By Peter Blaza
MANILA (Reuters) - 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.
A new paint variant created by local paint manufacturer Boysen contains modified titanium dioxides, which are designed to break down toxic fumes into harmless substances.
Though titanium dioxide is commonly used in regular paint, its molecules in the modified version are micronized, a process that compresses them ten-fold to enhance their intrinsic ability to break down toxic substances when activated by light.
"It acts as a photo catalyst and in the presence of sunlight or artificial lighting it brings down noxious gases such as nitrogen dioxides and other VOCs (volatile organic compounds) in the air," said Patrick Negrete, Boysen Project Management Engineer.
Negrete said that tests in Manila and Europe's busiest thoroughfares reported at least an 18 percent reduction of air pollutants.
Now, the Manila city government has partnered with Boysen to add more murals along the heavily polluted EDSA, part of a decades-old drive to combat air pollution there.
The highway has the highest traffic congestion in the Philippines, with over 2.5 million vehicles passing through daily. The World Health Organization has reported that pollution there is four times greater than recommended safe levels.
According to the United Nations, Manila is one of the world's five most polluted cities, with an estimated four percent of the vast metropolis's disease-related deaths linked to air pollution.
Ten local and foreign artists were invited to design murals covering over 8,000 square meters of walls, columns and bridges along EDSA's choke points, or where it narrows.
Fanciful flowers are among the works taking form in the distinctive green paint.
Company executives acknowledge that while the air-cleaning paint does help, it is far from a permanent solution.
"The best solution is to reduce the level of pollution to start with, to reduce pollutants coming out of cars," said Johnson Ongking, Boysen Vice President.
But the artists involved in creating the highway masterpieces were enthusiastic.
"I hope there would be many more paintings like these -- not just in Manila, but around the world," said Tapio Snellman, a Finnish artist and film maker who volunteered to design one mural.
"Because there's a huge need of air-cleaning paintings, and there's a huge need of visual stimulation of positive and inspiring artwork."
(Reporting by Elaine Lies, editing by Paul Casciato)