CHRISTOPHER BOOKER: Every night, usually somewhere between dinner time and putting her children to bed, Louisville nurse Dawn Sirek reaches for her inhaler.

DAWN SIREK: It's really simple … and that's it.

CHRISTOPHER BOOKER: On good days, this is only her second dose of a daily asthma maintenance routine. But on bad days, of which there are many, Dawn says she loses count of just how many times she has trouble breathing and needs the inhaler.

DAWN SIREK: I have symptoms every day. It factors into my life every single day. It affects my work, it affects my being a mom. It's awful.

DAWN SIREK: For the past few months, whether it is a good day or a bad one, Dawn's daily battle to breathe has become intricately linked to an innovative partnership of big data and public health.

Sitting atop her inhaler is a tiny GPS transmitter that with each puff passes valuable bits of information that not only helps dawn manage her asthma, but is also helping the city understand why so many of its residents are having trouble breathing.

MELISSA WILLIAMS: This is something that respiratory therapists like me kind of dream about.

CHRISTOPHER BOOKER: Melissa Williams works for Propeller Health, a respiratory health company, and the data collection partner for the program, known as Air Louisville.

MELISSA WILLIAMS: The first thing I do is log in, look at the dashboard. It'll give me a list of all of my patients in the program.

CHRISTOPHER BOOKER: Coupled with a participant's smartphone, the sensor sends the time and location to Propeller's central database – giving patients, doctors, and respiratory therapists like Melissa a day-to-day, real time understanding of just how the city's asthma patients are faring.

Since starting in 2012, Air Louisville has had hundreds of participants and hopes to enroll 1,000 by years end.

MELISSA WILLIAMS: It will show you when they typically have events. It will give you, like, the average temperature, the air quality, weather conditions on those days. So it will help to simplify triggers.

CHRISTOPHER BOOKER: With an estimated 13 percent of the population suffering from asthma, Louisville has one of the highest rates in the country.

Sitting in the Ohio River Valley, the city's unique geography, coupled with a steady flow of pollution from cars, makes the it particularly susceptible to poor air quality.

The American Lung Association ranks Louisville as the nation's 15th worst metropolitan area for air pollution.

TED SMITH: I have counterparts in our Chamber of Commerce, they collect best lists. Right? So Louisville's the best place to raise a poodle.

It's the best place for Asian Bourbon Fusion food. I collected the worst list. Right. And the worst lists are what the Chamber wants to burn all day long.

And so, one of the worst places to live in the country if you have asthma.

CHRISTOPHER BOOKER: For the past four years, as Louisville's first chief of civic innovation, Doctor Ted Smith has spent much of his time thinking how the city might get off of this list.

But Smith says the data-driven asthma hotspot map that resulted from the initial pilot program — brought a few surprises.

TED SMITH: The conventional wisdom around things like asthma, you know, may be, ‘Well, it's all about smoking. Or it's about older housing stock. Or it's about being next to a power plant or something.'

Right? And, you know, it turns out, at least the clustering we saw early was in other parts of our community entirely.

CHRISTOPHER BOOKER: So besides industrial areas and highway intersections, residential areas like this one in Southwest Louisville is a hot spot.

GREG FISCHER: It's been fascinating. Because we're pushing the envelope in terms of learning for the community, so that we could say precisely where do asthma sufferers have the most problem?

And how can we A) advise them about that? But B) mitigate how that might take place?

CHRISTOPHER BOOKER: When you see and look at the hotspots, I'm sure you can kind of correlate this to certain issues that exist within the city, whether that be the existence of a power facility or housing questions.

Do you foresee future battles that will be data-driven?

GREG FISCHER: I wouldn't call them battles. But I would say — call it informed decision making.

Before we didn't have that type of information to make a decision. So it makes people think about planning in a much more thoughtful way.

CHRISTOPHER BOOKER: For asthmatics like Dawn Sirek, this program isn't about lists, rankings, or city planning, it's a new tool to help her to live and breathe easier…

DAWN SIREK: My phone dings every night at 9 o'clock and every morning 9:00 a.m. to remind me to take my inhaler.

And the app that it's on my phone, it will tell me that it's a bad air quality day. And I had never paid attention to that in the past. And now I do.