Mapping air pollution with new mobile sensors

Air pollution is dangerous to our health, but we can’t see it and it’s hard to measure. So how do we protect people from it?

EDF and Google Earth Outreach convened a mobile measurement team to assess air pollution at a level of detail that was nearly impossible before.

Seeing pollution mapped this way makes us better advocates for cleaner air and smart development choices.

Cassandra Ely Project lead at EDF

Video: Google Street View cars equipped with Aclima’s environmental sensing platform measured black carbon, nitric oxide, and nitrogen dioxide.

Mobile sensing offers block-by-block insight

Conventionally, stationary air quality monitors provide most of the information we have about air quality in U.S. cities. This new mobile methodology allows us to collect much more data, and to collect it at street level, where people are actually breathing the air. While this data is not meant to be used to show compliance with air quality standards, it helps us better understand where people are at the greatest risk from unhealthy air.

This project is part of EDF’s growing body of work to use sensor technology to advance our environmental mission. For this project, we convened a wide range of partners. Engineers from the University of Texas at Austin worked closely with Aclima to measure and analyze pollution data collected by Google Street View cars. These cars were deployed to areas of Oakland, California, where there are three stationary, regulatory-grade air quality monitors.

Where did we find elevated levels of pollution?

Readings in hand, the research team consulted with community leaders at the West Oakland Environmental Indicators Project (WOEIP), a community-based organization with deep experience in local air pollution issues, to identify potential causes of poor air quality. They highlighted traffic on the freeway, heavy-duty trucks moving through the community, and industrial activities as major sources of pollution that can impact people nearby.

This is one of several spots that caught our interest: High levels of pollutants in an area that includes homes, and this playground, close to industrial warehouses. Any business that relies on heavy-duty diesel trucks can pose a health risk to its neighbors.

Explore: Interactive map and points of interest

Air quality data from Google/Aclima; analysis by Apte et al / EDF. Colors on the map do not correlate to colors on the Air Quality Index.

On this map, the researchers highlighted spots that demonstrate how pockets of higher pollution can form. Many of these locations are near homes, schools and community centers. We collected data during the day on weekdays, and sampled each road an average of 30 times.

How unhealthy are these higher-pollution areas? We know air pollution is linked to health problems. But based on our research to date, we can’t say exactly what the risks are for people who live, work and play nearby. So next, working with additional partners, we’ll analyze health data to examine that question — what are the health implications for people who experience long-term exposure to points of higher pollution like these?