METRO Vancouver is continuing an Air Quality Advisory for eastern parts of Metro Vancouver and the Fraser Valley because of high concentrations of ground-level ozone that are expected to persist until at least tomorrow.

The air quality advisory has been expanded to include fine particulate matter.  Levels of fine particulate matter may reach advisory levels in parts of Metro Vancouver and the Fraser Valley due to wildfire smoke from outside the region as well as local sources.

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.

Fine particulate matter, also known as PM_2.5, refers to airborne solid or liquid droplets with a diameter of 2.5 micrometres (µm) or less.  PM_2.5 can easily penetrate indoors because of its small size.

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.

Metro Vancouver works in cooperation with Environment and Climate Change Canada,  Fraser Valley Regional District and B.C. Ministry of Environment and Climate Change Strategy to look after air quality.

Information about real-time air quality readings for Metro Vancouver and Fraser Valley communities and potential health impacts can be found at www.airmap.ca and http://www.env.gov.bc.ca/epd/bcairquality/readings/find-stations-map.html.