Improve Indoor Air Quality Research Articles

Association Between Household Dust Exposure and Sleep Duration: Findings from NHANES 2005–2006

Objective: Indoor pollutants, such as household dust, are increasingly recognized as potential contributors to health problems, including sleep disturbances. This study investigates the association between household dust exposure and sleep quality among American adults, utilizing data from the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2006. Methods: Data from NHANES were used in a cross-sectional design. Total dust weight (mg) was the primary exposure variable, and sleep outcomes included self-reported sleep duration, sleep latency, and physician-diagnosed sleep disorders. Data analysis was conducted using univariate and regression models in STATA (version 18.5), with adjustments for confounders. Results: 5,582 adults aged ≥18 years had available data on sleep duration, and 4,893 on sleep latency. In an adjusted model controlling for age and emotional support, dust weight was significantly associated with a slight decrease in sleep duration (adjusted β = -0.0001, p = 0.047). In multivariate logistic regression, dust weight showed a significant negative association with sleep duration (adjusted OR = 0.999, 95% CI: 0.999 to 0.999, p = 0.030), with age and emotional support demonstrating positive associations. Sleep latency showed no significant relationship with dust weight in linear regression analysis, even when controlled for emphysema and PHQ-9 score (adjusted β = -0.0002, 95% CI: -0.001 to 0.0009, p = 0.712). Multivariate logistic regression analysis also confirmed no significant association between dust weight and sleep latency. Conclusions: This study suggests that household dust exposure modestly impacts sleep duration, highlighting the value of improving indoor air quality to enhance sleep health.

Housing conditions and the health and wellbeing impacts of climate change: a scoping review.

Housing conditions are emerging as an important consideration in climate change adaptation. Housing modifications have the potential to improve health outcomes by reducing exposure to changing weather conditions and extreme events. This scoping review aimed to explore the existing evidence examining the contribution of housing conditions to the impacts of climate change on health and identify any research gaps. Literature searches were conducted in Scopus and PubMed from January 2013 to September 2023 and data were analysed using thematic analysis. The review included 38 articles consisting of original studies, reviews, and reports, with broad geographical coverage. The most common focus among included articles was on heat-health impacts; housing conditions found to improve heat-health health outcomes included air conditioning, ventilation, and window shading, and there was support for multifaceted housing adaptations rather than single fixes. Ventilation was found to be a priority for improving indoor air quality, while inappropriate insulation and excessive air tightness were found to increase indoor heat and reduce indoor air quality. The scoping review reveals a need for more empirical and qualitative research into indoor heat in homes, climate change hazards other than heat, and intervention studies to inform climate change adaptation policies around housing and improve public health outcomes.

Application of Environmentally Friendly Building Materials in Urban Construction

Rapid industrialization and urbanization of modern society have led to significant environmental challenges, including climate change, resource depletion, and pollution. The construction industry, a major contributor to these issues, relies heavily on traditional building materials such as cement, steel, and bricks, which are associated with high energy consumption and environmental degradation. In response to these concerns, there has been a growing emphasis on integrating environmentally friendly building materials into urban construction to promote sustainability and reduce ecological impact. This review paper explores the development and optimization of eco-friendly materials, focusing on their benefits, types, and real-world applications. We discuss the environmental, health, and safety advantages of using sustainable materials, such as reduced resource consumption, improved indoor air quality, and enhanced energy efficiency. Various eco-friendly materials, including recycled aggregates, bio-based composites, and waste-derived products, are examined for their potential to mitigate environmental impacts and enhance building performance. Case studies of successful projects that incorporate green materials are presented to highlight practical implementations and lessons learned.

Next-generation air filtration nanotechnology for improved indoor air quality.

Indoor air quality (IAQ) significantly affects human health, with pollutants such as organic, inorganic substances, and biological contaminants contributing to various respiratory, neurological, and immunological diseases. In this review, we highlighted the need for advanced air filtration technologies to mitigate these pollutants, which are emitted from household products, building materials, combustion processes, and bioaerosols. While traditional HVAC systems and mechanical filtration methods have been effective, they are often energy-intensive and limited in their ability to capture specific pollutants. To address these limitations, nanotechnology-based air filtration technologies, particularly those utilizing electrospinning processes, offer promising alternatives. This review classifies pollutants and details the working principles of next-generation filters, focusing on passive, self-powered, and externally powered mechanisms. These advanced filters achieve high filtration efficiency with minimal pressure drop, enhanced pollutant capture, and in some cases, health monitoring capabilities. This review emphasizes the significance of ongoing research into eco-friendly and sustainable filtration systems to enhance IAQ and minimize health risks linked to long-term exposure to indoor air pollutants.

