Indoor Air Quality In Schools Research Articles

Schools and Indoor Air Quality: seasonal variation

Abstract Background Indoor Air Quality (IAQ) in schools is a public health concern, given the vulnerability of children as a demographic group and substantial amount of time that they spend in (highly occupied) classrooms. Conditions specific for school buildings, as well as location and outdoor air quality (OAQ), can adversely affect IAQ and children’s health. The aim of this study was to examine the seasonal variation in IAQ and the influence of OAQ herein in primary schools. Methods Sampling was carried out in summer and winter in 5 schools in central Poland. A culture-dependent method using impactors was applied to examine the total number of bacteria and fungi. Gas chromatography with flame ionization detector (quartz filters for sampling) was applied to determine concentrations of 16 polycyclic aromatic hydrocarbons (PAHs), crucial for their health impact. Results In poorly ventilated classrooms bacteria levels exceeded that of fungi. Bacterial contamination decreased in efficiently ventilated rooms, and before/after the lessons. In summer fungi concentration in indoor air was higher than in winter and reached the level of fungi outdoors. PAHs concentrations (especially those with 4 and more rings, which are biologically active) and the mutagenicity and carcinogenicity equivalents were elevated in winter and related to changes in concentrations in outdoor air. Conclusions IAQ in schools depends on a season. Occupants in classrooms are the main source of bacteria, but the type and number of microorganisms also depend on ventilation conditions. PAHs characteristic of coal/wood combustion indicates that in the absence of internal emission sources, external sources most likely affect IAQ in schools in winter.

Sources and determinants of exposure to indoor air pollutants in schools and hospitals: a review

Abstract Background Indoor Air Quality (IAQ) is an important determinant of health. This study aimed to review the available scientific evidence about indoor pollutants and determinants of exposure in several settings, in the scope of the K-HEALTHinAIR project. Methods The systematic review was performed for the sources, concentrations, and determinants of pollutants in schools in the European region for 2013-2023. Articles were selected for data extraction if they were epidemiological studies, reported primary data for indoor air and pollutant levels, and, identified sources and determinants of exposure. Results The main pollutants affecting IAQ in schools and hospitals were carbon dioxide, volatile organic compounds (e.g., formaldehyde, terpenes), particulate matter, nitrogen dioxide, radon, ozone, and carbon monoxide. Besides the outdoor environment, several important indoor sources of emissions were identified such as occupancy, resuspension, cleaning products. Ventilation was the main determinant influencing the indoor levels of pollutants, stressing the importance of good planning, installation, and maintenance of mechanical ventilation systems in buildings. Other determinants were the number of occupants and their activities, and the building characteristics (e.g., type of floor, location, etc). Conclusions Results revealed indoor air quality as a public health concern since several pollutants are present in indoor settings. The identification of sources and determinants of exposure is fundamental for determining preventive measures in a public health perspective. Acknowledgments: K-HEALTHinAIR team for screening and data extraction: Mariana Corda, Jose Fermoso, Alicia Aguado, Sandra Rodriguez, Hanns Moshammer, Mireia Ferri, Belén Costa, Leticia Pérez, Wojciech Hanke, Artur Badyda, Piotr Kepa, Katarzyna Affek, Nina Doskocz, Laura Martín, Oguz Mulayim, Cesar Mediavilla Martinez, Alba Gómez, Ruben González, Isaac Cano, Josep Roca, Simon de Leede.

Evaluating Indoor Air Quality in Schools: Is the Indoor Environment a Haven during High Pollution Episodes?

Pollution data were collected at five schools in Hong Kong using low-cost, sensor-based monitors both indoors and outdoors during two consecutive high pollution episodes. The pollutants monitored included NO2, O3, PM2.5, and PM10, which were also used as input to a health risk communication protocol known as Air Quality Health Index (AQHI). CO2 was also measured simultaneously. The study aimed to assess the relationship between indoor pollutant concentrations and AQHI levels with those outdoors and to evaluate the efficacy of building operating practices in protecting students from pollution exposure. The results indicate that the regular air quality monitoring stations and outdoor pollutant levels at schools exhibit similar patterns. School AQHI levels indoors were generally lower than those outdoors, with PM10 levels showing a larger proportional contribution to the calculated values indoors. NO2 levels in one school were in excess of outdoor values. CO2 monitored in classrooms commonly exceeded indoor guidelines, suggesting poor ventilation. One school that employed air filtration had lower indoor PM concentrations compared to other schools; however, they were still similar to those outdoors. O3 levels indoors were consistently lower than those outdoors. This study underscores the utility of on-site, sensor-based monitoring for assessing the health impacts of indoor and community exposure to urban air pollutants. The findings suggest a need for improved ventilation and more strategic air intake placement to enhance indoor air quality.

