthermore, the paper refers to designing traditional proportional integral derivative regulators and proportional, integral, derivative regulators with independent parameters based on a backpropagation neural network. In the end, we perform the experimental outputs of a suggested backpropagation neural network-based proportional, integral, derivative controller and analyze model results by applying the proposed system. The obtained results demonstrated that the proposed controller can provide the required level of clean air in the room. The proposed developed model takes into consideration international Heating, Refrigerating, and air conditioning standards as ASHRAE AND ISO. Based on the findings, we concluded that it is possible to implement a proposed system in homes and offer equivalent indoor air quality with continuous mechanical ventilation without a profuse amount of energy. [ABSTRACT FROM AUTHOR]

This paper discusses the importance of indoor air quality and indicates its relation with outdoor air quality in the area of spa treatment. Significant factors and sources causing indoor air pollution by particulate matter and radon are considered. Particular attention is drawn to specific functions of health resorts in spa treatment in the context of the importance of indoor and outdoor air for patients staying in the resorts. It is underlined the specificity of health resorts providing treatment for patients classified as the group most sensitive to air pollution, i.e. people with chronic respiratory diseases. The study comprised measurements of 24-h concentrations of PM10, PM2.5 and 10-minute instantaneous concentrations of radon-222 (222Rn) from February 5 to February 25, 2021 in a treatment room of one of the Polish spas located in Lower Silesia. The analysis of interactions between the concentrations of two fractions of particulates PM10 and PM2.5 was presented. The interaction and dependence of factors affecting the elevated values of concentrations of the studied pollutants were discussed. The presented analyses showed that the concentrations of the studied pollutants were influenced by air exchange and air infiltration from outside to inside. In the case of short-term measurements of 222Rn activity concentration in the air, it was found that the observed changes in hourly concentrations of 222Rn are analogous to those observed in residential buildings. For the specific time intervals, the variation of PM concentrations and 222Rn activity concentration was found to be similar. [ABSTRACT FROM AUTHOR]

The study aimed to determine and compare the mass concentration and size distribution of particulate matter (PM) at two Polish fire stations, one equipped with a washing machine intended for the decontamination of uniforms (FSN) and the other not equipped with this type of device (FSC), to assess the effectiveness of washing machines in reducing PM concentrations inside fire stations and estimate PM doses inhaled by firefighters while performing activities in truck bays and changing rooms during one work shift. The average PM concentrations at the FSN were 18.2–28.9 µg/m3 and 27.5–37.3 µg/m3, while at FSC they were 27.4–37.9 µg/m3 and 24.6–32.8 µg/m3 in the truck bays and changing rooms, respectively. At each measurement point, most of the PM mass (65–75%) was accumulated as fine particles. The dominance of fine particles in the total mass of PM results in high values of PM deposition coefficients (0.59–0.61) in three sections of the respiratory tract at each monitoring site. This study initially indicates the effectiveness of washing machines in reducing the concentration of fine particles and demonstrates the necessity, as well as directions for further research in this area. [ABSTRACT FROM AUTHOR]

Italy's education landscape witnessed a significant reform with the introduction of alternating school–work programs known as the School–Work Alternating System (PTCO). This innovative approach aims to enhance students' transversal skills and career orientation while addressing crucial health concerns, including indoor air and environmental quality within school environments. This study, conducted at an Italian high school in collaboration with a university as part of a PTCO initiative, engaged eight students in environmental monitoring data collection. The students focused on thermal comfort, CO2 levels, and microbiological pollutants, collecting data in 19 classrooms and other school areas using professional instruments during February 2019. The results revealed varying thermal comfort levels and acceptable room temperatures, but inadequate ventilation and elevated CO2 concentrations, particularly in crowded areas like the cafeteria. Microbial analysis identified potential health hazards, underscoring the need for proactive indoor air and environmental quality measures. Post-intervention data showed improved CO2 levels, suggesting increased student awareness about the importance of air circulation. Engaging students in indoor air and environmental quality research through PTCO fosters critical thinking and civic engagement, which are crucial for sustainable development. Advocating for improved ventilation and periodic indoor air and environmental quality assessments aligns with the United Nations' 2030 Agenda for Sustainable Development, particularly Goal 3 (Good Health and Well-being) and Goal 4 (Quality Education). The PTCO initiative empowers students to tackle real-world challenges like indoor air and environmental quality, developing essential skills and promoting positive change. Further research and policy efforts are needed to ensure equitable access to healthy learning environments, contributing to both educational success and long-term environmental sustainability. [ABSTRACT FROM AUTHOR]

