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Heat and smoke can be a health hazard — combined it's worse


Smoke and heat are making it unhealthy to breathe in parts of the U.S.


Yeah, the heat wave in the Southwest has spread. Parts of the Midwest and East Coast are getting smoke from Canada's wildfires.

FADEL: And NPR health correspondent Allison Aubrey is joining us this morning to discuss just how unhealthy this all is. Good morning.


FADEL: OK, so we've seen images from Chicago and Detroit, now smoke again in New York and in the D.C. area. How bad is this for people's health?

AUBREY: Sure. Well, in the Chicago area, the air quality index is hovering above 200, which is very unhealthy. In Washington, D.C., right now, it's about 165 - also unhealthy. I spoke to Dr. Ravi Kalhan. He's a pulmonologist at Northwestern Medicine in Chicago. He told me with the heavy smoke and haze, these tiny, minute particles from the forest fires can get into people's lungs. And this can trigger a flare-up for people with asthma or chronic lung disease.

RAVI KALHAN: And associations are pretty clear in the medical literature that if you inhale a bunch of particles - particulate matter - there's a systemic inflammatory reaction in the body that can actually do things like trigger heart attacks and strokes.

AUBREY: He says susceptible adults should limit outdoor exposure, consider masking when going out and invest in high-quality filters or air purifiers for their homes. Bottom line - he tells his patients to limit outdoor activity when air quality index hits a hundred. And right now, in many places, from Chicago to D.C., it's much higher than that. You can check out the air quality in your own town at the website

FADEL: OK, so what about people who don't have asthma or chronic lung disease, generally healthy people? Is the smoke and heat a concern for people who don't have any of these conditions?

AUBREY: Well, short-term exposure to the particulates from the forest fires is manageable, doctors tell me. And air quality is supposed to start improving tomorrow in many parts of the country. But Dr. Kalhan says when the air quality index is at 200, it's the equivalent of smoking about a half pack of cigarettes. And that's not likely to harm someone one time, but what if these exposures keep coming and coming, he asks.

KALHAN: If the frequency of those days increase or if the exposure occurs when the person is younger, spends more time outdoors, then it probably has more long-term impacts on health and creates, you know, a true public health problem that we need to understand.

AUBREY: He's actually starting a big national study to examine how smoke and other environmental factors can impact millennials' lung health.

FADEL: OK, so now that we've discussed all the unhealthiness of the smoke in the air...


FADEL: ...Let's talk about the heat wave and how unhealthy that is, which has been moving north and east. Does the heat combined with the wildfire smoke mean even more work for our lungs?

AUBREY: Well, the high heat can trigger ground-level ozone or smog, which is a gas that is harmful to our health. Smog forms when two types of air pollution - volatile organic compounds and oxides of nitrogen, which come from tailpipes and smokestacks - react with each other in the heat and sunlight. And Dr. Kalhan says this can be dangerous, too.

KALHAN: Ground-level ozone, when inhaled by people, is quite damaging to the respiratory tract. The respiratory epithelium has a very high susceptibility to injury and inflammatory reactions from ground-level ozone.

AUBREY: So when you have heat and wildfire smoke, you have two things that can trigger respiratory problems - the fine particulates from the smoke and the ground-level ozone in the heat. And when conditions are ripe for both to happen at the same time, it stands to reason it can be bad for our health.

FADEL: NPR's Allison Aubrey. Thanks.

AUBREY: Thank you. Transcript provided by NPR, Copyright NPR.

NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.

Leila Fadel is a national correspondent for NPR based in Los Angeles, covering issues of culture, diversity, and race.
Allison Aubrey is a correspondent for NPR News, where her stories can be heard on Morning Edition and All Things Considered. She's also a contributor to the PBS NewsHour and is one of the hosts of NPR's Life Kit.