Smog Eating


A Bloomberg BusinessWeek article. A Building Designed to Eat Smog

There’s a building in Mexico City that “eats smog.”

The Manuel Gea González Hospital has installed a decorative, white facade that’s not only beautiful, it’s also made from a sophisticated new material that helps purify the air. The project, funded by Mexico’s Ministry of Health, is part of a three-year, $20 billion investment into the country’s health infrastructure.

Designed by Berlin-based Elegant Embellishments, the 2,500-square-meter facade is constructed from the firm’s 3D Prosolve 370e (PDF) modules. These modules are coated with a special pigment that, when hit by ambient ultraviolet light, reacts with urban air pollutants, breaking them down into less noxious compounds like carbon dioxide and water. The pigment itself remains unchanged, which means the modules can keep purifying the air for as long as a decade, or until their coating wears off.

The special quasicrystalline geometry of the facade helps facilitate these reactions. “It gives us about a 200 percent increase in surface area,” says Daniel Schwaag, co-director of Elegant Embellishments. “The two factors influencing the overall de-polluting effect are ambient light and pollution, both of which are omni-directional, and … the quasi-randomness of this geometry is very good at catching [light, pollutants, and winds] from all directions.”

The results are nothing to sniff at: Based on third-party testing of their material, Schwaag estimates the facade will neutralize roughly the same amount of smog produced each day by about 8,750 vehicles in Mexico City.

The hospital facade is Elegant Embellishment’s first full-scale installation, but the Berlin firm hopes its white modules will eventually cover more buildings, as well as highways, car parks, and other areas with high levels of pollutants. (Other companies are also making air-purifying paints.)

Smog-eating wall coverings probably won’t save the world, but they could help, and there’s plenty of work to be done. China is suffocating under a thickening blanket of smog; the country estimates that outdoor air pollution in 2010 contributed to more than 1.2 million premature deaths. In the U.S., air quality is improving, according to the recently released State of the Air 2013 report (PDF), but the numbers are still alarming: Nearly 4 in 10 Americans live in areas with unhealthful levels of either ozone or particle pollution.

Meanwhile, Mexico City, once the home of choking smog rumored to kill birds in flight, is doing a remarkable job cleaning up. Back in 1992 the megapolis reported only eight days with good air quality. Last year, that number had risen to 248.