The face of pollution
Beijing: The World Health Organization has standards that judge an air-quality score above 500 to be more than 20 times the level of particulate matter in the air deemed safe. https://twitter.com/BeijingAir">twitter: @BeijingAir
Chinese officials prefer to publicly release air pollution measurements that give only levels of PM 10, although foreign health and environmental experts say PM 2.5 can be deadlier and more important to track.
There has been a growing outcry among Chinese for municipal governments to release fuller air quality data, in part because of the United States Embassy Twitter feed. As a result, Beijing began announcing PM 2.5 numbers last January. Major Chinese cities have had the equipment to track those levels, but had refused for a long time to release the data.
The existence of the embassy's machine and the @BeijingAir Twitter feed have been a diplomatic sore point for Chinese officials. In July 2009, a Chinese Foreign Ministry official, Wang Shu'ai, told American diplomats to halt the Twitter feed, saying that the data "is not only confusing but also insulting," according to a State Department cable obtained by WikiLeaks. Mr. Wang said the embassy's data could lead to "social consequences."