Indoor Air Quality Assessment Research Articles

Health risk assessment of indoor air quality, sociodemographic and kitchen characteristics on respiratory health among women responsible for cooking in urban settings of Oromia region, Ethiopia: a community-based cross-sectional study

ObjectivesIn Ethiopia, where biomass fuel is used by the majority of the population, women who are primarily responsible for cooking are at a higher risk of having respiratory symptoms. However,...

Comparative Study on the Indoor Air Quality in Critical Areas of Hospitals in Malaysia

Indoor Air Quality (IAQ) is the air quality within and around buildings and structures, particularly regarding building occupants’ health and comfort. IAQ assessments were performed using an objective measurement of molecular gaseous pollutants to determine the IAQ profile in the hospital’s critical areas. It also analyses the effects on patients in different environments and the sources that result in deviations from approved criteria. This comparative study is aimed to investigate the concentration of different compounds in different critical departments in the hospital and propose solutions to the related problem as an improvement in indoor air quality. The data was compared with the standards and regulations. It was found that the TVOC level in the CCU department, specifically in the fluoroscopy room, has exceeded the allowable limit. A few suggestions have been raised to lower the exceeded value. The risks and symptoms held by the occupants in the hospital buildings if they face poor indoor air quality were discussed. Further study can be conducted to relate the short and long-term health issues among medical staff to poor indoor air quality.

Indoor level of BTEX and health risk assessment at science laboratories in a university

The levels of volatile organic compounds (VOCs) such as Benzene, Toluene, Ethylbenzene, and Xylene isomers (BTEX) are important parameters for an indoor air quality assessment. Exposure to BTEX in science laboratories in a university can potentially cause health risks to workers. Active sampling was carried out using Tenax® GR sorbent tubes and analyzed with thermal desorption gas chromatography-mass spectrometry (TD-GCMS) to measure the BTEX levels at selected indoor areas. The average concentration of individual BTEX at the laboratories complex were as follows: Benzene (1.76 ± 0.44 μg/m3), Toluene (8.15 ± 2.99 μg/m3), Ethylbenzene (3.75 ± 0.69 μg/m3), m, p-Xylene (6.07 ± 1.19 μg/m3) and o-Xylene (4.84 ± 0.43 μg/m3). The distribution of the BTEX components varied depending on the floor level, laboratory activities, laboratory size, and interior furniture. Non-cancer risk estimates based on hazard quotient value for BTEX were < 1, indicating unlikely non-cancer risk. Lifetime cancer risk estimates for Benzene were in the range of 1.16 × 10-6 – 2.54 × 10-6 indicating possible cancer risk at the sampled indoor locations. Therefore, science laboratories can potentially pose a health risk to workers from long-term exposure to BTEX.

Smart Healthy Schools: An IoT-enabled concept for multi-room dynamic air quality control

Smart Healthy Schools (SHS) are a new paradigm in building engineering and infection risk control in school buildings where the disciplines of Indoor Air Quality (IAQ), IoT (Internet of Things) and Artificial Intelligence (AI) merge together. In the post-pandemic era, equipping schools with a network of smart IoT sensors has become critical to aspire for the optimal control of the IAQ and lowering the airborne infection risk of several pathogens, indirectly related to cumulated human emitted CO2 levels over time. Thermal energy waste in winter due to improved air renewal remains of major concern but can be well monitored within a SHS monitoring architecture thanks to the flexibility of the LoRaWAN protocol able to process also a large amount of energy and climatic data at room and building scale. In this work, we report the design of the AulaSicura platform, an IoT control system co-designed by the main author and Gizero Energie to implement the SHS paradigm via clearly visible (and audible) alarm signalling in existing and new school buildings. The cloud-based LoRa system is capable of continuous and simultaneous monitoring of a variety of sensors and IAQ parameters including indoor/oudoor temperatures, rel. humidities and human-emitted excess CO2. The multi-room monitoring concept of indoor-CO2 levels allows centralized control of natural ventilation levels in individual classrooms and can handle (quasi)-real-time data, relevant for data post-processing and future developments in (quasi)-real-rime assessment of IAQ and infection risk levels at single room scale. The sensor network is also extensible to up to one thousand of classrooms per LoRa-node allowing centralized control of entire school districts at an urban scale. Moreover, through Modbus-LoRa I/O converters, AulaSicura can also control the same amount of mechanical ventilation units per node either in pure or hybrid mechanical ventilation modes.

