The Building Blocks for Bad Air

Estimated reading time: 4 minutes

Plastic building blocks have been a favorite toy for kids wanting to construct everything from the Death Star to the Batmobile. But two University of Utah chemical engineering professors are using building blocks like LEGOs to teach students how to build something infinitely more important — a working air-quality sensor that can detect pollution.

University of Utah chemical assistant professor Kerry Kelly and chemical engineering associate professor (lecturer) Tony Butterfield are visiting Utah high schools this season to help students build a LEGO-type portable air quality sensor. Meanwhile the professors also will leave a higher-grade portable air quality sensor in each of the classrooms they visit to collect data on air quality around Salt Lake County. Researchers hope to create a map of the valley that shows where pollution hot spots are. PHOTO CREDIT: Dan Hixson/University of Utah College of Engineering

This season, assistant professor Kerry Kelly and associate professor (lecturer) Tony Butterfield have launched the AirU program for Salt Lake County high schools in which they visit science classrooms to talk about air quality and help students build a functional air pollution detector kit out of toy blocks and an inexpensive computer board. Beginning this month, the professors also will leave their own low-cost portable air-quality sensor with each classroom they visit so students can test and maintain them as well as collect data for researchers about pollution throughout the Salt Lake Valley.

“The program is meant to illustrate the concepts behind how we detect poor air quality and how the sensors we build as part of our research actually work,” says Butterfield.

Kerry and Butterfield will be visiting two classes at East High School, 840 S. 1300 East, Salt Lake City, in the school’s library, Room #B202, on Tuesday, Feb. 7, from 11:30 a.m. to 1 p.m. Local news media are invited to come where teachers, students and the professors are available for interviews. (School administrators have already granted permission for reporters to attend).

Butterfield says he and chemical engineering high school interns came up with the idea to use generic toy blocks similar to LEGOs for building the portable air quality sensors as a way to make the project more fun.

“We started out with candy containers like Tic Tacs and other things and decided that wouldn’t work,” he says. “Then we realized [toy blocks] were the way to go because they [students] could build them into any shape they want.”

So far, the team has built 15 kits out of the toy blocks, a low-cost Arduino computer board (a low-power computer for hobbyists and educators), LED lights, and a photo resistor that will detect pollution through light scattering. When assembled, these kits can detect the presence of particulate matter in the air. The professors use a small fog machine to demonstrate how the sensor works.

Butterfield and his outreach team of undergraduate students are visiting high schools with kits, while Breathe Utah, a community-based advocacy group for air quality, will bring the kits to middle schools. 

In addition to the toy-block sensors, Kelly, Butterfield and students from the University of Utah’s electrical and computer engineering department also designed and created low-cost portable air pollution monitors that they will begin leaving in each classroom they visit. These monitors — about the size of a small box of tissues — are similarly powered by a low-cost computer board but are higher-grade than the toy-block monitors and have sensors that can specifically detect and measure particulate matter, temperature, humidity, carbon monoxide and nitrogen dioxide. They also are equipped with GPS and will be connected to the Internet wirelessly. The professors will ask the students to maintain the sensors and help test their reliability.

Ultimately, Butterfield and Kelly want to distribute as many as 50 of their research-grade sensors in schools around Salt Lake County to track pollution throughout the valley. They also want to eventually sell the kits for personal home use once they get the cost down. Next winter, the team hopes to store the air-quality data on a server and display the results on a map in order to show where the valley’s hot spots are for pollution.

“We don’t want to just put a black box inside of their classroom and have them collect data from that. We want to create authentic citizen scientists,” Butterfield says. “To do that they first need to know how the sensor we’re giving them works. By helping them build it, we will give them a deep understanding of what the low-cost-sensor data means. Then they can better troubleshoot it and come up with better hypotheses to test.”

Last spring, Salt Lake City’s air quality was ranked sixth worst in the nation, according to the latest State of the Air report from the American Lung Association. A combination of topographic and meteorological factors create inversions during the winter, trapping pollution in the Salt Lake Valley.