Introduction: Healthcare-associated infections, primarily caused by microorganisms, are widespread in healthcare facilities. These infections pose a significant challenge, especially in low and middle-income countries, and have a detrimental impact on patient outcomes. It is crucial to assess the level of microbial load and associated factors to prevent the spread of these infections. The objective of this study was to assess the microbial load and identify the factors associated with it in various wards at Jimma Medical Center. Method: A cross-sectional study conducted at Jimma Medical Center. Indoor air samples were collected using the settle plate method with a 1/1/1 scheme. Inanimate surfaces and medical equipment were sampled using Swabs from a 10 × 10 cm area. A total of 268 samples were collected from 10 rooms. Pertinent information regarding the associated factors was gathered using an observational checklist. A multiple linear regression model was used to identify any associations with the microbial load. Result: Out of the total samples, 181 (67.5%) tested positive for culture, and 270 microbes were isolated. The average load of bacteria and fungi in the indoor air ranged from 124.4 to 1607 and 96 to 814.6 Colony-forming unit (CFU)/m3, respectively. The mean total aerobic colony counts of bacteria and fungi from all surfaces in the wards ranged from 5.25 to 43.3 CFU/cm2. Crowdedness [β = 2.748 (95% Confidence Interval (CI): 1.057-4.44)], the presence of waste material [β = 1.747 (95% CI: 0.213-3.282)], and an unclean room [β = 2.505 (95% CI: 0.990-4.019)] were significantly associated with the microbial load. Conclusion: The microbial load detected in indoor air, inanimate surfaces and medical equipment was posing potential health risks. Consequently, it is recommended to implement regular microbial surveillance of the hospital environment and enhance the infection prevention program to mitigate these concerns. [ABSTRACT FROM AUTHOR]

Metagenomics is a novel genomic tool employed to accurately study the composition of microbial communities in their ecological environments, including mass transport systems. Despite the potential significance of these sites as sources of exposure, the pathogenic microbiomes in these constructed settings remain unexplored. In this study, high-throughput sequencing was utilized to identify the microbiota obtained from the Metropolitan Transport of Shanghai (MTS) during the spring and summer. A diverse range of microbiota, especially pathogens, and models for mapping diversity and environmental variables were analyzed using the metagenomic techniques. The results indicate that bacteria accounted for 95.26% of the categorized genes in the 108 aerosol samples analyzed during the spring and summer, with the remaining 4.73% attributed to eukaryotes, viruses, and archaea. We successfully identified 86 microorganisms that align with the National Microbiology Data Center's List of Pathogenic Microorganisms, uncovering unique characteristics of various species with potential health implications throughout across seasons. Additionally, the distribution and diversity of the microbiota were significantly influenced by temperature, humidity, season, and time of day. The study's findings establish a framework for investigating and evaluating potential public health risks, offering early warning of biosecurity concerns related to these built environments. They also provide a comprehensive and unbiased perspective on the characteristics of microbial communities and potential pathogens in urban metros. Environmental and public health experts will find this investigation into the pathogenic microbiomes found in aerosol samples compelling. [ABSTRACT FROM AUTHOR]

The rapid spread and accumulation of microplastics (MPs) in environmental ecosystems result from extensive plastic usage. MPs have been found in both indoor and outdoor air. Outdoor MP levels vary widely across global cities, with reported ranges from 36 to 118 MPs m−2 day−1. However, differing measurement units complicate comparisons. Indoor MPs are particularly concerning due to the significant amount of time people spend indoors. For instance, MP concentrations in workplaces like reception areas and nail salons were found to be 309 ± 214 and 46 ± 55 MPs m−3, respectively. Technological limitations hinder the identification of MPs, with methods like µ-ATR-FTIR, µ-FTIR, and µ-Raman identifying MPs of different sizes. MPs smaller than 0.3 µm pose a health risk as they can be internalized in lung cells, while MPs larger than 10 µm are too large to enter alveolar macrophages. This review highlights the current understanding of airborne MPs, focusing on their sources, transport, and deposition mechanisms. It aims to provide a foundation for further studies to deeply assess the presence, abundance, and occurrence of MPs in aerosols, a subject that remains underexplored. [ABSTRACT FROM AUTHOR]

