With a variety of palm-size devices strapped across her chest and connected wirelessly to her smartphone, Gail Merritt discovered the air in Chicago's South Loop might be a lot dirtier than expected.
Merritt and her group of volunteer pollution hunters had assumed the low-cost sensors they carried during daily walks would confirm their fast-growing neighborhood had relatively decent air quality, at least when compared with the gritty industrial corridors in other parts of Chicago.
Color-coded graphs that popped up on Merritt's screen during an unseasonably warm October afternoon told a more complicated story. Something as common as a bus or city garbage truck passing by caused the amount of lung-damaging particulate matter in the air to temporarily jump off the charts.
The volunteers now are eagerly awaiting a review of their handiwork by scientists who oversaw air monitoring in the South Loop and three other Chicago neighborhoods during the past six months. Funded by the U.S. Environmental Protection Agency, the project is part of a nationwide effort to use rapidly developing technology to give people easy-to-access information.
"We came into this thinking we would be a control group they could use to compare to other neighborhoods with environmental justice issues," Merritt said. "Given all of the vehicle and train traffic around us, it looks like we have our own pollution problems."
The EPA began awarding grants during the Obama administration to determine if relatively inexpensive sensors developed by tech startups and hobbyists could supplement a network of official monitors.
Nobody thinks the new technology is reliable enough yet to be used in court or a regulatory proceeding. Rather, researchers and career staff at the EPA see it as a tool for citizens to conduct their own experiments and draw attention to pollution problems that otherwise might not be addressed.
"Doing good, low-cost sensor work is deceptively challenging," said Scott Fruin, a University of Southern California researcher who studies air pollution but isn't involved in the Chicago project. "Many of the sensors are not up to the task."