Assessment of indoor air quality and comfort by comparing an energy simulation and actual data in Native American shelters

Introduction: This research will determine if a native American shelter (wigwam) can create comfort and if while doing so can provide healthy indoor air quality (IAQ) levels as defined by current standards. Concurrent to this research a technique to digitally model the outcomes of comfort created within the shelter was developed.Methods: A fullsize example of a wigwam was built and data from inside and outside the wigwam monitored for comparison. Data collected both inside and outside was temperature and relative humidity of the air, collected inside the wigwam were CO2, VOC, and PM2.5 levels. The wigwam allowed us to compare the accuracy of a digital model created in Design Builder. The Design Builder model was made to the specific size, materials, and location of the actual wigwam. This allowed an accurate comparison of temperature and relative humidity levels. Design-Builder accurately recreated the attributes of the full-size wigwam.Results and Discussion: It was found that comfort can be achieved to modern standards in this native shelter; as temperature, relative humidity, and rainfall exposure can all be controlled to acceptable levels. Indoor air quality is always at an acceptable level when a fire isn’t active. When an open fire is introduced, the particulates and VOC released into the interior of the wigwam are at dangerous levels. A woodstove with flue pipe allowed for comfort to be maintained at healthier air quality levels but did not reach acceptable levels for particulate matter.

Assessment of thermal conductivity and indoor air quality of fired clay brick incorporated with electroplating sludge

Industrial activity is one of the main contributors in developing and growth of economy in Malaysia. Industries and agricultures in Malaysia, generate harmful waste which, if not properly disposed of can damage to landfills and the environment. Brick is one of an important masonry unit needed as building materials. This paper addresses the thermal conductivity and Indoor Air Quality (IAQ) when the fired clay bricks are combined with electroplating sludge (ES). The fired clay bricks were examined using five different ratios 2%, 4%, 6%, 8% and 10%. The X-ray Fluorescence (XRF) result showed that the highest percentage of electroplating sludge composition was aluminium oxide (Al2O3) which is 67.20%. The clay soil showed that the highest percentage of silicon dioxide (SiO2) and aluminium oxide (Al2O3) which was 67.60% and 19.70%, respectively. The IAQ result of carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), formaldehyde (HCHO) and particulate matter (PM10) of fired clay brick with 4% of electroplating sludge was acceptable and safe to be used as building material as it had the most lower gas emissions and compared to the control brick with 0% of sludge. Moreover, all parameters in every pattern did not have much contrast with the limit by Industry Code of Practice on Indoor Air Quality (ICOP-IAQ) standard. Therefore, electroplating sludge an alternative low-cost material that provides an environmentally friendly disposal method.

Assessment of Thermal Comfort and Indoor Air Quality in Library Group Study Rooms

Human performance and health are among the most relevant topics in modern society, especially at young ages, when academic performance is indispensable. Thus, as humans spend most of their life inside a building, thermal comfort and indoor air quality are essential aspects of a room. The aim of the current study is to numerically evaluate the main thermal comfort parameters such as PMV and PPD as well as indoor air quality, i.e., CO2 concentration, in library group study rooms at the University of Gävle in Sweden. Rotroninc Measurement Solutions CL11 sensors were utilized for temperature measurements. Simulation models were created and validated based on building data as well as temperature measurements. Several simulations were conducted throughout the year, covering different periods. The results show that even though the ventilation system, with only temperature control, works as intended for maintaining thermal comfort, the CO2 concentration rises above 1000 ppm when more than one student occupies the rooms, which is not recommended by different thermal comfort ruling institutions. Consequently, a modification to the ventilation system control is recommended, changing it from temperature control to CO2 and temperature control.

