We often picture urban pollution as a monolithic smear of smog. It looks that way, after all, from a descending airplane (or, in extreme circumstances, from an orbiting satellite). Yet actual levels of pollution experienced by people on the ground vary from neighborhood to neighborhood, even from one block to the next. The methane that comes from landfills and the carbon dioxide from refineries of course contribute to the poor air quality hovering over an entire metropolitan region. But live right next to one of those places – or send your kid to school there – and your problem is even worse. Then, factor in the wind.
This is the premise behind an interactive map of the Los Angeles region (best viewed in Chrome) created by Ted Timmons and Tom Marthaler. They've plotted on a single map many of the region's worst polluters: its airports, oil fields, refineries, wastewater treatment plants, superfund sites and oil fields (on a particularly depressing note, there are so many of these last two offenders in the region that Timmons and Marthaler warn the data overload might crash your browser).
Simultaneously, they've mapped those places in the community that are most vulnerable to pollution: schools, hospitals, and parks. The juxtaposition is dispiriting. Here, for instance, is the band of oil wells just west of downtown L.A. (random trivia: the Los Angeles Basin produced one-fifth of the nation's oil supply back in the 1920s). All of the blue houses here are schools, and the crosses hospitals. Each little black smudge below is an oil well that has been capped or buried, some of which are still producing today. Even the inactive, paved-over sites have been prone to seeping toxic gases.
Elsewhere in the city, major oil fields marked on the map by oil rigs are still actively in production.
Timmons and Marthaler would ultimately like to beef up the map to factor in the movement of pollution through wind patterns, to give an even more fine-grained sense of who's at risk not just near polluters but downwind of them.
As our own John Metcalfe has reported, NASA scientists in the L.A. area are already at work trying to map how emissions move through the Los Angeles metro area, in an effort to come up with a precise measurement of the region's carbon footprint. At a more intimate scale, though, this Vector Health map could show how that same picture of pollution impacts the places we should worry about the most.