The INGENIOUS project: towards understanding air pollution in homes.

This paper provides an overview of the INGENIOUS (UnderstandING the sourcEs, traNsformations and fates of IndOor air pollUtantS) project, aiming to better understand air pollution in homes. Although our homes are the microenvironment in which we spend most of our time, we know relatively little about the sources, transformation processes and fates of indoor air pollutants, or our exposure to them. INGENIOUS aims to address this knowledge gap by delivering: an indoor emissions inventory for UK homes; comprehensive air pollutant measurements in 310 homes in Bradford using a combination of low cost-sensors and more advanced air quality instrumentation; an analysis of the impact of indoor air pollution on outdoor air quality and vice versa using mobile measurements; insight into future indoor air quality using detailed air pollution models; identification of indoor air pollutants that warrant further toxicological study; and better understanding of the barriers and facilitators for behaviour that drives improved indoor air quality. Median daily PM2.5 and CO2 concentrations varied from 7.8 μg m-3 and 666 ppm in the summer, to 16.4 μg m-3 and 857 ppm in the winter respectively in our sampled homes. Peak daily PM2.5 concentrations above 150 μg m-3 were frequently observed across all seasons, and were driven by cooking. Cooking activities also generated high concentrations of volatile organic compounds during emissions measurements, such as harmful aldehydes (up to ∼50 ppb), and alcohols (up to ∼600 ppb) from a chicken stir-fry. Our sampled homes displayed a wide variation in indoor pollutant concentrations, with a strong link to behaviour, including frequency and type of cooking activities, and use of ventilation.

Evaluation of Efficiency of Radon-Blocking Wallpaper for Improving Indoor Air Quality

Evaluation of Efficiency of Radon-Blocking Wallpaper for Improving Indoor Air Quality

Development of Tracer Gas Method to Improve Indoor Air Quality: A Study on Ventilation Performance in Apartment Buildings in South Korea

This study analyzes the shortcomings of South Korea’s current evaluation method of ventilation performance for apartment buildings and suggests improvements. The current Korean regulations rely on the air change rate method, which is a prescriptive method and thus inadequately measures indoor air quality practically. Therefore, this study reviews various standards, finding that these standards can be categorized into those evaluating the mechanical performance of ventilators and those assessing indoor ventilation performance. This study highlights that the standards evaluating indoor ventilation performance are based on the tracer gas method but lack clear testing procedures and boundary conditions. This research also reviews the various previous research articles, noting that Korean research places emphasis on system design parameters, while international research focuses on architectural factors. It also identifies inconsistencies in the experimental setups across studies. To improve the current evaluation methods, the research suggests enhancing the tracer gas method with clear testing procedures and introducing indicators such as the age of air and uniformity coefficient together. Since the air change rate method does not consider the actual airflows and distribution in indoor spaces, this method is limited to deriving improvements in indoor ventilation performance. However, the suggested tracer gas method and indicators can be used to discover the optimal locations of vents for better indoor air quality or to drive a better building design to achieve better indoor ventilation performance. In other words, these enhancements aim to provide more accurate and comprehensive insights into the effectiveness of indoor ventilation systems, helping engineers, designers, and residents better understand and improve indoor air quality.

Designing an Interior Residential House with an Ecological Concept Approach (Friendly Environment)

The design of residential interiors with an ecological concept aims to create living spaces that are environmentally friendly, sustainable, and support the well-being of their occupants. This approach integrates ecological principles in material selection, space design, and green technology to minimize environmental impacts and optimize energy efficiency. The study examined strategies such as the use of recycled and natural materials, optimization of natural lighting and ventilation, and energy-saving technologies. Materials such as certified wood, bamboo, and VOC-free paint were selected to improve indoor air quality and sustainability (Digitalcommons@usu & Platt, 2007). The design of the space prioritizes natural lighting and air circulation through windows, skylights, and cross ventilation. Indoor plants and energy-efficient equipment such as LED lights are used to beautify the room and reduce energy consumption. Green technologies such as solar panels and rainwater collection systems are applied to reduce dependence on conventional resources. The design results show that the ecological concept in the interior of the house creates a healthier, more comfortable, and more sustainable environment.

