Air pollution is a major public health problem: the World Health Organization has estimated that it leads to more than 4 million premature deaths worldwide annually. However, it is not always widely measured. But now a research team at MIT is rolling out an open-source version of a low-cost mobile pollution detector that could enable people to track air quality on a larger scale.
The detector, called Flatburn, can be made by 3D printing or by ordering inexpensive parts. The researchers have now tested and calibrated them in relation to the most modern machines in existence, and have published all the information about them – how to build them, use them, 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 conditions that are more sustainable,” says Carlo Ratti, MIT’s Senseable City Director. cleanliness”. laboratory.
“We’ve done several pilot programs around the world, refining a range of prototypes, with hardware, software and protocols, to make sure that the data we collect is robust from an environmental science point of view,” Simon Mora says. , a research scientist at the Senseable City Lab and co-author of a newly published paper detailing the scanner testing process. The Flatburn device is part of a larger project, known as the City Scanner, that uses mobile devices to better understand urban life.
says An Wang, a researcher with the Senseable City Lab and another co-author on the paper.
The paper, “Utilizing Machine Learning Algorithms to Enhance Low-Cost Air Sensor Calibration in Stationary and Mobile Settings” appears in the journal atmospheric environment.
In addition to Wang, Mura, and Rati, the study authors are: Yuki Machida, former research fellow at Senseable City Lab; Priyanka De Souza, assistant professor of urban and regional planning at the University of Colorado at Denver. Tiffany Dohl, researcher in the Massachusetts Department of Environmental Protection and research fellow at Tufts University at the time of the project; Neelakshi Hadda, assistant research professor at Tufts University; Durant, Professor of Civil and Environmental Engineering at Tufts University; and Fabio Duarte, principal research scientist at the Senseable City Lab.
The concept of Flatburn at the Senseable City Lab dates back to around 2017, when MIT researchers began designing prototypes for a portable pollution detector, originally to be deployed on garbage trucks in Cambridge, Massachusetts. The detectors are battery-powered and rechargeable, either from power sources or from solar panels, with data stored on a card in the device that can be accessed remotely.
The current extension of this project involved testing the devices in New York City and the Boston area, by seeing how they performed compared to pollution detection systems already in operation. In New York, researchers used 5 detectors to collect 1.6 million data points over four weeks in 2021, working with state officials to compare results. In Boston, the team used portable sensors to evaluate the Flatburn devices against a state-of-the-art system deployed by Tufts University in collaboration with a government agency.
In both cases, the detectors were set up to measure concentrations of fine particles as well as nitrogen dioxide over an area of about 10 m. Special fine matter refers to the fine particles often associated with combustible matter, from power plants, internal combustion engines in automobiles, fires, and more.
The research team found that the mobile detectors estimated somewhat lower concentrations of fine particulate matter than the devices actually in use, but with sufficiently strong binding that Flatburn devices could produce reliable results, with adjustments for weather conditions and other factors.
“After following their deployment for a few months we can say with confidence that our low-cost monitors should behave the same way [as standard detectors]Wang says. We have a great vision, but we still have to make sure that the data we collect is valid and can be used for regulatory and political purposes.”
Adds Duarte: “If you follow these procedures with low-cost sensors, you can still get enough data to go back to [environmental] Agencies with her, they say, “Let’s talk.” “
The researchers found that using the units in a mobile environment – on top of cars – means they will currently have an operational life of six months. They also identified a series of potential issues that people will have to deal with when using Flatburn detectors in general. These include what the research team calls “drift,” the gradual change in detector readings over time, as well as “aging,” which is the fundamental deterioration in the physical condition of the unit.
However, the researchers believe the modules will work just fine, and they provide full instructions in their release of Flatburn as an open source tool. This also includes guidance for working with officials, communities, and stakeholders to address the findings and try to shape the action.
“It’s very important to engage with the communities, to allow them to think about the sources of pollution,” Mora says.
“The original idea of the project was to democratize environmental data, and that remains the goal,” adds Duarte. “We want people to have the skills to analyze data and engage with communities and officials.”