Article

# Associations Between Indoor CO2 Concentrations and Sick Building Syndrome Symptoms in U.S. Office Buildings: An Analysis of the 1994-1996 BASE Study Data

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## Abstract

Higher indoor concentrations of air pollutants due, in part, to lower ventilation rates are a potential cause of sick building syndrome (SBS) symptoms in office workers. The indoor carbon dioxide (CO2) concentration is an approximate surrogate for indoor concentrations of other occupant-generated pollutants and for ventilation rate per occupant. Using multivariate logistic regression (MLR) analyses, we evaluated the relationship between indoor CO2 concentrations and SBS symptoms in occupants from a probability sample of 41 U.S. office buildings. Two CO2 metrics were constructed: average workday indoor minus average outdoor CO2 (dCO2, range 6-418 ppm), and maximum indoor 1-h moving average CO2 minus outdoor CO2 concentrations (dCO2MAX). MLR analyses quantified dCO2/SBS symptom associations, adjusting for personal and environmental factors. A dose-response relationship (p < 0.05) with odds ratios per 100 ppm dCO2 ranging from 1.2 to 1.5 for sore throat, nose/sinus, tight chest, and wheezing was observed. The dCO2MAX/SBS regression results were similar.

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... Indoor environmental quality has considerable potential to affect workers' health, particularly sick building syndrome (SBS) [3]. SBS has become a key public health and occupational concern among office workers since most of them spend up to 90% of their working time in indoor environments [1,[4][5][6]. ...
... CO 2 , formaldehyde, and VOCs have been proven in other studies to be major indoor air contaminants due to the lack of ventilation [22]. SBS can be caused by insufficient ventilation per person and increased levels of indoor chemical pollution [4,5]. Indoor CO 2 concentrations could be used as a surrogate for occupant-generated pollution and indoor ventilation parameters [23,25]. ...
... Of 261 participants, the mean (±SD) age of workers was 40 (±11) years and the median (IQR) working experience was 9 (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) years. The majority of them were female (59.0%) and non-smokers (86.2%). ...
Article
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Sick building syndrome (SBS) is the term used to describe the medical condition in which people in a building suffer from symptoms of illnesses for no apparent reason. SBS was found to be associated with indoor air quality (IAQ) but there are a variety of determinants (buildings, in particular). Identifying and controlling factors related to SBS is crucial for improving worker health and efficiency. A cross-sectional study was conducted to investigate (1) the prevalence of respiratory symptoms and skin SBS and (2) their associations with IAQ among office workers in administrative offices in an academic medical institute. A self-reporting questionnaire assessing the worker’s characteristics, working conditions, and perception of working environments was used. The building assessment was via a walk-through survey and IAQ measurement. Of 290 office workers, 261 (90%) in 25 offices of 11 buildings took part in the survey. The highest prevalence of SBS was nasal symptoms (25.3%). We found that to reduce the risk of SBS, optimal air temperature levels in air-conditioned offices should be lower than 23 °C, with relative humidity between 60% and 70%. Lowering indoor CO2 levels below 700 ppm may be indicative of adequate ventilation to prevent SBS by reducing worker discomfort and indoor contaminants (e.g., formaldehyde).
... All of these studies have enriched the investigation of risk factors of SBS. and productivity. Apte et al. pointed out that an excess of indoor carbon dioxide significantly increases the incidence of SBS, but if ventilation rates are substantially increased, the prevalence of corresponding SBS symptoms could be reduced by 70% to 85% [45]. This paper predicts the improvement of SBS by ventilation in a quantitative way, providing data support for the appropriate SBS interventions. ...
... In addition to the previously introduced literature nodes, Wargocki et al. designed a control group experiment and concluded compared with the indoor non-pollution group, the indoor pollution group is more likely to have SBS and lower productivity [44], which laid the foundation for his research in 2000 to investigate the relationship between ventilation rate and improvement of SBS symptoms and productivity. Apte et al. pointed out that an excess of indoor carbon dioxide significantly increases the incidence of SBS, but if ventilation rates are substantially increased, the prevalence of corresponding SBS symptoms could be reduced by 70% to 85% [45]. This paper predicts the improvement of SBS by ventilation in a quantitative way, providing data support for the appropriate SBS interventions. Figure 8. Phase path analysis of the SBS from 1984 to 1996. ...
... Phase path analysis of the SBS from 1997 to 2009[30][31][32][35][36][37][38][44][45]. ...
Article
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At present, with more and more attention paid to the impact of buildings on the health and well-being of occupants, sick building syndrome (SBS) has become a global concern. Since the introduction of SBS by the World Health Organization (WHO) in 1983, thousands of research literatures have been published in this field. This paper systematically arranges knowledge development of SBS through bibliometric analysis, exploring the most influential countries, institutions, journals and scholars, as well as the main subject categories and keywords. Main path analysis (MPA) was used to list development trajectory under inheritance relationship of SBS knowledge, including symptom analysis, risk factors of SBS and the improved impact of ventilation on SBS and productivity. Furthermore, it is an emerging research trend to propose SBS solution in the building design stage.
... Carbon dioxide (CO 2 ) is an odorless, colorless gas whose accumulation indoors imposes detrimental consequences on human health. The primary source of CO 2 indoors is attributed to building occupant metabolism [1], with minimum CO 2 concentrations of 400 ppm typically observed in offices [3]. However, with increased building occupancy and exacerbated ventilation conditions, indoor CO 2 levels can easily exceed 1000 ppm [3]. ...
... The primary source of CO 2 indoors is attributed to building occupant metabolism [1], with minimum CO 2 concentrations of 400 ppm typically observed in offices [3]. However, with increased building occupancy and exacerbated ventilation conditions, indoor CO 2 levels can easily exceed 1000 ppm [3]. Thorough studies in the literature associate indoor climate variables (humidity, temperature, CO 2 concentration, and volatile organic compound concentration) with sick building syndrome (SBS), which entails adverse health symptoms experienced indoors such as shortness of breath, optic and nasal irritation, tightness of the chest, dizziness, and fatigue [1,4,5]. ...
... Carbon dioxide (CO 2 ) is an odorless, colorless gas whose accumulation indoors imposes detrimental consequences on human health. The primary source of CO 2 indoors is attributed to building occupant metabolism [1], with minimum CO 2 concentrations of 400 ppm typically observed in offices [3]. However, with increased building occupancy and exacerbated ventilation conditions, indoor CO 2 levels can easily exceed 1000 ppm [3]. ...
... The primary source of CO 2 indoors is attributed to building occupant metabolism [1], with minimum CO 2 concentrations of 400 ppm typically observed in offices [3]. However, with increased building occupancy and exacerbated ventilation conditions, indoor CO 2 levels can easily exceed 1000 ppm [3]. Thorough studies in the literature associate indoor climate variables (humidity, temperature, CO 2 concentration, and volatile organic compound concentration) with sick building syndrome (SBS), which entails adverse health symptoms experienced indoors such as shortness of breath, optic and nasal irritation, tightness of the chest, dizziness, and fatigue [1,4,5]. ...
Article
Carbon dioxide (CO2) has been shown to contribute to human health consequences indoors, such as shortness of breath, nasal and optic irritation, dizziness, and nausea. In this work, we explore the potential of metal–organic frameworks (MOFs) as highly-porous, crystalline sorbents for sensitive colorimetric CO2 detection. In particular, the zeolitic imidazolate framework (ZIF-8) is chosen as the sorptive material due to its chemical stability and tunable CO2 affinity. The colorimetric gas sensor is developed in methanol with three components: (i) MOF ZIF-8 as a high surface area adsorbent; (ii) ethylenediamine (ED) as the CO2-affinitive basic function; and (iii) phenolsulfonpthalein (PSP) as the pH indicator. Colorimetric assays and ratiometric analysis confirm a colorimetric response to variable CO2 concentrations of relevance to indoor air quality. The color response is attributed to a zwitterion mechanism whereby ED reacts with CO2 to form a zwitterionic intermediate. This intermediate is then deprotonated by the pH indicator, shifting the pH and inducing a color change. Given its simple fabrication, rapid and obvious response, and stability in ambient environment, the ZIF-8-based colorimetric sensor provides a promising route for an improved indoor air quality monitoring.
... Maula et al. 24 also found that these symptoms increased significantly at 29 versus 23°C which can support the results of the questionnaires. This also concurs with Apte et al. 15 who agreed that with increased CO 2 levels, significant associations were observed with headache, fatigue, eye, nose, and respiratory tract symptoms. Therefore, this strengthens the suggestion made that the observed effects are attributable to the pollutants that CO 2 is a proxy for; herein lies the scope of the study which is to investigate the effects of ventilation rates and not pure CO 2 levels. ...
... Abbreviations: IS, intervention study; RH, relative humidity; SD, standard deviation. leading to focus impairment, whether they detected dexterity in figures, and whether they detected sick building syndromes (SBS) symptoms like headache and fatigue when CO 2 levels were high since high CO 2 levels have been associated with subjectively assessed acute health symptoms in some studies, for example, Apte et al.15 and Norbäck et al.16 2.6 | Cognitive performance assessmentThe Behavioural Assessment and Research System (BARS) is the computer based cognitive performance battery used in this study.Copyright of the BARS testing system software is held by OregonHealth Sciences University. Eight neurobehavioral tasks were used(Table 3), and an example for one of the tests (reversal learning [RL]) ...
Article
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Impairment in mental functions attributed to the effects of indoor air quality and thermal conditions has received considerable attention in the past decade, particularly for educational buildings where students’ cognitive performance is essential to foster learning. This study explores the combined effects of indoor temperatures and CO_{2} levels as markers for ventilation rates on cognitive performance among female students (16–23 years old) in Saudi Arabia. The longitudinal experiments involved nine conditions combining three CO_{2} concentration levels (achieved via changes in ventilation) and three temperature levels involving 499 participants, all exposed to the nine conditions. The study implemented a computer-based cognitive performance battery with “9Button” keyboards. Univariable and multivariable multilevel regression models explored the association of indoor temperature and CO_{2} levels (as markers for ventilation rates) with cognitive performance after adjusting for potential confounders. Potential benefits were found on speed and accuracy of tasks of cognitive performance when indoor temperature was set between 20 and 23ºC and at CO_{2} levels of 600 ppm compared to higher temperatures and poorer ventilation rates and that both ventilation and thermal environmental control are important and need to be improved for achieving optimum learning conditions. Nevertheless, the results are relevant for short-term exposures lasting no more than 2 h.
