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[Display omitted] • Ventilation and air quality play crucial roles in affecting the elderly's health. • Stratum ventilation can effectively improve air quality in ECC bedrooms. • Contaminant removal by SV was 2.58, 3.22 and 2.12 times higher than MV, DV, and ZV. • SV reduced health risks by 46.3%, 53.7%, and 41.7% compared to MV, DV, and ZV. • Privacy of the elderly was important and need to be considered in ventilation design. Ventilation and indoor air quality are important factors that affect the health of the elderly. The purpose of this study was to find effective ventilation design measures for improving ventilation and air quality in typical two-bed bedrooms in elderly care centres (ECCs). Mixing ventilation (MV), displacement ventilation (DV), zone ventilation (ZV) and stratum ventilation (SV) were analysed with twelve scenarios to find the most effective ventilation design solutions including six scenarios with curtains between the beds and six scenarios without curtains between the beds. Airflow distribution, CO 2 concentration, ventilation efficiency and health risk assessment were adopted for discussion. SV was found to be an effective method for improving air quality in the ECC bedroom while also taking into account the needs and rights of elderly residents, such as privacy. Comparing scenarios with and without curtains between beds under same types of ventilation, scenarios without curtains showed a slight (≤8%) decrease in CO 2 concentration in the pillow area. However, this could increase virus transmission risk and compromise elderly privacy, so it is not recommended. Regarding the scenarios with curtains between the beds, the contaminant removal efficiency (CRE) of scenarios using SV was increased by 2.58, 3.22 and 2.12 times compared to the scenarios using MV, DV, and ZV respectively. Additionally, the health ratio (HR) of SV was reduced by 46.3 %, 53.7 %, and 41.7 %. Hence, it is recommended to install curtains between the beds and apply SV in ECC bedrooms. This study can be used as a guide for systematically designing ventilation systems in ECC bedrooms. Furthermore, collaboration among environmental engineers, designers, policymakers, and the wider community is essential to develop sustainable indoor environments for the elderly. [ABSTRACT FROM AUTHOR]

There are a large number of airplanes currently being operated, in which the ventilation system needs to be improved to more effectively remove air contaminants. A potential approach is to adjust the supply air directions with the use of simple airflow deflectors. This study proposed a method for optimizing the supply air direction of ventilation in aircraft cabins based on the Re-field synergy index and Bayesian optimization. A validated numerical model was used to calculate the air distribution and air contaminant transport in a single-row single-aisle aircraft cabin to obtain the Re-field synergy values. The Bayesian optimization approach was used to identify the supply air direction which maximizes the Re-field synergy, namely, maximizes the mass transfer effectiveness. Finally, the air contaminant transport in a 7-row single-aisle aircraft cabin with the optimized supply air direction was evaluated to demonstrate the enhancement of ventilation performance. The results show that the proposed method based on the Re-field synergy index and Bayesian optimization can efficiently optimize the supply air direction in order to enhance the air contaminant removal in aircraft cabins. In the 7-row single-aisle aircraft cabin, the optimized supply air direction can reduce the average air contaminant concentration in the breathing zone of the passengers by up to 23 %., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This systematic review and meta-analysis investigated studies on formaldehyde (FA) inhalation exposure in indoor environments and related carcinogenic (CR) and non-carcinogenic (HQ) risk. Studies were obtained from Scopus, PubMed, Web of Science, Medline, and Embase databases without time limitation until November 21, 2023. Studies not meeting the criteria of Population, Exposure, Comparator, and Outcomes (PECO) were excluded. The 45 articles included belonged to the 5 types of sites: dwelling environments, educational centers, kindergartens, vehicle cabins, and other indoor environments. A meta-analysis determined the average effect size (ES) between indoor FA concentrations, CR, and HQ values in each type of indoor environment. FA concentrations ranged from 0.01 to 1620 μg/m3. The highest FA concentrations were stated in water pipe cafés and the lowest in residential environments. In more than 90% of the studies uncertain (1.00 ×10−6 1.00 ×10−4) due to FA inhalation exposure was reported and non-carcinogenic risk was stated acceptable. The meta-analysis revealed the highest CR values due to inhalation of indoor FA in high-income countries. As 90% of the time is spent indoors, it is crucial to adopt effective strategies to reduce FA concentrations, especially in kindergartens and schools, with regular monitoring of indoor air quality. [Display omitted] • Formaldehyde (FA) is one of the most abundant pollutants in indoor air. • FA concentrations in various indoor environments ranged from 0.01 to 1620 μg/m3. • Formaldehyde levels were higher in kindergartens than in other educational centers. • In over 90% of the studies, the risk of carcinogenesis was higher than 1.00 × 10−6. [ABSTRACT FROM AUTHOR]

