Dr. Paul Hasselback, of the Interior Health Authority, says people should stay away from smoke if they can. (CBC)

B.C.'s Interior Health Authority is closely monitoring the air quality and drinking water in the Okanagan in light of two raging fires in that region.

At a news conference Sunday, Dr. Paul Hasselbeck said people with health problems should try to avoid the smoky air.

"The air quality is continuing to deteriorate as smoke accumulates in the [Okanagan] Valley and that is being monitored closely," he said.

"Advisories probably will be issued and we've already begun to provide the information on necessary or appropriate actions for those people who are more sensitive to poor air quality.

"Health problems do increase as air quality goes down."

In light of the smoky conditions, he said people should avoid any excess exertion, drink lots of fluids and move to cleaner air whenever possible.

Thousands of people were driven from their homes as the wildfire continued to grow Sunday. (Sumbitted by Anna Mason)

Hasselbeck said officials are also continuing to monitor water quality for the presence of fire retardant chemicals. So far, he said, there is no cause for concern.

"Fire retardants are being used in the watershed for one of the water systems and we are monitoring that very closely. It is a newer fire retardant that has fewer potential health concerns compared to some of the fires in the past, but we will continue to monitor [and] test as appropriate," he said.