Air quality warnings? Here's what to know #shorts

Smoke spreading from hundreds of wildfires in Canada and the northern U.S. is causing haze and unhealthy levels of air quality in at least 17 states from the Midwest to the Mid-Atlantic.

The air quality indexes for unhealthy particulates in the air Friday triggered code red air quality (“unhealthy") to code purple air quality ("very unhealthy") levels from Minnesota to Washington, D.C.

When air quality is at unhealthy levels, health experts advise everyone should limit outdoor activities. When it climbs to code maroon, or “hazardous” air quality levels, everyone should stay indoors.

Luke Montrose, an environmental toxicologist at Colorado State University, told PBS News Hour there are a number of health risks associated with smoke exposure.

“We know it gets into the systemic circulation and likely has impacts on other organs. And we're starting to see some instances where researchers are seeing effects on brain health, mental health and even the reproductive system,” Montrose said.

“This is catastrophic smoke. There are very few spaces that you can go to get away from that kind of smoke. It is going to infiltrate those spaces. Even people who have great immune systems and are really healthy will start to have respiratory effects,” Montrose added.

Symptoms may include sore throats, excessive phlegm, coughing, headaches and brain fog. Children, the elderly and people with chronic illnesses are the most vulnerable.

Experts advise staying indoors, turning on air conditioners and air filters, and wearing N95 masks, especially when going outside.

Storms and a cold front could ease conditions in many areas by Saturday, forecasters say.

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