These particles are small enough to travel deep into the lungs and are a major health concern during wildfire smoke events. This can be useful in a community such as Merritt, where wildfire smoke may move in quickly and conditions can differ from those reported in surrounding areas. Official stations may also monitor several pollutants, including fine particulate matter, ozone and nitrogen dioxide. During wildfire smoke events, uncorrected PurpleAir readings may report higher PM2.5 concentrations than official monitoring equipment. The Herald has reached out to the City for more information about Merritt’s PurpleAir sensor, including how its readings are used locally.