Learn with Trojans: How can we tell air pollution is bad for us?

This article is part of our new #LearnWithTrojans series, where we explore public health through student, faculty and alumni activities and research at USC.

We all know breathing dirty air is bad for our health. But do you know how we know this?  Noa Molshatzki, a candidate in the Doctor of Philosophy in Biostatistics program at the University of Southern California, set out to explain how researchers are discovering the link between air pollution and asthma—in a way we can all understand: a cartoon. See the video and transcript below.

Video courtesy Noa Molshatzki, PhD Biostatistics candidate

Air pollution, even at low levels, is linked with asthma and problems breathing, but the “how” part is not entirely clear.

Biomarkers are a promising tool for understanding the “black box” that links air pollution exposure and asthma.

What are biomarkers?

Biomarkers are measurements collected in many common medical tests that help us predict health outcomes. For example, high cholesterol, found in blood tests, is a risk factor for coronary heart disease.
Biomarkers found in exhaled breath are super cool because they are non-invasive. Blowing air into a detector beats blood tests, however—there’s always a “however”—at the moment, data on exhaled breath biomarkers is relatively noisy.
An obvious way to improve accuracy is to improve the measurement tools, but that could be expensive. Another way is to improve the statistical tools used to linking these biomarkers to health outcomes.
I work with exhaled nitric oxide—a breath biomarker that tends to be higher in people exposed to air pollution and higher in people with asthma.

So how does it go?

Exposure to air pollution causes airway inflammation. Airway inflammation causes increased production of nitric oxide in the lungs. This can be detected by simply exhaling into an analyzer.

But, it gets better.

The biological processes that cause nitric oxide production can be described by a physiological mathematical model. So, not only that, nitric oxide helps detect airway inflammation, we can use statistics to learn where exactly in the lungs nitric oxide is produced without actually cutting open a human body.

It takes time to develop asthma.

Tracking exhaled nitric oxide helped us open the black box and see how air pollution exposure causes asthma. And that could give us an early warning sign that something is wrong, way before the disease.

What do I do?

I work on cutting-edge statistical methods to find the best way to perform the exhalation test (Should you breathe fast or slow? How many times?), and find the best way to analyze the results.

My work can dramatically improve our ability to find the links between air pollution, exhaled nitric oxide and asthma.

While my research is focused on exhaled nitric oxide, the statistical methods I work with could be used in a wide range of scientific topics.
Is a career in biostatistics right for you? Learn more about our department’s biostatistics offerings.
Learn more about USC’s environmental health research.
Are you a Department of Population and Public Health Sciences student or alumni? Inquire today about making your own #LearnWithTrojans video!