A scoping review of indoor air quality assessment in refurbished buildings

PurposeExposure to poor indoor air in refurbished buildings is a matter of health concern due to the growing concentrations of various contaminants as a result of building airtightness without amendment of ventilation, or the use of building materials such as glue, paint, thinner and varnishes. Recent studies have been conducted to measure indoor air pollutants and assess the health risks affecting the quality of life, productivity and well-being of human beings. However, limited review studies have been recently conducted to provide an overview of the state of knowledge. This study aims to conduct a scoping review of indoor air quality (IAQ) in the context of refurbished or energy-retrofitted buildings.Design/methodology/approachA systematic screening process based on the PRISMA protocol was followed to extract relevant articles. Web of Science, Scopus, Google Scholar and PubMed were searched using customised search formulas. Among 276 potentially relevant records, 38 studies were included in the final review covering a period from 2015 to 2022.FindingsResearchers mapped out the measured compounds in the selected studies and found that carbon dioxide (CO2) (11%) and total volatile organic compounds (11%) were among the most commonly measured contaminants. Two trends of research were found including (1) the impact of ventilative properties on IAQ and (2) the impact of introducing building materials on IAQ.Originality/valueThe contribution of this study lies in summarising evidence on IAQ measurements in refurbished buildings, discussing recent advancements, revealing significant gaps and limitations, identifying the trends of research and drawing conclusions regarding future research directions on the topic.

Indoor Air Quality Assessment of Metro Stations Based on the Optimal Combination Weight and Improved Fuzzy Comprehensive Evaluation

Aair quality issues and respiratory diseases have become issues of particular concern since the outbreak of the COVID-19 pandemic. The indoor air quality of crowded places such as underground metro stations has received growing attention from passengers and staff, thus requiring both qualitative and quantitative assessment. However, the traditional fuzzy comprehensive evaluation is ineffective in this respect. Therefore, this paper proposed the method of optimal combination weight and improved fuzzy comprehensive evaluation to assess the air quality. First, subjective weights were calculated with the multiple-input weighted precedence chart and analytic hierarchy process; objective weights were computed using the entropy weight and exceedance multiple methods. Second, the moment estimation theory was introduced for the optimal combination of these weights. Results show that the optimal combination weighting method achieves the minimum relative deviation. Moreover, in the traditional fuzzy comprehensive evaluation, the air quality is generally classified based on the maximum membership, and the evaluation is inapplicable when the validity (K0) is less than 0.5. Therefore, the concept of confidence was introduced herein for improvement. Finally, the optimal combination weight and improved fuzzy comprehensive evaluation is proved to be the most reasonable in comparison with the traditional fuzzy comprehensive evaluation and indoor air quality index. This study not only suggests a good method to assess the indoor air quality of metro stations but also provides references for decision makers.

Assessment of indoor air quality and health risk from formaldehyde exposure in postnatal care centers and elderly care facilities in Seoul

Assessment of indoor air quality and health risk from formaldehyde exposure in postnatal care centers and elderly care facilities in Seoul

Monitoring and apportioning sources of indoor air quality using low-cost particulate matter sensors

Air quality is one of the most important factors in public health. While outdoor air quality is widely studied, the indoor environment has been less scrutinised, even though time spent indoors is typically much greater than outdoors. The emergence of low-cost sensors can help assess indoor air quality. This study provides a new methodology, utilizing low-cost sensors and source apportionment techniques, to understand the relative importance of indoor and outdoor air pollution sources upon indoor air quality. The methodology is tested with three sensors placed in different rooms inside an exemplar house (bedroom, kitchen and office) and one outdoors. When the family was present, the bedroom had the highest average concentrations for PM2.5 and PM10 (3.9 ± 6.8 ug/m3 and 9.6 ± 12.7 μg/m3 respectively), due to the activities undertaken there and the presence of softer furniture and carpeting. The kitchen, while presenting the lowest PM concentrations for both size ranges (2.8 ± 5.9 ug/m3 and 4.2 ± 6.9 μg/m3 respectively), presented the highest PM spikes, especially during cooking times. Increased ventilation in the office resulted in the highest PM1 concentration (1.6 ± 1.9 μg/m3), highlighting the strong effect of infiltration of outdoor air for the smallest particles. Source apportionment, via positive matrix factorisation (PMF), showed that up to 95 % of the PM1 was found to be of outdoor sources in all the rooms. This effect was reduced as particle size increased, with outdoor sources contributing >65 % of the PM2.5, and up to 50 % of the PM10, depending on the room studied. The new approach to elucidate the contributions of different sources to total indoor air pollution exposure, described in this paper, is easily scalable and translatable to different indoor locations.