Impact of Indoor Air Quality on Student Health in Closed Classroom Environments

This research explores the impact of Indoor Air Quality (IAQ) on students' well-being in crowded classrooms, emphasizing the necessity of optimal air quality for a conducive learning environment. It raises concerns about the public health implications of poor IAQ, particularly in densely populated and inadequately ventilated schools. The study examines the effects of various pollutants, such as PM10, PM2.5, SO2, and NO2, on students' respiratory health and cognitive function. Findings indicate that exposure to these pollutants can lead to respiratory diseases, diminished cognitive abilities, and increased absenteeism, ultimately affecting academic performance. The research underscores the importance of accurate air quality monitoring and implementing preventive measures to safeguard students' health. Educational institutions can create safer and healthier learning environments by adhering to IAQ guidelines and integrating advanced sensor technologies and real-time monitoring systems. This study highlights the critical role of maintaining good IAQ in enhancing students' overall quality of life and academic success, advocating for the convergence of science, technology, and policy to optimize indoor air quality in schools.

A complete review on enhancing air circulation and filtration for improving internal air quality in a healthy school environment

The health of staff and students is impacted by Indoor Air Quality (IAQ) in educational environments. A healthy atmosphere depends on good IAQ, yet millions of students worldwide might develop respiratory illnesses due to poor air quality. Immediate action is required to alleviate the burden of IAQ consequences in the pandemic-dominated period. This detailed evaluation focuses on techniques for improving air circulation and filtration systems to meet the critical demand for improved IAQ in schools. This research demonstrates the negative impacts of inadequate IAQ on students and educators’ cognitive capacities, health and performance based on an extensive examination of current records. A healthy learning environment, on the other hand, can minimize absenteeism, raise test results and increase pupil/teacher education/teaching productivity. This review explores the effectiveness of different ventilation as well as filtration methods, such as air purifiers, mechanical ventilation, natural ventilation and advanced filtration systems, in lowering airborne pollutants like particulate matter, volatile organic compounds (VOCs) and microbiological contaminants. This study reviews current information, emphasizes recent findings along with options and provides guidelines for the future of education. It underlines the limits of previous studies, gives ideas for further research and indicates a path forward for more enhancements to the air quality in schools. Comprehensive analysis with greater sample numbers is required to evaluate student performance, indoor contentment and environmental health exposure. On-site measurements are essential for comprehending the properties of contaminants. Intricate mitigation strategies must take health impacts, IAQ and energy efficiency into effect.

COVID-19 Mitigation in a K-12 School Setting: A Case Study of Avenues: The World School in New York City.

In this case study, we describe a well-resourced private school in New York City that implemented COVID-19 mitigation measures based on public health expert guidance and the lessons learned from this process. Avenues opened in New York City in 2012 and has since expanded, becoming Avenues: The World School, with campuses in São Paulo, Brazil; Shenzhen, China; the Silicon Valley, California; and online. It offers education at 16 grade levels: 2 early learning years, followed by a prekindergarten through grade 12. We describe the mitigation measures that Avenues implemented on its New York campus. We compare COVID-19 case prevalence at the school with COVID-19 case positivity in New York City, as reported by the New York State Department of Health. We also compare the school's indoor air quality to ambient indoor air quality measures reported in the literature. The school's mitigation measures successfully reduced the prevalence of COVID-19 among its students, staff, and faculty. The school also established a consistently high level of indoor air quality safety through various ventilation mechanisms, designed to reduce common indoor air pollutants. The school received positive parent and community feedback on the policies and procedures it established, with many parents commenting on the high level of trust and quality of communication established by the school. The successful reopening provides useful data for school closure and reopening standards to prepare for future pandemic and epidemic events.

