Mexico City drastically reduced air pollutants since 1990s

By Anne-Marie O'Connor
Washington Post Staff Writer
Thursday, April 1, 2010

MEXICO CITY -- This megalopolis once had the world's worst air, with skies so poisonous that birds dropped dead in flight. Today, efforts to clean the smog are showing visible progress, revealing stunning views of snow-capped volcanoes -- and offering a model for the developing world.

As Mexico prepares to host world leaders at a U.N. climate-change conference later this year, international experts are praising the country's progress. Many say its determined efforts to control auto emissions and other environmental effects of rapid urbanization offer practical lessons to cities in China, India and other fast-growing countries.

International officials say steady improvement of Mexico City's air could bolster President Felipe Calderón's bid for a leadership role among developing countries seeking to address global warming.

"We have seen a lot of improvement. It is very clear," said Luiz Augusto Cassanha Galvao, a senior environmental officer at the Pan-American Health Organization. "On a scale of one to 10, they were at 10, and now they're at five."

Mexican officials have attacked the root causes of pollution that plagues many large urban centers with spiraling growth.

They plan to further reduce vehicle emissions, which are the city's greatest source of pollution. Pemex, the state oil monopoly, plans to build a $9.3 billion plant to produce low-sulfur fuel. Mexico City Mayor Marcelo Ebrard is expanding the low-emissions Metrobus system, which has eliminated 80,000 tons of carbon monoxide annually since 2005. Officials plan to add hybrid buses. A suburban train system is to replace hundreds of thousands of vehicles.

The potential payoff for such efforts is now in sight: Mexico City does not even rank among the top 10 polluted cities worldwide, said Walter Vergara, a leader of the climate-change team at the World Bank, which is aiding public transportation projects in Mexico.

Mexico City appears to have cut most of its pollutants at least by half, said Miguel Naranjo, a Panama City-based official of the U.N. Environment Program, while recent studies show a number of cities in China and India recording higher levels of the most serious pollutants.

"They are having the same problems Mexico had in the past," Naranjo said. "They are growing faster than their capacity to adjust. They face a big challenge not to repeat the mistakes of Mexico."

In 1992, the United Nations declared Mexico City the most polluted on the planet. High ozone levels were thought to cause 1,000 deaths and 35,000 hospitalizations a year. Thermal inversions held a toxic blanket of dirty air over a grimy city that seemed to embody the apocalyptic "Makesicko City" of the fiction of Mexican author Carlos Fuentes.

Mexico was forced to act. It replaced the city's soot-belching old cars, removed lead from gasoline, embraced natural gas, expanded public transportation, and relocated refineries and factories.

Change was gradual, but the pace has quickened in recent years.

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