Regional officials have ended an air quality advisory for parts of Metro Vancouver and the Fraser Valley issued Monday due to high levels of ground-level ozone.
The advisory had affected the northeastern municipalities of Metro Vancouver, along with the Central and Eastern Fraser Valley, the Metro Vancouver Regional District said.
Metro Vancouver said the advisory was cancelled because of cooler temperatures and favourable winds.
Ground-level ozone is produced when pollutants generated from burning fuel interact with volatile organic compounds in the presence of sunlight.
It is usually observed at its highest concentrations in the mid-afternoon and early evening on summer days. British Columbia is currently in the midst of a heat wave producing temperatures usually observed in late July or early August.
A wildfire burning near Davis Lake, north of Mission, is also producing smoke that has contributed to hazy conditions in the region’s northeast, but Metro Vancouver said it wasn’t producing enough fine particulate matter to hit the threshold for an advisory.
Residents of the affected areas had been urged to avoid strenuous activity during the afternoon and early evening, especially if breathing is difficult.
People with underlying conditions like asthma, chronic obstructive pulmonary disease or other lung disease, heart disease or diabetes, pregnant people, children and older adults are considered at the highest risk.
People who work outdoors and people experiencing homelessness are also at a higher risk, Metro Vancouver said.