Creating green roofs in Peru to combat pollution

In 2014, the World Health Organization cited Lima, Peru, a city of almost 10 million, as having the worst air pollution in all of Latin America. Since then, various initiatives have been proposed to relieve the health threats that, literally, hang over the heads of Lima's residents.
http://latinalista.com/new-headline/creating-green-roofs-in-peru-to-combat-pollution