Mexico City

Image of the pollution that 150 brick kilns generate in San Luis Potosi, Mexico, Dec 4, 2009. [Photo/icpress.cn]

As a result of accelerated urbanization since the 1980s, Mexico City became one of the most heavily polluted cities in the world for a time as pollutants are further prevented from dispersing due to mountains on its three sides. The city has high concentrations of nearly every major harmful airborne pollutant, including sulfur dioxide, nitrogen oxides and carbon monoxide. By far the worst problem gripping the city is the massive cloud of smog that hangs over it almost every day. Mexico City has the highest level of ground-level ozone in the world, according to WHO.

Effort

 Ecological Balance and Environmental Protection Laws and Anti-Pollution Overall Plan were introduced

 Protection of environmental resources at the strategic level of national security

 Automatic air pollution monitoring system

 Two-Stage Air Emergency Response Program

 Scientific researches concerning environmental protection and new energy development

 Green transportation like "No drive today" since 1989 and vehicles exhaust emission examination every half-year.

Improvement

Statistics show that since the year 1990, lead levels in the air of Mexico City has fallen 90%, while suspended particles that cause asthma, emphysema, or even cancer have been reduced by 70%, and the emission of carbon monoxide and other pollutants has also plunged. The level of ozone has decreased 75% as well since 1992.

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