Affect Indoor Air Quality Research Articles

Wind tunnel modeling experiments on airflow characteristics of underground metro station with sunken squares

Building airflow characteristics can affect the indoor air environment, thereby affecting indoor air quality and building energy consumption. In recent years, the sunken square has increasingly designed and applied to underground transportation hub systems, because of their special advantages, such as improving the ventilation and lighting of the underground space, blurring the feeling of the ground and underground and improving the quality of the space. However, at present, there are few systematic and comprehensive researches on the airflow characteristics of the sunken squares to the underground metro station. In this study, the wind tunnel modeling experiment and the particle image velocity (PIV) technology are comprehensively used to study the influence of the sunken square on the airflow characteristics of the underground metro station, the influence of the sunken square on the flow field distribution and air exchange rate of underground metro station are obtained. The dimensionless average wind velocity at the large openings of the sunken square is 0.053-0.18, and the air exchange rate of the underground metro station is changed with the number and the relative positions of sunken squares. Conclusions of this research could provide useful reference to the design of airflow characteristics for underground buildings.

Real-time measurements of product compounds formed through the reaction of ozone with breath exhaled VOCs.

Human presence can affect indoor air quality because of secondary organic compounds formed upon reactions between gaseous oxidant species, e.g., ozone (O3), hydroxyl radicals (OH), and chemical compounds from skin, exhaled breath, hair and clothes. We assess the gas-phase product compounds generated by reactions of gaseous O3 with volatile organic compounds (VOCs) from exhaled human breath by real time analysis using a high-resolution quadrupole-orbitrap mass spectrometer (HRMS) coupled to a secondary electrospray ionization (SESI) source. Based on the product compounds identified we propose a reaction mechanism initiated by O3 oxidation of the most common breath constituents, isoprene, α-terpinene and ammonia (NH3). The reaction of O3 with isoprene and α-terpinene generates ketones and aldehydes such as 3,4-dihydroxy-2-butanone, methyl vinyl ketone, 3-carbonyl butyraldehyde, formaldehyde and toxic compounds such as 3-methyl furan. Formation of compounds with reduced nitrogen containing functional groups such as amines, imines and imides is highly plausible through NH3 initiated cleavage of the C-O bond. The detected gas-phase product compounds suggest that human breath can additionally affect indoor air quality through the formation of harmful secondary products and future epidemiological studies should evaluate the potential health effects of these compounds.

An Analysis of Natural Ventilation and Ventilation load in relation to Occupants’ window opening Behaviour in residential Building

For reducing the energy consumption in buildings, each country strengthened the standard of insulation without the standard of ventilation. However, because of it, sick building syndrome has occurred. Accordingly, the importance of ventilation in building has been increased to reduce the polluted indoor air and promote the better Indoor Air Quality. The previous study has only focused on the window opening behaviour and developed the machine learning algorithm of window opening. However, it is the ventilation rates that affects Indoor Air Quality. Therefore, in this study, the ventilation rates was derived from carbon dioxide decay method. From this ventilation behaviour, occupants are not only controlling their indoor environment, but also making the ventilation load in their building.

Determination of Indoor Air Quality in University Student Canteens

The negative effects of indoor air quality cause a decrease in the working efficiency of people, and health problems. For this reason, monitoring the indoor air quality of the places where students spend time such as canteen, cafeteria and library is important in terms of quality of life. Particulate matter is the leading source of pollutants affecting indoor air quality. For this purpose, the indoor air quality of student canteens in a public university located in Marmara Region, Turkey was examined in terms of temperature, relative humidity, person density, area, particulate matter (PM2.5 and PM10) parameters. The relative humidity in canteens was found to be within normal range in terms of comfort conditions, and the temperature was slightly higher depending on seasonal conditions and canteen conditions. It was observed that the density of people in canteens at certain hours affected PM2.5 and PM10 concentrations, and PM2.5 and PM10 concentrations increased with the increase in the number of students. It was determined that World Health Organization (WHO) limit values and air pollution regulation limit values were exceeded in canteens except E3 and A1 canteens. Due to the insufficient ventilation of the canteens, it was determined that particulate matter may pose a risk to the students and the employees of the canteen, and recommendations were made to improve the indoor air quality.

