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MIT Better World

By Genevieve Rajewski

But MIT junior Rebecca Sugrue wasn’t snapping selfies in front of its bubbling lava lake on her recent trip to the Big Island.

Instead Sugrue and six of her classmates were hiking eight miles across the scorched landscape of the Ka’ū Desert, just south of Mt. Kīlauea, to measure the levels of noxious sulfur dioxide emitted by the volcano. “It was surreal,” says Sugrue, of her work in this dramatic environment, undertaken through MIT’s Traveling Research Environmental Experiences program (TREX).

The undergraduate environment program at MIT first started taking students on weeks-long research trips over Independent Activities Period—MIT’s flexible January term better known as IAP—in 2000. “We started offering course credit for TREX a few years back,” notes Jesse Kroll, an associate professor of civil and environmental engineering who has directed the TREX experience for the last several years. As of 2014–2015, TREX became a core requirement for Course 1 (Civil and Environmental Engineering, or CEE).

“TREX is how we first introduce students to fieldwork, which is a critical component of environmental science and environmental engineering,” says Kroll. “Yet it’s often not a part of an undergraduate curriculum because it’s challenging to create a full-on field experience, given that it involves travel and a real investment in time and resources.”

This year, TREX focused on analyzing the risks of human exposure on the Big Island to volcanic smog (or “vog,” as it’s known locally), and also included a module led by CEE assistant professor Benjamin Kocar on assessing arsenic content in the soil, an unfortunate legacy of the days when sugarcane operations used the poison to kill weeds.

Before making the trip to Hawaii, the students spent a week at MIT learning about the environmental challenges of the Big Island, which can go from a desert to a tropical rainforest climate within just a few miles, and building their own air sensors. Designed by graduate students and postdocs in Kroll’s lab, the custom air sensors represent an exciting development in air-quality research. About the size of a tissue box and built for roughly $400 apiece, the sensors can operate on solar-powered batteries—a radical departure from a traditional air-quality monitoring site, which requires its own trailer, roughly the size of an office, and access to line power.

“It means you no longer need a $10,000 or $100,000 piece of equipment to make a measurement,” explains Kroll. “These little air sensors could be put up all over a city or some area or even on people to measure personal exposure.”

Once on the Big Island, the MIT team placed the sensors downwind of the volcano to map the direction, shape, and distribution of the vog plume, with special attention to areas where people live or play. Sulfur dioxide is an irritant that can cause respiratory problems. “Levels are high there, much higher than you’d ever see anywhere on the US mainland,” says Kroll. “I have asthma and on the bad air-quality days, my lungs were burning.”

Before making the trip to Hawaii, TREX students spent a week at MIT building solar-powered air sensors. Photo: M. Scott Brauer
The Traveling Research Environmental Experiences program (TREX), convened during MIT’s flexible January term better known as IAP, is a core requirement for Course 1 (Civil and Environmental Engineering, or CEE). Photo: Megan Spelman

The fabrication process better equipped the students to understand and manipulate the complex data set generated by sampling the air’s sulfur dioxide levels every five seconds. It also helped them better manage the hiccups that occurred once they hit the field, like the fact that the air sensors wouldn’t always save the time of day correctly if the battery was running low. The need to work around device failures is common to real field experience, Kroll notes. In this case, the students had to add an extra solar panel to minimize the chances of that error happening and then, once back at MIT, make some software adjustments to determine the correct time of day for the affected results.

The data analysis that took place back on campus over the spring semester may well have publishable results. It turns out the air quality can vary quite dramatically between nearby spots, much as it might block to block within a city, and depending on the time of day. For the people who live on the Big Island, such data could better inform decisions about safer locations and times for activities.

And for the young scientists themselves, the benefits are perhaps even longer lasting: the experience of working within the environments they seek to understand, and interacting directly with the public whose lives they hope to improve, may influence the way they approach their research for decades to come.

“Local residents would tell us the winds would or wouldn’t come in a certain area—and sometimes that changed our plan,” recalls Sugrue. “Talking to the community that already exists in that area put some of us outside our comfort zone, which is always a great learning opportunity as well.”