Evaluating the Role of Particulate Matter as a Surrogate Index for Mould Spores in Residential Tenancy: Implications of New Legislation in Australia

Abstract: This paper evaluates the practical implications of recent legislative changes in Australia for residential tenancy and minimum rental housing standards, with a focus on the known risks from mould exposure to health. Specifically, the study examines the use of particulate matter (PM) measurements as a surrogate index for mould spores during residential indoor air quality assessments. The findings indicate that PM10 is a useful surrogate index for mould spores, while PM2.5 is less reliable due to size differences between PM2.5 and mould spores. The paper also investigates the relationship between particulate matter, mould spore sizes, and ambient air quality by reviewing relevant literature and presenting case studies from various Australian and international sources. Overall, the study highlights the importance of early detection during onsite inspections to minimize health hazards related to mould and dampness and to improve indoor air quality in residential tenancy spaces.

Indoor and outdoor air quality assessment in daycare centres in Ghent (Belgium) in view of outdoor sleeping in an urban environment

Within Flanders, there is an increasing trend to let children sleep outdoors while in daycare. However, within an urban environment, the densely spread emission sources might affect the air quality and possibly limit the areas where outdoor sleeping is favourable. Nevertheless, there is a lack of data regarding the atmospheric pollution levels in and around daycare centres (DCC). Therefore, the focus of this study is to chemically characterize the air quality indoors, outdoors, and in specifically designed cubicles for outdoor sleeping at 12 DCCs spread over the city of Ghent (Belgium). The measuring of a very broad range of different pollutants, provides unique data for indoor and outdoor air quality at daycare centres in Ghent. The use of axial tube (for volatile organic compounds, VOCs) and Radiello (for NO2, SO2, O3) passive samplers enables multi-component sampling, resulting in time-weighted average concentrations for one week. Forty-seven VOCs are identified and, for the majority (40), indoor to outdoor concentration (I/O) ratios higher than one are found. For the remaining seven compounds (e.g. benzene) outdoor concentrations are a factor 1.3–17.9 (median) higher than indoors. Median indoor TVOC concentrations are 152 μg/m3 and 142 μg/m3 for the September and January campaign, respectively. Outdoors, these median TVOC concentrations are much lower (24.5 μg/m3 and 30.6 μg/m3). For NO2, no noticeable differences are observed between average indoor and outdoor concentrations (indoors 12 ± 3 μg/m3 and 13 ± 2 μg/m3 for the September and January campaign, respectively, and outdoors 11 ± 3 μg/m3 and 14 ± 4 μg/m3). The highest (outdoor) measured concentration is 21 ± 1 μg/m3. SO2 concentrations are below 2.62 μg/m3 (LOQ). Average indoor O3 concentrations are 4 ± 3 μg/m3 and 2 ± 2 μg/m3 for the September and January campaign, respectively. Much higher values are measured outdoors (46 ± 3 μg/m3 and 40 ± 11 μg/m3), but the concentrations stayed well below legal standards.

Assessing Indoor Air Quality and Ventilation to Limit Aerosol Dispersion—Literature Review

