Manila is one of the world’s five dirtiest cities, but graffiti? That’s not a problem. It’s not that people don’t paint on the walls in the hyper-polluted Philippines capital, because they do. But they do it with a paint that actually eats smog out of the air.
The catalytic paint, called Boysen KNOxOUT, reacts with light and water vapor to filter out nitrogen oxides. An environmental scientist interviewed in this BBC video says it can scrub out 20 percent of polluting nitrogen.
Manila is deploying the paint in the form of massive murals, which are both beautiful and, because of their size, effective. Eleven square feet of paint-covered surface can absorb as much pollution as a full-grown tree, and these murals are close to 11 THOUSAND square feet. If we could get this stuff into the hands of street artists and taggers, it would be like having an army of energetic teenagers planting trees all over the city all day, every day.
Manila's experiment with 'purifying paint', BBC.