Outdoor trends and indoor investigations of volatile organic compounds in two high schools of southern Italy

Volatile organic compounds (VOCs) are a class of ubiquitous substances that are present in outdoor and indoor air. They are emitted by a wide range of sources and can penetrate and accumulate specifically in indoor environments. Concern is growing among the scientific community regarding the potential health impacts of exposure to a high concentration of VOCs in indoor spaces. Due to their still-developing respiratory and immune systems, children may be the most fragile subjects in this regard, and therefore, the study of indoor air quality in schools is of the utmost importance. In this work, the concentrations of total volatile organic compounds (TVOCs) and of 20 specific compounds belonging to this class were determined in a school in Squinzano, a town in the province of Lecce (Apulia region, southern Italy). Sampling was carried out in indoor (classrooms and bathrooms) and outdoor (terrace) areas using passive diffusive samplers for VOCs and photoionization detectors for TVOCs. Average concentrations of both TVOC (303 ± 47 µg m−3) and individual VOCs (< 0.5 µg m−3) were below levels of concern; however, specific indoor sources such as cleaning activities and student occupancy were responsible for peaks in TVOC concentrations above harmless levels for children and school staff. The data were then compared to the ones obtained in a similar study conducted in a school in Galatina, another town of the Apulia region, highlighting the impact of the surrounding outdoor environment on the indoor profile of VOCs.

Robustness of point measurements of carbon dioxide concentration for the inference of ventilation rates in a wintertime classroom

Indoor air quality in schools and classrooms is paramount for the health and well-being of pupils and staff. Carbon dioxide sensors offer a cost-effective way to assess and manage ventilation provision. However, often only a single point measurement is available which might not be representative of the CO₂ distribution within the room. A relatively generic UK classroom in wintertime is simulated using Computational Fluid Dynamics. The natural ventilation provision is driven by buoyancy through high- and low-level openings in both an opposite-ended or single-ended configuration, in which only the horizontal location of the high-level vent is modified. CO₂ is modelled as a passive scalar and is shown not to be ‘well-mixed’ within the space. Perhaps surprisingly, the single-ended configuration leads to a ‘more efficient’ ventilation, with lower average CO₂ concentration. Measurements taken near the walls, often the location of CO₂ sensors, are compared with those made throughout the classroom and found to be more representative of the ventilation rate if made above the breathing zone. These findings are robust with respect to ventilation flow rates and to the flow patterns observed, which were tested by varying the effective vent areas and the ratio of the vent areas.

Indoor Air Quality in Schools Located in Poland, Lublin Province

Indoor Air Quality in Schools Located in Poland, Lublin Province

SchoolAIR: A Citizen Science IoT Framework Using Low-Cost Sensing for Indoor Air Quality Management.

Indoor air quality (IAQ) problems in school environments are very common and have significant impacts on students' performance, development and health. Indoor air conditions depend on the adopted ventilation practices, which in Mediterranean countries are essentially based on natural ventilation controlled through manual window opening. Citizen science projects directed to school communities are effective strategies to promote awareness and knowledge acquirement on IAQ and adequate ventilation management. Our multidisciplinary research team has developed a framework-SchoolAIR-based on low-cost sensors and a scalable IoT system architecture to support the improvement of IAQ in schools. The SchoolAIR framework is based on do-it-yourself sensors that continuously monitor air temperature, relative humidity, concentrations of carbon dioxide and particulate matter in school environments. The framework was tested in the classrooms of University Fernando Pessoa, and its deployment and proof of concept took place in a high school in the north of Portugal. The results obtained reveal that CO2 concentrations frequently exceed reference values during classes, and that higher concentrations of particulate matter in the outdoor air affect IAQ. These results highlight the importance of real-time monitoring of IAQ and outdoor air pollution levels to support decision-making in ventilation management and assure adequate IAQ. The proposed approach encourages the transfer of scientific knowledge from universities to society in a dynamic and active process of social responsibility based on a citizen science approach, promoting scientific literacy of the younger generation and enhancing healthier, resilient and sustainable indoor environments.

A Review of Artificial Neural Network Models Applied to Predict Indoor Air Quality in Schools.

Indoor air quality (IAQ) in schools can affect the performance and health of occupants, especially young children. Increased public attention on IAQ during the COVID-19 pandemic and bushfires have boosted the development and application of data-driven models, such as artificial neural networks (ANNs) that can be used to predict levels of pollutants and indoor exposures. This review summarises the types and sources of indoor air pollutants (IAP) and the indicators of IAQ. This is followed by a systematic evaluation of ANNs as predictive models of IAQ in schools, including predictive neural network algorithms and modelling processes. The methods for article selection and inclusion followed a systematic, four-step process: identification, screening, eligibility, and inclusion. After screening and selection, nine predictive papers were included in this review. Traditional ANNs were used most frequently, while recurrent neural networks (RNNs) models analysed time-series issues such as IAQ better. Meanwhile, current prediction research mainly focused on using indoor PM2.5 and CO2 concentrations as output variables in schools and did not cover common air pollutants. Although studies have highlighted the impact of school building parameters and occupancy parameters on IAQ, it is difficult to incorporate them in predictive models. This review presents the current state of IAQ predictive models and identifies the limitations and future research directions for schools.

