A new study co-authored by MIT reveals significant disparities in air pollution exposure based on daily mobility patterns. The research, conducted in the Bronx, New York, goes beyond traditional methods that estimate exposure based solely on residential or workplace locations. By using mobile data, the study provides a more detailed picture of how people’s movements throughout the day impact their exposure to air pollutants.
Increased exposure
The study shows that when daily travel is considered, exposure to particulate matter (PM2.5) increases by about 2.4%. The researchers emphasize the study’s strength lies in its detailed tracking of both air quality and human mobility, enabling them to construct trajectories of people’s movements. This approach marks the first time these data have been combined to offer a new measure of pollution exposure.
“People’s daily exposure to pollution is a complex mix of living near, working near, or traveling by sources of particulate matter,” the researchers note. The study collected air pollution data using solar-powered environmental sensors, including optical particle counters and GPS, mounted on New York City’s civic service vehicles in the Bronx. This innovative method demonstrates how cities can use existing fleets as environmental sensors.
To assess how different demographics experience pollution, the researchers analyzed anonymized phone records from 500,000 individuals, generating 500 million daily location records. They found that the southeastern Bronx, heavily intersected by expressways and industries, had the highest levels of particulate matter. The data also revealed disparities in exposure based on ethnicity, with some predominantly Hispanic communities experiencing higher pollution levels. However, significant variations existed even within these communities.
Profound implications
The health implications are profound, as the Bronx has the worst air quality among New York City boroughs, with asthma rates 2.5 times higher than in other areas. “You see the consequences of pollution exposure in the hospitalization rates of adults in the Bronx,” the researchers explain.
While the study was conducted in the fall of 2021, during the COVID-19 pandemic, which may have altered usual mobility patterns, the researchers believe their methodology can be applied to future studies of pollution exposure. They suggest that mobile data and vehicle-mounted sensors offer a cost-effective way to enhance air quality monitoring, leveraging existing infrastructure like cars and buses.
The authors also highlight the potential for this approach to be extended to studies of various air-quality hazards beyond PM2.5 particles. “This opens the door for new analyses in toxicity studies combined with exposure assessments,” they conclude.
