Cathy Cahill is an associate professor of chemistry at the University of Alaska Fairbanks. Her research focuses on atmospheric aerosols and their impacts on visibility, global climate and human health, and includes laboratory experiments, modeling, and field studies of atmospheric aerosols and their properties. She is currently investigating the size and composition of particulate matter entering the Arctic from Asia and other continents. In addition, she is quantifying the chemical composition and radiative properties of volcanic aerosols and developing airborne sensors for determining the concentration, composition and potential health effects of atmospheric aerosols.

Cahill sat down with Vice Chancellor Sharpton to discuss her work in atmospheric science, teaching and what her experiences growing up in a science-focused family. Following are excerpts from her interview. To read teh entire interview, please click here.

Sharpton: Start by telling us a little bit about how you got into science. I understand that you come from a family that has a science heritage.

Cahill: I’m what you call a hereditary academic. My father is a professor; my mother is a lawyer, but in her spare time teaches law at the University of California Davis; and my brother is a professor.

We didn’t have a lot of money growing up, so we’d go car camping through national parks. My brother and I went through geology phases and botany phases, and then dad started doing air quality work for the national park service network. That’s when our family vacations became national park car camping with air samplers.

We’d load air samplers in the back of the car and stop at say, Canyonlands National Park—we’d see all the sights and then we’d look for locations to set up air samplers.

Mount St. Helens started erupting in 1980, so my parents loaded me and my brother and four air samplers into our Dodge Aspen station wagon and drove up to stay with my aunt who had an apartment that overlooked the Columbia River with Mount St. Helens in the background.

When the mountain finally had its major eruption, two of the air samplers were buried, never to be seen again, and one caught the perfect sample and dad made Science magazine.

Sharpton: Where did you secure your formal education?

Cahill: My bachelor’s is from University of California Davis, where I started as a chemistry major. They didn’t let us do anything fun so I switched to applied physics where they let us be as dangerous as we wanted to be. So I actually ended up with a degree in applied physics. I wasn’t exactly the most focused student; I had concentrations in physical oceanography, atmospheric science and quantum optics. I had been doing air pollution research as my college job. Instead of flipping burgers, I weighed filters for the National Park Service network. I wanted to take a break from that so I went into physical oceanography at the University of Washington as a grad student. I enjoyed being out on boats, but I wasn’t really enjoying what I was doing. So I said, you know, let’s try atmospheric science.

I was still thinking about doing ocean-atmosphere interactions, but more on the atmospheric side, but Peter Hobbs was looking for a student and at the end of my first quarter he asked me what projects I was interested in. I chose the Kuwait oil fires aerosol data, and I was right back into aerosols. I got my master’s on that particular project and wanted some hands-on experience in terms of my Ph.D., so I went to the University of Nevada Reno where I worked at the Desert Research Institute.

Sharpton: Let’s talk about how you take your approach to science and apply it to issues that are relevant to Alaska.

Cahill: When I came up here, I’d done a lot of work with visibility. So I got ahold of the Denali data and started looking at it and seeing what was going on. The National Park Service was trying to protect Denali and ensure the park stayed pristine.

I looked at how clean the park is, what kinds of things are impacting air quality and what we can do about it. Arctic haze is a well-known phenomenon in which European and northern Russian emissions get swept around the pole during winter. They cross Alaska. So you will see metals and other things that are anthropogenic and occur every winter. This was documented by several researchers in the seventies, so I figured I’d see that, but every spring I was seeing soil signatures. I was seeing the elements you find in dust in the aerosol samples that were in Denali. I wondered why I was seeing dust at a time when Alaska is snow covered. It’s that whole “gee, that looks funny” science moment.

What I found was that when I looked at the meteorological trajectories, the air was coming from the Gobi Desert. And then I started to look at the satellite images. We’ve got some beautiful satellite images showing Alaska being completely snow-covered with this huge cloud of brown dust getting swept in behind a front.

In autumn, our cleanest time, we’re basically pristine in Denali. In winter though, it’s Russian emissions and in spring it’s Asian. We can’t control those, so we can’t bring ourselves down to pristine on those. We’re taking good care of our park, but we can’t get it to pristine because it’s beyond our control.

