Korea’s particulate matter policies remain in need of continued scrutiny, as particulate matter concentrations in Korea, while having trended downward recently, may well increase as the world progresses into recovery from covid-19. Our analysis of particulate matter data and death statistics for the city of Seoul found associations between short-term exposure to low-level particulate matter concentrations and the risk of death in certain sensitive groups. In the United States and Canada, national agencies such as the US Centers for Disease Control and Prevention the US Environmental Protection Agency, Health Canada, and Environment and Climate Change Canada have implemented policies on particulate matter and ambient air pollution and have provided action guidelines specifically tailored to sensitive and socially vulnerable groups in the event of high-level particulate matter concentrations. Assessments of the health hazards of particulate matter should be continuously updated, reflecting the latest findings. Monitoring of particulate matter concentrations needs to be strengthened, and such health services should be provided as to protect sensitive and socially vulnerable groups from exposure to high-level particulate matter concentrations. The system used for inspecting air quality in such public facilities as long-term care facilities and community elderly centers should undergo continuous examination for improvement.