Based on the air quality data, the high levels are mainly due to combustion emissions (smoke). Very dry stagnant conditions over the region resulted in particulates accumulating in the air shed. Particulate levels are expected to gradually decrease over the next 24 hour periods. There may be a possibility of relief this even as thunder showers are forecast over the region. The 24 hour PM_2.5 rolling average was 30 µg/m³ at the Plaza 400 downtown site and 21 µg/m³ at College Heights at 4:00 pm. The 24 hour PM₁₀ rolling average was 40 µg/m³ at the Plaza 400 downtown, 31 µg/m³ at BCR and 27 µg/m³ at College Heights. 

 

The Air Quality objective for fine particulates (PM_2.5) is 25 µg/m³ for a 24 hour average. Residents should be aware that advisories are only issued when the air quality objective is exceeded but that the majority of adverse health effects are due to long term exposure to particulate matter starting at levels well below 25 µg/m³

 

Residents are reminded that the City’s Clean Air Bylaw prohibits the use of wood-burning appliances, except for Sole Wood Burning Heat Users, and that open burning; including backyard burning and land clearing burning is banned during Air Quality Advisories. Please note that this advisory also prohibits recreational fires and street sweeping activities. Industry is asked to reduce emissions wherever possible during the air quality advisory.