Catalytic activity of 0.05 g catalyst to 10 m L 1 mg/L HCHO solution for 1h at 25 °C (a)and the concentration curves of CdS, CeO 2 , (H/C-CdS)/CeO 2 and Co–(H/C-CdS)/CeO 2 with degradation time. [Display omitted] • HCHO conversion rate arrived at 99.5 % in 1 h at room temperature under visible light. • A cobalt-doped (H/C-CdS)/CeO 2 catalyst with a high visible light catalytic activity. • Type II heterojunction between CdS NPs and CeO 2 NS for separation of e-/h+. • Dispersion of CdS NPs broadening the light absorption range and exposing active sites. • Close contact shortening the migration distance of photogenerated electron-hole pairs. The visible light catalytic oxidation of formaldehyde (HCHO) at room temperature is of great interest for improving the indoor air quality. Here, a cobalt (Co)-doped CdS-based catalyst ((H/C-CdS)/CeO 2) with high visible light catalytic activity was successfully synthesized for HCHO removal at room temperature. Co addition enhanced the catalytic activity of (H/C-CdS)/CeO 2 , and the HCHO conversion rate reached 99.5 % for a 1 mg/L aqueous HCHO solution on the Co–(H/C-CdS)/CeO 2 catalyst after 1 h at room temperature under visible light, which was greater than that of (H/C-CdS)/CeO 2 (92.0 %). The (H/C-CdS)/CeO 2 and Co–(H/C-CdS)/CeO 2 catalysts were systemically characterized, and the results showed that the interfacial phase junction between the hexagonal (H) and cubic (C) phases of the CdS nanoparticles (NPs) and the synergistic effect of the type II heterojunction between the CdS NPs and CeO 2 nanosheets (NSs) promoted the separation of e-/h+. Moreover, the addition of Co species strongly promoted the separation of photogenerated carriers. The excellent photocatalytic activity was attributed to the good dispersion of CdS NPs, which broadened the light absorption range, exposed more active sites, and provided close contact, decreasing the migration distance of photogenerated electron-hole pairs. After that, the visible light catalytic oxidation mechanism of HCHO on both (H/C-CdS)/CeO 2 and Co–(H/C-CdS)/CeO 2 followed the reaction pathway of HCHO to (CO 2 + H 2 O). [ABSTRACT FROM AUTHOR]

Organizations such as ASHRAE and the Centers for Disease Control and Prevention (CDC) have proposed guidelines for controlling infectious aerosols in buildings, which can be met through measures such as modified operation of the heating, ventilation, and air-conditioning (HVAC) system or incorporating air-cleaning technologies. However, more research is needed to understand the trade-offs between health, energy, and comfort aspects when designing measures for these guidelines. To address this gap, this paper presents an analysis using new models for air-cleaning technologies, including in-duct and in-room germicidal ultraviolet (GUV) systems and portable air cleaners (PACs). These models are incorporated into an existing prototypical office building model and six measures are designed to meet ASHRAE Standard 241 and CDC clean air targets: MERV 13 HVAC filtration, maximum outdoor air supplied to the building, PACs, and in-duct, upper-room, and whole-room GUV. The measures are simulated for an office building in a cool and humid climate compared against a baseline simulation using MERV 8 filtration. The results show that all measures, except for the maximum outdoor air case, can meet the ASHRAE 241 standard without significant impacts on energy or comfort. The HVAC system measures were not able to meet the CDC target with the default system sizing and lead to significant energy increases, while the in-room measures were able to meet the CDC target with small impacts on energy consumption. This paper consolidates the simulation findings and provides practical guidance for building operators to meet clean air targets while limiting energy and comfort impacts. • Created new models for air-cleaning technologies using Modelica Buildings library. • Designed pathogen mitigation measures to meet ASHRAE 241 and CDC clean air targets. • Simulated increased ventilation, in-duct and in-room air-cleaning for an office building. • In-room measures meet clean air targets without significant energy impacts. • HVAC system measures do not meet CDC target and lead to large energy increases. [ABSTRACT FROM AUTHOR]

This pilot study focuses on particulate matter (PM) while cooking in a South Texan household. Dishes such as Beef, Burger, Fish, Chicken, Egg Sandwich, and Hotdog were prepared. Indoor PM levels were compared with outdoor PM levels. A DustTrak DRX was used to monitor the PM released during the cooking process. PM2.5 levels were highest while cooking beef, 162.79 + 209.62 μg m−3. Hot Dog preparation resulted in the lowest PM2.5 concentration of 27.72 + 5.58 μg m−3. Indoor PM2.5 levels were observed to be greater in contrast to outdoor levels when compared to the outdoor levels (96 words).

Direct air capture (DAC) is a promising technology that can help to remove carbon dioxide (CO2) from the air. One application of DAC is indoor CO2 direct air capture (iCO2-DAC). A wide range of materials with unique properties for CO2 capture have been investigated, including porous materials, zeolites, and metal-organic frameworks. The selection of suitable materials for iCO2-DAC depends on several factors, such as cost, CO2 adsorption capacity, and stability. The development of new materials with improved properties for iCO2-DAC is an active research area. The captured CO2 can serve as a renewable carbon source to produce biofuels for internal use (e.g., for heating purposes), decreasing the environmental impact of buildings. This review article highlights the importance of iCO2-DAC to improve indoor air quality in buildings and boost the circular economy. We discuss the available carbon capture technologies and materials, discussing their properties and focusing on those potentially applicable to indoor environments. We also provide a hypothetic scenario where CO2 is captured from different indoor environments and transformed into sustainable fuels by using an emerging carbon capture and utilization technology (microbial electrosynthesis). Finally, we evaluate the economic feasibility of such an innovative approach in comparison to the use of traditional, fossil-based fuels.

