Comment on "China to achieve blue sky in 16 years, says official" (China Daily, Nov 26)

Sixteen years, I'm afraid, is a long time for reducing air pollution. The air pollution level in Mexico City was even worse than that in Beijing. But the city authorities managed to clear the skies in less than nine years.

Besides, vehicles may not be the only major problem that Beijing faces. Air pollution is also caused by industries, power plants and families that use coal, wood or charcoal for cooking and heating.

KANGFUJIE, from China Daily website

Deal with all polluting sources

Only new vehicles are equipped with exhaust pollution control catalytic converters that reduce the level of emissions. There are many cars, trucks and buses in China that don't have catalytic converters yet, and they cause most of the air pollution among vehicles.

Another source of air pollution in China is coal, which is burned to generate electricity and widely used in other industries. The authorities have to deal with all the sources of air pollution if they want to have permanent blue skies.

A READER, from China Daily website