If you stand next to an experimental Google StreetView car in Oakland, you’ll hear whirring. On top of the vehicle–below the usual cameras taking photos of the street–a mechanical system with pumps is pulling in the outdoor air, feeding it through a set of tubes to air-pollution monitoring equipment in the trunk, and then pumping the exhaust back outside again.

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The car is one of two from Google Earth Outreach that Aclima, a San Francisco-based company, equipped with a mobile air-quality platform. Over the last year–as each car drove six to eight hours a day around Oakland, repeatedly sampling every street in one section of the city–researchers collected the largest-ever set of urban air pollution data, and studied how the system could be used to better understand city air quality.

Today, most cities in the U.S. have only a small number of stations that monitor air quality to comply with federal laws like the Clean Air Act. For every million people in an urban area, there are typically only one to four monitoring sites. “That just doesn’t tell you what’s happening within a neighborhood,” says Joshua Apte, an assistant engineering professor at the University of Texas at Austin and lead author of a new paper about the research.

We wanted to know how much you need to drive before you’re not learning anything new. It turns out you don’t need to drive that much before you start to see really consistent patterns in air pollution. Maybe you need to drive down a street 20 times in a year, if you sample randomly. That’s a really small number.

While the company says that the stationary air-quality monitors in use in cities now can cost hundreds of thousands of dollars a year to maintain, the mobile platform can be between 100 and 1,000 times less expensive, while far more detailed. The company is currently working on making the units to quickly scale up and begin installing them in other types of vehicles, in other cities.

Read the source article at fastcompany.com