Particulate matter (PM) refers to tiny solid particles and liquid droplets suspended in air, categorized by size: PM10 (10 micrometers or smaller) and PM2.5 (2.5 micrometers or smaller). These particles come from combustion, industrial processes, construction, and natural sources like wildfires. PM2.5 is particularly concerning because particles small enough to penetrate deep into lungs can cause respiratory and cardiovascular problems. Air quality monitoring tracks particulate levels, with health advisories issued during high-pollution periods. Municipalities address particulate matter through emission controls, anti-idling bylaws, road dust management, and construction site regulations. Wildfire smoke has increasingly affected Canadian communities with hazardous particulate levels.