Hong Kong air pollution warning

In Hong Kong Mass Transit Railway stations, you can often see air pollution warnings like this one. On the other hand, in China the government tries not to publicise the subject. They even went to the extent of forcing the World Bank to censor a report which links lung cancer deaths with local air pollution statistics.some information does slip out; last December when the air pollution index in China touched 300, a local newspaper reported that the government was advising people to avoid going outdoors. The WHO maximum safe limit is 20.
this photo was taken on 2011-07-07 at Hong Kong,China