VERIFY | Breathing smoke-filled air on the East Coast is not quite the same as smoking cigarettes

WASHINGTON — Breathing the smoke-filled air that has descended on the East Coast this week is not good for us, but a lot of people online are comparing it to a different kind of smoke.

THE QUESTION

Is breathing air polluted by wildfire smoke the same as smoking cigarettes?

THE SOURCES

ANSWER

Breathing air filled with wildfire smoke is similar but not the same as smoking cigarettes

WHAT WE FOUND

Smoke from wildfires in Alberta drifted over much of the Northeast U.S. this week, giving the New York sky an eerie orange glow and causing health concerns for millions of people.

A viral tweet seen by more than 45 million people said 24 hours of exposure to the air in New York was equivalent to smoking six cigarettes. A similar tweet from Rep. Ro Khanna (D-California) said spending 24 hours outdoors in that air was the same as smoking a pack of cigarettes, while calling for environmental protection legislation.

The basis of those tweets is likely a 2015 study written by scientists with the nonprofit Berkeley Earth. They published a paper about air pollution in China and created a formula comparing the effect of breathing in polluted air to smoking cigarettes, based on the health impacts of each.

Various apps and online calculators take that formula and let users plug in an air quality index value and a duration of exposure. The calculator then provides the equivalent number of cigarettes for that amount of air pollution.

According to AirNow, a government service that combines data from several federal, state, tribal, and local agencies, the air quality index in Washington D.C. peaked Thursday at 314, and averaged 261 from 5 a.m. to 2 p.m.

This calculator says, if someone was outside during that time, their pollution exposure was the same as if they had smoked four cigarettes.

But Dr. Kirsten Koehler, an associate professor in the department of environmental health and engineering at Johns Hopkins University, says it is not a fair comparison.

"Several approaches have been used to make these comparisons and they can give you a rough sense of how the outdoor air pollution compares to cigarette smoke," she said via email.

"However, the chemical composition of the two types of smoke are not the same, and their impact on health may not be the same. Some health impacts can occur very quickly, while other health impacts happen when someone is exposed at high levels for years. So the comparison isn’t necessarily the same for someone who is exposed to wildfire smoke for a few days compared to someone who has smoked for decades.

"However, those short-term health impacts can still be important, especially for young children, older adults, or individuals with lung or heart conditions.”

In an article on Berkeley Earth's website, one of the study's authors explained that their comparison with air pollution was based on the "health impacts of cigarettes, rather than the amount of PM2.5 (the most deadly pollutant) delivered."

So while neither is good for you, the claim that breathing wildfire smoke is like smoking cigarettes needs additional context.