Particulate Matter in Santiago's Smog

Santiago Smog Moves to the Suburbs Latin Trade, Dec, 1998 by Greg Brown http://www.findarticles.com/p/articles/mi_m0BEK/is_12_6/ai_54760281
"Where indeed? Chile's environmental review board, known as the Conama (Comision Nacional del Medio Ambiente), admits it is far behind and stretched financially on issues such as toxic waste and garbage dumps. Meanwhile, independent university experts note that forcing the purchase of catalytic cars and trucks is not the answer. Some 85% of the pollution infecting the capital is particulate matter--ground-up tire tread, leaves and dust--which hangs in the air after traffic stirs it up. The sheer number of autos and buses moving around in the city pushes pollution counts higher, not simply the volume of exhaust from their tailpipes."
The smog is so dense in the city that when I was visiting in the summer of 2005 and climbed one of the large hills that overlooked the city you could see the sea of smog lapping up against the hills and up to the edge of the Andes. Although catalytic converters are useful for reducing the emissions of NOx, as seen here in the article about Santiago, the smog problem is far reaching past one chemical process. The particulate matter that plays a central role in the smog is not identified. Chemistry can be done to specify what are the main components of the particulate matter and then address directly their sources and create solutions to the problem. The seriousness of addressing all of the factors that contribute to smog is seen here. Simply implementing the use of catalytic converters is not going to take away from the other conditions that contribute to the smog.