Gary Kazanjian/AP Photo

The Kentucky metro has some of the worst air quality in the country. And it’s crowdsourcing a cure to help its large population of sufferers.

After an extreme respiratory infection in 2015 nearly destroyed her lungs, Dawn Sirek’s asthma was out of control.

Merely getting dressed and brushing her teeth strained her lungs; walking up stairs felt like suffocating. Exercise was out of the question. With her pulmonary function levels at just 35 percent, the Louisville nurse and mother of four was hitting her emergency inhaler dozens of times per day.

“It was all day, every day.”

Part of the problem was that Louisville has some of the worst air quality in the country. An industrial center nestled in the Ohio River Valley, the Kentucky metro* suffers from nasty air inversions. Some 12 percent of the city’s population is diagnosed with asthma, compared to 8 percent of the U.S.

But help came in the form of a newspaper ad for Sirek. A group called AIR Louisville was recruiting asthmatics to test out GPS-enabled medication sensors. An 30-month study* by the city government, a respiratory health start-up called Propeller, and the Institute for Healthy Air Water and Soil hoped to improve Louisville’s respiratory health. Along with nearly 1,200 Louisville residents, Sirek signed up and soon received her sensor.

Attached to her emergency inhaler, the device pinpointed the location, time, weather, and pollutants in the air for every puff she took. The data was relayed to a dashboard app, viewable to individual patients and Propeller healthcare professionals who could intervene in the worst cases.

This was the first time Propeller’s platform had been used on a city scale; mostly it’s used by doctors who specialize in respiratory care. Patients could opt out of sharing their information with the company, though most didn’t.

Within two weeks of receiving her sensor, Sirek got a call. Melissa Williams, a respiratory therapist at Propeller, explained that her use of the rescue inhaler was out of control.

“Some people grow accustomed to a ‘new normal,’” says Williams. “We wanted to help them redefine what it means to be in control.”

Along with sending notifications about bad air quality days, the dashboard helped patients predict asthma patterns by showing them when and where attacks cropped up. The data also help inform their conversations with prescribing physicians. Williams coached Sirek that her doctor might need to adjust her regular asthma medication, since she was using her emergency inhaler so often.

“If I’d not had all that data, I don’t think my providers would have paid attention,” Sirek says. “They’d have said I probably wasn’t compliant with my medication. But I could show that I was.”

The pilot was a runaway success. By late 2016, the end of the study period, participants saw an 82 percent decrease in their use of rescue inhalers, and experienced more than twice as many symptom-free days.

This map shows countywide asthma risk, as measured by the relationship between emergency inhaler puffs resulting from spikes in nitrogen dioxide, sulfur dioxide, and ozone. (AIR Louisville)

While an app that pings patients to stay inside on bad air days sounds practical, it could also mask underlying problems with Louisville’s bad air, and take pressure off leaders to address them. But the study was also designed to help the city take control of its air quality. AIR Louisville gathered data on more than 250,000 emergency inhaler uses, mapping the findings for a neighborhood-level view of countywide pollutant triggers.

The findings clearly show that Louisville’s poor, predominantly African-American west side bears the worst respiratory health risks. Nitrogen dioxide and sulfur dioxide, emitted by rubber and coal-fired power plants near residential neighborhoods, clog the air there and had people reaching for emergency inhalers more than anywhere else. That didn’t surprise the researchers.

But they were struck to find that ozone, the main ingredient in smog, kicked up inhaler puffs across the city, a relationship that had never been charted before. Ozone amplified asthma risk in neighborhoods well beyond the west side, tracking most noticeably with the busy roads and highways that quilt the city.

This map shows countywide asthma risk, as measured by the relationship between emergency inhaler puffs resulting from spikes in ozone alone. (AIR Louisville)

These findings could be used to lobby for regulatory changes that could clean up the air on the industrial west side. “We found that multiple air pollutants became a problem for asthmatic people below the legal limits,” says Veronica Combs, the executive director of the Institute for Healthy Air Water and Soil. And city officials are developing a plan to rein in roadway pollution by designating special freight routes, in the hopes of reducing ozone.

They’ll also review zoning codes to better separate people from emissions, and ramp up tree-planting efforts to absorb CO2 and reduce heat—“vegetative medicine,” as Louisville Mayor Greg Fischer calls it.

Besides increasing the city’s quality of health, cleaning up Louisville’s air “is a cost reduction as well,” says Fischer. High-pollutant days over the course of a year in the Louisville area can yield more than $2.4 million in healthcare costs. Nationwide, “we’re spending way too much on healthcare,” he says. “Cities can lead in the effort to cut back.”

Though Propeller’s therapists are no longer actively intervening with patient care, the app and sensors are available on the market —and the Louisville participants can still check their dashboards anytime. For Sirek, the change has been enormous. Her pulmonary function levels are up to 70-80 percent. And as a nurse, the way she thinks about helping patients has transformed. She wishes she could track insulin shots for diabetics, just as she tracked her own inhaler puffs.

“Not everyone is so aware or informed about their disease,” she says. “This could be life-changing for all kinds of chronic conditions.”

*CORRECTION: A previous version of this article referred to Louisville as the Kentucky capital, and misstated the length of the study.

This article is part of our project, “The Diagnosis,” which is supported by a grant from the Robert Wood Johnson Foundation.

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