PORTLAND, Ore. (KOIN) — An air quality advisory for the Portland and Vancouver metro area has been issued amid higher levels of smog as the region deals with a heat wave.

The Oregon Department of Environmental Quality and Southwest Clean Air Agency issued the advisory Thursday morning and expect smog pollution to reach levels later in the afternoon that could be considered unhealthy for sensitive groups.

Sensitive groups include children, seniors, pregnant women and people with heart disease or respiratory conditions.

Officials also recommend these groups limit their outdoor activity.

Residents in the region are asked to help reduce smog levels by doing things including:

  • Not driving and using public transportation, carpooling or other alternative transportation
  • Not idling their engine if they must drive
  • Refuel vehicles during cooler evening hours
  • Not mowing lawns or using leaf blowers
  • Not painting or doing aerosol spray projects

“Ozone pollution increases throughout the day with exposure to sunlight, so pollution levels tend to be highest during afternoons and early evenings,” officials said in a press release Thursday. “Air quality monitors may show good air quality in the morning, then quickly jump to unhealthy levels later in the day.”