Comparison of the effects of three types of heating tobacco system and conventional cigarettes on indoor air quality

Environmental tobacco smoke (ETS) from conventional cigarettes is reported to affect indoor air quality (IAQ) in various real indoor environments. Recently, Japan Tobacco Inc. introduced three types of tobacco product that are heated rather than combusted. These comprise one direct heating tobacco system and two in-direct heating tobacco systems. In this study, the impact of using these products on IAQ was evaluated in an environmentally controlled chamber. Two environmental conditions, simulating restaurant and residential spaces, were examined. Under the same conditions, cigarette smoking and the presence of people only were used as positive and negative controls, respectively. The indoor air concentrations of 48 constituents (tobacco-specific nitrosamines, carbonyls, volatile organic compounds, total volatile organic compounds, polycyclic aromatic hydrocarbon, polycyclic aromatic amines, mercury, metals, ETS markers, propylene glycol, glycerol, carbon monoxide, carbon dioxide, suspended particle matter, ammonia, and nitrogen oxides) were measured. Compared with the presence of people, the concentrations of some constituents were actually increased when using heating tobacco products under both environmental conditions, simulating restaurant and residential spaces. However, the constituent concentrations were lower than those obtained by cigarette smoking, except for propylene glycol and glycerol, and below the exposure limits for constituents in air, as defined by air quality guidelines or regulations. Based on these data, the use of heating tobacco systems in appropriate indoor environments has less impacts compared to conventional cigarettes.Article HighlightsWe measured the indoor air concentrations of chemical constituents generated when using three heating tobacco systems with different heating mechanisms in two environment conditions simulating restaurant and residential spaces (positive control: when smoking cigarettes, negative control: the presence of people only).In the measurement and analysis method used this study, it was possible to find not only that the air concentration generated when using the heating tobacco systems in this study were considerably lower than that when smoking cigarettes, but also the differences of the concentrations between heating tobacco systems with different heating mechanisms.We showed some constituents which actually increased the air concentrations when using heating tobacco systems compared with the presence of people only.

Effect of spring grass fires on indoor air quality in air-conditioned office building

Open biomass burning (OBB) is a significant air pollution source, but it is still not clear to what extent OBB events affect indoor air quality [1]. Outdoor and indoor measurements of submicron particulate matter (PM1) were conducted on 25–29 April (2019) in the capital city Vilnius (Lithuania). Fires from neighbouring countries (Belarus, Ukraine and Russia) and in the vicinity of Vilnius broke out during the measurement campaign. The temporal evolution and transport of OBB plume were investigated by combining the air mass backward trajectory analysis and fire satellite observation (MODIS) database. Measurements of the PM1 chemical composition in real-time were performed using an aerosol chemical speciation monitor (ACSM) and an aethalometer. Organic matter was the clearly dominant component, accounting for >70%, in both indoor and outdoor PM1. The air filtering system of the office building removed approximately up to 55% of PM1. Despite a significantly lower PM1 pollution level in the office, highly acidic indoor PM1 could have harmful effects on the human health. Source apportionment of particulate carbonaceous matter revealed a significant importance of OBB-related particles (average 56%) to indoor air.

Assessment of mold infestation of conditioning devices and indoor air

Introduction. Indoor air quality is an essential component of a healthy human environment. Air conditioning units can affect indoor air quality, including mycogenic contamination of the air if the condition is not adequately monitored. Material and method. The paper presents the results of a mycological study of air samples and flushes from the surface of filters and gratings of air conditioning devices taken from 40 residential and office premises. Results. The presence of micromycetes fungi was noted in 100% of the samples taken from the surface of filters and air conditioning grids and 81.6% of air samples. A greater species diversity of fungi (26 species) was revealed in air samples compared to air conditioning devices (15 species). A higher frequency of occurrence of dark-coloured species of fungi, incl. Aspergillus spp. and Alternaria spp., and fungal species belonging to the third group of pathogenicity, were noticed on the surface of air conditioners, compared with air samples, in which Penicillium spp., Fusarium spp., Trichoderma spp. were more often detected. It was found that the surface of air conditioners functioned sporadically. For a short time (28 rooms), there is a large species diversity of mycobiota at a low or moderate level of seeding (no more than 103 CFU). In rooms with long-term continuous air conditioners (12 rooms), a high level of seeding (more than 104 CFU) by 1-2 species of fungi was more often noted. The existence of a close relationship, confirmed by the values of the Pearson contingency coefficient, between the species composition of the mycobiota of air conditioning devices and air, and a higher level of mycogenic contamination in rooms with long-term continuous operation of air conditioners, were shown. Conclusion. Thus, air conditioning devices can be a source of mycogenic air contamination, especially during long-term continuous operation, which must be taken into account to ensure indoor air quality.