Of course, as China industrializes it’s going to get worse for us. Actually, as the Russian economy has improved it has gotten worse for us. So when the Russian economy tanked, we didn’t get the same arctic haze emissions because they weren’t producing as much. Now that their economy has revved up and they are producing more, they’re producing more pollution too, and we’re downwind. So I’ve done measurements around the state looking for what’s coming in at different times and that’s evolved into looking at all sources of aerosol in the state. So I’m doing studies on wildfire smoke and on volcanoes and other things where I’m looking at local sources and what the impacts are.

Sharpton: Your research has recently taken you back to the Middle East as well, right?

Cahill: It’s taken my samplers back to the Middle East. I’ve been lucky enough to avoid it so far. I have an aversion to the aerosols known as bullets.

Last February we sent two samplers into Baghdad to look at what was in the air. One is designed for looking at elemental composition so we can fingerprint various sources, and the other is meant to look at the biological component, like what fungi, viruses, bacteria and other things are in the air.

So we started sampling on Valentine’s Day of 2008, and when I opened that first box I thought, “Oh my God, I’ve never seen samples this bad.” And I’ve seen samples from Beijing. These had dust flaking off of them because they had just incredibly high concentrations of dust. Your first thought is, these are our guys over there and they’re breathing this. So we’ve been having briefings up to the four-star general level. The commander of the Army Material Command got briefed on what we were doing and said yes, this is exactly what should be done; this is the research in an operational environment; this is for the health of the troops; this is wonderful.

So the samples keep coming in and we’re seeing differences. With this data I can tell you the diurnal cycles. When is the exposure occurring? Is it occurring kind of during rush-hour periods? Is it occurring at night? What wind direction is it occurring under? The health and preventative medicine folks showed that the levels are exceeding the military exposure guidelines consistently, year-round.

Sharpton: Let’s talk more directly about your teaching and service responsibilities. What do you do in those areas?

Cahill: I’m in the department of chemistry and biochemistry. I’m also split with the Geophysical Institute for my research. I’ve taught everything from chemistry for nonscience majors through graduate environmental fate and transport. I primarily teach physical and environmental chemistry with a periodic foray into freshman chemistry, which I enjoy because it lets me blow stuff up. You know, if you can demonstrate a concept, they’re more likely to remember it than if you just talk about it.

Sharpton: You actually blow things up?

Cahill: I actually blow things up. It’s so much more fun. I’ll do things like thermite reactions which produce a lot of smoke and sparks.

Sharpton: Oh, really?

Cahill: We have a neat bunch of students up here. And in the chemistry department, we just have fun students and they’ve got a sense of community, they help each other out. The department really tries to foster that sense of community. We have departmental potlucks at the beginning of the semester and at the end of each semester to have people interact and, you know, realize the faculty aren’t evil tormenters who eat students for breakfast. They actually get to know us.

We require students to do undergraduate research if they want to earn an American Chemical Society-accredited degree. This is an opportunity for students to work one on one with our faculty members and do hands-on work where the answer is not in the back of the book. This leads to papers for the students and lets them realize what the process of science is like. It also lets us write really nice letters of recommendation for the students because we’ve gotten to work with them, to know them, and to say, yes, this person grabbed the bull by the horns and ran. We get a real sense of the student and what their strengths and limitations are.

In terms of service, Fairbanks has a really strong sense of community and I think a lot of us want to do our best to help the community. I’ve done everything from judge science fairs to do the Alaska High School Science Symposium mentoring where I mentor students or judge, depending on what year I’m doing it. I try to make sure that I answer questions from around the country from reporters and other people to try to explain what’s going on. But I really like to help the borough. I serve on the Fairbanks North Star Borough IM and Air Pollution Control Commission. I also sit on an Ash Fall Task Force, which consists of people from the Alaska Volcano Observatory, the U.S. Geological Survey, the Alaska Department of Public Health and the Municipality of Anchorage. There’s just a whole wide variety of things I do to try to help the public, the state and our community. Nationally, I sit on some boards to help set research priorities in various areas, so it’s a case where, in terms of service, I probably do something every week.

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