Indoor Air Quality Assessment Research Articles

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.

DESIGN AND EVALUATION OF A SMART INDOOR AIR QUALITY MONITORING SYSTEM

This paper presents the design and development of an intelligent air quality monitoring system that utilizes the widely adopted and versatile Arduino Uno microcontroller as its foundational platform. The system underwent comprehensive testing procedures to ensure its adherence to specified requirements. Moreover, a series of experiments were conducted in diverse areas of a residential environment to generate datasets for various air quality indicators. The research findings showcase the potential of the developed system in accurately monitoring and assessing indoor air quality in real time. Enhancing indoor air quality plays a crucial role in mitigating the transmission of common airborne viruses and pollutants, thus significantly benefiting respiratory health.

User’s Perception of Indoor Air Quality (IAQ) in Tall Office Buildings as the Cause of Symptoms of Sick Building Syndrome

The user’s assessment or perception of indoor air quality (IAQ) refers to an individual’s subjective assessment or perception of the quality of the air they breathe inside a particular building or space. This assessment or perception is very individual and can vary from one individual to another. This study aims to determine the IAQ felt by users of the Rectorate Building, State University of Malang, and its effect on Sick Building Syndrome (SBS) symptoms. This research is included in the quantitative research with the study population being all employees at the building, which has 215 people. The data collection technique in this study used the MM040NA questionnaire and the data analysis technique used was binary logistic regression analysis with the help of the IBM SPSS Statistics with crosstabs test. The results of this study indicate that all independent variables have no significant relationship with SBS symptoms experienced by respondents and all independent variables have a very weak correlation. In addition, from 80 respondents, 27 people (33.75%) experienced SBS and 53 people (66.25%) did not experience SBS. This shows that there is a SBS phenomenon in the building. The significance value for all independent variables is greater than the significance level value (&gt;0.05). Furthermore, based on the test criteria, it is concluded that the variable airflow, high temperature, temperature change, low temperature, stale air, dry air, odor, air electrostatics, cigarette smoke, sound level, lighting, and air pollution have approximate significance values greater than 0.05 (null hypothesis was failed to be rejected). It is concluded that those variables have no significant relationship to the dependent variable (the SBS symptoms) experienced by the respondents.

Indoor air quality assessment to design a model for indoor air quality management and health impact assessment in Northern Thailand

Indoor air quality (IAQ) has become an important area of concern these days and tends to be more serious to human health as well as resident convenience, especially in smoke haze season (February - April) in Upper Northern Thailand (UNT). Indoor air monitoring and model development for controlling the air quality indoors is necessary for all buildings, particularly in urban areas and polluted areas. This study aims i) to study indoor air quality, ii) to assess health impacts and factors related to indoor air quality, and iii) to develop an effective model for controlling indoor air quality in Sub-district Health Promoting Hospital (HP) and Early Childhood Development Center (ED). Temperature, relative humidity, air movement, PM2.5, PM10, Carbon Dioxide (CO2), Carbon Monoxide (CO), Ozone (O3), Formaldehyde (CH2O), Total Volatile Organic Compound (TVOC), Total bacterial and fungal were used to evaluate indoor air quality. It was found that PM2.5 and PM10 concentrations in all buildings exceeded indoor air quality standards. Moreover, CO2 concentration was higher than recommended levels, especially during the daytime. HP and ED found high values of total bacteria and total fungi, which were higher than recommended level. The indoor air quality management model of a clean room that involved with the calculation of total airflow in cubic feet per hour was created and a specific size of air cleaner for the room was selected. The results showed that PM2.5 and PM10 concentrations including other parameters of the selected rooms were reduced to the recommended levels after implementing the rooms. This result indicated the effectiveness of developing an indoor air quality management model. Thus, this model can be used as a successful study case for other HP and ED, leading to a positive impact on building occupant health.

Design factors affecting the passive release of tracer gas for ventilation measurements

The ventilation rate is an important parameter for assessing indoor air quality and energy efficiency. In occupied buildings, ventilation measurements utilising passive methods are preferable to active methods due to their simplicity and less intrusive nature. The perfluorocarbon tracer method can be used to measure long-term ventilation rates for this purpose. This method requires the passive release of a tracer gas which is often a liquid chemical diffusing out of a vial. The tracer gas emission rate is a key parameter of the vial design as if it is too low, the sampler will not be able to detect the tracer gas. If the emission rate is too high, the sampler can become saturated. Both scenarios will lead to inaccurate ventilation results. There is wide variability in vial design but little information about the relative impact of each design factor. Thus, the aim of this study was to compare the emission rate of a common tracer gas, perfluoromethylcyclohexane, using different vials designs i.e. capping styles, septa materials, and fill levels. Samples were kept in an incubator and gravimetric analysis was carried out using a semi-microbalance (resolution: 0.01 mg). The results demonstrate that the emission rate is significantly affected by capping style but not by fill level.

