scholarly journals Indoor Air Quality Intervention in Schools; Effectiveness of a Portable HEPA Filter Deployment in Five Schools Impacted by Roadway and Aircraft Pollution Sources

Author(s):  
Nancy Carmona ◽  
Edmund Seto ◽  
Timothy Gould ◽  
Jeffry H. Shirai ◽  
Lisa Hayward ◽  
...  

The Healthy Air, Healthy Schools Study was established in January 2020 to better understand the impact of ultrafine particles (UFP) on indoor air quality in communities surrounding Seattle-Tacoma (Sea-Tac) International Airport. The study team took multipollutant measurements indoor and outdoor air pollution at five participating school locations to infiltration indoors. The schools participating in this project were located within a 7-mile radius of Sea-Tac Airport and within 0.5 miles of an active flight path. Based on experimental measures in an unoccupied classroom, infiltration rates of a) Ultrafine particles of aircraft origin b) Ultrafine particles of traffic origin and c) Wildfire smoke or other outdoor pollutants were characterized before and after the introduction of a classroom based portable HEPA filter intervention. The portable HEPA cleaners were an effective short-term intervention to improve the air quality in classroom environments, reducing the ultrafine particles to approximately 1/10th of that measured outside. Before the HEPA filter deployment, approximately one-half of all outdoor UFPs were measured indoors. This study is unique in focusing on UFP in school settings and demonstrating through multivariate methods that the UFP measured in the classroom space is primarily of outdoor origin. Although existing research suggests that improvements to indoor air quality in homes can significantly improve asthma outcomes, further research is necessary to establish the benefit to student health and academic performance of improved air quality in schools.

2017 ◽  
Vol 25 (2) ◽  
pp. 1-6
Author(s):  
Imrich Sánka ◽  
Veronika Földváry

Abstract This study investigates the impact of energy renovation on the indoor air quality of an apartment building during the heating season. The study was performed in one residential building before and after its renovation. An evaluation of the indoor air quality was performed using objective measurements and a subjective survey. The concentration of CO2 was measured in the bedrooms, and a sampling of the total volatile compounds (TVOC) was performed in the living rooms of the selected apartments. Higher concentrations of CO2 and TVOC were observed in the residential building after its renovation. The concentrations of CO2, and TVOC in some of the cases exceeded the recommended maximum limits, especially after implementing energy-saving measures on the building. The average air exchange rate was visibly higher before the renovation of the building. The current study indicates that large-scale renovations may reduce the quality of an indoor environment in many apartments, especially in the winter season.


2021 ◽  
Vol 13 (8) ◽  
pp. 4139
Author(s):  
Muriel Diaz ◽  
Mario Cools ◽  
Maureen Trebilcock ◽  
Beatriz Piderit-Moreno ◽  
Shady Attia

Between the ages of 6 and 18, children spend between 30 and 42 h a week at school, mostly indoors, where indoor environmental quality is usually deficient and does not favor learning. The difficulty of delivering indoor air quality (IAQ) in learning facilities is related to high occupancy rates and low interaction levels with windows. In non-industrialized countries, as in the cases presented, most classrooms have no mechanical ventilation, due to energy poverty and lack of normative requirements. This fact heavily impacts the indoor air quality and students’ learning outcomes. The aim of the paper is to identify the factors that determine acceptable CO2 concentrations. Therefore, it studies air quality in free-running and naturally ventilated primary schools in Chile, aiming to identify the impact of contextual, occupant, and building design factors, using CO2 concentration as a proxy for IAQ. The monitoring of CO2, temperature, and humidity revealed that indoor air CO2 concentration is above 1400 ppm most of the time, with peaks of 5000 ppm during the day, especially in winter. The statistical analysis indicates that CO2 is dependent on climate, seasonality, and indoor temperature, while it is independent of outside temperature in heated classrooms. The odds of having acceptable concentrations of CO2 are bigger when indoor temperatures are high, and there is a need to ventilate for cooling.


Author(s):  
Farhang Tahmasebi ◽  
Yan Wang ◽  
Elizabeth Cooper ◽  
Daniel Godoy Shimizu ◽  
Samuel Stamp ◽  
...  

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application: This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.


2020 ◽  
pp. 1420326X2096076
Author(s):  
Pedro F. Pereira ◽  
Nuno M. M. Ramos

In Portugal, residential buildings commonly have their ventilation strategy changed after commissioning. This occurs due to the building managers' willingness to reduce shared costs with the electricity needed for fan operation. However, this option is not technically supported, and the effects of such a strategy on indoor air quality-related to human pollutants are yet to be quantified. CO2 was monitored in 15 bedrooms and air exchange rates were calculated for each room. The air exchange rate values ranged from 0.18 to 0.53 h−1 when mechanical extraction ventilation was off, and from 0.45 to 0.90 h−1 when mechanical extraction ventilation was on, which represents an average increase of 119%. With the current intermittent ventilation strategy, all rooms remain above 1500 ppm for a given percentage of time, and 12 rooms presenting CO2 concentrations above 2000 ppm. Simulations of theoretical CO2 concentrations, for a non-interrupted mechanical ventilation strategy show that no rooms would accumulate CO2 concentrations above 2000 ppm, and only 25% would present CO2 concentrations above 1500 ppm. Pearson correlations between the monitored CO2 and human and spatial factors identified two relevant parameters. Those parameters correspond to ratios between CO2 generation and floor area ([Formula: see text]), and airflow with CO2 generation ([Formula: see text]). The proposed ratios could be used as ways to optimise ventilation costs and indoor air quality.


Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1606
Author(s):  
Małgorzata Basińska ◽  
Michał Michałkiewicz ◽  
Katarzyna Ratajczak

Dissatisfaction with indoor air quality is common even in relatively new or renovated Polish school buildings. To improve air quality in educational buildings, portable devices have seen increased use, for which manufacturers guarantee a high level of indoor air purification. However, their optimized operation largely depends on their correct use. The aim of this article was to determine the effectiveness of air purification in a primary school using an air purification device with an analysis of the classroom indoor air quality (IAQ). Two criteria were used, microbiological and particulate matter concentration. Measurements were made before device installation and during its continuous operation, and before and after lessons on chosen days. Measurements related to IAQ did not detect clear differences in the analyzed measurement periods. For microbiological contamination, in the morning before lessons, the total count for all bacteria and microscopic fungi was definitely lower than after lessons. Comparing the periods before and after device installation, no clear tendency for reducing the bacteria count or microscopic fungi occurred during air purifier operation, nor was there any noticeable trend in the reduction of particulate matter. There was no improvement in air quality in the classrooms during the operation of the purification devices.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Prince Junior Asilevi ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Bernard Fei-Baffoe ◽  
Yen Adams Sokama-Neuyam

AbstractNon-thermal plasma (NTP) is a promising technology for the improvement of indoor air quality (IAQ) by removing volatile organic compounds (VOCs) through advanced oxidation process (AOP). In this paper, authors developed a laboratory scale dielectric barrier discharge (DBD) reactor which generates atmospheric NTP to study the removal of low-concentration formaldehyde (HCHO), a typical indoor air VOC in the built environment associated with cancer and leukemia, under different processing conditions. Strong ionization NTP was generated between the DBD electrodes by a pulse power zero-voltage switching flyback transformer (ZVS-FBT), which caused ionization of air molecules leading to active species formation to convert HCHO into carbon dioxide (CO2) and water vapor (H2O). The impact of key electrical and physical processing parameters i.e. discharge power (P), initial concentration (Cin), flow rate (F), and relative humidity (RH) which affect the formaldehyde removal efficiency (ɳ) were studied to determine optimum conditions. Results show that, the correlation coefficient (R2) of removal efficiency dependence on the processing parameters follow the order R2 (F) = 0.99 > R2 (RH) = 0.96, > R2 (Cin) = 0.94 > R2 (P) = 0.93. The removal efficiency reached 99% under the optimum conditions of P = 0.6 W, Cin = 0.1 ppm, F = 0.2 m3/h, and RH = 65% with no secondary pollution. The study provided a theoretical and experimental basis for the application of DBD plasma for air purification in the built environment.


Atmosphere ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 742 ◽  
Author(s):  
Ewa Brągoszewska ◽  
Magdalena Bogacka ◽  
Krzysztof Pikoń

Air pollution, a by-product of economic growth, generates an enormous environmental cost in Poland. The issue of healthy living spaces and indoor air quality (IAQ) is a global concern because people spend approximately 90% of their time indoors. An increasingly popular method to improve IAQ is to use air purifiers (APs). Indoor air is often polluted by bioaerosols (e.g., viruses, bacteria, fungi), which are a major concern for public health. This work presents research on culturable bacterial aerosol (CBA) samples collected from dwellings with or without active APs during the 2019 summer season. The CBA samples were collected using a six-stage Andersen cascade impactor (ACI). The CBA concentrations were expressed as Colony Forming Units (CFU) per cubic metre of air. The average concentration of CBA in dwellings when the AP was active was 450–570 CFU/m3, whereas the average concentration when the AP was not active was 920–1000 CFU/m3. IAQ, when the APs were active, was on average almost 50% better than in cases where there were no procedures to decrease the concentration of air pollutants. Moreover, the obtained results of the particle size distribution (PSD) of CBA indicate that the use of APs reduced the proportion of the respirable fraction (the particles < 3.3 µm) by about 16%. Life cycle assessment (LCA) was used to assess the ecological cost of air purification. Our conceptual approach addresses the impact of indoor air pollution on human health and estimates the ecological cost of APs and air pollution prevention policies.


Sign in / Sign up

Export Citation Format

Share Document