The COVID-19 pandemic highlighted the importance of indoor air quality (IAQ) and ventilation, which researchers have been warning about for years. During the pandemic, researchers studied several indicators using different approaches to assess IAQ and diverse ventilation systems in indoor spaces. To provide an overview of these indicators and approaches in the case of airborne transmission through aerosols, we conducted a literature review, which covered studies both from before and during the COVID-19 pandemic. We searched online databases for six concepts: aerosol dispersion, ventilation, air quality, schools or offices, indicators, and assessment approaches. The indicators found in the literature can be divided into three categories: dose-, building-, and occupant-related indicators. These indicators can be measured in real physical spaces, in a controlled laboratory, or modeled and analyzed using numerical approaches. Rather than organizing this paper according to these approaches, the assessment methods used are grouped according to the following themes they cover: aerosol dispersion, ventilation, infection risk, design parameters, and human behavior. The first finding of the review is that dose-related indicators are the predominant indicators used in the selected studies, whereas building- and occupant-related indicators are only used in specific studies. Moreover, for a better understanding of airborne transmission, there is a need for a more holistic definition of IAQ indicators. The second finding is that although different design assessment tools and setups are presented in the literature, an optimization tool for a room’s design parameters seems to be missing. Finally, to efficiently limit aerosol dispersion in indoor spaces, better coordination between different fields is needed.

Assessment of indoor air quality and their inter-association in hospitals of northern India-a cross-sectional study.

This study was commenced to evaluate the indoor and outdoor air quality concentrations of PM2.5, sub-micron particles (PM>2.5, PM1.0-2.5, PM0.50 -1.0, PM0.25-0.50, and PM<0.25), heavy metals, and microbial contaminants along with their identification in three different hospitals of Lucknow City. The study was conducted from February 2022 to April 2022 in hospitals situated in the commercial, residential, and industrial belts of the city. The indoor concentration trend of particulate matter as observed during the study suggested that most of the highest concentrations belonged to the hospital situated in an industrial area. The highest obtained indoor and outdoor concentrations for PM1.0-2.5, PM0.50-1.0, PM0.25-0.50, and PM<0.25 are 40.44µg/m3, 56.08µg/m3, 67.20µg/m3, 74.50µg/m3, 61.9µg/m3, 79.3µg/m3, 82.0µg/m3, and 93.9µg/m3, respectively, which belonged to hospital C situated in the industrial belt. However, for PM>2.5, the highest indoor concentration obtained belonged to hospital B, i.e., 30.7µg/m3, which is situated in the residential belt of the city. Regarding PM2.5, the highest indoor and outdoor concentrations obtained are 149.41µg/m3 and 227.45µg/m3, which were recorded at hospital A and hospital C, respectively. The present study also observed that a high bacterial load of 1389.21CFU/m3 is recorded in hospital B, and the fungi load was highest in hospital C with 786.34CFU/m3. Henceforth, the present study offers thorough information on the various air pollutants in a crucial indoor setting, which will further aid the researchers in the field to identify and mitigate the same more precisely.

Assessment of Indoor Air Quality in Small and Medium Food Industries and Effects towards Perceived IAQ Symptoms

Background: Cooking activities generate pollutants that can cause adverse health effects to occupants. This study aims to characterize the indoor air environment in small and medium food enterprises (SMEs), as studies in this area are scarce. Methods: A series of field measurements were conducted to investigate the IAQ at 14 SMEs selected in Pulau Pinang for three different cooking methods (frying, boiling, and baking). Data on environmental perception and health symptoms were obtained from 76 workers by using a validated questionnaire. Boosted regression tree (BRT) analysis and parametric tests were performed to evaluate the impact of the IAQ on the prevalence of disease symptoms. Results: The results showed that CO2, temperature, and relative humidity were higher than the standard limits, while PM2.5 and TVOC were below the standard limits. Using BRT analysis, CO2 was indicated as the highest pollutant to cause complaints by workers (41.55%), followed by CO (21.93%), relative humidity (11.81%), temperature (10.66%), PM2.5 (7.07%), and TVOC (6.99%). This study indicated that workers in SMEs food industries are affected by the indoor air quality at their workplace in which CO2 was the main parameter influencing their health. This study suggests that future research focuses on boiling and frying SMEs with CO2, CO, temperature, and relative humidity to be afforded emphasis.