Spatiotemporal Mapping of Ultrafine Particle Fluxes in an Office HVAC System with a Diffusion Charger Sensor Array.

Commercial HVAC systems intended to mitigate indoor air pollution are operated based on standards that exclude aerosols with smaller diameters, such as ultrafine particles (UFPs, Dp ≤ 100 nm), which dominate a large proportion of indoor and outdoor number-based particle size distributions. UFPs generated from occupant activities or infiltrating from the outdoors can be recirculated and accumulate indoors when they are not successfully filtered by an air handling unit. Monitoring UFPs in real occupied environments is vital to understanding these source and mitigation dynamics, but capturing their rapid transience across multiple locations can be challenging due to high-cost instrumentation. This 9-month field measurement campaign pairs four medium-cost diffusion charger sensors with volumetric airflow rates modulated and monitored in a cloud-based building automation system of an open-plan living laboratory office and dedicated air handling unit to evaluate spatiotemporal particle number and surface area concentrations and migration trends. Particle number flux rates reveal that an estimated daily median of 8 × 1013 UFPs enter the air handling unit from the outdoors. Switching from a MERV14 to a HEPA filter reduces the number of UFPs supplied to the room by tens of trillions of UFPs daily, increasing the median filtration efficiency from 40% to 96%. These results demonstrate the efficacy of an optimal air handling unit's performance to improve indoor air quality, while highlighting UFP dynamics that are not accounted for in current filtration standards nor in occupant-centered HVAC control. Scalable sensor development can popularize UFP monitoring and allow for future UFP integration within building control and automation platforms. The framework established for this campaign can be used to evaluate particle fluxes considering different analytes.

Strategic Pathways to Sustainable Development: A Comprehensive Review of the Benefits and Barriers of Green Buildings

As environmental concerns grow globally, green building practices have become essential in promoting sustainable development. This paper provides a comprehensive review aimed at evaluating the multifaceted benefits, barriers, and strategic pathways related to the implementation of green buildings. The study employs a systematic literature review, analysing 90 significant studies from databases such as Scopus, Google Scholar, and Web of Science, to assess the economic, environmental, and social impacts of green building practices. The results highlight that green buildings offer substantial benefits, including reduced energy consumption, improved indoor air quality, enhanced occupant health and productivity, and long-term cost savings. Despite these advantages, the widespread adoption of green building practices faces considerable challenges, notably high initial construction costs, regulatory obstacles, and limited awareness among stakeholders. Furthermore, the study identifies significant gaps in the existing literature concerning the regional and contextual variations in the effectiveness of green building strategies. The implications of this research are crucial for policymakers, developers, and industry professionals who are working towards sustainable urban development. The findings suggest that overcoming the identified barriers requires coordinated efforts, including the implementation of supportive policies, financial incentives, and extensive public education campaigns. By addressing these challenges, green buildings can play a pivotal role in achieving global sustainability goals and fostering resilient, eco-friendly urban environments.

Reduced scale experiment and numerical simulation study on different airflow organization modes in large ship painting workshop

Mechanical ventilation is a key means to improve indoor air quality in shipbuilding industry. Appropriate airflow organization will have a perceptible impact on environmental safety, personnel health, and energy conservation. Many ship painting workshops use fully mixed ventilation, making it difficult to meet indoor pollutant standards and save energy. Therefore, it is necessary to optimal design the airflow organization in the ship painting workshop reasonably. This article introduces three new air supply strategies for ship painting workshops, namely piston flow air supply, attached jet air supply, and side air supply, and compares them with the existing mixed air supply. Three operating scenarios have been established, including isothermal conditions in spring and autumn, cooling condition in summer, and heating condition in winter. The airflow and pollutant distribution of each airflow organization are compared through scale model experiments and numerical simulations. Finally, the most suitable strategy for the workshop in each season is selected and promoted for engineering applications.