Indoor volatile organic compound (VOC) concentrations are often dynamic because the ventilation and emission rates of VOC usually change. Adsorption filters used for air purification may operate with a capacity that fluctuates with unsteady VOC concentrations in buildings. Modeling the dynamic interactions between adsorption filters and indoor air is crucial for predicting their performance under real-world conditions. This study presents a numerical model of partially reversible adsorption equilibrium coupled with a mass transfer model to create a predictive model for adsorption efficiency in environments with dynamic VOC concentrations. A honeycomb adsorption filter for benzene adsorption was simulated and tested, including the breakthrough and purging curve and the long-term efficiency in an experimental chamber with dynamic concentrations. The results reveal that the curve generated with the partially reversible adsorption equilibrium model closely aligns with the measured one. Furthermore, the model was coupled with a chamber model and the simulation results were compared with those calculated using the filter model with a single adsorption isotherm. When VOCs were emitted intermittently in the chamber and there was sufficient ventilation, the concentration peaks in the chamber derived from the models with different assumptions on adsorption reversibility were significantly different from each other. Moreover, it was observed that the reversible adsorption capacity of the filter was crucial for long-term operation in rooms with dynamic concentration. Despite the reversible adsorption capacity constituting only 6.7% of the total adsorption capacity of the tested filter, it contributes to a significant "peak shaving and valley filling" effect, even when the irreversible adsorption capacity is saturated. The adsorption reversibility should be taken as an important parameter for selecting adsorbents for dynamic concentration conditions. [ABSTRACT FROM AUTHOR]

Per- and polyfluoroalkyl substances (PFAS) are a unique class of chemicals synthesized to aid in industrial processes, fire-fighting products, and to benefit consumer products such as clothing, cosmetics, textiles, carpets, and coatings. The widespread use of PFAS and their strong carbon-fluorine bonds has led to their ubiquitous presence throughout the world. Airborne transport of PFAS throughout the atmosphere has also contributed to environmental pollution. Due to the potential environmental and human exposure concerns of some PFAS, research has extensively focused on water, soil, and organismal detection, but the presence of PFAS in the air has become an area of growing concern. Methods to measure polar PFAS in various matrices have been established, while the investigation of polar and nonpolar PFAS in air is still in its early development. This literature review aims to present the last two decades of research characterizing PFAS in outdoor and indoor air, focusing on active and passive air sampling and analytical methods. The PFAS classes targeted and detected in air samples include fluorotelomer alcohols (FTOHs), perfluoroalkane sulfonamides (FASAs), perfluoroalkane sulfonamido ethanols (FASEs), perfluorinated carboxylic acids (PFCAs), and perfluorinated sulfonic acids (PFSAs). Although the manufacturing of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) has been largely phased out, these two PFAS are still often detected in air samples. Additionally, recent estimates indicate that there are thousands of PFAS that are likely present in the air that are not currently monitored in air methods. Advances in air sampling methods are needed to fully characterize the atmospheric transport of PFAS. [Display omitted] • 85 papers detected PFAS in indoor and outdoor air from 2002 to 2022. • FTOHs, FASAs, and FASEs are the PFAS classes most frequently detected in air. • Most studies have used high volume-active air sampling to measure PFAS in air. • Novel air sampling methods are needed to characterize emerging PFAS. [ABSTRACT FROM AUTHOR]

As the dangers of volatile organic compounds (VOCs) and their potential as non-invasive diagnosis biomarkers have been reported, there has been a need for instrument capable of real-time and in-situ monitoring of multiple low-concentration VOCs in indoor air or human metabolites. A promising technology that can qualitatively and quantitatively analyze numerous VOCs as an alternative to conventional bench-top instruments is a micro-gas chromatography (µ-GC) system, which integrates three main components: a micro-gas preconcentrator, a µ-GC column, and a mini- or micro-detector fabricated using microelectromechanical system (MEMS) processes. This review covers the integration methods, features, and analysis capabilities of recently developed µ-GC systems and examines the materials, designs, and principles of the three main components. In addition, the challenging issues that must be addressed for the commercialization of this technology are discussed. [ABSTRACT FROM AUTHOR]

In this case study, we describe a well-resourced private school in New York City that implemented COVID-19 mitigation measures based on public health expert guidance and the lessons learned from this process. Avenues opened in New York City in 2012 and has since expanded, becoming Avenues: The World School, with campuses in São Paulo, Brazil; Shenzhen, China; the Silicon Valley, California; and online. It offers education at 16 grade levels: 2 early learning years, followed by a prekindergarten through grade 12. We describe the mitigation measures that Avenues implemented on its New York campus. We compare COVID-19 case prevalence at the school with COVID-19 case positivity in New York City, as reported by the New York State Department of Health. We also compare the school's indoor air quality to ambient indoor air quality measures reported in the literature. The school's mitigation measures successfully reduced the prevalence of COVID-19 among its students, staff, and faculty. The school also established a consistently high level of indoor air quality safety through various ventilation mechanisms, designed to reduce common indoor air pollutants. The school received positive parent and community feedback on the policies and procedures it established, with many parents commenting on the high level of trust and quality of communication established by the school. The successful reopening provides useful data for school closure and reopening standards to prepare for future pandemic and epidemic events. [ABSTRACT FROM AUTHOR]

