Topic
3 guides.
EPA's AQI is built for outdoor air and 24-hour averages. The AQI or score on a home monitor is a maker's translation of a live reading. Here is how to read both.
PM10 is every inhalable particle up to 10 micrometers; PM2.5 is the fine fraction inside it. The fine fraction is the bigger health concern, but the coarse part is the dust and pollen you can see.
PM2.5 is the particle size EPA says poses the greatest risk to health. Here are the official limits, what your monitor's number means, and what actually brings it down indoors.
