Particulate matters(PM) air pollution may be measured in PM2.5, PM10 and even PM1.0 level fine particulate matters and dust. The newly ISO 16890 Global Air Filtration Standard classifications are based on where particles are deposited in the human lung. PM1 are extremely fine particles and a major subset of PM2.5 that are likely to reach deeper into the body than PM2.5 making them even more harmful as they can reach other organs through the bloodstream.There are more evidences show that COVID-19 coronavirus also spreads through aerosols. PM1 also possible cause for poor visibility. Now, it becomes mandatory for air quality monitors and air purifiers adopt PM1 as measuring parameters, not only PM2.5 & PM10. Click Here