With New Sensors, A Clearer View Of Air Quality

High-resolution air pollution sensor networks and wearable sensors that give real-time data on common air pollutants could usher in a new generation of air quality studies.

That's what Prof. Drew Gentner is aiming for with a project that begins at the Center for Engineering Innovation & Design (CEID) this semester. With students, he will design and build about 50 stationary air sensors, each smaller than the size of a shoebox. They will also design and build about 15 portable units. These sensors, similar in size to smartphones, will be worn by volunteers in Baltimore as they go about their daily routines.

Most cities have a handful of stationary field sites to monitor air quality. "Single-point measurements of air pollutants have historically been used to represent a whole region or city, and that's been a problem for air quality studies," Gentner said, adding that "new opportunities abound as low-cost sensors become more accurate and precise, so we are pushing to gain access to very powerful information through detailed networks comprising stationary and portable monitors." These types of studies will help elucidate the understanding and monitoring of emission, chemistry, transport, and human exposure.

The effort is one of four core projects of the new Solutions for Energy, Air, Climate, and Health (SEARCH) Center, created with a five-year, $10 million grant from the U.S. Environmental Protection Agency (EPA) to study the relationships between air quality, energy policy, climate change, and public health. Michelle Bell, Mary E. Pinchot Professor of Environmental Health at the Yale School of Forestry & Environmental Studies, will serve as the director of the multidisciplinary research center. Johns Hopkins University and other institutions will serve as partners. It is only one of three centers funded by the EPA.

When the portable sensors are complete, people will be able to wear them for days at a time. The stationary sensors will be located in representative locations around the city: roads, schools and other places where people spend a lot of time. "With these networks we'll have real time measurements, 24 hours a day of the fine spatial, temporal, and chemical resolution on the air pollutants responsible for detrimental effects on human health and climate," said Gentner, Assistant Professor of Chemical & Environmental Engineering, who is also associated with the School of Forestry & Environmental Studies.

Baltimore was the chosen site for sensors partly because of the proximity to SEARCH partner Johns Hopkins University and for the availability of participants from a wide range of backgrounds.

"It will allow us to look at a diverse group of people interacting with transit and the built environment in different ways," he said. "As part of the center, we're very interested in energy-related impacts – how do personal choices and regional-scale choices related to sustainability affect individuals' exposure to air pollution?"

Gentner said the portable sensors should be ready for use in 2017. "We'll be collecting the data for about two years and our subsequent analyses will look at how individual and broader policy choices affect air pollution and human exposure," Gentner said. "This is a big effort going through the end of the decade and we're really excited about it. These sensors have the potential to not only impact this study, but future studies with powerful methods for elucidating air quality."

Go here to read more about the SEARCH Center.