• Indoor-quality oriented approach is proposed for building post-retrofit analysis. • The approach is based on readily monitored indoor data and on mangers and users' opinions. • As case study, the student dormitory of University of Athens is presented. • Thermal comfort indices greatly vary with management strategy and personal choices. • The analysis of indoor air quality highlights the key role of mechanical ventilation. The rapid expanding of refurbishment incentives requires to deserve more attention on how to reach nearly zero energy standard without compromising occupant wellness, when the building is undergone to important architectural transformations. To overcome the above drawbacks mainly for student dormitories, the paper introduces a new indoor quality oriented post-retrofit evaluation approach that simultaneously quantifies the impact of design decisions on thermal, respiratory and visual comfort. Investigations on the building quality and readily monitored indoor variables are the core of the approach that also provides sensitivity analysis on some subjective parameters and questionnaires for the main involved stakeholders. The proposed approach is tested on a student dormitory belonging at National and Kapodistrian University of Athens, refurbished in the frame of Horizon Project Pro-GET-OnE. The results reveal an improvement in the passive control of thermo-hygrometric comfort as well as in the satisfaction level. The adoption of mechanical ventilation consistently ensures dioxide emissions lower than 430 ppm, TVOC below 300 μg/m3 and PM2.5 and PM10 lower than 6 μg/m3. More in general, it is remarkable the importance of considering all comfort domains and occupant behavior, as one design or management choice might improve one indoor quality domain at the cost of others. [ABSTRACT FROM AUTHOR]

Zero-energy buildings constitute an effective means of reducing urban carbon emissions. High airtightness, a typical characteristic of zero-energy building, is closely related to the building's air infiltration and has a significant impact on the performance of the building envelope, indoor air quality, building energy consumption, and efficient operation of air-conditioning systems. However, thus far, systematic developments in high-airtightness assurance technologies remain scarce. Most existing studies have tested the airtightness of buildings and typical building components; however, in-depth analyses into the formation of infiltration have not been reported. Therefore, for realizing zero-energy buildings, ensuring airtightness is an urgent problem that needs to be addressed. Accordingly, in this study, based on several building airtightness measurement studies, the typical air leakage paths in buildings were summarized, and the causes of typical air leakage components in buildings were further analysed by tracing construction processes. Moreover, targeted measures for airtightness in buildings were established and applied to practical cases. Lastly, the resulting improved building airtightness was measured and the results show that the airtightness of the measured ultra-low energy consumption buildings ranges from 0.13 h - 1 to 0.57 h - 1, with a mean value of 0.32 h - 1. The effectiveness of the airtightness safeguard measures was verified. This study serves as a basis for the assumption of the air leakage path distribution when simulating building air infiltration and also provides a design reference for improving the construction technologies and airtightness of buildings. [ABSTRACT FROM AUTHOR]

Purpose: Due to land resource scarcity, sustainable urban development in high-density cities has long been challenging. As such, many cities are formulating plans to "dig deep", resulting in more citizens working and/or staying underground for longer periods of time. However, owing to the particularities of underground space, the factors involved in the creation of a healthy environment are different from those involved in aboveground developments. This study thus aims to investigate the influences of various underground environment factors on users' health through a holistic approach. Design/methodology/approach: To achieve this aim, 12 underground sites and 12 corresponding aboveground sites are selected for a large-scale questionnaire survey, resulting in 651 survey samples. The survey covers post-occupancy evaluation of health (physical and psychosocial), underground environmental quality (visual, thermal, acoustic comfort, indoor air quality and ventilation), space design and greenery. Independent-sample T-test, Pearson correlation, multiple regression modelling and structural equation modelling are used to investigate whether significant differences exist between health of underground and aboveground users, and to develop an underground environment-health model for unveiling the significant associations between underground environment factors and users' health. To cross validate the results, an objective field measurement study is further conducted on six underground sites. The objective measurement results are used to cross validate the survey results. Findings: The questionnaire results provide the following evidence: (1) health of underground users is significantly poorer than that of their aboveground counterparts; (2) underground development users' health is significantly affected by space design, greenery and environmental quality in terms of thermal comfort, indoor air quality, ventilation and acoustic comfort but not visual comfort; and (3) amongst the various identified factors, space design has the strongest predicting effects on human health. The field study echoes the survey findings and further unveils the relationships between different environmental factors and human health. Originality/value: The results shed light on the importance of distinguishing between underground developments and aboveground ones in various guidelines and standards, especially those related to space management. [ABSTRACT FROM AUTHOR]

This article discusses the issue of indoor ozone in research laboratories, particularly during the COVID-19 pandemic. While outdoor ozone has both beneficial and detrimental effects, indoor ozone is often overlooked and can pose health risks. The article explores ozone formation, its use in research, health effects, incidents of ozone poisoning, and guidelines for safety in laboratories. It emphasizes the need for proper handling and monitoring of ozone in indoor laboratory spaces to ensure the safety of workers. The article also highlights the age and gender-specific susceptibility to ozone exposure and provides recommendations for improving safety in laboratories. [Extracted from the article]

The indoor air quality should provide adequate temperature and humidity levels, free from harmful pollution concentration. Proper heating, ventilation and air-conditioning (HVAC) system management is crucial in hospitals to prevent transmission of contaminated air and diseases. To verify whether healthcare facilities meet standard criteria for thermal comfort and indoor air quality, a field investigation in waiting and operating rooms was conducted in six hospitals in Brazil, in the summer. Thermal comfort parameters, carbon dioxide (CO2) concentration and differential air pressure were collected in loco. The results demonstrated that CO2 concentration was over 1,000 ppm in four waiting rooms, and no positive pressure was guaranteed in the operating room. The medical staff showed different thermal sensation variations in zone 1 (around the operating table) and zone 2 (remaining space around zone 1). In conclusion, most operating rooms had significant contamination risks and did not provide thermal comfort conditions to occupants. Due to improper HVAC design or high occupational density, air change rates were insufficient to guarantee adequate air renewal in the waiting rooms. There is an opportunity to improve the operation and maintenance process to provide healthy and comfortable environments in healthcare facilities, reducing nosocomial infections, especially during pandemic times. [ABSTRACT FROM AUTHOR]