Study on influencing factors for occupant window-opening behavior: Case study of an office building in Xi'an during the transition season

Window-opening behavior profoundly affects indoor air quality, thermal comfort, and the energy consumption of HVAC systems in office buildings. This paper presents the results of a field study on manual window control conducted in five typical individual offices in the building of a research institute in the city of Xi'an, located in the cold region of China. The average duration of window-open and window-closed states was 5.3 h/day and 6.7 h/day during working hours, respectively, and thus the window-open state accounted for 44% of the total duration during the transition season. Unlike previous studies, the results show that once a window was opened when occupants first come to the office, it would not be left like that for long, until the occupants left the office at the end of day. In addition, window opening behavior is more strongly correlated with indoor PM2.5 concentration and indoor temperature. A new algorithm has been developed that applies dummy variables based on a binary logistic to provide a more accurate description of the relationship between the window state and influencing factors at different levels. The proposed model increased the prediction accuracy of the window being open by 5.9% compared to the continuous variable model. This study focuses on understanding the characteristics of window operation and establishing a more accurate model that offers suitable data and theoretical support for applications to simulate energy consumption in office building.

Verification of particle matter generation due to deterioration of building materials as the cause of indoor fine dust

Particles of fine dust are pollutants that adversely affect indoor air quality and exacerbate human respiratory diseases. The aging of the building was pointed out as a source of fine dust indoors. The aging of buildings has various causes of deterioration. During various deterioration, friction adversely affects the building floor finish. In this study, an accelerated friction deterioration device was used to confirm the generation of fine dust particles through the frictional deterioration of floor finishes in buildings. The study found that the concentration of fine dust particles attributed to deteriorating flooring was 327 mg/m3 in PM2.5 and 4828 mg/m3 in PM10 and confirmed that particle distribution differs depending on the surface of the flooring. Particles of 10 µm or less were observed through particle analysis. The study confirmed that fine dust particles did not diffuse in a specific direction and that the detected fine dust particles could be attributed to deterioration. Further research is needed on the detection of fine dust in degraded building finishing materials.

In-use emissions and usage trend of pellet heating stoves in rural Yangxin, Shandong Province

The use of coal in Chinese households for winter heating emits harmful pollutants that severely affect indoor air quality and climate. Therefore, China has made efforts to transition into clean heating using improved heating stoves and biomass pellets. Although the economic and policy implications of such demonstration projects have been extensively investigated, little has been done to understand the real-world performance and adoption trends of such stoves. This study measured in-use emissions from nine different pellet stoves used for heating among 52 rural households in Yangxin, Shandong Province. The temperature of the stove chimney of 21 households was monitored and 56 households were surveyed to explore the stove use trend. The particulate and gaseous emission concentrations for most of the stoves exceeded the limits specified in the Chinese national standard. The measured fuel energy-based emission factors (mean±standard deviation) for CO2, CO, NOx, and PM2.5 were 103±3, 1.41±1.19, 0.336±0.237, and 0.146±0.108g/MJ, respectively. Between January to February, the average daily heating duration was 8.71h, and the sustained use of heating stoves was seen among over 85% of the households. On average, the households used their heating stoves for 3.28 months and the estimated annual pellets consumption for a household was 2.7 tons. Besides inherent variabilities associated with user habits, the stove's design-related shortcomings and low-grade pellets hindered the performance and effectiveness of pellet stoves. This study provides insights into opportunities and challenges for the promotion of cleaner fuels and heating technologies. Furthermore, it will provide information on emissions from rural residential sources to build the emission inventory and inform policymaking for successful stove promotion programs.