... Sick building syndrome (SBS) symptoms describe buildingrelated symptoms experienced by building occupants that are relieved or go away after leaving the building. These symptoms can be influenced by environmental and personal factors and can be classified as (1) upper respiratory and mucosal symptoms such as dry or itchy eyes; (2) lower respiratory irritation like cough; (3) neurophysiological symptoms such as headache and mental fatigue; and (4) skin irritation symptoms like itching or reddening (Apte et al., 2000;Bluyssen et al., 2016;Sakellaris et al., 2020). Several studies associated air quality factors such as CO 2 , NO 2 , nicotine, particulate matter (PM), volatile organic compounds (VOCs), and microbial contamination with SBS symptoms (Erdmann et al., 2002;Menzies et al., 2003;Mitchell et al., 2007;Colton et al., 2014;Azuma et al., 2018). ...
... To the authors' knowledge, previous studies have not used μEMAs to check SBS symptoms. This is expected because participants typically report the frequency of experiencing symptoms over the past month using detailed questionnaires (Apte et al., 2000). ...
Article
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An understanding of indoor environmental quality (IEQ) and its effects on occupant well-being can inform building system design and operation. The use of wearables in field studies to collect subjective and objective health performance indicators (HPIs) from a large number of occupants could deliver important improvements in IEQ. To facilitate the use of wearables in IEQ studies, there is a need to identify which HPIs should be collected and to evaluate data accessibility from these devices. To address this issue, a literature review of previous IEQ studies was conducted to identify relationships between different IEQ factors and HPIs, with a focus on HPIs that were collected using wearables. A preliminary assessment of data accessibility from a selected wearable device (Fitbit Versa 2) was performed and documented. The review suggested the need to further investigate and collect sleep quality parameters, heart rate, stress response, as well as subjective ratings of comfort using wearables. The data accessibility assessment revealed issues related to missing data points and data resolution from the examined device. A set of recommendations is outlined to inform future studies.
... Carbon Dioxide (CO 2 ) level is of great importance in the IAQ and is often used as the proxy for ventilation rates (Fisk 2017). CO 2 concentrations indicate IAQ acceptability, air exchange suitability, and whether adequate fresh air is being supplied to the indoor spaces in buildings (Apte 2000). The concentration of CO 2 in buildings can be higher than outdoors in magnitude, typically ranging from 350 to 2,500 parts per million (ppm) (Seppänen, Fisk, and Mendell 1999), but in some cases reaching 4,000-4,500 ppm or Table 2. 4. From a practical point of view, CO 2 concentration is often taken as an approximate surrogate for levels of occupant-generated pollutants (X. ...
... The concentration of CO 2 in buildings can be higher than outdoors in magnitude, typically ranging from 350 to 2,500 parts per million (ppm) (Seppänen, Fisk, and Mendell 1999), but in some cases reaching 4,000-4,500 ppm or Table 2. 4. From a practical point of view, CO 2 concentration is often taken as an approximate surrogate for levels of occupant-generated pollutants (X. Zhang et al. 2017), and for estimating a proper ventilation rate per occupant (Apte 2000). There are a variety of methods for the CO 2 concentration estimations in a well-mixed space, as described in some studies (T. ...
Thesis
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The indoor environment critically affects occupant health and comfort, especially since humans spend most of the day indoors. Meanwhile, occupant activities, preferences, and behaviors may contribute to a significant amount of building energy consumption. The focus of environmental buildings shifted from automated systems to a paradigm of collective environmental design since the second half of the 20th century, emphasizing human dimensions in building performance, which allows occupants to participate as active/passive actuators and sensors. Concurrently, increased environmental awareness further spurred the green building movement intending to encourage more high-performance buildings. The question remains as to whether high-performance buildings are also healthy buildings. This dissertation aims to cast new light on how environmental design and building systems work for people as well as how building sensors and human senses work together to inform the organization and optimization of various performance targets such as sustainability, public health, and resiliency. Special attention is given to the non-visual environment attempting to facilitate human-in-the-loop of the building design and operation processes. In order to achieve this goal, environmental monitoring, data analysis, and human subject recruitments are developed to characterize the human dimension of building performance.
... Snow et al. (2019) showed substantial links exist between the prevalence of SBS and elevation of indoor CO2 concentrations. As stated by Apte et al. (2000), the indoor CO2 concentration is approximately the surrogate for indoor concentrations of other occupant-generated pollutants and the ventilation rate per occupant. By keeping CO2 concentrations below 1,000 ppm, it is able to improve the occupants' task performance (Hong et al., 2018). ...
Article
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The development of liveable space made from shipping containers becomes a trend even in Malaysia with the hot and humid climate persisting throughout the year. For sustaining the indoor comfort, building insulation is well adapted to increase thermal resistance and reduce the dependency on the mechanical cooling systems. The prospective of a shipping container as an efficient construction material and bamboo as a sustainable insulation material is well documented but basic information on the internal environment that has an impact on a person, particularly risk potential towards sick building syndrome (SBS) has been absent. Therefore, the measurements of both indoor and outdoor temperatures, relative humidity and CO2 concentration with two different conditions were done by using different sets of data loggers for at least 70 days under each condition. The first condition is a bare unit of the shipping container and followed by the installation of untreated bamboo as insulation for the second condition. This research reveals that high temperatures were recorded up to 40°C in both conditions and untreated bamboo as insulation increased the relative humidity levels up to the maximum, 100%. The mean values of CO2 concentration are in the range of 1,869 ppm to 2,938 ppm and they reach up to 5,000 ppm at the most of the intervals, indicating a significant contribution to SBS. The condition of the equatorial climate denies the compatibility of the shipping container to be used as the building material of liveable space. The quality and treatment of the bamboo must be the ultimate priority.
... One of the main factors affecting the previously mentioned symptoms was low supply airflow rate . Furthermore, Apte et al. (2000) studied the importance of ventilation and found that good ventilation and control of impurities decreased SBS symptoms by 70-85%. On the other hand, in rooms that had high air exchange rate occupants experienced eye or mucous membrane irritation that can be linked to the dry indoor air (Seppänen et al. 1999). ...
Article
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In this study, volatile organic compounds (VOC) were measured from 47 hospital rooms to determine the most suitable sampling location for VOCs indoors. Another goal was to find out the most predominant VOCs and their emission per floor area in a hospital environment. Three samples were taken from each room simultaneously, one from the center of the room, one from the floor near the wall, and one from the exhaust air terminal. Concentrations of the VOCs were relatively low in all the cases, and the most abundant compounds were decamethylcyclopentasiloxane, d-limonene, xylenes, and 2-methyl-2-propanol. The average emission rates of the main compounds per floor area varied in between 49-81 µg/m2h. Statistical analyses showed that room area and volume affected differently the TVOC concentrations among the sampling locations. Concentrations were higher in exhaust air terminal than in floor and middle of the room. VOC levels were the same between the sampling locations when size of the room was below 10 m2. However, field measurements and statistical analyses showed that when the size of the room increased, the most evenly distributed VOCs can be measured most reliably in the vicinity of the exhaust terminal device or in the exhaust air.
... Research has shown that occupants in buildings, in general, and in workplaces, in particular, are affected by many building-related factors. Studies about the impact of indoor environmental quality (IEQ) have shown that indoor factors such as thermal, visual, and acoustic factors can produce a noticeable influence on the well-being and satisfaction of occupants [1][2][3][4][5][6][7]. Correlations between health problems, including mental and physical illnesses were also found in numerous studies [7,8]. ...
Article
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Satisfaction is a very important factor in improving productivity and performance in the work environment. This study aims to investigate the levels of occupants’ satisfaction with the indoor environmental quality (IEQ) in the governmental buildings in the Kingdom of Bahrain and to investigate the impact of occupants’ demographics and building attributes (non-IEQ factors) on these levels. For these purposes, the study used a questionnaire that has 17 indoor environmental quality (IEQ) factors in addition to a group of non-IEQ factors. The questionnaire was distributed by hand or using email to 279 employees in the Bahraini governmental sector. The findings of the study revealed that occupants in the Bahraini governmental buildings are not strongly satisfied with IEQ factors, especially with sound privacy, followed by visual privacy and amount of space, and then noise levels. The findings also showed that for most IEQ factors, men are more satisfied than women are, those who work in enclosed private offices are more satisfied than those who work in open-plan offices, and those who have central air-conditioning at their workplace are more than those who have a wall-mounted air conditioner. The impact of age, nature of work, duration of working in the current building and at the current workstation, weekly working hours, and proximity to the window were also investigated. Accordingly, a group of recommendations was suggested aiming to improve the levels of occupants’ satisfaction.
... In the indoor environment of such locations, CO 2 concentrations are influenced by generations from human respiration or combustion in factories [16], usage of copying machines [2], etc. The effects of high levels on CO 2 on respiratory system as well as the effects on human decision making are studied by Satish et al. [19] by reducing the risk of absenteeism [9]. In indoor workplaces, to maintain acceptable indoor air quality the ventilation rates can be altered [12] along with air conditioning maneuvering designs as in various available models. ...
... Poor indoor air quality significantly affects the health and condition of people staying in rooms. It may also reduce the productivity of building users and increase the absence frequency of employees [1][2][3][4][5][6][7][8]. In educational facilities, it may reduce learning efficiency [9][10][11][12][13][14]. ...
Article
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The study contains an analysis of a decentralised unit installed in a building façade, where air supply and exhaust cycles are swapped by proper positioning of dampers. The analysis was carried out in real conditions in an office building. The Computational Fluid Dynamics (CFD) simulation is an important element of the system design, and has become more and more widely used. Simulation of the analysed unit has shown air stream distribution in a room. Moreover, it allowed for determination of indoor air temperature. Completed analysis and CFD simulations allow for the observation that façade ventilation systems provide a good way to improve the indoor microclimate, as they effectively reduce air pollution. The decentralised façade ventilation unit reduced the carbon dioxide concentration to a level lower than 1000 ppm and maintained the indoor air temperature in the range of 19.5–22 °C. The error for CFD simulation equals 0.5%, which is not much. The results of research and analysis show that the highest reduction of carbon dioxide concentration occurred when supply/exhaust time equalled 10 min. At the same time, when supply/exhaust time equalled 10 min, the indoor air temperature was the lowest of the recorded values.
