A dust advisory has been issued for Smithers, Telkwa, and Burns Lake.
The Ministry of Environment and the Northern Health Authority say this is due to high concentrations of course particulate matter because of the road dust.
Persons with chronic underlying medical conditions should postpone strenuous exercise and consider staying indoors until the advisory is lifted.
Also, drivers are being asked to reduce the use and idling of vehicles.
The current dusty conditions are caused by road traffic stirring up winter traction materials that have accumulated on roadways over the past winter.
The advisory is expected to last until enough wind or rain can change the conditions.