아파트단지 피트니스센터의 실내공기질 측정분석

The purpose of this study is finding out the indoor air quality and its relevant factors of fitness centers located in apartment housing complexes, while also suggesting plans for improving the air quality of these centers. Indoor air quality was examined in each of the four fitness centers in the apartment housing complexes over the course of one day, during the service hours of 12 PM to 8 PM, from the month of February 2019 to March 2019. Indoor concentration levels of PM10, CO₂, CO, HCHO, TVOC were measured, and background elements such as indoor temperature and relative humidity were also measured. The interviews with the managers of these fitness centers and the field observation recordings were conducted simultaneously on the measuring day. The recordings observed are a variety of conditions which may affect indoor air quality, such as the number of users, the ventilation system operation, the period of window being opened, and other factors. The results showed that the concentrations of PM10, CO₂, TVOC were higher than the legal standard in particular spaces at certain times of day. From the analysis, it appears that the most relevant factors affecting indoor air quality was the operation status and the filter maintenance level of ventilation system. Therefore, this study suggests that managers should operate the ventilation system continuously and change the filter periodically, and that related regulations for keeping healthy indoor air in apartment complex fitness centers should be established.

Application of pre-filter system for reducing indoor PM2.5 concentrations under different relative humidity levels

In most urban environments, outdoor air pollutants affect indoor air quality. In 2019, Seoul, South Korea mandated filtered ventilation systems in newly constructed buildings to reduce PM2.5 levels. This study aimed to evaluate PM2.5 concentrations before and after the installation of a pre-filter and to analyze their behavior under different relative humidity conditions. The pre-filter system was installed in two selected houses (A and B) with the same ventilation system to evaluate indoor and outdoor PM2.5 concentrations. To reduce indoor PM2.5 concentrations through the ventilation system, a high-performance filtering system (G4 + F8 + H13) was installed. The ventilation system was better at maintaining indoor air quality than an air cleaner. Furthermore, the pre-filter was more effective in reducing PM2.5 that was introduced from the outside rather than that generated indoors. The results revealed that after installation of the pre-filter system, the percentage of PM2.5 concentration below 10 μg/m3 increased for house A and B, respectively. In addition, when the pre-filter was not installed, the average I/O ratio was 1.4 ± 0.09 and 2.3 ± 0.09 for house A and B, respectively. However, after the pre-filter was installed, the average I/O ratio for house A was 0.4 ± 0.58 and that for house B was 2.1 ± 0.05. After pre-filter installation, the percentage of I/O ratio (range of 0–1) increased with an increase in the relative humidity, that is from 72.1% to 95.1% for house A and from 8.5% to 24.7% for house B.

Air quality measurements in four sheep barns part II: pollutant gas emissions.

Pollutant gas emissions from animal barns affect indoor air quality, the health and well-being of farmers, and the surrounding environment. This study was carried out in four sheep barns (SB) in Bursa, an important region for animal husbandry operations. Concentrations of NH3, CO2, H2S, and CH4 were measured in four sheep barns by monitoring throughout 24 h in 1 year. Pollutant gas emissions from barns were also calculated and modeled. The average pollutant gas emissions obtained in this study were 5 kg day-1 barn-1 for NH3, and 18 kg day-1 barn-1 for CH4. The average NH3 and CH4 emissions from each barn were 2.1 and 2.7 kg day-1 barn-1 for SB1; 9.4 and 12.9 kg day-1 barn-1 for SB2; 4.0 and 3.6 kg day-1 barn-1 for SB3; and 4.5 21 kg day-1 barn-1 for SB4, respectively. There are statistically significant differences between daytime and nighttime for pollutant gas emissions. Pollutant gas emissions in the monitored barns are generally higher in summer than in other seasons. Models for estimating NH3, and CH4 emissions were developed using measured temperature and relative humidity values in the barns. These models can only be used in the Bursa region. The results of this study were compared with other studies under similar conditions in the literature.