In Chinese northwestern rural households where the indoor air quality is worse than the outside, rural residents face much higher health risks than urban residents. In this study, remote physical sensor devices and detectors technology were used to monitor and calculate the dwelling environmental quality index of 12 dwellings of traditional villages in the Hehuang area of China based on four environmental parameters to assess the indoor air quality of local dwellings. The results show that (1) the DEQI value reached 76 in summer but only 50 in winter, and the indoor dwelling environment quality in the Hehuang area was better in summer than in winter. (2) The S T was only 34 in summer and even lower in winter, at only 10, and low indoor temperatures were a chronic problem for the indoor dwelling spaces throughout the year. (3) In both summer and winter, the S RH reached 86, which was satisfactory overall. (4) In summer, the S CO2 value was 89 and the S PM10 value was 96, reflecting relatively good overall conditions. In winter, the S CO2 value was 65, the concentrations generally increased, and the S PM10 value was equal to 40, with concentrations exceeding the national standard value more than half the time. This study enables local governments and residents to accurately evaluate and analysis existing indoor dwelling environment problems based on this remote sensing technology, enhance the environmental health awareness of local residents, and provide an objective basis for improving the local dwelling environment and developing relevant policies. • The study conduct an evaluation of indoor dwelling environment with remote sensing. • The study make local governments and residents recognize indoor dwelling problems. • It provides better methods for evaluating indoor dwelling environments in rural areas. [ABSTRACT FROM AUTHOR]

Energy efficiency norms require effective insulation techniques for buildings in order to minimize energy consumption. The paper presents simulations, carried out throughout the year, regarding the efficiency of energy recovery units (ER) to ensure the quality of fresh indoor air. Indoor air energy recovery calculations were performed using plate and rotary heat exchangers in different operating scenarios. The evaluated parameters led to the stability of the optimization solutions in order to obtain a higher energy efficiency on the equipment. By comparing the obtained results, optimal measures and solutions were identified for energy efficiency in the operation of ER. [ABSTRACT FROM AUTHOR]

In recent years, the use of electronic vaping products (also named e-cigarettes) has increased due to their appealing flavors and nicotine delivery without the combustion of tobacco. Although the hazardous substances emitted by e-cigarettes are largely found to be much lower than combustible cigarettes, second-hand exposure to e-cigarette aerosols is not completely benign for bystanders. This work reviewed and synthesized findings on the second-hand exposure of aerosols from e-cigarettes and compared the results with those of the combustible cigarettes. In this review, different results were integrated based upon sampling locations such as residences, vehicles, offices, public places, and experimental exposure chambers. In addition, the factors that influence the second-hand exposure levels were identified by objectively reviewing and integrating the impacts of combustible cigarettes and e-cigarettes on the environment. It is a challenge to compare the literature data directly to assess the effect of smoking/vaping on the indoor environment. The room volume, indoor air exchange rate, puffing duration, and puffing numbers should be considered, which are important factors in determining the degree of pollution. Therefore, it is necessary to calculate the "emission rate" to normalize the concentration of pollutants emitted under various experimental conditions and make the results comparable. This review aims to increase the awareness regarding the harmful effects of the second-hand exposure to aerosols coming from the use of cigarettes and e-cigarettes, identify knowledge gaps, and provide a scientific basis for future policy interventions with regard to the regulation of smoking and vaping., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Resuspension caused by human walking activities is an important source of indoor bioaerosols and has been associated with health effects such as allergies and asthma. However, it is unknown whether inhalation of resuspended bioaerosols is an important exposure pathway for airborne infection. Also, crucial factors influencing the resuspension of settled microbes have not been quantified. In this study, we experimentally investigated the resuspension of culturable bacteria from human-stepping on polyvinyl chloride (PVC) flooring under different conditions. We determined the bacterial resuspension emission factor (E R ), a normalized resuspension parameter for the ratio of resuspended mass in the air to the mass of settled particles, for two common bacteria, Escherichia coli and Salmonella enterica. The investigation involved varying factors such as microbial surface-attached durations (0, 1, 2, and 3 days), the absence or presence of nutrients on flooring surfaces, and changes in relative humidity (RH) (35%, 65%, and 85%). The results showed that, in the absence of nutrients, the highest E R values for E. coli and S. enterica were 3.8 × 10 -5 ± 5.2 × 10 -6 and 5.3 × 10 -5 ± 6.0 × 10 -6 , respectively, associated with surface-attached duration of 0 days. As the surface-attached duration increased from 0 to 3 days, E R values decreased by 92% and 84% for E. coli and S. enterica, respectively. In addition, we observed that E R values decreased with the increasing RH, which is consistent with particle adhesion theory. This research offers valuable insights into microbial resuspension during human walking activities and holds the potential for assisting in the assessment and estimation of risks related to human exposure to bioaerosols., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

