The map on this site displays the spatial distribution of PM2.5 concentrations mostly across Canada from both low-cost PurpleAir monitors and the “gold standard” Agency monitors. If there are discrepencies between nearby Agency and PurpleAir monitors, the Agency sensor is considered superior and should be assumed to be correct.
In 2017, several PurpleAir monitors were collocated with the Agency air quality sensor located at Plaza 400 in downtown Prince George, BC. As these collocated monitors are measuring the same air as the Agency sensor, we were able to produce a correction formula for fitting the PurpleAir sensor data to the Agency data. We then applied this formula to the PA observations to produce a corrected output for display on this map.
This project was supervised by Dr. Peter Jackson (UNBC) and consisted of three stages. Initially, 3 PurpleAir monitors were donated by PurpleAir and collocated at Plaza 400 in early 2017. In January 2018, 14 more PurpleAir monitors were purchased and collocated at Plaza 400 alongside the initial 3 installed there. Following a 6-month collocation period at Plaza400, these monitors were dispersed in a network across Prince George and elsewhere in BC. The third stage of this project began in May of 2018 and consisted primarily of building this website and producing the correction formula for the network of PurpleAir monitors in BC. This correction formula was updated again in 2019/2020 following additional work partnering with Environment and Climate Change Canada, including a major update of the website and the addition of monitors across western Canada. Current work in 2020/2021 involves the expansion of the map out to most of eastern Canada, as well as the future update of the PurpleAir correction formula.