Indoor air pollution is a critical health issue. We studied particle emissions, concentration changes and size distribution mechanisms using an indoor space with air quality monitors, incense stick burning, and ventilation. Temporal changes in the concentrations of particles with sizes of 10 nm to 10 µm were monitored. Our findings show that particles affecting particle number concentration (PNC) were mainly in the Aitken mode (50–100 nm) and accumulation mode I (100–200 nm). Particle surface area concentration (PAC) was primarily in the 100–300 nm range, while particle volume concentration (PVC) was in the 100–200 nm and 300–1000 nm ranges. After extinguishing the incense sticks, ventilation was initiated. The ventilation period was split into FAO1–3 (i.e., the first 3 min, 1–3 min of ventilation system operation) and FAO4–15 (i.e., the last 12 min, 4–15 min of ventilation system operation). During FAO1–3, particle concentrations increased by 18.3 to 21.5%. This rise was due to the initial activation of the ventilation system, dispersing settled particles (mostly ≥ 41.2 nm) into the air. The FAO4–15/FAO1–3 ratio for 12.3−2489.3 nm particles was always < 1, indicating that as the ventilation continued, it effectively removed particles of < 2.5 μm. After subsequent ventilation of 15-min operation, total PNC, PAC, and PVC were 70.3%, 70.0%, and 67.8% lower than during FAO1–3 and the particle number mode diameter was 106.0 nm, with geometric standard deviations of 1.50 and 1.51 (left and right), indicating that the ventilation system was successful in removing smoke particles of all sizes simultaneously and evenly and achieved an approximate total removal efficiency of 70%, effectively filtering particles and reducing indoor air pollution. [ABSTRACT FROM AUTHOR]

This article addresses the issue of VOC emissions from upholstery materials (natural leather) used for the manufacturing of upholstered furniture. The main intention of this paper is to compare VOC emissions released from different types of natural upholstery leathers. This research has assessed the impact of various factors (e.g. the organic origin of leather, the type of tanning, the type of upholstery leather and the leather finish etc.) on the amount of VOC emissions from natural leathers used for the production of upholstered furniture. 1 m² samples of natural leather were prepared for testing before being placed into a small test chamber (1 m³ volume). VOC emission measurements were taken in a small test chamber with predefined conditions (an ambient temperature of 23ºC and 50% relative air humidity). With the use of sorbent Tenax TA were, the values of VOC emissions released by the test sample of different types of leather into desorption tubes was then recorded. VOC emissions were analysed in an Agilent GC 6890 N gas chromatograph using an Agilent 5973 Network mass spectrometer using cryofocusing, thermal desorption and a GC-MS data library (NIST 05). The analyses conducted provide qualitative and quantitative data regarding the concentration of selected VOC representatives measured in µg.m-3. The quantitative difference in all emitted organic compounds is shown by the measured values of the TVOC parameter. [ABSTRACT FROM AUTHOR]

Cannabis is a genus of plants in the Cannabaceae family that contains tetrahydrocannabinolic acid. When heated or burned, the acid decarboxylates to form tetrahydrocannabinol (THC). Its (-)-trans-Δ9-THC isomer is a psychoactive substance that has been used as a drug for centuries. In most countries, both the private sale of cannabis products and their use for non-medical purposes are still prohibited by law. However, for some time now there has been societal and political pressure to at least partially legalize cannabis products. It can be expected that such a measure will lead to a significant increase in the consumption of cannabis. However, this also increases the possibility of involuntary passive exposure to THC and contamination of the indoor environment. In indoor sciences, THC is still a largely unknown or underrepresented substance. In this perspective paper, THC will therefore first be presented on the basis of its physical properties. Then, the distribution of THC in different indoor compartments and potential routes of passive exposure are discussed. Finally, an assessment of the future importance of THC for indoor use is made. Previous experience has shown that early monitoring is always advantageous so that preventive and protective measures can be taken quickly if necessary. [Display omitted] • The psychoactive tetrahydrocannabinol is released from cannabis smoke and vapor. • THC is a typical SVOC and accumulates in the indoor environment. • THC has been found in indoor air, house dust and on surfaces. • The planned legalization of cannabis is likely to increase passive exposure to THC. • There is a need to monitor THC indoors for preventative and protective reasons. [ABSTRACT FROM AUTHOR]