... The recommended minimum ventilation rate of indoor CO 2 above which there are sick building syndrome symptoms in an indoor environment is 10 L/s. This corresponds to a steady-state indoor concentration of approximately 870 ppm [19]. Organic gases having similarity in their chemical composition but not easily distinguishable classified as TVOC also has a direct link with the indoor air quality. ...
Article
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Introduction: Toxic gases emitted from electricity generating plants used for energy production process diffuse in the environment thereby causing environmental air pollution. The effect of the installation and usage of portable gasoline electricity generating plants at the balcony of different households on the indoor air quality was assessed in this study. Materials and methods: The data collected were the air quality chemical composition variables which include carbon-dioxide, formaldehyde, total volatile organic compounds, coarse (PM10), and fine (PM2.5) particulate matters at the indoor of the households in Abeokuta metropolis, Ogun state, Nigeria. Physical measurement techniques used for the data collection was through the instrumentation design of two air quality testers, models WP6910 and ZN-202S. The indoor air quality assessment followed the generator nighttime usage routine between the hours of 6:30 – 10:00 pm at a measurement height of 1.3 m and the center in the living rooms of the residences assessed. Results: The analysis of the data obtained showed that the mean values for each of the air quality parameters obtained during generator usages were significantly higher when compared to the indoor air quality parameters before generator usages at p
... Poor air quality affects not only health [12], but also work efficiency, reducing it, and increasing the frequency of absenteeism [13][14][15][16][17][18][19][20]. In the case of schools, it lowers learning efficiency, as described in the literature [21,22]. ...
Article
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Poor indoor air quality affects the health of the occupants of a given structure or building. It reduces the effectiveness of learning and work efficiency. Among many pollutants, PM 2.5 and 10 dusts are extremely important. They can be eliminated using mechanical ventilation equipped with filters. Façade ventilation devices are used as a way to improve indoor air quality (IAQ) in existing buildings. For their analysis, researchers used carbon dioxide as a tracer gas. They have shown that façade ventilation devices are an effective way to improve IAQ, but require further analysis due to the sensitivity of façade ventilation devices to the effects of wind and outdoor temperature. In addition, legal regulations in some countries require verification in order to enable the use of this type of solution as a way to improve IAQ in an era characterised by the effort to transform buildings into passive houses (standard for energy efficiency in a building).
... Therefore realizing the detection of CO 2 and outputting real-time response have become essential for many applications [4][5][6][7]. For example, the concentration of CO 2 is an important indicator to measure the cleanliness of indoor air in daily life, because excessive CO 2 will increase workers' sick building syndrome symptoms in the office [8]. Also, the content of CO 2 can be used as an information stream for danger alarms such as fire alarms [9]. ...
Article
The realization of detection of carbon dioxide (CO2) is important for environmental protection. A critical challenge is how to fabricate low-cost fiber Bragg grating (FBG) sensor. Here, a new type of polyether sulfone (PES)-coated FBG sensor for CO2 detection is reported to address this challenge. The PES coating exhibits volume dilation in CO2 exposure and can transfer the stress to the grating, causing changes of the period and the refractive index of the grating. The uniform and smooth PES coating is critical for the repeatability and reliability of the sensor, which is realized through the low-temperature spin coating and high-temperature curing. The influence factors and the performance of the FBG sensor were investigated. The maximum Bragg wavelength shift is positively related to coating thickness and negatively related to temperature. The PES-coated FBG sensor possesses good selectivity to CO2 and the minimum response time is 3.27 min. The limit of detection (LOD) can be down to 0.78 % for CO2 detection. Finally, an over-concentration alarm system for on-line CO2 monitoring was developed. The outstanding features of the PES-coated FBG sensor with low-cost and simple fabrication process provide widely prospect in applications.
... Research suggests that the Indoor Environmental Quality (IEQ)-wellbeing relationship is complex. A variety of indoor variables such as thermal, visual, acoustic and chemical can affect occupants ' wellbeing (Apte, Fisk & Daisey, 2000;Jantunen, Hanninen, Katsouyanni, Knoppel, Kuenzli, Lebret, Maroni, Saarela, Sram & Zmirou, 1998;WHO, 2002). These relationships can sometimes be very complicated and can affect individuals both in the short and long term (Babisch, 2008;Fisk, Lei-Gomez & Mendell, 2007;Lewtas, 2007). ...
Conference Paper
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Indoor air pollution has been a significant an health concern, especially for the children. Breathing clean air at Schools is essential for children's healthy development, but due to use of marker, air freshener, aerosol and vehicular emission from nearby roads, the indoor air quality of schools may be polluted. In this study, the indoor air quality of ten selected Schools along CUET to Bahaddarhat road in Chattogram was assessed from March 2019 to May 2019. A questionnaire survey was also conducted in study area for about 100 number of people mostly 60 students, 20 teachers & 20 guardians. The maximum average concentration of PM2.5 and PM10 were found 81.1μg/m 3 and 313.1 μg/m 3 respectively at school in S4 locations. The minimum concentration of PM2.5 was found in S7 locations (42.3μg/m 3) and that for PM10 was also found in S1 location (121.7μg/m 3). As the study is related to very short exposure and there is no standard for indoor air quality of Bangladesh, ambient air quality standards of Bangladesh was used for comparison. The average concentration of PM10 for all schools were exceeded threshold value of ambient air quality of Bangladesh. At the schools of S2, S4 & S6 location the mean concentrations of PM2.5 were exceeded. This study also shows that the indoor PM2.5 and PM10 concentration were higher at the schhols adjacent to roadside.
... The PLT840 gas analyzer model used to evaluate CO in the kitchens has a measurement range of 0 -100 ppm and a detection frequency of < 30 seconds. The measurement height of an approximate height of 1.3 m from the kitchen floor at an adult sitting position used was adopted from similar studies (Apte, et al., 2000;Abulude, et al., 2019). The CO and CO₂ emission exposure rate concentration was three categories of measurements; pre-fire start-up time, wood fuel combustion at still air, and fire-tending functions. ...
Conference Paper
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The combustion reaction of solid cooking fuels generates air pollutants of concern to human health and the environment. The carbon monoxide (CO) and carbon dioxide (CO₂) concentration in some selected commercial kitchens that use wood fuel in Wukari, Nigeria, were investigated using a quantitative research approach. The study sites were selected using a purposive sampling technique. The quantification of the CO and CO₂ combustion gases were through the instrumentation design of air quality analyzers, models ZN-202S and PLT840 at an approximate height of 1.3 meters from the floor of the kitchen. The investigation considered realistic cooking conditions targeted on the occupational exposure level threshold time-weighted average limit value recommended by the National Institute for Occupational Safety and Health (NIOSH). The multiple paired t-tests analyses of data obtained showed significant CO and CO₂ emissions during the cooking processes disclosed p < 0.05 but considerably safe. However, the intensity of CO and CO₂ emissions from the cooking process in the commercial kitchen requires a mask to reduce inhaled air pollutants for accumulation potential..
... Indoor exposure induced BRIs could be as high as 10,000 disability-adjusted life years loss (DALY) per million in Europe (Hänninen and Asikainen, 2013). Furthermore, exposure to indoor air pollution also affects mental health (Apte et al., 2000;Zabiegala et al., 1 Air exchange rate from 10 to 20 l/s (liters/second) per person is considered 2007). The BRIs vary in residential and tertiary buildings due to exposure time and occupancy rate, rather than the type of building itself. ...
Article
High-efficiency buildings do not only save energy but also have multiple further impacts or co-benefits. These impacts are often excluded from the policy evaluation partly because their quantification and integration into cost-evaluations have challenges. Thus, the purpose of this paper is to develop a method to quantify labour productivity which is one of the key multiple impacts, as well as demonstrate the use of the method for calculating the productivity impacts of high-efficiency buildings. The paper uses Germany and Hungary as examples to conduct the quantifications. The result of the study shows that high-efficiency buildings can result in substantial health and labour productivity benefits. Concretely, a German worker can gain 5.2 productive days a year, while a Hungarian 2.2 days by avoiding sick days, after living in high-efficiency buildings. Similarly, through high-efficiency retrofits or high-efficiency new constructions in the tertiary building sector, German and Hungarian workers can gain 2.4 and 1 productive days a year, respectively, by avoiding sick days. The monetary equivalent of the total number of days gained would be as high as 337 million and 7 million Euros/year only from the residential building sector, and 398 million and 3 million Euro/year from the tertiary building sector for Germany and Hungary respectively. In addition to the productive workdays gain, by avoiding mental stress, the German and Hungarian workforce can gain 95 and 2 million Euro respectively in a year by improving work performance from working in high-efficiency tertiary buildings. Furthermore, this paper shows that along with more workdays and improved work performance, both Germany and Hungary can gain 1870 and 3849 healthy life years/million population which is equivalent to 277 and 134 million Euros per year respectively. The findings of this study would provide a strong motivation to the policymakers to design policies that promote construction and renovation of buildings at the passive-house or NZEB standards. The substantial productivity impacts of high-efficiency buildings can be an entry-point for the policymakers as any policy that promote high-efficiency buildings would fit in well in the multi-objective policy framework of the European Union.
... UK) and no overlap between the countries' IQR in some cases. Regarding temperature and relative humidity, the values are largely within previously observed values in indoor environmental quality investigations of office buildings (Apte et al 2000, MacNaughton et al 2017. ...