This work presents a novel application of gas-diffusion microextraction (GDME) combined with high-performance liquid chromatography with diode-array detection (HPLC-DAD) for the comprehensive analysis of volatile carbonyl compounds released from wood-based panels. GDME is a simple, fast, and environmentally friendly technique that allows the simultaneous extraction and derivatization of volatile carbonyls directly from solid samples. Commercial particleboards were analysed together with particleboard panels specifically produced using controlled conditions, materials, and reagents, to evaluate the differences in the emission profile of volatile carbonyl compounds. The effect of different production parameters, such as the type of wood particle, resin, and moisture content, on the emission profile of volatile carbonyls from particleboards was investigated using principal component analysis (PCA). The results showed that GDME-HPLC-DAD could successfully differentiate particleboards according to their emission of carbonyl compounds, such as formaldehyde, furfural, benzaldehyde, and other aliphatic carbonyls. Besides the differences on the emission of formaldehyde caused by the type of resin used, UF (urea-formaldehyde) and mUF (UF fortified with melamine), it was found that pine (Pinus pinaster Ait.) particleboards exhibit higher emissions of compounds such as acetaldehyde or hexanal when compared to the higher emissions of compounds such as furfural or benzaldehyde on the recycled particleboards., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Traditional methods for detecting harmful gases in air are often limited in their widespread deployment, accuracy, and real-time monitoring capabilities due to their complexity and cost. To address this challenge, optimization algorithms such as the Particle Swarm Optimization (PSO) algorithm have shown promise. The PSO algorithm, is applied to calculate the concentrations of harmful gases in air, maximizing detection accuracy. Detecting indoor gas pollution is a crucial concern due to the abundance of odors and vapors, particularly those emanating from activities such as cooking. The presence of these substances in the air poses a challenge in identifying traces of other harmful gases. This research endeavors to pioneer a novel approach characterized by heightened sensitivity, even in the presence of unidentified elements in the air. In this work, PSO algorithm is used in conjunction with Chirped Spectral Modulation (CSM) technique to increase system sensitivity to detect small traces of harmful gases inside buildings and protect the environment through early detection of pollution. The use of PSO and CSM altogether allowed for detecting carbon dioxide C O 2 , carbon monoxide CO , and nitrogen dioxide N O 2 down to 10 − 6 % in volume, and sulfur dioxide S O 2 down to 5 × 10 − 4 % in volume, while keeping the error below 0.1% [ABSTRACT FROM AUTHOR]

Friction between subway wheels and tracks and inadequate combustion of fuel are causes of respirable particulate matter. Restricted underground ventilation and high population density make it difficult for particulate matter to dissipate, posing a threat to human health. An effective data-driven model for indoor pollutant prediction can enhance preparedness for high pollution situations. This study introduces a feature extraction method that combines kernel principal component analysis with max-relevance and min-redundancy algorithm. The temporal convolutional network, enhanced with a multi-head self-attention mechanism, adeptly captures time series features and effectively manages attention weight allocation. Additionally, the incorporation of the light gradient boosting machine method enhances overall efficiency. The proposed framework for PM 2.5 concentration prediction was employed to a high-traffic subway station in Seoul. In the test set, the model demonstrated strong performance with evaluation metrics including an R2 value of 0.92, RMSE of 6.02 μg/m3, MAE of 4.36, and MAPE of 20.58 μg/m3. Compared to the conventional LSTM, the proposed method reduces the RMSE by 20.5% and the MAPE by 49.05%. Notably, the model we propose demonstrates superior capabilities in managing large datasets and offers enhanced predictive accuracy compared to baseline models. It effectively addresses the limitations observed in models like LSTM, which often struggle with adequately capturing feature information, and overcomes the generalization weaknesses inherent in models such as the Transformer. This advancement significantly boosts the efficiency of environmental monitoring and fosters both automation and intelligence in the analysis of environmental data. • KPCA and mRMR integrated to extract and select input attributes. • A novel temporal feature extraction model captures the temporal pattern of PM 2.5 concentration. • The decision tree model of LightGBM improves the efficiency and accuracy of prediction. • Compared with the baseline model, MHATCN-LightGBM shows better performance. [ABSTRACT FROM AUTHOR]

In an open office environment with high occupant density and random occupancy patterns, excessive energy consumption is often observed because mechanical ventilation (MV) is usually designed and operated assuming a full-occupancy-based ventilation rate (VR). Considering the duo challenges of post-pandemic and climate change, this study proposes a real-time monitoring and optimization approach for operating portable air cleaners (PACs) to assist and reduce the energy consumption of the MV while maintaining the minimal VR and improving indoor air quality (IAQ). The approach was as follows. First, by assuming four VRs and 36 different emission sources, numerical simulations were conducted and validated based on an actual open office on non-uniform concentrations of a surrogate for indoor air pollutants (IAPs) throughout the breathing zone. Second, the pre- and post-purified IAP distributions were obtained using a limited number of sensors and trained by two artificial neural networks. Third, the real-time optimization of PACs' on/off operation and placements was accomplished by the particle swarm optimization algorithm to balance energy output and improve IAQ simultaneously. Results showed that by deploying four sensors, the predictions of post-purifying concentrations were in acceptable accuracy (i.e., CV-RMSE <2.0%) within 30–40s. Using at most three PACs resulted in a significant decline in local IAP concentration levels. Meanwhile, an average reduction of total energy consumption of MV and PACs was 34.6% compared to using MV to reach the same levels. Overall, this study supports the use of PACs to assist MV in achieving energy efficiency and good IAQ. • Proposed a method to quickly optimize air cleaners' on/off operation and placements. • Considered pre- and post-purified and non-uniform concentrations of a IAQ surrogate. • To reduce the total ventilation-related energy consumption while improving IAQ. • Observed an average energy reduction of 34.6% compared to using mechanical ventilation. [ABSTRACT FROM AUTHOR]

