Low-Cost Device Can Measure Air Pollution Anywhere

Massachusetts Institute of Technology, Cambridge, MA

Researchers have made an open-source version of the “City Scanner” mobile pollution detector that lets people check air quality anywhere, cheaply. Pictured are some examples of the latest version of the device, called Flatburn, as well as a researcher attaching a prototype to a car. (Image: Courtesy of the researchers. Edited by MIT News)

Air pollution is a major public health problem. The World Health Organization has estimated that it leads to over four million premature deaths worldwide annually. Still, it is not always extensively measured. But now an MIT research team is rolling out an open-source version of a low-cost, mobile pollution detector that could enable people to track air quality more widely.

The detector, called Flatburn, can be made by 3D printing or by ordering inexpensive parts. The researchers have now tested and calibrated it in relation to existing state-of-the-art machines and are publicly releasing all the information about it — how to build it, use it, and interpret the data.

“The goal is for community groups or individual citizens anywhere to be able to measure local air pollution, identify its sources, and, ideally, create feedback loops with officials and stakeholders to create cleaner conditions,” said Carlo Ratti, director of MIT’s Senseable City Lab.

“We’ve been doing several pilots around the world, and we have refined a set of prototypes, with hardware, software, and protocols, to make sure the data we collect are robust from an environmental science point of view,” said Simone Mora, a research scientist at Senseable City Lab and co-author of a newly published paper detailing the scanner’s testing process. The Flatburn device is part of a larger project, known as City Scanner, using mobile devices to better understand urban life.

The paper, “Leveraging Machine Learning Algorithms to Advance Low-Cost Air Sensor Calibration in Stationary and Mobile Settings,” appears in the journal Atmospheric Environment.

The Flatburn concept at Senseable City Lab dates back to about 2017, when MIT researchers began prototyping a mobile pollution detector, originally to be deployed on garbage trucks in Cambridge, Massachusetts. The detectors are battery-powered and rechargeable, either from power sources or a solar panel, with data stored on a card in the device that can be accessed remotely.

The current extension of that project involved testing the devices in New York City and the Boston area by seeing how they performed in comparison to already-working pollution detection systems. In New York, the researchers used five detectors to collect 1.6 million data points over four weeks in 2021, working with state officials to compare the results. In Boston, the team used mobile sensors, evaluating the Flatburn devices against a state-of-the-art system deployed by Tufts University along with a state agency.

In both cases, the detectors were set up to measure concentrations of fine particulate matter as well as nitrogen dioxide, over an area of about 10 square meters. Fine particulate matter refers to tiny particles often associated with burning matter from power plants, internal combustion engines, fires, and more.

The research team found that the mobile detectors estimated somewhat lower concentrations of fine particulate matter than the devices already in use, but with a strong enough correlation so that, with adjustments for weather conditions and other factors, the Flatburn devices can produce reliable results.

The researchers found that using the units in a mobile setting — on top of automobiles — means they will have an operating life of six months. They also identified a series of potential issues that people will have to deal with when using the Flatburn detectors generally. These include what the research team calls “drift,” the gradual changing of the detector’s readings over time, as well as “aging,” the more fundamental deterioration in a unit’s physical condition.

Still, the researchers believe the units will function well, and they are providing complete instructions in their release of Flatburn as an open-source tool. That even includes guidance for working with officials, communities, and stakeholders to process the results and attempt to shape action.

For more information, contact Abby Abazorius at This email address is being protected from spambots. You need JavaScript enabled to view it..