Ground Level Ozone Warning Issued

August 9, 2017

The ongoing Air Quality Advisory for Metro Vancouver and the Fraser Valley has been updated once again to include concentrations of ground-level ozone. High levels of fine particulate matter (PM 2.5) continue to persist as outflow winds transport smoke from wildfires burning in the BC Interior.  

Ground-level ozone is not emitted directly into the air. It is formed when nitrogen oxides (pollutants emitted when fuels are burned) and volatile organic compounds (emitted from solvents) react in the air in the presence of sunlight. The highest levels of ground-level ozone are generally observed between mid-afternoon and early evening on summer days.

The public is advised to avoid strenuous outdoor activities, particularly during mid-afternoon and early evening when ozone levels are highest. Exposure to ozone and fine particulate matter is particularly a concern for infants, the elderly and those who have underlying medical conditions such as lung disease, heart disease, diabetes or asthma. If you are experiencing symptoms such as chest discomfort, shortness of breath, coughing or wheezing, follow the advice of your healthcare provider. As we are in the summer season with warm temperatures, it is also important to stay cool and hydrated. Indoor spaces with air conditioning may offer relief from both heat and air pollution.

This advisory is expected to continue until there is a change in the current weather.