The effects of CO 2 on emotional processing are still incompletely understood, although its effects on cognitive performance are widely recognized. This study hypothesized that elevated CO 2 concentration would affect the processing of different valence emotions, which leads to more negative emotions and fewer positive emotions. A within-subject experiment was conducted to compare subjective emotional scores, emotional processing behavioral performance, EEG patterns, and other physiological changes of 30 participants exposed to CO 2 concentration at 600 ppm and 5000 ppm. The results suggested that CO 2 concentration could affect neural arousal patterns during emotional processing, changes in blood pressure, and salivary cortisol secretion in healthy participants. Emotional experience task performance of participants was also affected by CO 2 , which was not statistically significant. At the high CO 2 concentration, the systolic blood pressure (SBP) level was significantly lower (p = 0.005), while the salivary cortisol level was significantly higher (p = 0.037). Power spectral density analysis showed that there was a significant interaction between CO 2 concentration and emotional valence for theta waves in frontal regions (p = 0.029), beta waves in temporal regions (p = 0.017), and gamma waves in frontal-parietal occipital regions (p = 0.013). The present study found that CO 2 has a negative effect on emotional processing, such as reducing the speed and accuracy of emotional processing. To some extent, there are also some positive effects, like reducing emotionally-induced increases in blood pressure. This finding warrants further research. • The effect of CO 2 on human emotion based on multimodal indicators are analyzed. • Elevated CO 2 concentrations reduce emotional processing speed and efficiency. • The BP, EEG and cortisol during emotional stimuli are affected by CO 2 concentration. • The CO 2 has existential potential for application in mental health treatment. [ABSTRACT FROM AUTHOR]

This research endeavors to elevate indoor air quality within aging school environments by concentrating on refining interior finishing materials and windows. Renovations, encompassing window and floor remodeling in classrooms, aim to mitigate particulate matter (PM) infiltration and enhance air exchange rates. Utilizing SPS30 sensors for the analysis of 0.3–2.5 μm particles, with a focus on their implications for human health, the study evaluated air exchange rates, deposition rates, infiltration rates, and particle generation during classroom activities. Post-renovation results demonstrated a noteworthy decrease in air exchange rates, indicating an enhancement in airtightness. The investigation delves into particle generation with various flooring materials, accentuating the importance of opting for durable and low-particle-generating alternatives. Health risk assessments, considering multiple exposure routes (inhalation, dermal contact, and ingestion), revealed reduced risks post-renovation, particularly for children. To further optimize indoor air quality, the study suggests the implementation of air purification systems. Examination of PM generation during student activities showcased a substantial reduction post-renovation. This study underscores the positive influence of architectural enhancements on indoor air quality while acknowledging the necessity for holistic solutions and continuous research. [Display omitted] • The point is particulate matter and its implications on indoor air quality. • The focal point lies in the renovation of schools (windows and building materials). • The methodology approach assesses infiltration rates and particle generation. • Despite these positive shifts, it unveils lingering concerns for children's health. [ABSTRACT FROM AUTHOR]

People spend majority of their lifetime indoors making comfortable dwellings one of the major requirements otherwise it may primarily impact the occupant's health and productivity. Indoor temperature and relative humidity (RH) are the two major parameters for determining comfort level, whilst airflow and heat transfer are having an influential role in controlling these parameters. Since solar radiations are the primary source of heat inside a building and ceiling fans play a significant role in improving air circulation. The present study strives to develop a model for evaluating the thermal behavior of commercial space under the influence of solar radiations and ceiling fans. It involves "solar ray tracing" and "3D-Fan zone" models to assess their impact on indoor air quality and thermal comfort. The developed model is validated by comparing the simulated results of air velocity and temperature with experimental data accumulated from space. Further, the validated model is used to evaluate the impact of different levels of solar irradiation between 200 W/m2 and 1000 W/m2 on the indoor environment. Results revealed that an increment of 200 W/m2 irradiations is raising the mean indoor temperature by 0.2 °C, percentage dissatisfaction by 8% while a reduction in RH is reported to be 0.5%. [ABSTRACT FROM AUTHOR]

Ultrafine particle (UFP) pollution should be controlled to reduce its effects on health. The design of control measures is limited owing to the uncertainty of source contributions in Chinese residences, where indoor UFP pollution is more severe than in Western residences. Herein, a source-specific, time-dependent UFP concentration model was developed by applying an infiltration factor model incorporating coagulation effects. A Monte Carlo framework with the UFP concentration model was employed to estimate the probabilistic distribution of source contributions in Chinese residences. The input parameter distributions were determined based on our survey and previous studies. The annually averaged indoor UFP concentration was estimated at (2.75 ± 1.71) × 10 4 #/cm 3 , ranging from 2.35 × 10 3 to 1.27 × 10 5 #/cm 3 outside the kitchen, and at (5.48 ± 3.08) × 10 4 #/cm 3 , ranging from 2.90 × 10 3 to 1.94 × 10 5 #/cm 3 in the kitchen. Indoor sources contributed more to indoor UFPs, accounting for 61% in the nonkitchen and 80% in the kitchen, surpassing their contribution to indoor PM 2.5 in Chinese residences. Meanwhile, the indoor UFP emission contributions were higher than those in the United States, Canada, and Germany, owing to higher emissions from cooking and cigarette smoking. These results will aid in elucidating human exposure to UFPs and in designing more targeted control measures.

