The challenge: how does air quality vary within cities?

Most routine air pollution measurements in cities are collected at a small number of "ambient" monitoring sites that provide information on urban-background concentrations. In the US cities, there are generally 2-3 ambient monitoring sites for every million people. Therefore, despite the fact that air pollution can vary sharply in urban areas, our understanding of how pollution varies at the block-to-block scale is quite limited. This study demonstrates a new approach to filling this data gap by using specially equipped Google Street View cars to map urban air pollution every 30 meters, at 100,000× higher spatial resolution than possible with official monitors.

Article: Apte JS, Messier KP, Gani S, Brauer M, Kirchstetter TW, Lunden MM, Marshall JD, Portier CJ, Vermeulen RCH, Hamburg SP. High resolution air pollution mapping with Google Street View cars: Exploiting big data. Environ. Sci. Tech, 2017. [open access, link]. Selected as ES&T's "Top Environmental Technology Article of 2017."