Indoor and Outdoor Air Quality Assessment of So2 and No2 in Suburban Schools in Imphal, Manipur

Air quality assessments for NO2 and SO2 levels in indoor and outdoor environments were conducted in three suburban schools in Imphal. Season-wise, the highest NO2 and SO2 concentrations were observed during winter, while the lowest occurred during the monsoon. The concentration of SO2 in the indoor air was comparatively cleaner than in the outdoor air. Similarly, indoor air was found to be cleaner than outdoor air with respect to NO2. The overall concentration obtained for the entire study period for SO2 was 4.9±1.5 µg m-3, and for NO2, it was 9.2±3.0 µg m-3. The concentrations of the two gases obtained during the study were below the NAAQs and WHO permissible limits. Seasonal variation of SO2 concentrations between the pre-monsoon period and monsoon months and also between the monsoon period and winter months (at p&lt;0.001) was significant. For NO2, seasonal variation in the concentrations between the monsoon and winter (at p&lt;0.001) was found significant. The estimated I/O ratios for the two studied gases, which were below one, plus the positive correlation between the classroom and campus environment concentrations of NO2 (r=0.96), and SO2 (r=0.96), reflected the influence of the indoor air quality by outdoor pollution sources. Data on similar studies for the country’s northeastern region, in particular, is scanty, and that’s why it may provide valuable insights to the scientific world.

Use of Arduino for Monitoring the Air Quality of Indoor Environments

In this work, a prototype was developed to assess indoor air quality using an Arduino system. The system is based on the measurement of the light level, smoke concentration, temperature and air humidity. A thermal comfort index (TCI) was proposed, where a scale from 0 to 1 based on the weighted average of the individual indices was developed. Another approach, based on artificial neural networks, was formulated in which the parameters were used as input arguments of the network and the TCI was used as a target parameter. The response of the two models was compared, where it was possible to observe that the TCI values calculated by the network were considerably close to the values obtained by the deterministic model, with MSE of 1.73?10-5.

Ecological Study of Sick Building Syndrome among Healthcare Workers at Johor Primary Care Facilities.

Persistent exposure to indoor hazards in a healthcare setting poses a risk of SBS. This study determines the prevalence of and risk factors for SBS among healthcare workers in health clinics. A cross-sectional study was conducted across four health clinics from February 2022 to May 2022. As part of the study, self-administered questionnaires were completed to determine symptoms related to SBS. An indoor air quality (IAQ) assessment was conducted four times daily for fifteen minutes at five areas in each clinic (laboratory, lobby, emergency room, pharmacy, and examination room). Most of the areas illustrated poor air movement (&lt;0.15 m/s), except for the laboratory. The total bacterial count (TBC) was above the standard limit in both the lobby and emergency room (&gt;500 CFU/m3). The prevalence of SBS was 24.84% (77) among the healthcare workers at the health clinics. A significant association with SBS was noted for those working in the examination room (COR = 2.86; 95% CI = 1.31; 6.27) and those experiencing high temperature sometimes (COR = 0.25; 95% CI = 0.11; 0.55), varying temperature sometimes (COR = 0.31; 95% CI = 0.003), stuffy air sometimes (COR = 0.17; 95% CI = 0.005; 0.64), dry air sometimes (COR = 0.20; 95% CI = 0.007; 0.64), and dust sometimes (COR = 0.25; 95% CI = 0.11; 0.60) and everyday (COR = 0.34; 95% CI = 0.14; 0.81). Only healthcare workers in the examination room (AOR = 3.17; 95% CI = 1.35; 7.41) were found to have a significant risk of SBS when controlling for other variables. SBS is prevalent among healthcare workers at health clinics.

Measurement and rapid assessment of indoor air quality at mass gathering events to assess ventilation performance and reduce aerosol transmission of SARS-CoV-2.

