Led by MIT researchers, the study, which focused on New York City, used mobile phone data in an attempt to understand how people’s movement affects urban air pollution.
Based on data collected in 2013, the study broke New York City into 71 districts, finding that exposure to particulate matter in 68 of the 71 districts was different when the movement of people was accounted for. The movement of people into parts of Manhattan, Brooklyn, and areas Queens close to Manhattan increased exposure to PM in those areas, while the movement of people away from Staten Island during the day lowered overall exposure in that area.
The study – titled “Exposure Track: The Impact of Mobile-Device-Based Mobility Patterns on Quantifying Population Exposure to Air Pollution” – marks a turning point for studying urban air pollution, which has traditionally been studied by looking at air quality levels in fixed locations. The researchers combined the phone data with the pollution information collected by the New York City Community Air Survey. The information resulted in the creation of two maps of exposure to PM. One map shows exposure that an immobile population would have while the other shows exposure based on the dynamics of urban mobility.
According to Carlo Ratti, professor at MIT’s Department of Urban Studies and Planning, and director of MIT’s Senseable City Lab, if applied to other studies, the methodology can help to create a more detailed understanding of environmental and urban air pollution. The study also highlights the importance of analyzing transportation systems in relation to PM pollution.
Marguerite Nyhan, a researcher at Harvard’s T.H. Chan School of Public Health, led the study, along with Ratti, among other co-authors. The researchers examined data collected on a variety of wireless devices from different service providers between April and July 2013.