Optimal Air Flow Modeling in Real Healthcare Facilities for Quick Removal of Contaminated Air

Background: Contaminated air can have a negative impact on patient recovery, leading to longer hospital stays, higher healthcare costs, and even death. Objective: Our study focuses on improving indoor air quality for patient recovery in healthcare facilities. Methods: We conducted computational analysis using the finite element modeling (FEM) technique to investigate the flow of contaminated air exhaled by a patient. Distinct models were examined: a neonatal intensive care unit (NICU) with two-beds and a coronavirus isolation room (CIR). Using ANSYS, we designed models using actual and real specifications of both NICUs and IRs from local hospitals. We determined the optimal dimensions and locations of outlet vents in NICUs and CIRs using simulations with ANSYS software drawing on our designed modeling of air flow. Outlet vent dimensions and locations were modified to achieve optimal air flow for quickly venting out contaminated air from a patient in a room. Results: The results show a substantial improvement in directly venting out the contaminated air from the patient. Conclusions: It can be concluded that the optimal design of outlet vent locations and dimensions using ANSYS simulation results in finding the optimal path for the quick removal of contaminated air flow from the patient in an NICU and CIR.

Diffusion characteristics of re-suspended PM2.5 within a radiant floor heating room under various ventilation modes

Few studies have revealed the effects of re-suspension of particulate matter deposited by radiant floor heating on indoor environments. The present study utilized Computational Fluid Dynamics (CFD) to investigate the impact of radiant floor heating and ventilation mode on indoor airflow patterns, as well as the dispersion and migration of re-suspended particulate matter, based on a turbulence model validated by an environmental test cabin. The Archimedes number (Ar) was employed to represent the strength of interaction between the thermal buoyancy force generated by floor radiation and the inertial force of the supply airflow. The results indicates that as Ar increases, the supply airflow exhibits a downward deflection, thereby forming a stable vortex below to prevent the diffusion of heat and re-suspended PM2.5 generated from the heated floor. As the Ar increases, the re-suspended PM2.5 deposited on the surrounding walls increased significantly, and the indoor PM2.5 concentration gradually decreased. When the Ar exceeds 6.03, the increase in Ar will no longer affect the indoor re-suspension PM2.5 diffusion, deposition characteristics, and removal efficiency. Therefore, it is recommended the critical Ar (Arcrit) of 6.03 for a radiant floor heating room under various ventilation modes, beyond which the indoor flow structure and distribution characteristics of re-suspended PM2.5 no longer change with increasing Ar. This study is helpful to further understand the diffusion and distribution characteristics of re-suspended particulates in floor heating and ventilation rooms, and provide technical reference for improving indoor air quality.

Optimizing Ventilation Systems in Barcelona Schools: An AHP-Based Assessment for Improved Indoor Air Quality and Comfort

The success of educational institutions is fundamentally intertwined with the well-being and academic progress of their students. In this context, indoor air quality (IAQ) and thermal comfort play a critical role in creating conducive learning environments that support both health and academic performance. This work evaluates six ventilation systems and strategies for enhancing IAQ and thermal comfort, which prevail in educational buildings in the Spanish region of Catalonia. To do so, a multi-criteria analysis is performed based on the Analytic Hierarchy Process (AHP) method, considering economic, social, and environmental aspects. Ventilation systems are pairwise compared in terms of six criteria: initial and maintenance cost, classroom air quality, students’ thermal comfort in summer and winter, and energy consumption. Subsequently, weighted combinations of these criteria are established to rank the ventilation systems under five case scenarios. The results indicate that natural ventilation systems, particularly those with atriums and courtyards (N-AAC), offer a balanced solution, achieving satisfactory IAQ and thermal comfort while being more cost-effective and environmentally sustainable in certain contexts. The variation in the best solution across different scenarios demonstrates that the optimal choice is highly context-dependent, influenced by factors such as budget, climate, and infrastructure. This research provides a valuable foundation and methodology for decision-makers in educational institutions, supporting the selection of ventilation systems that maximize sustainability while enhancing students’ comfort and fostering learning environments.

