1. IQAir (2023, February 15). 2019 World Air Quality Report (Region & City PM2.5 Ranking). Available online: https://www.iqair.com/world-most-polluted-cities/world-air-quality-report-2019-en.pdf.
2. CDC (2023, February 20). Ventilation in Buildings, Available online: https://www.cdc.gov/coronavirus/2019-ncov/community/ventilation.html.
3. A systematic review on global pollution status of particulate matter-associated potential toxic elements and health perspectives in urban environment;Ali;Environ. Geochem. Health,2019
4. WHO (2023, February 11). Health Effects of Particulate Matter. Available online: https://www.euro.who.int/__data/assets/pdf_file/0006/189051/Health-effects-of-particulate-matter-final-Eng.pdf.
5. (2023, February 11). Manual for Indoor Air Quality Management of Daycare Centers and Children’s Welfare Facilities. Available online: https://www.jgicare.or.kr/bbs/board.php?bo_table=documentorm&wr_id=86&sca=%EB%AC%B8%EC%84%9C%EC%9E%90%EB%A3%8C%EC%8B%A4.