Problems with schools' indoor-air quality are common, and they can cause health problems to adolescents. However, no previous research has examined how adolescents make sense of such contaminated socio-material environments or what kinds of agency those environments afford. Taking an ecological psychology perspective informed by frame analysis, we analysed longitudinal focus group interviews with adolescents in a Finnish school with longstanding indoor-air problems. We constructed three composite first-person narratives that reflected different experiential frames, with corresponding forms and changes of agency. We found that our adolescents made sense of the same socio-material environment and its affordances in very different ways, and this process afforded them to develop many kinds of agency that changed over time., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: More frequent and intense wildfires will increase concentrations of smoke in schools and childcare settings. Low-cost sensors can assess fine particulate matter (PM 2.5 ) concentrations with high spatial and temporal resolution., Objective: We sought to optimize the use of sensors for decision-making in schools and childcare settings during wildfire smoke to reduce children's exposure to PM 2.5 ., Methods: We measured PM 2.5 concentrations indoors and outdoors at four schools in Washington State during wildfire smoke in 2020-2021 using low-cost sensors and gravimetric samplers. We randomly sampled 5-min segments of low-cost sensor data to create simulations of brief portable handheld measurements., Results: During wildfire smoke episodes (lasting 4-19 days), median hourly PM 2.5 concentrations at different locations inside a single facility varied by up to 49.6 µg/m 3 (maximum difference) during school hours. Median hourly indoor/outdoor ratios across schools ranged from 0.22 to 0.91. Within-school differences in concentrations indicated that it is important to collect measurements throughout a facility. Simulation results suggested that making handheld measurements more often and over multiple days better approximates indoor/outdoor ratios for wildfire smoke. During a period of unstable air quality, PM 2.5 over the next hour indoors was more highly correlated with the last 10-min of data (mean R 2  = 0.94) compared with the last 3-h (mean R 2  = 0.60), indicating that higher temporal resolution data is most informative for decisions about near-term activities indoors., Impact Statement: As wildfires continue to increase in frequency and severity, staff at schools and childcare facilities are increasingly faced with decisions around youth activities, building use, and air filtration needs during wildfire smoke episodes. Staff are increasingly using low-cost sensors for localized outdoor and indoor PM 2.5 measurements, but guidance in using and interpreting low-cost sensor data is lacking. This paper provides relevant information applicable for guidance in using low-cost sensors for wildfire smoke response., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Porous fabrics have a significant impact on indoor air quality by adsorbing and emitting chemical substances, such as volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). Understanding the partition behavior between organic compound molecules and indoor fabrics is crucial for assessing their environmental fate and associated human exposure. The physicochemical properties of fabrics and compounds are fundamental in determining the free energy of partitioning. Moreover, environmental factors like temperature and humidity critically affect the partition process by modifying the thermal and moisture conditions of the fabric. However, existing methods for determining the fabric-air partition coefficient are limited to specific fabric-chemical combinations and lack a comprehensive consideration of indoor environmental factors. In this study, large amounts of experimental data on fabric-air partition coefficients (K fa ) of (S)VOCs were collected for silk, polyester, and cotton fabrics. Key molecular descriptors were identified, integrating the influences of physicochemical properties, temperature, and humidity. Subsequently, two typical quantitative structure-property relationship (QSPR) models were developed to correlate the K fa values with the molecular descriptors. The fitting performance, robustness, and predictive ability of the two QSPR models were evaluated through statistical analysis and internal/external validation. This research provides insights for the high-throughput prediction of the environmental behaviors of indoor organic compounds., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

[Display omitted] • CO can be catalyzed into CO 2 via three routes with different TS energy barriers. • Impurity of lattice and small specific surface areas cause low CO conversion ratios. • Interfering gases work via competitive adsorption, oxidizability and hydrogen bonds. • Activation energy is sensitive to temperature power exponents or temperature. • Chemical reactions with SO 2 or NO involved occur in reality to affect CO conversion. With the intention of thoroughly eliminating carbon monoxide (CO) from indoor environment, it is one of the most promising methods of converting it into carbon dioxide (CO 2) via catalytic oxidation processes. Therefore, in this study, catalytic oxidation mechanisms of CO over copper oxide (CuO) with interfering gases involved are investigated via theoretical calculations and experimental verification, which mainly include basic catalytic oxidation processes over CuO, effects of different interfering gases and analyses of thermodynamic features. According to results, catalytic oxidation of CO over CuO can be performed in three different routes and rate-determining transition-state (TS) energy barriers vary a lot from route to route at high temperature owing to different thermal stability. In the meantime, SO 2 , H 2 O and NO are theoretically proved to affect catalytic oxidation of CO via competitive adsorption, high oxidizability and hydrogen bonds, which are accompanied with different sensitivities to changes of temperature or temperature power exponents. In experiments, it is found that impurity of lattice planes and small specific surface areas in CuO are key to restricting catalytic oxidation performances. What is more, some extra chemical reactions in experiments (e.g. SO 2 + O 2 + CuO → CuSO 4 , NO + O 2 + CO → CO 2 + NO) caused by interfering gases colossally affect catalytic oxidation performances of CuO. The whole study provides crucial information for indoor air purification in industrial buildings by using cheap adsorbents/catalysts. [ABSTRACT FROM AUTHOR]

