http://www.planetark.org/dailynewsstory.cfm/newsid/16325/story.htm Planet Ark : Mexico must crack down on diesel trucks - scientist
MEXICO: June 7, 2002 MEXICO CITY - Mexico must crack down on smoke-spewing old trucks and buses to see improvement in its 20-year effort to cut pollution in the sprawling capital, a top expert on Mexico City pollution said yesterday. Outdated commercial trucks and buses are top contributors to two of Mexico City's most persistent pollution problems, ozone and fine particles, Mario Molina, an MIT professor and 1995 Nobel laureate for chemistry, said in a speech at a Mexico City university. During the 1990s the Mexico City metropolitan area, which now has about 18 million people and 3.5 million vehicles, lost its place at the top of the most-polluted-cities list as it cracked down on car and factory emissions. The anti-pollution programs greatly reduced levels of lead, sulfur, carbon monoxide, and other pollutants. But levels of fine particles (also known as microparticles) and ozone, have remained stubbornly high, and both are linked to health problems. Mexico City exceeds international ozone level standards nine out of every 10 days. Mexico City, where high altitude and a deep valley geography contribute to air pollution problems, also needs cleaner-burning gasoline, more mass transit solutions, and other measures to curb pollution further, Molina said. But if the urban area could reduce the concentration of microparticles - or fine particles that measure 2.5/1,000ths of a millimeter and penetrate deep into lungs - by 10 percent, that could prevent 2000 heart attacks a year, Molina said. "People with heart problems die on days when particle levels are high. Studies all over the world are very clear on that," he said. Molina said it was not clear which of the many types of tiny particles in the air cause the most trouble for people with heart conditions, but one of the biggest contributors to microparticles in the pollution for the Mexico City metropolitan area comes from diesel trucks and busses. Some 33 percent of microparticle pollution, and 35 percent of oxides of nitrogen pollution in Mexico City come from diesel bus and truck emissions. Oxides of nitrogen exposed to the sun are one of several important precursors for the formation of ozone. He said the federal government currently places no restrictions on commercial trucks that enter the city. He added trucks that circulate in the valley of Mexico City should be forced to pass pollution control tests, go through regular maintenance, be placed on a registry, and eventually phased out. But he said that sort of crackdown would not work unless the government persuaded truckers that they need to contribute to pollution solutions, and unless small commercial truck businesses could tap into low-interest loans to buy new, less-polluting vehicles. Molina acknowledged that a politically viable solution was difficult, however. The Federal government, the government of Mexico City proper, and the government of Mexico state that surrounds much of Mexico City, are each controlled by a different one of Mexico's three biggest political parties. Story by Fiona Ortiz REUTERS NEWS SERVICE ------------------------ Yahoo! Groups Sponsor ---------------------~--> Free $5 Love Reading Risk Free! http://us.click.yahoo.com/3PCXaC/PfREAA/Ey.GAA/9bTolB/TM ---------------------------------------------------------------------~-> Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html Biofuel at WebConX http://www.webconx.com/2000/biofuel/biofuel.htm List messages are archived at the Info-Archive at NNYTech: http://archive.nnytech.net/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
