Smoke from B.C. forest fires hangs in Calgary on Friday. (CBC)

Smoke from forest fires in British Columbia prompted continuation of a public health advisory from Alberta Health officials on Friday.

Despite the warning, a number of activities in Calgary are scheduled to proceed. Those include an outdoor Christian rock concert, a provincial youth soccer tournament, a bike race and several other cultural and musical events.

"If athletes do need to take a break to use inhalers or catch their breath … there would be a lot of flexibility granted. So in the team meetings that occur before the games that information was given to not only the coaches but the same information was given to the officials," said Karrie Kreutz, one of the organizers of the soccer tournament.

Alberta's chief medical officer first issued a public health warning Thursday, advising people with respiratory or heart-related health conditions to avoid the outdoors if possible.

Thick smoke continued to blow eastward from British Columbia's burning forests and stretched across much of Alberta and, as of Friday, into Saskatchewan.

Air quality early Friday in southern Alberta was ranging from poor in the Calgary area to very poor in Red Deer and Lethbridge, said Bob Myrick, manager of air policy evaluation with Alberta Environment.

"The advisory is in effect until Sunday," he said. "In Calgary you're getting the smoke directly from the Prince George-William's Lake area." He said conditions might improve in some areas Friday afternoon.

Even healthy people were being advised to avoid strenuous outdoor activities, said Alberta's chief medical officer of health, Dr. André Corriveau.

Those who have concerns about the smoke's effects can call Health Link Alberta at 1-866-408-LINK (5465) to speak to a registered nurse.