Indoor air quality (IAQ) is critical to the health and wellbeing of people. As the majority of people spend greater amounts of time indoors, either in office spaces or households, the level of air pollutants in such environments is critical. Building materials and furniture are known sources of air pollutants such as Volatile Organic Compounds (VOCs) and may be associated with discomfort, detrimental health of the occupants, etc. In this study, the VOCs found in a brand new office complex were monitored over a period of 6 months, with an emphasis on monitoring and quantifying harmful VOCs and identifying their emission source. Air samples were taken from a closed, unoccupied office space on a weekly basis and analysed using Thermal Desorption-Gas Chromatography-Mass Spectrometry (TD-GC-MS), while continuous monitoring of the air quality was performed using two commercially available IAQ sensors. To identify the source of the emitted VOCs, pieces of all construction material that were used in the office, including flooring, finished wall material, and adhesive glues, were removed, and placed in air-tight glass containers prior to analysis confirming that the source of VOCs is indeed the flooring. Identified compounds included mainly material origin VOCs such as BTEX (benzene, toluene, ethylbenzene, xylene) and styrene, but also common VOCs such as acetone and propan-2-ol. Of significant importance was the concentration of toluene that was found to be the most abundant VOC in both the flooring material and the indoor air., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Metro systems play a crucial role in public transportation worldwide. Given that metro stations are unique built environments with a significant volume of daily commuters, ensuring a satisfactory air quality in these spaces becomes paramount. This study involved measurements of indoor air quality (IAQ), staff satisfaction, particulate matter (PM) chemical composition, and heavy metal health risks at a typical metro station in Tianjin over two seasons. Although the air exchange rate was sufficient to maintain a CO 2 concentration less than 1000 ppm, the proportion of staff reporting no sick-building symptoms decreased from 83 % in spring to 25 % in winter. An average mass concentration of PM with an aerodynamic diameter smaller than 2.5 μm (PM 2.5 ) of 68.0 ± 42.2 μg/m 3 and an average PM 1 mass concentration of 51.8 ± 33.3 μg/m 3 were observed on the platform in winter. PM 2.5 contained more metal in winter than in spring. PM 2.5 in winter contained more metal in winter than in spring. With a lower relative humidity in winter, the coefficient of friction between railway wheels and rails increased, thus increasing particle emission. The carcinogenic risk of Cr on the platform was unacceptable. Moreover, the health risks induced by Ba should be investigated. The findings indicate that PM control at metro stationss, particularly on platforms in winter, should be emphasized., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

In Malaysia, chemical management in workplaces is managed under the Occupational Safety and Health Act 1994. Hence, the introduction of the Occupational Safety and Health (Use and Standards of Exposure of Chemicals Hazardous to Health) Regulations 2000 has strengthened the chemical management level in workplaces, including higher academic institutions. The introduction of chemical health risk assessment through the regulation required management to conduct the assessment at workplaces. Poor levels of Indoor Air Quality (IAQ) in chemical laboratories may also cause discomfort among workers when there is sick building syndrome in laboratories. IAQ is managed through the Industry Code of Practice on Indoor Air Quality 2010. Although both are different in method and approach, both are meant to ensure the workers' safety and comfort. This study is aimed to investigate the need to integrate both chemical health risk assessment and IAQ assessment in laboratories to ensure optimum safety levels among workers.

Improving asthma outcomes for underserved populations can be addressed through interventions to improve indoor air quality (IAQ). New protocol for measuring IAQ and health outcomes are imperative given advances in IAQ monitoring technology and challenges in conducting intervention research in homes. In this pilot study HEPA air purifiers and HEPA vacuum cleaners were provided to five homes with children with asthma. For 6 weeks, eight common components of air quality were measured using a low-cost multi-channel air quality monitoring device, with data conveyed directly from participant homes via Wi-Fi connection. In conjunction with periodic surveys on asthma control, impact of asthma on quality of life and intervention compliance, outcomes compared IAQ, home characteristics, and asthma-related measures. This pilot study demonstrates the feasibility of a protocol to evaluate a dual component intervention to improve IAQ in homes, as measured with a low-cost air quality monitoring device.

Accelerated concrete carbonation is an expanding option for decarbonizing construction. Factors such as concrete mixture design and carbonation environment can influence the maximum CO2 utilization that can be achieved during such a process. A carbonation process designed to utilize a water‐saturated dilute CO2 source wherein 2 < CO2 concentration (v/v%) < 16, was modeled in AspenPlus©. A regression model was developed to correlate CO2 uptake, relative humidity (11%–100%), CO2 concentration ([CO2] = 2—16 v/v%), and temperature (T = 11–74°C) conditions within a carbonation reactor. It was determined that [CO2] was the most significant variable as higher concentrations enhanced CO2 transport through the concrete. The energy use intensity per mass of CO2 utilized (kWh/kgCO2) was determined across a range of processing conditions. As a function of the operational conditions, accelerated carbonation provides a net CO2 reduction of up to 28 kgCO2/tonne of concrete; a reduction of up to ~45% compared to typical formulations. [ABSTRACT FROM AUTHOR]

Traditional methods for detecting harmful gases in air are often limited in their widespread deployment, accuracy, and real-time monitoring capabilities due to their complexity and cost. To address this challenge, optimization algorithms such as the Particle Swarm Optimization (PSO) algorithm have shown promise. The PSO algorithm, is applied to calculate the concentrations of harmful gases in air, maximizing detection accuracy. Detecting indoor gas pollution is a crucial concern due to the abundance of odors and vapors, particularly those emanating from activities such as cooking. The presence of these substances in the air poses a challenge in identifying traces of other harmful gases. This research endeavors to pioneer a novel approach characterized by heightened sensitivity, even in the presence of unidentified elements in the air. In this work, PSO algorithm is used in conjunction with Chirped Spectral Modulation (CSM) technique to increase system sensitivity to detect small traces of harmful gases inside buildings and protect the environment through early detection of pollution. The use of PSO and CSM altogether allowed for detecting carbon dioxide CO2, carbon monoxide CO, and nitrogen dioxide NO2 down to 10−6 % in volume, and sulfur dioxide SO2 down to 5×10−4 % in volume, while keeping the error below 0.1%