Identification of Indoor Air Quality Factors in Slovenian Schools: National Cross-Sectional Study

Poor indoor air quality (IAQ) in schools is associated with impacts on pupils’ health and learning performance. We aimed to identify the factors that affect IAQ in primary schools. The following objectives were set: (a) to develop a questionnaire to assess the prevalence of factors in primary schools, (b) to conduct content validity of the questionnaire, and (c) to assess the prevalence of factors that affect the IAQ in Slovenian primary schools. Based on the systematic literature review, we developed a new questionnaire to identify factors that affect the IAQ in primary schools and conducted its validation. The questionnaires were sent to all 454 Slovenian primary schools; the response rate was 78.19%. The results show that the most important outdoor factors were the school’s micro location and the distance from potential sources of pollution, particularly traffic. Among the indoor factors, we did not detect a pronounced dominating factor. Our study shows that the spatial location of schools is key to addressing the problem of IAQ in schools.

Back to School Approach for Air Filtration

Indoor air quality in schools has become a major concern in recent years with factors such as pollution and the impact of Covid-19 highly significant. Here we look at how filtration is playing a key role in protecting the health of students.

Natural ventilation in classrooms for healthy schools in the COVID era in Mediterranean climate

Indoor air quality in schools has a direct impact on the performance and wellbeing of students. In 2020, the health emergency required the reconsideration of ventilation conditions in indoor spaces, especially for educational buildings. This paper advances previous investigations to identify affordable, sustainable, and healthy designs for the refurbishment and new construction of schools, analysing the design parameters of the buildings and the indoor air quality in a representative sample of schools in the Mediterranean climate. The set of schools represents the regional composition regarding ages, daily scholar schedules and building designs. This study evaluates indoor CO2, TVOCs, PM 2.5 and PM 10, concentration profiles regarding indoor temperature, relative humidity, and occupation rates to identify adequate natural ventilation strategies. The results show a wide dispersion in CO2 concentrations, ranging between 4110 and 5366 ppm (peak values), TVOC mean concentration varies from 206.99 μg/m3 to 589.71 μg/m3 and particulate matter fractions ranging between 1.14 and 15.6 μg/m3 for PM 2.5 and 2.04 and 34.86 μg/m3 for PM 10 during the occupancy period. Concentrations are related to the effect of ventilation actions, the occupation rates and the metabolism of occupants. The combination of values shows how natural ventilation designs can assure adequate indoor air quality within comfort conditions under these mild climate conditions.

Assessing ventilation strategies in a school with observed indoor air problems

Purpose Poor indoor air quality in schools is a worldwide challenge that poses health risks to pupils and teachers. A possible response to this problem is to modify ventilation. Therefore, the purpose of this paper is to pilot a process of generating alternatives for ventilation redesign, in an early project phase, for a school to be refurbished. Here, severe problems in indoor air quality have been found in the school. Design/methodology/approach Ventilation redesign is investigated in a case study of a school, in which four alternative ventilation strategies are generated and evaluated. The analysis is mainly based on the data gathered from project meetings, site visits and the documents provided by ventilation and condition assessment consultants. Findings Four potential strategies to redesign ventilation in the case school are provided for decision-making in refurbishment in the early project phase. Moreover, the research presents several features to be considered when planning the ventilation strategy of an existing school, including the risk of alterations in air pressure through structures; the target number of pupils in classrooms; implementing and operating costs; and the size of the space that ventilation equipment requires. Research limitations/implications As this study focusses on the early project phase, it provides viewpoints to assist decision-making, but the final decision requires still more accurate calculations and simulations. Originality/value This study demonstrates the decision-making process of ventilation redesign of a school with indoor air problems and provides a set of features to be considered. Hence, it may be beneficial for building owners and municipal authorities who are engaged in planning a refurbishment of an existing building.