(Invited) Practical Evaluation Methods of Photocatalyst from Dialogue with the Industry

Now we propose a comprehensive review of our recent contributions to the field of photocatalytic environmental purification. As a public research institute, our studies have focused on the practical evaluation of photocatalytic materials informed by the fundamental principles of photocatalysis and ongoing dialogue with industry partners.Our first study introduced non-woven fabric-supported photocatalysts that effectively adsorb and decompose odorous and tar components in tobacco smoke1. These photocatalysts, which respond to both UV and visible light, have shown promise in improving indoor air quality. Among the tested materials, non-woven fabric-supported Fe/TiO2 demonstrated superior efficacy, suggesting its potential for practical applications in creating a comfortable indoor environment.In another study, we explored the decomposition of gaseous styrene, a prevalent pollutant, using a combination of photocatalysts and ozone treatment2. This synergistic approach resulted in the complete decomposition of styrene, suggesting its potential for widespread use in air purifiers and odor management systems. The study provided insights into the practical application of photocatalysis and ozone oxidation technologies in air purifiers and their performance management.Furthermore, we developed a novel screening test to assess the anti-viral performance of photocatalytic materials against SARS-CoV-23. This method provides a rapid and efficient means to evaluate the anti-viral capabilities of photocatalysts, which is particularly relevant in the context of the ongoing COVID-19 pandemic. The proposed screening test, based on the ‘acetaldehyde decomposition test’, offers a correlation between air purification efficiency and viral inactivation, providing a promising tool for rapid evaluation of photocatalytic materials.These studies underscore our commitment to advancing the application of photocatalysts in environmental purification, bridging the gap between laboratory research and real-world applications. By establishing practical evaluation methods and engaging in productive industry dialogue, we aim to contribute significantly to the development of sustainable and effective environmental purification technologies.References Ochiai, T.; Aoki, D.; Saito, H.; Akutsu, Y.; Nagata, M. Analysis of Adsorption and Decomposition of Odour and Tar Components in Tobacco Smoke on Non-Woven Fabric-Supported Photocatalysts. Catalysts 2020, 10, 304. https://doi.org/10.3390/catal10030304Hamada, K.; Ochiai, T.; Aoki, D.; Akutsu, Y.; Hirabayashi, Y. Decomposition of Gaseous Styrene Using Photocatalyst and Ozone Treatment. Catalysts 2022, 12, 316. https://doi.org/10.3390/catal12030316Ochiai, T.; Nagai, T.; Hamada, K.; Tobe, T.; Aoki, D.; Sunada, K.; Ishiguro, H. Estimating the Anti-Viral Performance of Photocatalytic Materials: The Correlation between Air Purification Efficiency and Severe Acute Respiratory Syndrome Coronavirus 2 Inactivation. Catalysts 2024, 14, 163. https://doi.org/10.3390/catal14030163 Figure 1

Numerical analysis and control of contaminant leakage during personnel movement across differential pressure zones

Artificial pressure differential environments play a vital role in various fields, including healthcare, industrial applications, and laboratory safety. Despite numerous studies conducted in this area, contaminant leakage due to personnel movement across pressure zones remains a significant challenge, increasing the risk of infection or contamination. This study aims to systematically analyze and control contaminant particle leakage during such movements, using numerical simulations and field experiments that incorporate the moving mesh method. This study investigates the effects of pressure gradients, door types, and temperature differences on particle migration. The results indicate that maintaining a pressure gradient can reduce particle leakage by up to 35.33 %. Sliding doors proved more effective than hinged doors, reducing leakage by up to 74.36 %. Introducing a temperature difference between areas also decreased leakage by up to 64.9 %. These findings provide practical recommendations for optimizing the design of negative-pressure isolation wards and can be extended to other environments that maintain differential pressure. This study offers valuable insights into the control of contaminant leakage, contributing to improved indoor air quality and infection control.

