By Julian Spector, September 28, 2015
A Google Street View car equipped with Aclima air quality sensors, photographed in Denver in 2014.
To make cities safer from air pollution, urban planners need to know exactly where the damaging particles originate and how they move through the air. A new partnership between Google and San Francisco-based air sensor company Aclima promises to collect that data and make it publicly available.
Google Street View cars equipped with Aclima mobile air sensors will map pollution at the neighborhood level in Los Angeles, San Francisco, and California’s Central Valley, Aclima CEO and co-founder Davida Herzl announced at the Clinton Global Initiative on Monday. The resulting data will appear on Google Earth Engine for scientists to examine, while everyone will be able to track environmental health where they live through street-level air pollution maps on Google Earth and Google Maps. The project is already underway in San Francisco and is set to expand in 2016.
“Today when you look at an air quality index you're seeing data compiled that's based on a model, and what limited data is available,” Herzl tells CityLab via email. “As scientists and modelers gain more data—we hope through our driving—our knowledge base will greatly improve and contribute richer dimension to the models they are creating that inform our understanding of daily air quality.”
Granular, consistent, and reliable dataThat information is especially needed in the places Aclima and Google chose for the pilot. Those California regions rank among the American cities most polluted by particulate matter, which scientists have linked to heart disease, lung disease, and premature deaths (L.A. and the Central Valley are heavyweights on the list of ozone pollution, too). Air pollution annually kills approximately 3.3 million people worldwide, and 55,000 in the U.S. alone.
The EPA operates stationary air sensors throughout the country to monitor background air quality for compliance with the Clean Air Act. These expensive and reliable tools don’t have much to say about variations in on-the-ground air quality from street to street and neighborhood to neighborhood. That’s where portable air sensors come in: a new generation of cheaper and smaller sensor technology allows users to track air quality as they move through their days and transmit the data to crowdsourced online databases.
Moving away from authoritative government data sources opens up a set of reliability concerns. It’s hard to know whether a given unofficial sensor is accurate, or if different people’s sensors are calibrated to each other. The Aclima-Google partnership, though, brings the credibility of those two companies to the table—promising to generate more granular data than the EPA sensors, but with more consistency and reliability than crowdsourcing.
Aclima collaborated with Google Street View cars in Denver last year to calibrate the sensors. They collected mobile readings throughout the city, then worked with the EPA to cross-check them with the official government sensors in the area. Having passed that test, the company is ready to scale up the operation.
Google will provide free public access to these data. Scientists can delve into Google Earth Engine’s geospatial analysis tools to overlay air quality readings with years of archived satellite imagery, for instance, seeing how changes in land use relate to present-day pollution. Herzl is particularly excited about the ability to merge public health datasets with new geotagged readings of particulate matter and other pollutants.
“This will really be the first time that we’ll be able to connect these two datasets at scale,” Herzl says.
Informing daily decisionsThe information could drive public policy at the local level, Google Earth Outreach Program Manager Karin Tuxen-Bettman said at a press conference following the announcement. If city governments knew where the dirtiest intersections were, for instance, they could plant buffers of trees to keep fumes away from children playing on a nearby playground. The pollution maps can also inform casual observers on very simple lifestyle choices.
“I’m a mother. If I had an asthmatic child, I would want to know where to take my child to the playground, what time of day is healthier, how to avoid poor air quality, just to be able to avoid asthma attacks,” says Tuxen-Bettman. “I’m a biker. If I want to bike to work, I would want to know how to choose the healthiest route for my trip.”
We’ll have to wait to see how this commitment turns out in practice, but highly granular street-level data on the pollutants that Californians inhale every day could play a huge role in smarter city design. A question as important as whether a new school location is going to damage its students lungs should not be left up to chance.