Indoor air quality in natural-ventilated bedrooms in renovated Norwegian houses

The objective of this work is to investigate the indoor environment in bedrooms ventilated by window opening during night-time. How window opening behaviour affects indoor air quality (IAQ), and how window opening behaviour and IAQ is influenced by external factors, are important questions. The context is renovation of detached wooden houses in Norway. To motivate building owners to renovate their ventilation system, it is important to know the typical indoor environment in bedrooms of existing buildings with natural ventilation. Ten bedrooms in six case houses were investigated by measuring temperature, relative humidity, CO2, particulate matter, formaldehyde and TVOC. The window opening angle was also logged with an accelerometer. The measurements were conducted over 2 to 3 weeks, during March and April. The dwellings were renovated single-family and terraced houses from 1950 – 80, in Trondheim. All the bedrooms had natural ventilation, and the occupants stated they used to open bedroom windows at night. Participants answered a questionnaire about motivations and habits regarding window opening. The most common reason given for not opening was low outdoor temperatures. The window opening behaviour was both predictable and continuous. Windows were open every night in most of the bedrooms, and most of the windows were opened to the same position every night. High CO2 levels during night were found in two bedrooms. In the other bedrooms, the CO2 concentration was satisfying during night-time, although higher concentrations were found in some bedrooms during daytime. Finally, indoor temperature measurements confirmed that many occupants prefer a low bedroom temperature.

Türkiye’de Doğalgazın Tüketildiği Mahallerde Kullanılan Havalandırma Menfezlerin Optimizasyonu

Doğalgaz kullanılan dairelerde TS 7363 standardına göre sabit kanallı havalandırma sistemi olarak cam menfezi veya 150 cm2’lik havalandırma sistemlerinin kullanılmasının zorunluluğu araştırılmıştır. Türkiye’de kullanılan evsel gaz yakıcı cihazlarda A tipi bacasız cihaz (ocak) ve C tipi denge bacalı cihaz (hermetik kombi) ikilisi kullanıldığı görülmüştür. Hermetik cihazlar temiz havayı dışarıdan alıp kirli havayı dışarıya verdiği için iç hava kalitesine etkisinin olmadığı ancak bacasız gaz yakıcı cihazların (daireler için ev tipi ocakların) iç hava kalitesini etkileyip etkilemediği araştırılmıştır. Örnek il olarak Türkiye’nin en soğuk illerinden biri olan Erzurum seçilmiştir. Menfezden geçen havanın hacimsel debisi ANSYS-Fluent paket programı yardımıyla hesaplanmıştır. Havalandırma menfezinden ortama giren taze hava miktarının yanma için ihtiyaç duyulan taze hava miktarından 90 kat fazla olduğu bulunmuştur. Bu sonuç tüketicilerin 150 cm2’lik havalandırma menfezlerinin önemli miktarda enerji kaybına neden olduğu iddiasının doğru çıkartmaktadır. Dairelerde sabit kesit alanlı havalandırma menfezi yerine kullanılan yakıcı cihazların çeşidine ve mevsim şartlarına bağlı olarak değişken kesitli menfez kullanımı önerilir.

ENHANCING COMMUNITY ENVIRONMENTAL AWARENESS THROUGH INDOOR AIR QUALITY WORKSHOP

Abstract - This research is motivated by the poor air quality in the room at home that can cause Sick Building Syndrome (SBS). The purpose of this research is to increase public awareness of the environment through indoor air quality workshops, with a Pre-Experimental method and One Group Pre-Test Post-Test research design. The sample in this study was Pasteur RW6, Sukajadi District at Bandung City, which was selected based on criteria including non slum areas, as well as high community participation. The results showed that the level of public awareness, knowledge, attitudes, and actions on air quality in the room before the Workshop was in the medium category. Then it increased after the Workshop, which was on a relatively moderate increase in knowledge. This can be seen from the majority of people who already know the importance of indoor air quality, but the knowledge of specific components that affect indoor air quality is still not understood. Whereas attitudes and actions experienced a relatively small increase due to the knowledge gained in the Workshop not being implemented in the form of real attitudes and actions in daily life because people's habits are difficult to change. Keywords – Environmental Awareness, Indoor Air Quality, Workshop, Community Awareness

COVID-19 RISK ASSESSMENT IN PUBLIC TRANSPORT USING AMBIENT SENSOR DATA AND WIRELESS COMMUNICATIONS

Covid-19 causes one of the most alarming global health and economic crises in modern times. Countries around the world establish different preventing measures to stop or control Covid-19 spread. The goal of this paper is to present methods for the evaluation of indoor air quality in public transport to assess the risk of contracting Covid-19. The first part of the paper involves investigating the relationship between Covid-19 and various factors affecting indoor air quality. The focus of this paper relies on exploring existing methods to estimate the number of occupants in public transport. It is known that increased occupancy rate increases the possibility of contamination as well as indoor carbon dioxide concentration. Wireless data collection schemes will be defined that can collect data from public transportation. Collected data are envisioned to be stored in the cloud for data analytics. We will present novel methods to analyze the collected data by considering the historical data and estimate the virus contagion risk level for each public transportation vehicle in service. The methodology is expected to be applicable for other airborne diseases as well. Real-time risk levels of public transportation vehicles will be available through a mobile application so that people can choose their mode of transportation accordingly.

