Air Quality Reaches Hazardous Levels from Slide Fire

May 28, 2014

The Slide Fire has reached more than 20,000 acres in size and smoke has created dangerous breathing conditions in some areas. As Arizona Public Radio’s Ryan Heinsius reports, the most harmful levels of air quality are expected for Sedona through the rest of the week.

Smoke from the Slide Fire fills Oak Creek Canyon on May 21.
Credit Ryan Heinsius

During daytime hours, winds from the south have blown smoke from the Slide Fire into Flagstaff. But at night, as temperatures cool and winds decrease, the smoke settles into Oak Creek Canyon and drains south. As a result, on recent mornings in Sedona air quality has reached the hazardous level on the Arizona Department of Environmental Quality’s Air Quality Index. This is the agency’s most unsafe category.

Mark Shaffer is the director of communications for the Arizona Department of Environmental Quality. He’s most concerned about particulate matter in the smoke that’s about one-twenty-fifth the diameter of a human hair.

“This kind of matter will deeply imbed into your respiratory system and it can create all kinds of lung and heart problems … Basically, when you get into this hazardous range it affects everyone, whether they’re unhealthy or healthy,” Shaffer says.

For now, he says the best hope for improved air quality is continued progress in suppressing the Slide Fire.

“This probably is going to continue as it has been the past few days. The best hope is that the fire dies down, obviously,” he says.

Shaffer recommends residents of the Sedona area stay inside with windows and doors closed, preferably breathing only filtered air when the smoke is at its worst.

For the most up-to-date information on air quality in northern Arizona, see