Metro Vancouver is continuing the fine particulate matter advisory that has been in effect since September 8 for Metro Vancouver and the Fraser Valley Regional District due to wildfire smoke from outside the region. Wildfire smoke from fires in Washington and Oregon continues to pass through the region, and is expected to continue to impact air quality today. The dense smoke is forecast to begin clearing late this evening and into tomorrow.Smoke levels on Monday are expected to be lower. However, localized smoke concentrations may vary widely across the region as winds and temperatures change, and as wildfire behaviour changes.Fine particulate matter, also known as PM2.5, refers to airborne solid or liquid droplets with a diameter of 2.5 micrometres (µm) or less. PM2.5 can easily penetrate indoors because of its small size.Persons with chronic underlying medical conditions or acute infections such as COVID-19 should postpone or reduce outdoor physical activity until the advisory is lifted, especially if breathing feels uncomfortable. Exposure to PM2.5 is particularly a concern for people with underlying conditions such as lung disease, heart disease, chronic obstructive pulmonary disease (COPD), asthma, and/or diabetes, individuals with respiratory infections such as COVID-19, pregnant women and infants, children, and older adults. Individuals who are socially marginalized may also be at elevated risk.As we are in the summer season with warm temperatures, it is also important to stay cool and hydrated. Indoor spaces with HEPA air cleaner filtration and air conditioning may offer relief from both heat and air pollution, but physical distancing guidelines for COVID-19 should still be observed. If you are experiencing symptoms such as chest discomfort, shortness of breath, coughing or wheezing, seek prompt medical attention. Call 9-1-1 in the case of an emergency.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. To sign up for air quality alerts in your area, go to: http://www.metrovancouver.org/services/air-quality/mailing-list.