Innovative Approaches to Windcatcher Design: A Review on Balancing Tradition Sustainability and Modern Technologies for Enhanced Performance

This review investigates the role of windcatchers in modern architecture, exploring their optimization through the integration of traditional designs with contemporary technologies. Historically utilized in hot and arid climates for passive cooling, windcatchers offer energy-efficient solutions for improving indoor air quality (IAQ). This study examines the sustainability of traditional windcatcher designs and their relevance in preserving heritage structures. Using advanced tools like computational fluid dynamics (CFD) modeling, modern adaptations of windcatchers can be optimized for urban environments. This review also explores hybrid systems, combining windcatchers with solar chimneys, evaporative cooling, or heat pumps, to enhance performance in low-wind conditions by balancing natural and mechanical ventilation. Additionally, it addresses the role of artificial intelligence (AI) in heritage planning, facilitating the design and integration of windcatchers into contemporary architecture. The findings suggest that windcatchers, combined with modern design strategies and hybrid systems, continue to be viable and sustainable solutions for passive cooling, contributing to energy-efficient and climate-resilient buildings across different environmental and urban contexts.

Enhanced and Sustainable Indoor Carbon Dioxide Monitoring by Using Ambient Light to Power Advanced Biological Sensors

Enhancing carbon dioxide (CO2) detection is crucial for improving indoor air quality and environmental surveillance. Traditional CO2 sensors face drawbacks like high costs, large sizes, environmental impact, and reliance on external power, limiting their practicality for continuous indoor monitoring. In this research, an innovative indoor CO2‐sensing system using a self‐powered bio‐solar cell (BSC) platform is introduced. Utilizing cyanobacteria as a sensitive biocatalyst and sustainable power source, the system offers a cost‐effective, eco‐friendly, and maintenance‐free alternative to conventional sensors. It operates by monitoring electron‐transfer processes in cyanobacteria during photosynthesis, converting CO2 and water into oxygen and chemical energy, enabling accurate CO2 level monitoring. The system responds to CO2 fluctuations and issues alerts when levels are outside the recommended range of 500–1000 ppm for human health and productivity. A self‐sustaining configuration of eight BSCs—one for sensing and others for power generation—ensures continuous operation without external power. An integrated energy‐harvesting board efficiently manages power distribution to a microcontroller and display system for real‐time data visualization, with the array producing up to 400 μW. Additionally, a machine‐learning model interprets BSC outputs to accurately quantify CO2 levels, enhancing the sensor's adaptive performance.

Concrete Actions for Improving Indoor Air Quality in Korea: Advancing Public Health for Vulnerable Populations

In modern society, individuals spend an increasing amount of time indoors, emphasizing the importance of understanding the health impacts of indoor environments. This study focused on measuring indoor air quality to identify vulnerable populations and observe the effects of residential environment improvements on air quality. Targeting low-income families and elderly households, known for their heightened vulnerability to environmental health risks, the study involved direct visits to 2328 low-income households across 16 cities and provinces in South Korea from 2021 to 2022. Indoor air quality parameters, including PM2.5, PM10, total volatile organic compounds (TVOC), formaldehyde (HCHO), and airborne mold, were measured. Among these households, 300 with critically compromised living conditions received support for wallpaper and paneling replacement. Comparative measurements before and after the renovations revealed that single-person households had higher levels of PM2.5 and TVOC compared with households with four or more members. Additionally, households with elevated concentrations of airborne mold also exhibited higher levels of PM2.5 and PM10. Importantly, households that received environmental improvements showed a significant reduction in airborne mold concentration by approximately 50% or more. This study underscores the importance of indoor environmental health and provides valuable evidence supporting policies focused on health promotion and residential welfare improvements for vulnerable populations. The research is distinguished by its comprehensive nature, involving direct measurements from nearly 2000 households nationwide, rather than relying solely on secondary data.

Performance analysis of a novel photocatalytic double-layer ventilation window

The application of renewable energy in the building sector has received increasing attention. In this work, a zero-energy photocatalytic double-layer ventilation window was proposed to reduce building energy consumption and improve indoor air quality. The effects of environmental and operational parameters on the system’s performance were investigated through experimental testing and simulation analysis. The results show that the thermal efficiency of the system increases with the rise in solar irradiation, while the degradation rate initially increases and then decreases. The performance of the system is significantly affected by the inlet air speed and temperature. When the photocatalyst is coated on both sides of the window compared to one side under solar irradiation of 600 W/m2, the thermal efficiency and degradation rate of the system increase by 29 % and 74 %, respectively. This study demonstrates the potential of photocatalytic double-layer ventilation windows in energy-efficient buildings and provides an important reference for sustainable building design.