Taiwan - Public Health recommends indoor CO2 below 800ppm
The COVID-19 epidemic has confirmed that wearing masks, maintaining social distance, and increasing ventilation in indoor spaces can effectively reduce infection.
The latest research from the National Taiwan University School of Public Health puts forward three suggestions, including strengthening ventilation to control indoor carbon dioxide concentration below 800ppm, reducing the number of people in classrooms to one-third, reducing indoor stay time, and increasing outdoor course arrangements.
The Department of Environmental Occupational Medicine, National Taiwan University Hospital, and a research team from the School of Public Health, National Taiwan University, successfully applied kindergarten air quality monitoring data to COVID-19 infection risk assessment. Provided by National Taiwan University Hospital.
COVID-19 can be spread through droplets or aerosols. Past research on kindergartens and elementary schools in Georgia, USA, has shown that mandatory wearing of masks by teachers can reduce the incidence of COVID-19 by 37%, and mandatory wearing of masks by students can reduce the incidence of COVID-19 by 21%. , maintaining safe social distance and table partitions in indoor confined spaces have failed to significantly reduce the incidence of COVID-19.
American research also pointed out that improving classroom ventilation measures can reduce the incidence of COVID-19 by 39%. Opening doors and windows in classrooms or using fans can reduce the incidence of COVID-19 by 35%. Opening doors and windows in classrooms or using fans, and using air purifiers can reduce the incidence of COVID-19. Reduce COVID-19 incidence by 48%.
A research team from the Department of Environmental Occupational Medicine of National Taiwan University Hospital and the School of Public Health of National Taiwan University has successfully applied kindergarten air quality monitoring data to COVID-19 infection risk assessment by continuously monitoring indoor carbon dioxide concentrations and using an epidemiological model to quantify airborne transmission risks in kindergartens, this research was published in the internationally renowned journal "Indoor Air" in November 2024.
Dr. Chen Zongyan, Department of Environmental Occupational Medicine, National Taiwan University Hospital. Provided by National Taiwan University Hospital.
Dr. Chen Zongyan from the Department of Environmental Occupational Medicine of National Taiwan University Hospital explained that this research team conducted continuous indoor air quality monitoring for three months from August to November 2021 in a kindergarten in Taipei City. The study found that the carbon dioxide concentration in the kindergarten classroom increased during the week. It accumulates day by day and reaches its peak in the afternoon. The average carbon dioxide concentration can generally reach more than 850 ppm. The risk increases sharply within 2 hours of starting class.
During class, if teachers and students do not wear masks and maintain social distance in the classroom and other epidemic prevention measures, one person infected with the new coronavirus can transmit the disease to three people (R0 value range is 3.01 to 3.12). To reduce the risk of infection in kindergarten classrooms, the research team made three suggestions. First, the number of people allowed in the classroom needs to be reduced to one-third. In a classroom of about 20 square meters, the number of people allowed in the classroom needs to be reduced from 30 to 2-10 people. , can R0 drop below 1.
Zhan Changquan, a professor at the School of Public Health at National Taiwan University. Provided by National Taiwan University Hospital
Second, in crowded indoor environments, classroom ventilation can be improved by opening windows, installing exhaust fans, air purifiers, etc. Chen Zongyan suggested that indoor carbon dioxide concentration should be reduced to 550–650 ppm. Even if the indoor capacity is full of school children, try to keep it below 800 ppm.
Third, in a classroom of about 20 square meters, the residence time must be reduced from 8 hours to about 3 hours, so that the R0 value can be reduced to less than 1, which means that one infected person cannot infect one person. Therefore, it is recommended that kindergartens can increase outdoor learning courses and reduce long periods of time in the classroom. Control the number of school children indoors and reduce the time they stay indoors.
Professor Su Dacheng, Department of Environmental Occupational Medicine, National Taiwan University Hospital. Provided by National Taiwan University Hospital
Zhan Changquan, a professor at the School of Public Health at National Taiwan University, emphasized that the government needs to formulate anti-epidemic ventilation standards for buildings as soon as possible and update building ventilation equipment. He hopes class suspensions and work suspensions can be reduced.
Translated using Google Translate - original source via this link: https://knews.com.tw/news/F5ED0450A6692D0D66CF1B8C84CC5D69