Article
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Despite evidence of the air pollution effects on cognitive function, little is known about the acute impact of indoor air pollution on cognitive function among the working-age population. We aimed to understand whether cognitive function was associated with real-time indoor concentrations of particulate matter (PM2.5) and carbon dioxide (CO2). We conducted a prospective observational longitudinal study among 302 office workers in urban commercial buildings located in six countries (China, India, Mexico, Thailand, the United States of America, and the United Kingdom). For 12 months, assessed cognitive function using the Stroop color-word test and addition–subtraction test (ADD) via a mobile research app. We found that higher PM2.5 and lower ventilation rates, as assessed by CO2 concentration, were associated with slower response times and reduced accuracy (fewer correct responses per minute) on the Stroop and ADD for eight out ten test metrics. Each interquartile (IQR) increase in PM2.5 (IQR = 8.8 $\,\mu$ g m⁻³) was associated with a 0.82% (95% CI: 0.42, 1.21) increase in Stroop response time, a 6.18% (95% CI: 2.08, 10.3) increase in Stroop interference time, a 0.7% (95% CI: −1.38, −0.01) decrease in Stroop throughput, and a 1.51% (95% CI: −2.65, −0.37) decrease in ADD throughput. For CO2, an IQR increase (IQR = 315 ppm) was associated with a 0.85% (95% CI: 0.32, 1.39) increase in Stroop response time, a 7.88% (95% CI: 2.08, 13.86) increase in Stroop interference time, a 1.32% (95% CI: −2.3, −0.38) decrease in Stroop throughput, and a 1.13% (95% CI: 0.18, 2.11) increase in ADD response time. A sensitivity analysis showed significant association between PM2.5 in four out of five cognitive test performance metrics only at levels above 12 $\,\mu$ g m⁻³. Enhanced filtration and higher ventilation rates that exceed current minimum targets are essential public health strategies that may improve employee productivity.
... In a closed room where most people sleep (Especially middle class and poor) on the floor without using the bed since there is a high possibility to inhale a high amount of CO2, excess CO2 is likely to be emitted by their metabolite [10]. Still, high CO2 levels can result in unhealthy symptoms such as sore throat, irritated nose/sinus, combined mucous membrane, tight chest, and wheezing [11]. They are developing and accumulating proof showing that genetic and environmental factors assume significant jobs in the etiology of allergic diseases. ...
Conference Paper
Ventilation is essential to expel indoor generated pollutants from indoor air or weaken their focus to satisfactory levels. CO2 and bio-effluents are natural products of human metabolism, but consuming high CO2 levels can result in unhealthy symptoms such as sore throat, irritated nose/sinus, combined mucous membrane, tight chest, etc., wheezing. The modern air conditioner is designed to exhaust polluted indoor air. Ventilation is not an issue for those who rich enough. But indoor polluted air is a big problem for the middle-class and poor. As part of this study, the homes of 20 middle-class families (Families with at least one Pulmonary patient were chosen) with different numbers of occupants were inspected among 50 selected families. As part of the inspection, the concentration of CO2 in the families' bedrooms was ceaselessly measured over an average of 3 days. An average CO2 concentration was recorded at night in bedrooms of all families, 03 bedrooms had below 1000 ppm, and 17 bedrooms had above 2000 ppm, and in 03 bedrooms had above 4000 ppm. The CO2 concentration was recorded in the identical bedrooms after deploying the developed Automated Ventilation System. Our system and architecture have 100% of efficiency in maintaining the bedroom CO2 concentration below 1000 ppm.
... Previous research has found that for every additional 250 ppm rise in indoor carbon dioxide concentrations above 800 ppm, the odds of sore throats, irritated nose and sinus symptoms and combined mucous membrane symptoms increase by 1.3-2.3 [13]. Continuous carbon dioxide (CO2) exposure exceeding 1000 ppm has also been suggested to lead to the impairment of higher-level cognitive abilities [14]. ...
Article
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Previous studies have shown that indoor environmental quality (IEQ) parameters may have a considerable effect on office employees’ comfort, health and performance. Therefore, we initiated a research program to help occupants identify IEQ parameters they perceive as risk factors for their health in an office and enhance their comfort levels in an office environment. Since we assumed that office employees might have different indoor environmental quality expectations related to their work area and that these differences could be measured, our objective was to develop an office ‘comfort map’ based on occupants’ individual IEQ preferences. Thus, the goal of the comfort map would be to help tailor office spaces to their occupants’ health and comfort expectations. The comfort survey was developed to assess the comfort-related opinions of the occupants, based on IEQ parameters (visual comfort, acoustic comfort, air quality and thermal comfort) of a chosen open-plan office building. The survey also assessed the degree to which the given IEQ parameter was considered a health risk factor by occupants or caused a negative comfort sensation for them. The survey was filled in by 216 occupants. The answers were then analyzed with the help of a frequency table depicting relative frequency. The measurements of IEQ parameters took place in an open-plan office in the chosen office building (a Hungarian subsidiary’s office building belonging to an international company in Budapest). The occupants had different opinions regarding the perceived effects of the IEQ parameters on their health and comfort. Almost two-thirds of the respondents (64.8%) were dissatisfied with the adjustability of the noises and sounds IEQ parameter at their workstation. Furthermore, half of the respondents (50.1%) were dissatisfied with the adjustability of ventilation. Most of the occupants (45.8%) considered noises and sounds as the IEQ parameter that had a negative effect on their health. There were also IEQ differences between different areas of the office space. Based on these results, a comfort map was developed for the office. The comfort map contains information about the IEQ characteristics of each workstation by depicting the thermal comfort, carbon dioxide, visual comfort and acoustic comfort characteristics of a given workstation on a relative scale. Based on the thermal, air, acoustic, and lighting differences between the workstations, occupants can select their preferred workstations when a desk-sharing system works. Although still in its pilot phase, the comfort map could increase the chances for office employees to find the workstation best suited to their IEQ expectations. This could improve occupants’ overall comfort level, which could in turn enhance occupants’ productivity and mental as well as physical health.
... CO2 concentration and SBS symptoms measured in non-residential buildings showed an increase in SBS symptoms with higher 26 www.scholink.org/ojs/index.php/uspa Urban Studies and Public Administration Vol. 4, No. 1, 2021 CO2 concentration, there is also a similar relationship between CO2 concentration and health (Seppanen et al., 1999;Apte et al., 2000). ...
Article
Full-text available
Nowadays, non-renewable energy sources are declining rapidly which they require a lot of energy and a lot of time and resources. They also require costly maintenance; the manufactured artifacts have a lot of rubbish and contaminants that are difficult to recycle. Using renewable energy sources and low cost with the least pollution can help to reduce the consumption of non-renewable energy sources and reduce environmental pollution. In this work, research and study has been done on the advantages of using clean energy such as wind energy, wind-catchers construction method, advantages of using wind-catchers and finely comparison of parameters created when using wind-catchers and comparing them with the optimal standard parameters. Six buildings with different conditions wind-catchers in Yazd city, which is a desert city in center of Iran, were selected for research. All specifications of these wind-catchers such as model, length, width and etc., are shown. Then important parameters such wind speed, outside temperature, indoor temperature and humidity of each case is measured in two stages during the day and night in intervals of 1 to 4 months. Investigation of indoor and outdoor pollution, when the wind-catchers valves are open or close, and the effect of wind-catchers on the entry of noise, dust and air pollution such as carbon dioxide into the building, and compare it to the acceptable standard limit provided by the health organization, as well as the effect of size of opening and height of the wind catchers on amount of increase or decrease in the entry of pollutants into the building. Recognizing the benefits of using clean energy, and recognition of types of wind-catchers, their construction methods and other parameters expressed, in general, all the information collected and comparisons and evaluations can be used to select best type of wind catcher and best use of resources and knowledge.
... However, some results are conflicting and when confounding factors are unaccounted for, as is the case for many of the non-laboratory investigations, it is very difficult to understand with confidence which of several factors may have been responsible for the reported health effects. For example, the temperature may have an effect on performance in standardised tests [40,43] and relative humidity can cause respiratory effects which resemble SBS [93]. In cognitive performance studies, the choice of cognitive function test may influence the study outcome as there are several different tests that assess different aspects of brain function. ...
Article
Full-text available
With modern populations in developed countries spending approximately 90% of their time indoors, and with carbon dioxide (CO2) concentrations inside being able to accumulate to much greater concentrations than outdoors, it is important to identify the health effects associated with the exposure to low-level CO2 concentrations (<5000 ppm) typically seen in indoor environments in buildings (non-industrial environments). Although other reviews have summarised the effects of CO2 exposure on health, none have considered the individual study designs of investigations and factored that into the level of confidence with which CO2 and health effects can be associated, nor commented on how the reported health effects of exposure correspond to existing guideline concentrations. This investigation aimed to (a) evaluate the reported health effects and physiological responses associated with exposure to less than 5000 parts per million (ppm) of CO2 and (b) to assess the CO2 guideline and limit concentrations in the context of (a). Of the 51 human investigations assessed, many did not account for confounding factors, the prior health of participants or cross-over effects. Although there is some evidence linking CO2 exposures with health outcomes, such as reductions in cognitive performance or sick building syndrome (SBS) symptoms, much of the evidence is conflicting. Therefore, given the shortcomings in study designs and conflicting results, it is difficult to say with confidence whether low-level CO2 exposures indoors can be linked to health outcomes. To improve the epidemiological value of future investigations linking CO2 with health, studies should aim to control or measure confounding variables, collect comprehensive accounts of participants’ prior health and avoid cross-over effects. Although it is difficult to link CO2 itself with health effects at exposures less than 5000 ppm, the existing guideline concentrations (usually reported for 8 h, for schools and offices), which suggest that CO2 levels <1000 ppm represent good indoor air quality and <1500 ppm are acceptable for the general population, appear consistent with the current research.
... The PLT840 gas analyzer model used to evaluate CO in the kitchens has a measurement range of 0 -100 ppm and a detection frequency of < 30 seconds. The measurement height of an approximate height of 1.3 m from the kitchen floor at an adult sitting position used was adopted from similar studies (Apte, et al., 2000;Abulude, et al., 2019). The CO and CO₂ emission exposure rate concentration was three categories of measurements; pre-fire start-up time, wood fuel combustion at still air, and fire-tending functions. ...
Conference Paper
Full-text available
... CO2 above 1000 ppm and especially between 1500 to 4000 ppm reduce the performance and even impact the health of the users of buildings (cmp. [28] - [31]). Especially the Sick-Building-Syndrome is associated with the CO2 concentration. ...