Assessment of indoor air quality in air-conditioned small business units with no mechanical ventilation

Shophouses, a common building type in Singapore, host small business units typically cooled by non-mechanically ventilated strategies. Activities in these spaces include cooking food and handling nail and hair products, which emit volatile organic compounds (VOCs), carbon monoxide (CO), and other airborne contaminants that could compromise indoor air quality (IAQ). This study assessed potential IAQ risk by quantifying total VOCs (TVOC), formaldehyde, carbon dioxide (CO2), and CO levels in 100 air-conditioned small business units in Singapore's shophouses. The median (maximum) concentrations across all units were TVOC:179 (54,880 ppb), formaldehyde:0 (1.0 ppm), CO2:586 (2750 ppm) and CO:0 (0.5 ppm). The majority (90%) of the units did not have mechanical ventilation provision, and TVOC and formaldehyde levels correlated significantly with corresponding CO2 levels (p ≤ 0.05). The highest levels of TVOC and formaldehyde were measured at nail salons (TVOC: 54,880 ppb, formaldehyde: 1.0 ppm). Improving ventilation combined with use of alternative low-emission products could improve IAQ in small business units.

Toxicokinetics of Major Anthropogenic Indoor Air Pollutants and Their Effects on Human Health: A Review of Literature

Research studies have shown that about 90% of the time is spent in indoor environments (homes, hospitals, schools, offices, restaurants and subways). During the past decade, many studies have been conducted to assess indoor air quality in school environments. A large number of indoor air pollutants have been measured including volatile organic compounds, nitrogen oxides, sulphur dioxide, carbon dioxide, carbon monoxide, bioaerosols and particulate matters. In most low and medium-income countries, biomass fuel-based cooking and heating is considered to be a significant source of the household as well as ambient air pollution formaldehyde from clipboard and hydrocarbons from paints, cleaners and furnishings (anthropogenic sources). A wide range of acute and chronic diseases are now associated with exposure to air pollution, starting from diabetes mellitus, declining cognitive functions, and obstructive pulmonary diseases, haematopoietic diseases, to cardiovascular disease.

Indoor Air Quality Guidelines Connection to IAQ Certification and Labelling Process

Abstract The world’s leading indoor air quality guidelines provide for the identification of certain parameters with a specific limit value based on the latest empirical measurements, however, most of them do not have legal coverage and are voluntary. This leads to unequal assessment of indoor air quality, because there is an identifiable difference between the limit values set out in the various guidelines. And these values would be related to the results obtained during the experimental activities of the application of the specific parameters and the interpretation of their effects on human health. The aim of this IAQ guideline and IAQ certification review was to develop IAQ label for Nordic countries and to find gaps the legislation established by the Latvian government. The development of indoor air quality labels provides an opportunity to maintain and promote the optimal functionality of human physiological processes and the sustainability of the building.

The impacts of cooking and indoor air quality assessment in the southwestern region of Bangladesh

The main objective of this study is to assess the impacts of cooking and indoor air quality (IAQ) in the southwestern region of Bangladesh. Here we report and compare the IAQ in considering a total of eight kitchens and living rooms of four selected households (HHs) in Jashore city and suburb area, the southwest district of Bangladesh. Air quality parameters, such as particulate matter (PM2.5) and volatile organic compounds (VOC), were assessed continuously for 24 h. In addition, Carbon dioxide (CO2) was evaluated in different phases during the study period. PM2.5, VOC, and CO2 levels were ranged from 18.52 to 207 μg/m3, 7.95–35.66 ppm, and 1061–2459 mg/m3, respectively, in the indoor cooking HHs. Conversely, while the average concentration was found between 20.63 and 23.72 μg/m3 PM2.5, 11.18–12.36 ppm VOC, and 1097–1747 mg/m3 CO2 in the outdoor cooking HHs. A significant increase in CO2 due to kitchen activities (cooking, frying, boiling) was observed that ranged between 5 and 77% compared to the background level. The calculated range of toxicity potential (TP) values was between 0.8 and 8.3 for PM2.5 in the HHs. In most of the observations, PM2.5, VOC, and CO2 exceed the standard values. The study reports that well ventilation systems and clean fuel use significantly reduce the indoor air contaminants level. Our study offers new insights about the IAQ of the southwest region of Bangladesh, particularly for suburbs and urban setups, and provides a background for further study, and decision-making. It will serve as a reference for the formulation and implementation of policies to improve air quality.