Wildfire smoke returns to Colorado: "It's happening more frequently"

For several days, thick smoke has plagued Colorado's Front Range.

The haze has been so thick, at times, that views of the mountains have been obstructed for people who might ordinarily have a clear view of the Rockies.

"It is happening more frequently," said Sheryl Magzamen, a professor in Colorado State University's Department of Environmental and Radiological Health. "Climate change is driving these increases in fires in the west."

The haze in Colorado is largely coming from wildfires currently burning in Canada and the Pacific Northwest.

"There's not a whole lot of good that comes out of breathing smoke and Ozone," Magzamen said. "We see increases in hospitalizations, emergency department visits, physician visits."

Some may experience coughing, sneezing, itchy eyes or other relatively minor symptoms from the haze. However, those with more concerning health issues may be at greater risk if exposed to the haze for long periods.

"We are particularly worried about people with asthma and chronic obstructive pulmonary disease," Magzamen said.

Overall, healthy people may not notice any issues when breathing during this time. And, according to Magzamen, there is limited data to fully understand what health risks those people experience as a result of the haze. That's because overall healthy people are far less likely to be hospitalized or visit a doctor during that time, therefore their experiences aren't being documented as frequently.

Magzamen said pregnant women are also more vulnerable during poor air quality days.

"We know smoke can pass the placental barrier and impact the fetus," Magzamen told CBS News Colorado's Dillon Thomas.

Air quality maps created, in part, by Environmental Protection Agency monitors show a clear path for the current haze, showing red and orange low-quality monitors peppered from Washington, headed southeast toward Colorado. The monitors start to return to green and yellow, or better readings, the further you head toward Oklahoma and Arkansas.

"We think about wildfires as an emergency, but smoke is an emergency as well," Magzamen said. "We are getting used to being downwind from fires that are further upwind. We know there are several fires burning in the mountain west, in the U.S. and Canada."

Meteorologists suggest the haze may begin to clear even further on Wednesday and Thursday. However, Magzamen said it isn't clear how likely it is that days in the coming weeks will once again feature the haze.

"It really depends on meteorology and topography," Magzamen said. "The way the winds change can have one community impacted and a nearby community not impacted."