Street artists join the war on Manila smog

Their canvas is a stretch of dingy concrete wall along Manila's main highway, where millions of vehicles stream past every day, belching exhaust that helps to create a noxious, unhealthy smog. But the murals now blooming under the hands of street artists along Epifanio delos Santos Avenue (EDSA) are not only there for art's sake -- they are created with paint that doubles as an air purifier.