Exposure to di(2-ethylhexyl) phthalate (DEHP) in the indoor environment has been linked with significant health risks for Chinese children. Multi-phase DEHP concentrations in Chinese residences and kindergartens were estimated using a mass balance model based on the current baseline condition and control strategies (i.e., increasing ventilation rate, reducing area of sources, using mechanical ventilation systems, and using portable air cleaners). The health benefits of each control strategy were quantified as the reduction in lifetime cancer risks (LCR) and burden of disease (BoD). In the current situation, the mean LCR and disability-adjusted life years (DALY) number attributable to indoor DEHP exposure for Chinese children were around 6.0×10−6 and 155 thousand, respectively. The mean LCR and DALY might be reduced by 25%–54% and 16%–40%, respectively, by increasing air exchange rates by 100%, reducing the use of source materials by two-thirds or deploying commercial air cleaners in naturally ventilated buildings. Meanwhile, avoidable DALYs could result in a reduction of mean economic losses of 2.2–5.3 billion RMB. Mechanical ventilation systems with filtration units may not be helpful for reducing children's health risks. House-specific and tailor-made control measures are critical in lowering indoor exposure to DEHP to promote sustainable buildings and children's health in China. [ABSTRACT FROM AUTHOR]

We previously reported that indoor odorous chloroanisoles (CAs) are still being emitted due to microbial methylation of hazardous chlorophenols (CPs) present in legacy wood preservatives. Meanwhile, Swedish researchers reported that this malodor, described since the early 1970s, is caused by hazardous mold. Here, we examined to what extent CP-treated wood contains mold and if mold correlates with perceived odor. We found no studies in PubMed or Web of Science addressing this question. Further, we investigated two schools built in the 1960s with odor originating from crawlspaces. No visible mold was evident in the crawlspaces or on the surfaces of treated wood samples. Using a microscope, varying amounts of mold growth were detected on the samples, all containing both CP(s) and CA(s). Some samples smelled, and the odor correlated with the amount of mold growth. We conclude that superficial microscopic mold on treated wood suffices produced the odor. Further, we argue that CPs rather than mold could explain the health effects reported in epidemiological studies that use mold odor as an indicator of hazardous exposure. [ABSTRACT FROM AUTHOR]

Perception of temperature and relative humidity has an important influence on feelings of thermal comfort or discomfort. The aim of this study is to analyse the thermal sensations of 222 people aged 19-30 years, taking into account air temperature and relative humidity in four educational buildings at Kielce University of Technology. Two methods were used to conduct the study, indirect (use of an environmental meter) and direct (use of questionnaires). Air temperature ranged from 20℃-27.5℃ and humidity from 18.16%-50.9%. Approximately 60% of the students rated the humidity as pleasant, nevertheless 32% would prefer it to be more humid. Furthermore, thermal comfort was declared by 69% of the students, while 31% rated their feelings as uncomfortable. In addition, a correlation analysis was carried out for temperature and humidity. In the overall assessment of the students, the buildings created good conditions for feeling comfortable. [ABSTRACT FROM AUTHOR]

Two issues embedded in air pollution research are considered to be the long-observed effect of outdoor exposure to sunlight having a germicidal effect—the Open Air Factor (OAF)—and the wavelength dependence and implications of the use of UV-C light indoors to achieve germicidal action. Suggestions are made about the mechanism of the OAF and about the possible emergence of resistant strains indoors. [ABSTRACT FROM AUTHOR]

Talaromyces is a genus within the phylum Ascomycota (class Eurotiomycetes, order Eurotiales, family Trichocomaceae). Many species in this genus are known to produce diverse secondary metabolites with great potential for agricultural, medical, and pharmaceutical applications. During a survey on fungal diversity in the genus Talaromyces in Korea, six strains were isolated from soil, indoor air, and freshwater environments. Based on morphological, physiological, and multi-locus (ITS, BenA, CaM, and RPB2) phylogenetic analyses, we identified five previously unrecorded species in Korea (T. brevis, T. fusiformis, T. muroii, T. ruber, and T. soli) and a new species (T. echinulatus sp. nov.) belonging to section Talaromyces. Herein, detailed descriptions, illustrations, and phylogenetic tree are provided. [ABSTRACT FROM AUTHOR]