Smoke fills the sky as Stan Kiefer, left, walks with dog, Nelly, and Bert Allen on the Nature Trail at Pilot Butte on Tuesday in Bend. “I was up here yesterday. I couldn’t see downtown,” Allen said. (Joe Kline/Bulletin photo)

The heavy smoke drifting into Central Oregon from major wildfires in Washington and British Columbia has led to an unhealthy air advisory until noon Thursday, according to the Oregon Department of Environmental Quality.

Statewide, all counties except Coos County are under similar air quality advisories this week.

The dense smoke is considered unhealthy for all residents, but especially those with heart disease, asthma or those older than 65, according to Oregon DEQ spokeswoman Katherine Benenati.

It is important to stay in air-conditioned places and avoid strenuous outdoor activities, Benenati said.

Kirsten Aird, who works in the public health division of the Oregon Health Authority, said under these smoky conditions the state agency recommends people stay indoors, which can be uncomfortable for those without air conditioning.

Aird suggests people without access to air conditioning find public indoor spaces such as libraries or community centers. Even a short time in an air conditioned area can be beneficial, she said.

For those who have air conditioning in their homes, the Oregon Health Authority is advising them to keep the fresh air intake closed and the filter clean to prevent the outdoor smoke from getting inside. A high efficiency particulate air filter or an electro-static precipitator — a kind of filtration device — can also help keep indoor air clean, according to the state health authority.

In addition, people should avoid adding to indoor air pollution by smoking or burning candles, fireplaces and gas stoves, the state health authority warned.

The state health authority is also warning people not to wear paper masks often found in hardware stores. The masks do not protect lungs from smoke, Aird said.

“We do not recommend those,” Aird said. “They are not designed to keep out the small particles.”

People can wear respirators to filter wildfire smoke, but they must be properly fitted and tested by a health-care professional, Aird said.

The smoke-filled skies may start to hinder tourism in the High Desert, but the effects haven’t been felt yet, according to the Central Oregon Visitors Association.

“It might be too early to tell,” Ted Taylor, director of content and communications at COVA, said. “The worst of it just arrived in the last couple of days.”

Some recreational activities have been canceled this week due to the smoke.

On Tuesday, Bend Park and Recreation District had to cancel multiple sports and child-care programs, including Cougar Camp, youth trail biking, Paddlepalooza, youth survival camps and Skyhawks soccer camp.

— Reporter: 541-617-7820, kspurr@bendbulletin.com