air quality

AirNow’s fire map includes data from PurpleAir sensors (that’s what the small circles represent), and Watch Duty, a nonprofit app for tracking fires, also displays PurpleAir data. But likely due to different calculations and processing delays, the air quality index reported by the same sensors can vary greatly from map to map. For what’s known as PM2.5 pollution, or tiny inhalable particles of smoke and dust, a PurpleAir sensor located south of Los Angeles International Airport simultaneously returned on Monday an air quality index of 28 on AirNow’s website, 20 on WatchDuty, and 5 on PurpleAir’s official page.Each of those…