EMBARQ, the World Resources Institute's Center for Transport and the Environment, the U.S. Environmental Protection Agency, the Mexico City government, the Mexican Ministry for Environment and Natural Resources (SEMARNAT), and the Center for Sustainable T

La contaminación del aire en la ciudad de México representa cada vez menos una amenaza para la salud de sus habitantes, gracias a las inversiones realizadas en la materia, por mil 200 millones de pesos.

Hong Kong's pollution problem seem utterly hopeless. But other cities have been where it is now – and cleaned up. Five cities who beat their own smog problems give some advice to Hong Kong.

Under the pilot project, a dozen 2001 model buses were fitted with particle traps and fueled with ultra-low sulfur diesel, or ULSD, which was imported for the test. Particle and carbon monoxide emissions were lowered by 90 percent, and emissions of nitro