Last summer’s heat wave produced high concentrations of ground-level ozone not seen in Metro Vancouver in more than 30 years.

Ground-level ozone is an air pollutant harmful to human health.

A staff report to Metro Vancouver’s climate action committee recalled that the regional government issued four air quality advisories between June and August 2021.

The advisories were released due to high concentrations of ground-level ozone and particulate matter, also an air contaminant.

Metro Vancouver’s ambient air quality standards sets 82 parts per billion and 62 ppb as targets for one-hour and eight-hour periods, respectively.

The staff report related that on June 28, nine air monitoring stations exceeded the one-hour and eight-hour ambient air quality objectives for ozone.

The record includes a one-hour average of 151.1 ppb at the Maple Ridge station.

“The last time the region experienced ozone concentrations that high was in 1988,” the report stated.

The report was authored by Geoff Doerksen, an air quality planner, and Ken Reid, superintendent for environmental sampling and monitoring.

“While the frequency and severity of ground-level ozone advisories has been reduced in the last two decades due to actions taken to reduce emissions of ozone precursors, the extreme temperatures this year resulted in high ozone concentrations, reaching peak levels not measured since the late 1980s,” Doerksen and Reid wrote.

The report is included in the meeting agenda Friday (November 5) of Metro Vancouver’s climate action committee.