Efficacy of a school-based air filtration project on indoor air quality and children's health

Active (intervention group) high-efficiency particulate air (HEPA) filters will be conducted in the classrooms in Primary schools from Monday to Friday for three months. We will choose the Air filter: Aeris 3-IN-1 Pro Air Purifier(Aeris Cleantec, AG, Switzerland). The AERIS 3-IN-1 Pro Air Purifier has 3 layers of filters: pre-filter for large particles, activated carbon deodorization filter for gas and odours, and HEPA filtration with ultra-fine dust filter for ultra-fine dust. Air filters will be checked for functionality by professional personnel before deploying in a school. Researchers will install air filters in the appropriate place in the classroom. During the implementation of the intervention, project staff will be required to switch on and off the air filters, check the quality, and fill in the air filter usage log every day. All purifiers should be switched on 1 h before schoolchildren enter the classroom and switched off after the schoolchildren leave the room. The intervention will be starting at 7:30 and ending at 15:30 from Monday to Friday according to the school schedule. Regular weekly field observations will be made. A research assistant will assess the air filters at the school visits to document functionality and whether the air filters are on at the time of the school visit. If the air filters do not work properly, the research assistant will contact professional personnel repair it. If the air filters are not in correct position, the research assistant will communicate with the school contacts to encourage compliance.