To assess risk factors for COVID-19 transmission and address the closure of mass gathering events since March 2020, the UK Government ran the Events Research Programme (ERP), following which it reopened live events in sports, music, and culture in July 2021. We report the rapid post-occupancy evaluation of Indoor Air Quality (IAQ) and associated long-range airborne transmission risk conducted in the Environmental Study of the ERP. Ten large venues around the UK were monitored with CO2 sensors at a high spatial and temporal resolution during 90 events. An IAQ Index based on CO2 concentration was developed, and all monitored spaces were classified in bands from A to G based on their average and maximum CO2 concentrations from all events. High resolution monitoring and the IAQ Index depicted the overall state of ventilation at live events, and allowed identification of issues with ventilation effectiveness and distribution, and of spaces with poor ventilation and the settings in which long-range airborne transmission risk may be increased. In numerous settings, CO2 concentrations were found to follow patterns relating to event management and specific occupancy of spaces around the venues. Good ventilation was observed in 90% of spaces monitored for given occupancies. Practical applications: High-resolution monitoring of indoor CO2 concentrations is necessary to detect the spatial variation of indoor air quality (IAQ) in large mass gathering event venues. The paper summarises COVID-19 ventilation guidance for buildings and defines a methodology for measurement and rapid assessment of IAQ during occupancy at live events that can be implemented by venue managers. Comparisons of the CO2 concentrations measured during the events identified the spaces at high risk of long-range transmission of airborne pathogens. Building operators should be mindful of the ventilation strategies used relative to the total occupancy in different spaces and the occupant's activities.

Indoor Air Quality Assessment in Grocery Stores

Indoor Air Quality (IAQ) is a public and occupational health concern, as we are exposed to air pollutants daily given that we spend a great amount of our time in indoor environments. IAQ can be affected by numerous factors, from outdoor pollutants that get indoors through ventilation to building materials, furnishings, and activities carried by the building occupants. Exposure to air pollutants has been linked to a panoply of adverse effects on our health, well-being, and performance. The aim of this study was to assess the IAQ in grocery stores (GSs) in the municipality of Cascais in the Lisbon metropolitan area (Portugal) to characterize the workers’ occupational exposure to air pollutants. The study was conducted in 13 small “family” grocery stores. The IAQ monitoring campaign was conducted using low-cost sensor technologies and focused on several parameters, namely: carbon dioxide (CO2), volatile organic compounds (VOCs), particulate matter (PM10 and PM2.5), temperature (T), and relative humidity (RH). Overall, the IAQ of the studied GSs complied with Portuguese legislation, except for PM2.5, where 23% of GSs presented levels above the established limit value. The mean inhaled dose of workers during a workday was estimated to be 157.7 ± 57.2 μg for PM2.5 and 165.8 ± 56.0 μg for PM10. The IAQ assessment allowed the identification of the best strategies to improve worker experience in indoor workplace environments.

Subjective assessment of indoor air quality and thermal environment in patient rooms: A survey study of Polish hospitals

The indoor environment of patient rooms should provide adequate conditions for the safe recovery of the patient. However, in clinical standards, the requirements for conditions in standard patient rooms are either omitted or limited to stating the temperature or humidity. Simultaneously, patients in different countries often feel uncomfortable, and the data indicate large discrepancies in patient room thermal conditions across the world.Therefore, this study aimed to determine how patients in Polish hospitals perceive the indoor environment in their rooms, as well as the relationship between individual patient characteristics (gender and age) and feelings about selected elements of the indoor environment, in addition to feelings related to the self-assessment of the impact of the indoor environment on the recovery process.The results of the presented study indicate that the analysed thermal environment elements are essential in patient rooms and should be given appropriate attention. The individual characteristics of patients, including those caused by illness and medication, make it impossible to create a comfortable environment for each patient in a multi-patient room, and solutions and guidelines to support the recovery process of patients should continue to be developed, including solutions that provide opportunities to create a controlled environment around each patient.

Microbial Assessment of Indoor Air Quality of Laboratory Sections in Obong University, Obong Ntak, Nigeria

