Billboards often line busy roads and highways where there's lots of traffic — and by association, lots of air pollution. But what if those billboards could be transformed into giant air purifiers, scrubbing the air and turning polluted areas into fresh ones? That's the idea behind a new billboard archetype created by researchers at UTEC, the University of Engineering and Technology of Peru, reports Time

The project is the brainchild of the same clean tech researchers who last year invented a billboard capable of generating drinkable water out of thin air. That billboard generated up to 26 gallons of water a day by collecting humidity from the air. This new billboard is, arguably, even better for the environment. It can purify 100,000 cubic meters of urban air per day, which is equivalent to the work of about 1,200 mature trees!

The billboard's air filtration system is also capable of scrubbing the air of some pretty heavy-duty pollutants, such as the dust, metal and stone particles common around construction zones. Since the "fresh air radius" of the billboard is up to five blocks, it could go a long way toward reducing the health risks to inhabitants of large urban areas.

Lima, Peru, where the first air-purifying billboard is located, is in particular need of the technology. According to the World Meteorological Association, Lima has the highest air pollution levels in all of South America, most of it related to transportation and factories. Hills surrounding the city also trap in the pollution, making a bad situation worse. Overall, the city’s pollution levels are triple the maximum recommended by the World Health Organization.

The billboard works on the basis of simple thermodynamic principles. It makes use of shifts in temperature, pressure and vacuum to scrub the air. Aside from separating pollutants from the air, UTEC claims that the technology can also eliminate 99 percent of airborne bacteria. Even better, the filtration system uses just 2.5 kilowatts (2,500 watts) of electricity per hour, so it's energy-efficient too. 

Researchers also hope that by analyzing the pollutants collected by the billboard, they can better understand air circulation around the city. This could lead to other methods for reducing the accumulation of pollution.

If these early prototypes are successful, one can imagine similar billboards being erected in urban areas around the world. Large cities in the U.S. with poor air quality and high traffic, such as Los Angeles and Houston, would be good places to implement the technology.

Check out the video below, provided by UTEC, for additional information about the billboards:

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