Conference Paper
Full-text available
One year ago the European Union defined the Environmental, Social and Governance (ESG) directive to foster investment in sustainability. This directive asks for energy monitoring / optimization and actions to foster human well-being. To cover that demand especially historical buildings in Europe need solutions in these respects, to be more energy efficient and at the same time to safeguard the well-being of its users. These buildings have almost no building automation installed. So, the basic prerequisite to identify high energy consumers valid usage data is not available. For that, the following research questions have to be answered: Which data is necessary to reach both, the environmental and social goals? How can data be captured in a valid and efficient way? How can data be made available to optimize energy usage and well-being? To answer these questions, a literature research was executed to define the relevant parameters. Firstly, based on the results of that step and a previous mixed-methods-research project, the relevant tools and the IT architecture were defined. Secondly, based on the ESG-reporting demands, data structure and relevant building structures were defined. Thirdly, a case study was conducted, which is based on the previously defined IT architecture, using IoT measuring devices, two different databases and two analytic tools. As a result, this paper presents the final decision on the database and the analytics tool, based on the users’ interaction and feedback of the case study.
... Beyond microclimatic parameters, CO 2 and VOCs are two common indoor air pollutants associated with indoor ventilation rates, SBS symptoms and health risks (Apte et al., 2000;Apte and Erdmann, 2002;Norbäck and Nordström, 2008;Gallego et al., 2011). CO 2 is a typical indirect metric of occupancy levels, amount of ventilation, and electronic appliances use, whereas VOC emissions are in the form of gases released from common furniture materials and appliances, such as wood products, photocopiers, printers and cleaning products. ...
Article
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Maintaining indoor environmental (IEQ) quality is a key priority in educational buildings. However, most studies rely on outdoor measurements or evaluate limited spatial coverage and time periods that focus on standard occupancy and environmental conditions which makes it hard to establish causality and resilience limits. To address this, a fine-grained, low-cost, multi-parameter IOT sensor network was deployed to fully depict the spatial heterogeneity and temporal variability of environmental quality in an educational building in Sydney. The building was particularly selected as it represents a multi-use university facility that relies on passive ventilation strategies, and therefore suitable for establishing a living lab for integrating innovative IoT sensing technologies. IEQ analyses focused on 15 months of measurements, spanning standard occupancy of the building as well as the Black Summer bushfires in 2019, and the COVID-19 lockdown. The role of room characteristics, room use, season, weather extremes, and occupancy levels were disclosed via statistical analysis including mutual information analysis of linear and non-linear correlations and used to generate site-specific re-design guidelines. Overall, we found that 1) passive ventilation systems based on manual interventions are most likely associated with sub-optimum environmental quality and extreme variability linked to occupancy patterns, 2) normally closed environments tend to get very unhealthy under periods of extreme pollution and intermittent/protracted disuse, 3) the elevation and floor level in addition to room use were found to be significant conditional variables in determining heat and pollutants accumulation, presumably due to the synergy between local sources and vertical transport mechanisms. Most IEQ inefficiencies and health threats could be likely mitigated by implementing automated controls and smart logics to maintain adequate cross ventilation, prioritizing building airtightness improvement, and appropriate filtration techniques. This study supports the need for continuous and capillary monitoring of different occupied spaces in educational buildings to compensate for less perceivable threats, identify the room for improvement, and move towards healthy and future-proof learning environments.
... Genelde ortam havasında 1000 ppm değeri gözlendiğinde ortam havasının yeterli kalitede olmadığı ve yetersiz ventilasyon yapıldığı belirtilmekte, ancak CO 2 'nn 1000 ppm'in altında olması ise ortamın sağlıklı ve yeterli kalitede olduğu anlamına gelmediği ifade edilmektedir [50]. Okullarda yapılan bir araştırmada havalandırma miktarı arttırıldığında CO 2 seviyesinin hızla düştüğü ve maksimum seviye olarak 4850 ppm'e, ortalama değer olarak ise 2861 ppm'e kadar yükseldiği belirtilmiştir [51]. ...
Article
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Bu çalışma, Covid-19 salgınının ülkemizde resmi olarak ilk vakanın gözlendiği tarih-lerde, çalışmaya gönüllü olarak katılan bir spor salonunda 3 farklı günde (10-12 Mart 2020) gerçekleştirilmiştir. Çalışma sırasında salondaki kişi sayısı ve çeşitli parametreler de kaydedilmiştir. Çalışmanın yapıldığı spor salonunda eğitmen gözetiminde bayanlar toplu olarak pilates aktivitesini gerçekleştirmiştir. Bu çalışmada biyoaerosollerin tür ve miktar tayini ile sıcaklık, bağıl nem, atmosferik basınç ve karbon dioksit (CO 2) düzeyleri spor salonunun içinde ve dış ortam havasında eşzamanlı olarak ölçülmüştür. Spor salonunda en yüksek CO 2 seviyeleri aktivite sırasında ve/ya aktivitelerden hemen sonra ölçülmüştür. Spor salonunda toplam bakteri ve mantar seviyeleri 10 2 ila >10 3 CFU/m 3 arasında bulunmuştur. İç ortamda havadan kaynaklı bakteri düzeyleri en düşük aktivite öncesinde ve en yüksek aktivite sırasında ve/ya sonrasında gözlenmiştir. Ortam-daki kişi sayısı ile bakteri ve CO 2 düzeyleri arasında lineer ilişki bulunmuştur (r 2 ~ 0,7). İç ve dış ortamda sıklıkla gözlenen Aspergillus, Penicillium, Cladosporium ve Alternaria mantar türlerine ilaveten; deri ve/ya saç mantar enfeksiyonuna neden olan Microsporum ve Trichophyton; insan patojeni Nigrospora ile su sızıntısı olan binalarda kullanılan izo-lasyon köpüğünde büyüyen Stachybotrys türlerine ise spor salonlarının sadece iç ortam havasında rastlanılmıştır. ABSTRACT This study was carried out on 3 different days (10-12 March 2020) in a gym that voluntarily participated in the study, on the dates when the first case of Covid-19 was officially observed in our country. The number of people in the gym and various parameters were recorded. In the gym where the study was carried out, the women carried out the pilates activity collectively under the supervision of the instructor. In this study, composition of bioaerosols and temperature, relative humidity, atmospheric pressure and carbon dioxide (CO 2) levels in the air were measured simultaneously inside the gym and the outdoor air. The highest CO 2 levels were measured during and/or immediately after the activities in the gym. The total bacteria and mold levels in the gym were between 10 2 and > 10 3 CFU/ m 3. In indoor environment, the lowest airborne bacteria levels were observed before the activity and the highest levels were observed during and/or after the activity. A linear relationship was found between the number of people in the gym and the airborne bacteria and CO 2 levels (r 2 ~ 0,7). In addition to Aspergillus, Penicillium, Cladosporium and Alternaria, which are frequently observed fungi species both indoor and outdoor; Microsporum and Trichophyton, which are known to cause fungal infections of the skin and/or hair; the human pathogen Nigrospora and Stachybotrys species growing in the insulation foam used in buildings with water leakage were found only in the indoor air of the gym. It is concluded here that the environmental conditions and individual health conditions are important in terms of spread of diseases.
... Overall, the main findings of this study are in broad agreement with previous studies by Seppänen et al. (1999) and Apte et al. (2000) who demonstrated that concentrations of CO 2 below 1,000 ppm do not always guarantee that the ventilation rate is adequate for the removal of air pollutants from other indoor sources. Indeed, the results of the present study suggest that whilst increased ventilation was capable of diluting some VOCs it was incapable of addressing the IAQ problems associated with every VOC. ...
Article
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Young people spend extended periods of time in educational buildings, yet relatively little is known about the air quality in such spaces, or the long-term risks which contaminant exposure places on their health and development. Although standards exist in many countries in relation to indoor air quality in educational buildings, they are rarely subject to detailed post-occupancy evaluation. In this study a novel indoor air quality testing methodology is proposed and demonstrated in the context of assessing the post-occupancy performance of a recently refurbished architecture studio building at Loughborough University, United Kingdom. The approach used provides a monitoring process that was designed to evaluate air quality in accordance with United Kingdom national guidelines (Building Bulletin 101) and international (WELL Building) standards. Additional, scenario-based, testing was incorporated to isolate the presence and source of harmful volatile organic compounds, which were measured using diffusive sampling methods involving analysis by thermal desorption - gas chromatography - mass spectrometry techniques. The findings show that whilst the case-study building appears to perform well in respect to existing national and international standards, these guidelines only assess average CO 2 concentrations and total volatile organic compound limits. The results indicate that existing standards, designed to protect the health and wellbeing of students, are likely to be masking potentially serious indoor air quality problems. The presence of numerous harmful VOCs found in this study indicates that an urgent revaluation of educational building procurement and air quality monitoring guidelines is needed.
... Some scholarly works (Chau et al., 2007;Roulet et al., 2006) have also demonstrated that current hypothetical thoughts and practical data about present building technologies and processes can impact IEQ in a way that can improve building occupants' wellbeing and efficiency. Furthermore, Apte et al. (2000) found that building design indicators and the quality of the interior air environment had a substantial impact on the rates of allergy, asthma symptoms, sick building syndrome (SBS) and worker performance. As a result, the provision of a friendly and acceptable environment for all building inhabitants is critical for a hospital facility to fulfill its duty as a healing environment (Guenther and Gillmore Hall, 2007). ...
Article
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Purpose The most challenging aspect of hospital design is the creation of an environment that heals rather than the one acting as a barrier to healing. Much has not been done in the aspect of ascertaining the level of impact “indoor environmental quality (IEQ)” has on building occupants in healthcare facilities. Therefore, this study aims to investigate the impact of IEQ on patients' health and well-being. Design/methodology/approach The study investigates the hypothesis that four IEQ parameters (thermal quality, acoustic quality, lighting quality and indoor air quality [IAQ]) influence patients' overall satisfaction with the performance of hospital wards. Questionnaire responses were sought from the patients as the main occupants of hospital ward buildings. A proposed weighted structural model for IEQ establishing the relationship between IEQ parameters, patients' overall satisfaction and patients' health outcome was analyzed using structural equation modeling (SEM). Findings The most influential IEQ parameters on patients' overall satisfaction with IEQ in hospital wards are thermal quality, IAQ and lighting quality. The findings from this study revealed that the parameters of influence on patients' overall satisfaction and health outcomes vary with hospital ward orientation and design configuration. Originality/value This study has explored the need for the integration of all factors of IEQ at the building design stage towards providing a hospital environmental setting that reflects occupants' requirements and expectations and also promotes patient healing processes. This should be the focus of architects and healthcare managers and providers.
