Wildfire smoke has impacts across America

Just as some cities were about to see relief from the degraded air quality caused by wildfire smoke, another plume is expected to trickle in from the West, highlighting what authorities say is a reality for the remainder of a long and intense wildfire season.

Why it matters: Several studies in recent months are sounding alarms about how harmful microscopic particles from smoke can wreak havoc on the public's health despite being hundreds of miles from the fire sites.

Threat level: Children or older adults, people without air conditioning and those with heart and lung conditions are particularly affected by the smoke plumes.

• Emerging evidence suggests links between disease, death and air pollution. Experts say long-term health effects of exposure to wildfire smoke need to be further studied.
• Bad air can even cause problems among the general population when outside, especially during strenuous exercise. When breathed in, these small particles can penetrate deep into the lungs, which triggers inflammation.
• Hospitalizations and emergency room visits related to smoke air pollution on average are also higher for people further away from wildfires compared to those directly nearby, due to a lack of warning systems of smoke and association of risk, according to a 2020 study.

The big picture: Many U.S. cities from as far east as New York City to as south as New Orleans had recording-breaking heat, which can also reduce air quality.

• Just as the smoke from the Western Canadian fires dwindled, wildfires are expanding in Northern California with the Dixie Fire now ranking as the second-largest blaze in state history.

By the numbers: The number of unhealthy air quality days recorded in 2021 by pollution monitors nationwide is more than double the number to date in each of the last two years, according to the Environmental Protection Agency.

• Denver has been under air quality alerts for more than a month consecutively. Satellite images show a massive amount of smoke over northern Nevada and Utah headed for the Rocky Mountain state over the weekend.
• In Minneapolis, most of the state remains under an "unprecedented" air quality alert thanks to a thick plume of smoke from Canadian wildfires.
• Atmospheric conditions allowed the smoke to be carried by the jetstream and inhabit some states while sparing others. New England states like Vermont are likely to see smoke and haze on and off throughout the summer.

State of play: The smog lingering during the sunrise is a problem if it reaches ground level, where residents risk breathing in microscopic particles burned from the fires, Vivek Shandas, founder and director of the Sustaining Urban Places Research Lab at Portland State University, tells Axios.

The effects of smoke are compounding.

• "Folks who live alongside a freeway getting that dose of air pollution and all of a sudden you add to that a dose of particulate matter that has all kinds of components in it from the burns that have happened and that’s where it gets really severe," he said.

Air quality apps, messages to stay indoors in sealed spaces, air filters and portable filtration systems and respirators are all tools authorities have been using to help inform the public.

• Stronger recommendations may be needed, and the public's familiarity with masks could be an advantage, Jeff Pierce, an atmospheric scientist at Colorado State University, tells Axios.
• A June study in review co-authored by Pierce from Colorado State University shows the use of N95 masks outside could reduce respiratory hospital admissions by as much as 60%.

The bottom line: Any relief from the smoke plumes this summer is temporary, health experts say, emphasizing a need for new solutions as exposure to smoke from bigger wildfires becomes a regular occurrence.