Background: Poor indoor air quality constitutes a significant health problem in schools, mostly in the laboratory sections due to a high number of students per laboratory vis-a-vis space confinement, insufficient outside air supply, poor construction and maintenance of laboratory buildings. Aim: This study was carried out to assess the air quality and identify airborne bacteria and fungi in selected sections of Obong University Laboratory. Materials and Methods: Institutional based study employing passive air sampling, settle plate or gravitational sampling method to collect airborne bacteria and fungi was conducted in 3 selected laboratory sections of the University. Culture, isolation, colony count/air quality assessment and identification of airborne bacteria and fungi were done using standard methods. Results: The mean bacterial load was 111.75 CFU/m3 in the morning and 125.25 CFU/m3 in the afternoon. The highest and lowest bacterial loads were recorded at the Laboratory Animal Room (LAR) to be 165 CFU/m3 and 201 CFU/m3 in the morning and afternoon, respectively. The total fungal load was 100 CFU/m3 in the morning and 170 CFU/m3 in the afternoon with the mean estimate of 25 CFU/m3 in the morning and 42.5 CFU/m3 in the afternoon. The highest fungal load was equally estimated in the LAR at a percentage rate of 55% and 54.12% in the morning and afternoon, respectively. The results of the indoor air quality assessment of the different laboratory sections revealed a very low (&lt;50 CFU/m3) to low (50-100 CFU/m3) degree of both fungal and bacterial air pollution within the sampling time. A total of 3 bacterial and 5 fungal species were isolated as follows: Staphylococcus aureus 16(61.5%), coagulase negative Staphylococcus species (CoNS) 7 (27%) and Bacillus species 3 (11.5%); Aspergillus flavus 7 (25%), Aspergillus niger 8 (28.5%), Penicillium chrysogenum 4 (14.3%), Rhizopus spp. 5 (17.9%) and Fusarium spp. 4 (14.3%). The levels of indoor airborne bacteria and fungi as revealed in this study were found to be within the acceptable and permissible limits of microbial load ≤500 CFU/m3. Conclusion: Attention should be given to control those human, animal and environmental factors which favour the proliferation of bacteria and fungi in the indoor environment of school laboratories to safeguard the health of students, lecturers and laboratory personnel in the University. Keywords: Microbial Quality, Indoor Air, Laboratory, Colony, Pollution

Assessment of indoor air quality and risk of COVID-19 infection in Spanish secondary school and university classrooms

Despite the risk of transmission of SARS-CoV-2, Spanish educational centers were reopened after six months of lockdown. Ventilation was mostly adopted as a preventive measure to reduce the transmission risk of the virus. However, it could also affect indoor air quality (IAQ). Therefore, here we evaluate the ventilation conditions, COVID-19 risk, and IAQ in secondary school and university classrooms in Toledo (central Spain) from November 2020 to June 2021. Ventilation was examined by monitoring outdoor and indoor CO2 levels. CO2, occupancy and hygrothermal parameters, allowed estimating the relative transmission risk of SARS-CoV-2 (Alpha and Omicron BA.1), Hr, under different scenarios, using the web app COVID Riskairborne. Additionally, the effect of ventilation on IAQ was evaluated by measuring indoor/outdoor (I/O) concentration ratios of O3, NO2, and suspended particulate matter (PM). University classrooms, particularly the mechanically ventilated one, presented better ventilation conditions than the secondary school classrooms, as well as better thermal comfort conditions. The estimated Hr for COVID-19 ranged from intermediate (with surgical masks) to high (no masks, teacher infected). IAQ was generally good in all classrooms, particularly at the university ones, with I/O below unity, implying an outdoor origin of gaseous pollutants, while the source of PM was heterogeneous. Consequently, controlled mechanical ventilation systems are essential in educational spaces, as well as wearing well-fitting FFP2–N95 masks indoors is also highly recommended to minimize the transmission risk of COVID-19 and other airborne infectious diseases.

Assessment of Indoor Air Quality of Four Primary Health Care Centers in Qatar.

Airborne bacteria pose a potential risk to human health upon inhalation in the indoor environments of health care facilities. Airborne bacteria may originate from various sources, including patients, workers, and daily visitors. Hence, this study investigates the quantity, size, and identification of airborne bacteria indoors and outdoors of four Primary Health Care Centers (PHCC) in Doha, Qatar. Air samples were collected from the lobby, triage room, and outside environment of the centers, including, Qatar University (QU-HC), Al-Rayyan (AR-HC), Umm-Ghuwailina (UG-HC), and Old Airport (OA-HC) between August 2020 and March 2021, throughout both the hot and the cold seasons. Samples were collected using an Anderson six-stage cascade impactor. The mean of the total colony-forming units was calculated per cubic meter of air (CFU/m3). QU-HC had the lowest mean of total bacterial count compared with other centers in the indoor and outdoor areas with 100.4 and 99.6 CFU/m3, respectively. In contrast, AR-HC had the highest level, with 459 CFU/m3 indoors, while OA-HC recorded the highest bacterial concentration of the outdoor areas with a total mean 377 CFU/m3. In addition, 16S rRNA sequencing was performed for genera identification. Staphylococcus, Acinetobacter, Bacillus, and Pseudomonas were the four most frequently identified bacterial genera in this study. The abundance of airborne bacteria in the four health centers was higher in the cold season. About 46% of the total airborne bacterial count for three PHCC centers exceeded 300 CFU/m3, making them uncompliant with the World Health Organization’s (WHO) recommendation for indoor settings. Consequently, an IAQ standards should be shaped to establish a baseline for measuring air pollution in Qatar. Additionally, it is crucial to understand seasonal fluctuations better so that hospitals can avoid rising and spreading infection peaks.