... Indoor CO 2 mainly originates from human exhalation and indoor combustion. Although the health effect of CO 2 within a common indoor concentration range remains unclear, the association between elevated CO 2 level and decreased human productivity and cognitive performance has been well documented [15][16][17][18]. ...
Article
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Healthy building design is an emerging field of architecture and building engineering. Indoor air quality (IAQ) is an inevitable factor that should be considered in healthy building design due to its demonstrated links with human health and well-being. This paper proposes to integrate IAQ prediction into healthy building design by developing a simulation toolbox, termed i-IAQ, using MATLAB App Designer. Within the i-IAQ, users can input information of building layout and wall-openings and select air pollutant sources from the database. As an output, the toolbox simulates indoor levels of carbon dioxide (CO2), total volatile organic compounds (TVOC), inhalable particles (PM10), fine particles (PM2.5), nitrogen dioxide (NO2), and ozone (O3) during the occupied periods. Based on the simulation results, the toolbox also offers diagnosis and recommendations to improve the design. The accuracy of the toolbox was validated by a case study in an apartment where physical measurements of air pollutants took place. The results suggest that designers can integrate the i-IAQ toolbox in building design, so that the potential IAQ issues can be resolved at the early design stage at a low cost. The paper outcomes have the potential to pave a way towards more holistic healthy building design, and novel and cost-effective IAQ management.
... Also building ventilation rates are positively associated with the cited symptoms [26]. Furthermore, significant exposure-response relationships have been measured between CO2 concentration and respiratory symptoms, like sore throat, tight chest, irritated nose, and sinus combined mucous membrane symptoms and wheeze [3]. ...
Preprint
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Smart infrastructures uses are growing and with them the need for dependability and correctness. To provide better correctness guarantees and bring formal verification into the equation, we present SVSHI, a platform for developing, verifying, and running Python applications in KNX installations, one of the most used smart buildings standards. SVSHI leverages abstract syntax tree (AST) manipulation, code generation, symbolic execution, and static configuration verification to make writing advanced apps easy, quick, and safe. With SVSHI, the reliability and compatibility of the applications are guaranteed without foregoing users' productivity.
... This leads some practitioners to erroneously refer a fixed CO 2 concentration limit to ASHRAE 62.1 [8]. In the meantime, CO 2 concentration limit of 1000 ppm is commonly recommended in different countries standards for the management of generic IAQ concerns and sick building syndrome symptoms [18][19][20]. However, it is noted that these recommended values are generally provided without sufficient rationales [21]. ...
Article
The carbon dioxide (CO2)-based demand-controlled ventilation (DCV) has attracted prompt attention from the Heating, Ventilation, and Air-Conditioning (HVAC) industry since its very first invention. Since then, it has been penetrating from simple single-zone systems to complex system configurations in commercial buildings. While there has accumulated a large number of research on DCV applications, the most recent review paper on this topic was dated back to 2001 and inevitably missed a lot of recent revolutionary technologies. Therefore, to understand the opportunities and challenges associated with the CO2-based DCV, this study presents a timely review on the revolutions of the CO2-based DCV in commercial buildings, with a focus on the literature published in the last two decades. This paper is mainly centered on the trends and fundamental updates of the CO2-based DCV, with a particular focus on the nexus of the indoor CO2 concentration and ventilation “demands”. First, the changes in building energy codes and standards related to the CO2-based DCV are reviewed. Second, the trends of paper distribution and the topic keywords are identified through the bibliographic analysis. Third, the fundamental updates regarding the indoor CO2 concentration are presented. The correlations between the CO2 and its influencing factors are discussed, and the CO2 concentration spatial distribution in different scenarios is summarized. Fourth, the role of CO2 in ventilation control is clarified. The correlation studies of the CO2 concentration and various ventilation “demands” are reviewed, and the impacts of the CO2-based DCV on indoor air quality are presented.
Article
This study investigated the indoor air quality (IAQ) during humid season in an old badminton hall, to explore the IAQ characteristics of natural ventilated sports buildings for public use. The indoor air parameters (temperature, relative humidity and air velocity) and indoor air pollutants (CO2, TVOC, PM2.5 and PM10) were measured. A subjective approach was carried out through questionnaire survey. 185 valid questionnaires were recovered, and 68.7% of the participants had exercised. Results show that the indoor air qualities obtained through objective and subjective approaches were obviously different. Indoor PM, TVOC and CO2 concentrations were normal, but 37.3% of the participants complained about the building materials’ smell and 73.5% of the participants reported obvious sweaty odor. Physical activity might reduce a person’s sensitivity to the environment. The participants generally felt warm and hot because of the high relative humidity. Post-exercise participants felt significantly hotter than those who did not exercise, and were generally more receptive to IAQ. The method of Fanger was employed to narrow the gap between subjective and objective approaches with a modified parameter, and to furtherly estimate the ventilation. The present study demonstrates the necessity to combine two approaches together to assess the IAQ in sports buildings.
Article
Indoor carbon dioxide (CO2) concentrations have been considered for decades in evaluating indoor air quality (IAQ) and ventilation, and more recently in discussions of the risk of airborne infectious disease transmission. However, many of these applications reflect a lack of understanding of the connection between indoor CO2 levels, ventilation, and IAQ. For example, a single indoor concentration such as 1000 ppmv is often used as a metric of IAQ and ventilation without an understanding of the significance of this or any other value. CO2 concentrations are of limited value as IAQ metrics, and a single concentration will not serve as a ventilation indicator for spaces with different occupancies and ventilation requirements. An approach has been developed to estimate a space‐specific CO2 level that can serve as a metric of outdoor ventilation rates. The concept is to estimate the CO2 concentration that would be expected in a specific space given its intended or expected ventilation rate, the number of occupants, the rate at which they generate CO2, and the time that has transpired since the space was occupied. This paper describes the approach and presents example calculations for several commercial, institutional, and residential occupancies.
Preprint
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Cities face many environmental challenges while providing opportunities for integrating human infrastructure with the surrounding environment. One effort to improve environmental conditions in cities is to increase the amount of green space in creative ways within city limits. Here we propose a unique system taking carbon dioxide (CO2) from indoor spaces and applying it to rooftop gardens or farms through existing ventilation systems with the elevated CO2 levels leading to a fertilization effect that increases plant growth. CO2 measurements were taken inside multiple classrooms as well as at the exhaust vents on a rooftop and air from exhaust was applied to crops and biomass and leaf number were measured. High concentrations of CO2 ([CO2]) persisted inside university classrooms as well as at rooftop exhaust vents in correlation with expected human occupancy and stayed around 1070 ± 70 and 830 parts per million (ppm) CO2 reaching a max of 4470 and 1300 ppm CO2 respectively. Growth in Spinacia oleraceae L. (spinach) grown next to exhaust air increased 4-fold in comparison to plants grown next to a control fan applying atmospheric air. High wind speed decreased growth by approximately 2-fold. Zea mays (corn), a C4 plant, grown next to exhaust experienced a 2 to 3-fold increase, indicating alternative environmental factors additionally playing a part in growth enhancement. Enhancing growth in rooftop gardens using indoor air, could help rooftop plants grow larger and survive harsh conditions. This would make rooftop gardens more viable and better able to provide environmental services and connect urban areas to the surrounding environment.
Chapter
The occupants of all buildings have a right to healthy indoor air. Yet the air in buildings can contain a range of contaminants that adversely affect the cardiovascular, endocrine, immune, nervous, and respiratory systems of the human body. Exposure lowers physical and mental health, wellbeing, and productivity with social, political, and economic consequences. Providing plenty of fresh air is not always a solution because it has energy and carbon penalties. This article highlights the benefits of acceptable indoor air quality, and provides methods of identifying exposure to contaminants, and of controlling them to keep occupants of buildings, happy, healthy and productive.
Article
Among office workers, the sedentary work-related health challenges are mainly associated with the fact that they often sit for up to 10 hr a working day. Members of the Research Group conducted a research program to assist the office workers of an international telecommunication company's affiliate in Budapest to enhance comfort levels in the office work environment. The data collection included a Comfort Survey to reveal employees' sense of comfort related to Indoor Environmental Quality (IEQ) components and the characteristics of employees' feelings and behavior during working hours. Moreover, a measurement of IEQ components was carried out and focused on air quality, lighting, sound exposure and thermal comfort parameters. Based on the survey's results, a Creative Concept was developed to empower office workers to address work-related health risks, notably sedentary work risks. The Creative Concept consists of five elements: a Comfort Map as an IEQ-related application to select a suitable workplace, redesigning concepts to increase the use of lounges, a newly developed work pad to improve personal hygiene in an office environment, recommendations for creating a health-enabling work environment and a workplace training program to raise health awareness. After validation, our Creative Concept can function as a multi-component workplace health promotion method to offer assistance for a wide variety of offices to create a health-enabling working environment.
Chapter
Currently used automatic control systems for electric drives of ventilation systems do not fully meet the requirements for the quality of performance of heat engineering production processes. It is necessary to develop new management systems through the use of intelligent technologies. The mathematical description of the control object is obtained by the methods of the classical theory of automatic control. Optimization of control loops is performed using fuzzy algorithm synthesis methods. A model of a ventilation system using a fuzzy controller is considered. Methods for developing intelligent control systems for electric drives of ventilation and air conditioning systems are proposed. It is established that the developed intelligent methods of control of electric drives of ventilation systems can be used under strict requirements to the microclimate in the room to ensure comfortable conditions. The developed fuzzy model was applied in a university sport complex, and the results showed the effectiveness of the proposed model when comparing traditional systems.
