An air quality advisory for the Fraser Valley has been upgraded to add concerns over wildfire smoke.
Metro Vancouver had initially issued the advisory for its eastern municipalities and the communities of the Fraser Valley on Wednesday due to high concentrations of ground-level ozone.
Ground-level ozone is produced when pollutants react with sunlight during the hot parts of a day.
Now, the region says high concentrations of fine particulate matter (PM2.5) in the eastern Fraser Valley are a concern as well.
Fine particulate matter refers to airborne solid or liquid droplets smaller than 2.5 micrometres in size, which can easily penetrate indoors because they are so small.
Wildfires burning in Aggasiz, Chilliwack and east of Manning Park are contributing to increases in localized smoke, Metro Vancouver said.
In Metro Vancouver itself, wildfire smoke concentrations have not exceeded the region’s guidelines for health and safety.
However, the region said a wildfire burning above Horseshoe Bay may contribute to higher localized concentrations of smoke.
It added that there is a visible haze in the area related to local fires, those in the interior and wildfires burning across the Pacific Northwest.
The ground-level ozone advisory for Coquitlam, Port Coquitlam, Surrey, Langley, Maple Ridge, Pitt Meadows remains in effect.
People in the region are being advised to avoid strenuous activities outdoors, particularly in the mid-afternoon and early evening.
Infants, the elderly and people with health issues such as heart and lung disease are particularly at risk.
Anyone who shows symptoms such as coughing, wheezing, shortness of breath or chest discomfort should seek medical advice.
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