Self-reported voice disorders of teachers and indoor air quality in schools: a cross-sectional study in Finland

Objective We aimed to study the association between self-reported voice disorders among teachers and indoor air quality in school buildings. Methods We performed a questionnaire study of 538 Finnish teachers working in 67 school buildings utilizing both perceived and technical evaluations; the agreement between these two assessments was also studied. The technical assessment was provided by technical experts. Results Teachers with voice disorders reported significantly more complaints from indoor air than those without voice disorders. The results also indicated a possible connection between the technical assessment and voice disorders. After adjustment for sex, stress and asthma, the prevalence of voice disorders was 47% higher in teachers working in renovated buildings compared to those working in the non-problem buildings (aRR1.47; CI 95% 1.11–1.95). The prevalence of voice disorders was 28% higher among teachers working in buildings with problems compared to those working in non-problem buildings (aRR 1.28; 95% CI 0.99–1.64). Discussion In our study, poor perceived indoor air was significantly associated with self-reported voice disorders in teachers and there was an agreement between the perceived and technical assessments. Our results also indicated a possible connection between the technical assessment and voice disorders. Our results imply the need for longitudinal research with technical assessment to study the effect of renovation on voice disorders.

Indoor air quality in schools in Beijing: Field tests, problems and recommendations

This study investigated indoor CO2 and PM2.5 real-time concentrations together with air temperature, humidity and air-cleaning effectiveness of 33 classrooms in 21 schools in Beijing, China by natural ventilation with air cleaners (NV system) compared to mechanical ventilation with fresh air ventilators (MV system).We found that: (1) The proportions of PM2.5 concentrations >37.5 μg/m3 when the classrooms were occupied were 28 % and 31 % in MV and NV classrooms. (2) During periods of severe ambient pollution, the averaged PM2.5 I/O ratio was 0.47. (3) The proportions of CO2 concentrations >1000 ppm when the classrooms were occupied were 40 % and 60 % in MV and NV classrooms, although we note that the maximum CO2 concentration in NV classrooms occasionally exceeded 5000 ppm. (4)The mean ventilation rate was only 1.9 L/(s⋅person) during class in NV classrooms, and the air exchange rates (AERs) for NV and MV classrooms were smaller by 58 % and 4 % during class in times of severe ambient pollution than during those days that ambient PM2.5 ≤35 μg/m3. (5) During the days close to the beginning or end of central space heating, both MV and NV classrooms had indoor air temperatures lower than the 18 °C mandated by the Chinese Thermal Comfort Standard (GB/T 17225-2017). (6) Although MV systems showed lower energy efficiency than NV systems in removing PM2.5 in classrooms, the benefits of CO2 reduction and ventilation rates increase afforded by MV systems are important. These findings can help to identify or develop a suitable ventilation system (NV or MV system) and an operating strategy in classrooms in severe ambient pollution regions.

Proposal for improvement and management status of indoor air quality in School

Proposal for improvement and management status of indoor air quality in School

On-Site Monitoring Indoor Air Quality in Schools: A Real-World Investigation to Engage High School Science Students

This article describes the on-site monitoring of indoor air quality (IAQ) in school classrooms and laboratories. The students were personally involved in the monitoring experience, by using low-cost IAQ sensors, and then in evaluation and interpretation of the measured values. The joint school–university project, which provides lessons, equipment, and support to high school classes, is a model of how to engage students in real-world science research and learning. The obtained results pointed out two alerts: unacceptable high levels of fine particle matter (PM2.5)—mainly entered into indoor environments from highly polluted outdoor air—and uncomfortably high CO2 levels—due to classroom crowding and inadequate ventilation.

학교시설 최적 실내공기질 제공을 위한 환기시스템 및 제어 방법 분석

Purpose: Recently, as the interest in particulate matter increased, standards for indoor air quality (IAQ) in schools have been strengthened. Among indoor air pollutants, the main issue for school IAQ is carbon dioxide (CO₂) and particulate matter (PM). To satisfy CO₂ and PM concentration standard, the mechanical ventilation is essential. However, most systems are operating without the optimal control methods which result in inefficient system operation. Thus, the purpose of this study is to analyze ventilation regulations, system and control methods to establish the theoretical basis for developing the optimal control algorithm. Method: Regulations and researches of school ventilation were compared by cases to identify deficiencies of ventilation systems. Result: Domestic regulations were insufficient for properly operating ventilation systems and for managing the indoor air quality compared to other countries. Most researches focused on reducing the energy consumption of the system and CO₂ concentration. Therefore, the optimal control algorithm for school ventilation system is required which considers various indoor air pollutant elements and supplies comfortable indoor air quality conditions.