Technical Report
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This paper reports the outputs of research: longitudinal occupant satisfaction case-studies of buildings analysed at a high level of contextual detail. The research involved seven UK buildings, 2307 individual survey responses, and response rates averaging 82%. Study gaps varied between three and 21 years. Self-reported occupant survey scores and free text feedback for 24 comfort and functionality variables were obtained. Statistical differences in the perceptions of building occupants were triangulated with longitudinal changes in the physical and morphological contexts and respondents' free-text feedback to determine whether changes have a measurable effect on comfort and satisfaction. Interim results prompted the theory of building 'comfort signatures': the propensity for occupant surveys to exhibit statistical consistency in occupants' comfort and satisfaction scores unless and until changes in context occur to alter occupants' perceptions. Analysis of the full research dataset led to the theory that a building's distinctive comfort signature, derived from longitudinal occupant perceptions, may be a basis for setting its comfort and satisfaction thresholds for a wide range of comfort and functional variables, termed a building's 'carrying capacity'. The paper suggests that metrics based mainly on occupant comfort perceptions could be the basis for ongoing management of carrying capacity thresholds.
Article
In this paper different mechanical ventilation methods were analysed in a test room, having similar dimensions with a small office room. A series of measurements were performed with mixing, displacement and personalized isothermal ventilation having one or two occupants in the room. The main goal of this research was to investigate the air cleaning performance of different ventilation strategies in the breathing zone. The CO2 emission of involved persons was determined and it was shown that one person released 13.4 l/h CO2 while two persons released 23.63 l/h CO2. Taking into account the spread of viruses and the requirements related to separation of persons in public buildings, measurements were carried out with “open” working desk and with “screened” desk as well. Using the balance equation of pollutants, the equation which describes the CO2 concentration variation in the closed space was developed and used for calculations. Air flow visualization was done for different ventilation modes. The local ventilation effectiveness was determined for each ventilation mode based on the measured and calculated CO2 concentrations depending on the provided fresh air flow, air distribution and occupants number. In the case of screened desk the personalized ventilation shows the highest local effectiveness (1.6–2.7 in comparison with 0.6–1.4 in the case of mixing and displacement ventilation).
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Anthurium andraeanum Linden. ‘Pink Champion’, Spathiphyllum kochii Engler & Krause ‘Petite’, and Dracaena marginata Lam. ‘Tricolor Rainbow’ were placed in airtight chambers, respectively, each with a fresh wooden board that released formaldehyde. The experiment was constructed with two initial CO2 concentrations (500 or 1200 ppm) and three light intensities (0, 60 or 120 μmol·m-2·s-1 PPF) for three hours. Results showed that CO2 concentration increased and formaldehyde reduced slightly in the chamber for plants under dark conditions. Under light conditions, plants with 500 ppm CO2 had higher stomatal conductance and reduced more formaldehyde than those with 1200 ppm CO2. Increased light intensity resulted in increased net photosynthetic rate, stomatal conductance, and removal rates of formaldehyde and CO2. The efficiency of removing formaldehyde per leaf area ranked as: Anthurium > Spathiphyllum > Dracaena. Dracaena exhibited the lowest net photosynthetic rate, stomatal conductance and removal rates of formaldehyde and CO2 under the conditions constructed in this study.
Article
We demonstrate NDIR CO2 gas sensing using CMOS compatible MEMS ScAlN-based pyroelectric detectors. The ScAlN-based pyroelectric detectors are fabricated using 8-inch wafer level technology with 12% Sc-doped AlN deposited at a temperature of ∼200 °C. Together with a blackbody thermal emitter, a 10 cm long enclosed gas channel with only inlet and outlet holes connected to tubings, and testing using 2 different reference gases (N2 and synthetic air), measurements show voltage signal drop due to CO2 gas absorption at the 4.26 μm wavelength at CO2 gas concentrations ranging from 5000 ppm down to 25 ppm. The signal change due to the CO2 gas response ranges from ∼2% at 100 ppm CO2 concentration to ∼40% at 5000 ppm CO2 gas concentration for both CO2 gas measured in N2 and in synthetic air. CO2 gas response times are also measured for CO2 gas in N2 and in synthetic air at concentrations of 5000 ppm, 1000 ppm and 400 ppm. The gas response times measured around 2 secs and lower. Introduction of humidity show some minor effect (<3%) to the CO2 gas response and seems most perturbed at 10% relative humidity. To the best of our knowledge, this is the first demonstration using ScAlN-based pyroelectric detectors in NDIR CO2 gas sensing, towards practical sensor applications. The results obtained show promise in using CMOS-compatible MEMS ScAlN-based pyroelectric detectors for NDIR gas sensing, opening up possibilities for low cost, wafer-level, monolithic NDIR gas sensors with small footprint integrated with CMOS circuits.
Article
It is promising to apply model predictive control (MPC) scheme to demand-controlled ventilation (DCV) for the energy-efficient provision of indoor air quality (IAQ). However, the application of MPC in actual multi-zone DCV systems is challenged by the complexity of the ventilation duct network as well as the difficulty in handling uncertainties in actual systems. To tackle these issues, we proposed a novel robust model predictive control (MPC) strategy for multi-zone DCV systems. First, a data-driven model is established for ventilation duct network to represent relationships between airflow and damper angles. Then, with the above model and zone IAQ dynamics models, a two-layer tube-based MPC scheme is designed to efficiently handle uncertainties in actual systems: the first-layer MPC generates nominal state trajectories based on nominal systems without uncertainties while the second-layer MPC generates control actions to direct states of actual uncertain system to nominal trajectories. With the proposed strategy, the optimal trajectories of damper angles and fan pressure can be determined to minimize energy consumption while maintaining satisfying IAQ in the presence of uncertainties. Experimental results show that, in the presence of uncertainties, the proposed strategy can reduce IAQ cost by 10% and energy consumption by 14% compared with the strategy adopting conventional feedback control scheme. When compared with the baseline strategy without optimization, the proposed strategy can reduce IAQ cost by 38% and energy consumption by 30%. In addition, the proposed strategy can provide flexible trade-off between energy-efficiency and robustness against uncertainties based on designers’ interest.
Article
The objectives of this study are to investigate building professionals' experience, awareness, and interest in occupant health in buildings, and to assess the impact of the COVID-19 pandemic on their opinions, as well as to compare the research on occupant health in buildings to professionals' opinions. To address these objectives, a mixed research methodology, including a thorough review of the literature (NL = 190) and an online survey (NS = 274), was utilized. In general, there is an increasing research interest in occupant health and a heightened interest in health-related projects, among professionals, following the COVID-19 pandemic. Specifically, among the nine different building attributes examined, indoor air quality was the most researched building attribute with a focus on occupant health and was also presumed to be the most important by the professionals. Professionals considered fatigue and musculoskeletal pain to be the most important physical well-being issues, and stress, anxiety, and depression to be the most important mental well-being issues that need to be the focus of design, construction, and operation of buildings to support and promote occupant health, while eye-related symptoms and loss of concentration were the most researched physical and mental well-being symptoms in the literature, respectively. Finally, professionals indicated that COVID-19 pandemic had significant effect on their perspectives regarding buildings’ impact on occupant health and they believed future building design, construction and operation will focus more on occupant health because of the pandemic experience.
Article
The aims of this study were to determine the concentrations of selected gaseous indoor air pollutants (CO2, VOC, NO2, SO2), evaluate the ventilation system efficiency, and identify the factors determining air quality in a typical Polish sports center. Measurements were conducted simultaneously inside and outside the building during the non-heating (05/18/2017–06/21/2017) and heating (10/16/2017–11/20/2017) seasons. CO2 concentrations were measured automatically (MultiRAE), while VOCs, NO2, and SO2 samples were collected by the passive method and determined using gas chromatography, spectrophotometry, and ion chromatography, respectively. The average concentrations of the tested pollutants, except for CO2 outside, were higher in the heating season. Average CO2 concentrations in both seasons were higher inside the building (761–815 ppm) than outside (521–525 ppm). The average VOC (129.4–193.3 μg/m³), NO2 (20.2–21.3 μg/m³), and SO2 (0.9–1.4 μg/m³) concentrations in both seasons were comparatively lower inside. CO2 concentrations were mainly related to physical activity and determined by the number of people exercising on a given day, while VOC, NO2, and SO2 concentrations were influenced mainly by outdoor sources (traffic emissions, combustion of fossil fuels). The presence of specific substances (e.g. propanol, ethanol derivatives) only in indoor air were influenced by specific indoor sources, such as cleaning activities, hall maintenance, and cosmetics. The results can be used to develop appropriate control strategies to improve indoor air quality in sports facilities and improve the safety of their users by minimize the adverse health effects due to exercise in conditions of poor air quality.
Article
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Abstract A European project started at the end of 1992, in which, in addition to current methods, trained sensory panels were used to investigate office buildings all over Europe. The main aim of this EC-Audit was to develop assessment procedures and guidance on ventilation and source control, to help optimize energy use in buildings while assuring good indoor air quality. In each of nine countries, six or more office buildings were selected. Measurements were performed at five selected locations in each building. The buildings were studied while normally occupied and ventilated to identify the pollution sources in the spaces and to quantify the total pollution load caused by the occupants and their activities, as well as the ventilation systems. The investigation included physical and chemical measurements, assessment of the perceived air quality in the spaces by a trained sensory panel, and measurement of the outdoor air supply to the spaces. A questionnaire for evaluating retrospective and immediate symptoms and perceptions was given to the occupants of the buildings. The building characteristics were described by use of a check-list. The annual energy consumption of the buildings and the weather conditions were registered. This paper presents results and conclusions of the audit in 56 buildings in Europe. However, the analysis and discussions of the results are a summary of the work done, and are focused mainly on comparison between sensory assessments and the other measurements performed. Furthermore, this paper brings the results of the study based on a two-factor analysis. A paper dealing with results on a multifactorial analysis is in preparation. https://onlinelibrary.wiley.com/doi/10.1111/j.1600-0668.1996.00002.x
Article
Full-text available
indoor air quality (IAQ) to fill a significant data gap that exists regarding baseline IAQ in public and commercial office buildings. The goal of the study is to define the status of the existing building stock with respect to IAQ and occupant perceptions. The on-going cross-sectional study, entitled Building Assessment Survey and Evaluation (BASE) Program, is collecting baseline data characterizing public and commercial office buildings. The study buildings are randomly selected without regard to IAQ complaints. Core parameters are measured in a representative space in each building. This paper discusses the study design and the building and study space selection. Summaries of building descriptions and the results of measurements related to thermal comfort and ventilation for the first thirteen buildings are also included. The building descriptions include information about building age; size; study area location within the building; heating, air-conditioning and ventilation (HVAC) system type; occupant activities; smoking policy; and percent outdoor air. The measurements related to thermal comfort include indoor and outdoor temperatures and relative humidities. The data collected are coded for confidentiality and are in a publicly-accessible database. A separate paper (Part II) presents the results of pollutant measurements and occupant perceptions. DISCLAIMER: Any opinions expressed in this paper are those of the authors, and do not necessarily reflect those of the U.S. Environmental Protection Agency nor is any official endorsement to be implied.
