With over 7 million victims every year, air pollution is on a fast track to becoming the most salient health issue on the global level. Every passing day, urban dwellers breathe in particulate matter (PM), fine particles so dangerous that science still hasn’t found the threshold below which they no longer pose a sanitary risk. Beyond the invaluable cost of human lives, pollution also bears significant financial consequences: from lower life expectancy to the price of healthcare and absenteeism, the degradation of health caused by exterior and interior air pollution represents a yearly aggregate cost of 20 to 30 billion euros.
All eyes are now on states, as the responsibility of implementing the Paris Agreement largely rests on their shoulders, but the struggle against pollution is also taking place at the municipal level. Often considered as the starting point for epidemics and at odds with well-being, cities actually hold the intellectual, human, and financial resources which can allow them to provide urban citizens with a more breathable air. From promoting shorter supply chains to planning green spaces, they hold many of the keys to improving air quality, starting with traffic regulation and controlling the circulation of polluting vehicles. In France, Nantes has opted to extend the validity of public transport tickets from one hour to one day during pollution peaks, while an air quality certificate system implemented this month in Grenoble precludes some vehicles from driving during these episodes.
On the other side of the English Channel, it only took London one week to exceed the maximum pollution threshold authorized by the E.U. for the entire year 2016. No surprise, then, that air quality is one of mayor Sadiq Khan’s top priorities. An effort that begins with increasing public information: electronic displays on bus stops and in tube stations will now show the level of pollution, while a text message system may soon warn fragile populations of dangerously high levels of pollution. In Amsterdam, anyone curious about air quality will only need look up to the trees, soon to be outfitted by startup TreeWifi with birdhouse-shaped sensors that change color depending on air quality.
A successful battle against pollution is contingent upon being able to measure air quality in a precise and local manner, progress made possible as rare fixed sensors and satellite data come to be supplemented and replaced by mobile sensors. This is a welcome evolution for cities, long deprived of a micro vision of the problem. Google has picked up on this need and equipped its Street View vehicles in Los Angeles and San Francisco with sensors collecting data on air quality in individual neighborhoods and streets. Farther east, the MIT Senseable Lab recently used 3G data produced by several million users to calculate New Yorkers’ exposure to PM based on their daily commute and movements throughout the city. The study’s authors called on municipalities to use their findings and methodology to focus resources on the most exposed neighborhoods. Thanks to finer information on air quality, cities will be able to measure the impact of the corrective measures they implement and finally assert themselves as producers of health.
This op-ed first appeared in Urban Snapshot (November2016) by La Fabrique de la Cité.
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