Air quality changes constantly. It could be safe to walk down one block, but the next one over could be so polluted that you need a mask. With so much variance, it’s difficult to measure air quality on the hyperlocal, block by block level–a problem for anyone trying to gauge pollution in cities.
But what if cars themselves had air-quality sensors? That’s the premise of a pilot study from Google in which the tech company used its Street View cars to map air quality in some of California’s major urban and rural areas, block by block. The results of the pilot reveal a new picture of pollution in the state.
Now, the results are in. Google focused on three areas in California: the San Francisco Bay Area, the Los Angeles metro area, and the Central Valley. Heat maps of these three regions show the level of air quality on the streets on a scale from yellow, which represents high pollution, to blue, which represents low pollution. The maps themselves only show the quality of the air, from blue to yellow, on the roadways themselves. But they still reveal just how much air pollution varies from street to street, making it dangerous to make blanket assertions about the quality of air across an entire city.
Unsurprisingly, the highest concentration of pollution in all three of the areas is along major freeways and streets. That’s a problem in Los Angeles in particular, where traffic is horrendous. The city’s geography doesn’t help either. Because the city is located near the ocean in a giant basin surrounded by mountains, pollution tends to get trapped–particularly when pollution is blown inland by the weather.
Aclima plans to continue parsing the data and releasing its analysis online. Google says it’s continuing to focus on collecting air quality data in California, but the company hopes to scale up its efforts. Having access to pollution data on the local level–similar to how we access weather information–could help people make more informed decisions about how to stay healthy. But it all starts with having the data in the first place.