Article
Control and abatement of indoor air quality (IAQ) problems are dependent upon reliable investigation and diagnosis. Sick building syndrome (SBS), building-related illness (BRI), and other health and comfort problems are selectively reviewed and discussed. Psychological and social as well as physical, chemical, and biological factors that affect occupant physiological and health responses are identified. Confusion exists regarding definitions and attributes of problem buildings. Timely, comprehensive, systematic investigations are rare, expensive, and difficult. Systematic and other biases result in inadequate investigations and incomplete or incorrect diagnoses. Building ecology and building diagnostics are described as a comprehensive framework for understanding and investigating indoor air quality problems. Hypothesized causes of SBS are identified based on published SBS and BRI investigation reports and review articles. Methods to control SBS, BRI, and other building-associated illnesses are presented and discussed. Preventive measures to control IAQ-related health and comfort problems and recommendations for further research are given.
Article
Indoor air quality (IAQ) complaints have steadily increased since 1973 when the Arab oil embargo forced building owners and operators to reduce energy costs in their buildings, in part by reducing indoor/outdoor air exchange rates. Carbon dioxide measurements are commonly used as an indicator of the amount of fresh air that is being introduced into a building. Particulate measurements have also been used in the evaluation of IAQ. The purpose of this study was to evaluate the relationship between carbon dioxide and particulate levels and subjective human responses in office buildings without previous or current indoor air quality problems. Carbon dioxide and particulates were measured in six separate ventilation zones with direct-reading instruments. Subjective human responses about environmental conditions and health symptoms were subsequently measured with a self-reporting questionnaire developed in Sweden. Relationships between environmental measurements and human responses were investigated using chi-square analysis. Although not statistically significant, response rates were higher for all questions about environmental conditions and health symptoms in the higher carbon dioxide exposure group. The same trend existed between particulate exposure groups, along with a statistically significant correlation between particulate exposure and headache. Associations also existed between gender and age and questionnaire responses. This study shows the usefulness of environmental measurements coupled with self-report measures in the evaluation of IAQ. Since the study was conducted in “healthy” buildings, it provides valuable baseline data useful when analyzing data collected in buildings with IAQ problems.
Article
Causal associations between "Sick Building Syndrome" (SBS) symptoms and specific environmental stressors were explored using a recently developed approach employing Principal Components Analysis (PCA) and Logistic Regression (1). This approach was applied to data collected by the U.S. EPA from 1995 to 1996 in 28 large U.S. office buildings in the Building Assessment Survey and Evaluation study. PCA was used to apportion measurements of 13 VOC species and carbon monoxide into source-related vectors. A reduced set of four source-based exposure vectors, tentatively identified as photocopiers, automotive emissions, environmental tobacco smoke, and latex paints were derived from the data. Regression analyses indicate statistically significant associations between mucous membrane related symptoms and the PCA photocopier vector (odds ratio=1.2, p=0.04), after adjustment for age, gender, smoking status, presence of carpeting, and thermal exposure. Similar relationships (odds ratio=1.2, p=0.03) were found between sore throat symptoms and the PCA paint vector. Odds ratios are given per unit increase in PCA vector which range over 5-6 units.
Article
Epidemiologic research into the causes of non-specific symptoms among office workers has produced a variety of conflicting findings which are difficult to synthesize. This paper first discusses methodologic issues important in the interpretation of epidemiologic studies, and then reviews the findings of 32 studies of 37 factors potentially related to office worker symptoms. Among environmental factors assessed, there were generally consistent findings associating increased symptoms with air-conditioning, carpets, more workers in a space, VDT use, and ventilation rates at or below 10 liters/second/person. Studies with particularly strong designs found decreased symptoms associated with low ventilation rate, short-term humidification, negative ionization, and improved office cleaning, although studies reviewed showed little consistency of findings for humidification and ionization. Relatively strong studies associated high temperature and low relative humidity with increased symptoms, whereas less strong studies were not consistent. Among personal factors assessed, there were generally consistent findings associating increased symptoms with female gender, job stress/dissatisfaction, and allergies/asthma. For other environmental or personal factors assessed, findings were too inconsistent or sparse for current interpretation, and there were no findings from strong studies. Overall evidence suggested that work related symptoms among office workers were relatively common, and that some of these symptoms represented preventable physiologic effects of environmental exposures or conditions. Future research on this problem should include blind experimental and case-control studies, using improved measurements of both environmental exposures and health outcomes
Article
Abstract Occupants of office buildings are exposed to low concentrations of complex mixtures of volatile organic compounds (VOCs) that encompass a number of chemical classes and a broad range of irritancies. “Sick building syndrome” (SBS) is suspected to be related to these exposures. Using data from 22 office areas in 12 California buildings, seven VOC exposure metrics were developed and their ability to predict self-reported SBS irritant symptoms of office workers was tested. The VOC metrics were each evaluated in a multivariate logistic regression analysis model adjusted for other risk factors or confounders. Total VOCs and most of the other metrics were not statistically significant predictors of symptoms in crude or adjusted analyses. Two metrics were developed using principal components (PC) analysis on subsets of the 39 VOCs. The Irritancy/PC metric was the most statistically significant predictor of adjusted irritant symptoms. The irritant potencies of individual compounds, highly correlated nature of indoor VOC mixtures, and probable presence of potent, but unmeasured, VOCs were variously factored into this metric. These results, which for the first time show a link between low level VOC exposures from specific types of indoor sources to SBS symptoms, require confirmation using data sets from other buildings.
Article
Twelve public office buildings were selected for a study of relationships between worker's health symptoms and a number of building, workspace, job, and personal factors. Three buildings were naturally ventilated, three were mechanically ventilated, and six were air conditioned. Information on the prevalences of work-related symptoms, demographics, and job and personal factors were determined via a questionnaire completed by 880 occupants. Several indoor environmental parameters were measured. Logistic regression models were used to evaluate associations between symptom prevalences and features of the buildings, indoor environments, jobs, and personal factors. A substantial fraction of the occupants in these typical office buildings reported frequent work-related symptoms. The occupants of the mechanically ventilated and air conditioned buildings had sipifcantly more symptoms than occupants of the naturally ventilated buildings after adjustment for confounding factors. Increased prevalences of some symptoms were associated with several job and workspace factors including: presence of carpet, increased use of carbonless copy paper and photocopiers, space sharing, and distance from a window
Article
Published studies of the relation between type of building ventilation system and work-related symptom prevalence in office workers have been contradictory. A reanalysis was performed of six studies meeting specific eligibility criteria, combining published data with unpublished information obtained from study authors. Five eligible studies were from the United Kingdom, and one was from Denmark. Standardized categories of building ventilation type were created to allow comparison of effects across studies. Within each study, prevalence odds ratios (PORs) were calculated for symptoms in each ventilation category relative to a baseline category of naturally ventilated buildings. Air-conditioned buildings were consistently associated with increased prevalence of work-related headache (POR = 1.3-3.1), lethargy (POR = 1.4-5.1), and upper respiratory/mucus membrane symptoms (POR = 1.3-4.8). Humidification was not a necessary factor for the higher symptom prevalence associated with air-conditioning. Mechanical ventilation without air-conditioning was not associated with higher symptom prevalence. The consistent associations found between type of building ventilation and reported symptom prevalence have potentially important public health and economic implications.
Article
Over the past 30 years, a new man-made ecosystem has developed — the controlled indoor environment within the sealed exterior shells of modern office buildings. This new environment has considerable potential to affect public health because more than half the adult work force in North America and Western Europe works in offices or “office-like” nonindustrial environments.1 The indoor environment of modern office buildings may be affected by the occupants, their work activities, equipment, plants, furnishings, building materials, ventilation systems, and outdoor air pollution. In the vast majority of buildings, this complex environment is controlled by one or two technicians who . . .
Article
This paper reviews current literature on the associations of ventilation rates and carbon dioxide concentrations in non-residential and non-industrial buildings (primarily offices) with health and other human outcomes. Twenty studies, with close to 30,000 subjects, investigated the association of ventilation rates with human responses, and 21 studies, with over 30,000 subjects, investigated the association of carbon dioxide concentration with these responses. Almost all studies found that ventilation rates below 10 Ls-1 per person in all building types were associated with statistically significant worsening in one or more health or perceived air quality outcomes. Some studies determined that increases in ventilation rates above 10 Ls-1 per person, up to approximately 20 Ls-1 per person, were associated with further significant decreases in the prevalence of sick building syndrome (SBS) symptoms or with further significant improvements in perceived air quality. The carbon dioxide studies support these findings. About half of the carbon dioxide studies suggest that the risk of sick building syndrome symptoms continued to decrease significantly with decreasing carbon dioxide concentrations below 800 ppm. The ventilation studies reported relative risks of 1.5-2 for respiratory illnesses and 1.1-6 for sick building syndrome symptoms for low compared to high low ventilation rates.
Epidemiology Bio-statistics and Preventive Medicine, Philadelphia, Saunders Text and Review Series Epidemiologic research: principles and quantitative methods
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Sources of information on indoor air quality: IAQ in large office buildings
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Develop-ing Baseline Information on Buildings and Indoor Air Quality (BASE '94): Part II–Environmental Pollutant Meas-urements and Occupant Perceptions
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Comparing symptoms in United States Office Buildings
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Symptoms and environmental perceptions for occupants in European of-fice buildings
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Carbon diox-ide levels in the indoor office environment
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Womble, S.E., Ronca, E.L., Girman, J.R. and Brightman, H.S. (1996) ''Developing Baseline Information on Buildings and Indoor Air Quality (Base '95)''. In: IAQ 96/Paths to Better Building Environments/Health Symptoms in Building Occu-pants, Atlanta, GA, American Society of Heating Refriger-ation and Air-Conditioning Engineers, pp. 109–117.
Experimental research on the indoor air quality and sick building syndrome in office buildings
• J-Y Sohn
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