Volatile organic compounds, odor, and inhalation health risks during interior construction of a fully furnished residential unit in Nanjing, China

Volatile organic compounds (VOCs) are a group of chemical pollutants affecting indoor air quality (IAQ) with proved adverse health effects. The construction processes and materials used predetermine to a large extent of the IAQ in newly-built buildings. However, little is known about the exposure of construction workers. To investigate VOCs, odor, and preliminary estimates of the VOC-related health risk of construction workers, VOC concentrations were measured at eight stages of construction in a residential unit of a fully furnished residential block in Nanjing, China. The results show that VOC type and concentrations were higher for the “dry” material stages (completed by the carpenter) than that for the “wet” material stages (completed by the painter). Total VOC (TVOC) concentration was the highest (1710 μg/m3) during the “doors and doorframes” stage and the lowest for the “gypsum plaster” (226 μg/m3) and “putty-1” (222 μg/m3) stages. Alkanes were the most abundant VOC type and constituted 22.2%–69.2% of the TVOC. The odor activity value (OAV) was the lowest at the “putty-2” stage (20.7) and the highest at the “wooden flooring” stage (224). Octanal was the major odor contributor (60.1%–82.8%). The median total cancer risks were 4.8 × 10−5 and 6.6 × 10−5 for the painters and carpenters, respectively. Formaldehyde constituted 78.0% and 65.7% of the total risk for the painters and carpenters, respectively, followed by naphthalene. The carpenters were exposed to a greater variety of VOCs, odorants, and higher odor concentrations than the painters.

How human biology and behavior affect indoor air quality

People in the United States spend more than 90% of their lives inside buildings or vehicles (1), and yet most research into air pollution focuses on the outdoors. Relatively little is known about what we breathe for most of our lives. HOMEChem researchers took analytical measurements while volunteers carried out typical at-home activities. Here, they measured a wok’s temperature, which affects the chemical emissions. Image credit: Callie Richmond (photographer). The research that has been conducted on indoor air mainly examines chemicals released from building materials and contents. “Because of that work, those emissions have been gradually reduced,” explains Pawel Wargocki, an indoor air scientist at the Technical University of Denmark in Lyngby. But there is growing evidence that everyday activities also pollute indoor air. Cooking, cleaning, and burning candles all contribute to indoor air pollution—and researchers are now finding that a building’s occupants, simply by being present, significantly change the air chemistry inside as well. Our breath creates a plume of hot, moist air full of reactive trace gases, and our skin emits chemicals into the room. The details of human breath and skin emissions have recently been probed in detail, showing for example that our ammonia emissions increase at higher room temperatures and with more exposed skin (2). These insights, say researchers, will support modeling of indoor chemistry and may pave the way for policy changes—such as increased ventilation and more informative cleaning product labels—to clean up the air in our homes. Indoor air is a complex soup of numerous chemical species (3). Gaseous organic compounds emanate from materials, people, and their actions and can rapidly transform into new gases or particles. Cascades of chemical reactions occur both in the air and after species have settled on surfaces. Newly generated species on surfaces often then become airborne. In the …

Influence of Neutralization Accelerated by the Soak Method on the Radon Exhalation of Cement-based Materials.

Radon is considered a significant contaminant that affects indoor air quality. Neutralization is one of the most important environmental factors in changing pore structure of cement-based materials that may release radon. Therefore, it is necessary to study the radon exhalation of cement-based materials impacted by neutralization, which is extremely lacking. Some concrete blocks were accelerated to neutralization by soaking in sodium bicarbonate solution, and the radon activity concentrations over the blocks were measured to investigate the effect of neutralization on radon exhalation. Controlled experiments were conducted with blocks in the initial dry state and soaked in pure water. The results show that the radon activity concentration exhaled from block is promoted by neutralization, and the promoting role of water is quite limited. The radon surface exhalation rate increases by increasing the sodium bicarbonate solution concentration from 0.5% to saturation.