There are lots of ways to look at measurements for air pollution and different time frames that people and regulators look at. If we look at the weekly average for particulate at the PM 2.5 scale across several PurpleAir sensors, some interesting and troubling trends become evident. Here are some 7 day averages from a sample of sensors in British Columbia and one wild card sensor - downtown Los Angeles near Dodger Stadium. LA is known around the world for the poor quality of its air. Here's what we see. The worst weekly average in Canada can be found in Prince George BC with 16.06. Prince George has an active pulp and paper mill, other significant sources of industrial pollution, and lots of people who burn wood for residential heating. In Parksville we see a weekly average of 10.85. This is mostly a retirement community on Vancouver Island and the readings from this sensor are likely due fully to wood smoke emissions from residential sources. One of our sensor...