An anonymous reader writes: The Chinese capital of Beijing has issued a "red alert" for air quality within the city, the first time the city has reached the level of caution where it's deemed "unhealthy" for all residents. Starting Tuesday morning, schools will be shut down, the production of smoke will be limited, and cars will be under an odd/even alternate day ban while the local government waits for air quality to improve. It's expected to last until mid-day on Thursday when the weather looks likely to blow it away. "Air pollution monitors showed that areas of Beijing had more than 256 micrograms per cubic metre of the poisonous particles. The World Health Organisation (WHO) says that anything over 25 micrograms is considered unsafe. The poisonous smog in Beijing is caused by the burning of coal for industry and heating, as well as huge amounts of dust from the city's many construction sites. The problem is being made yet worse by high humidity and low wind." The city has been in bad shape for a while now, and Greenpeace called for this very measure a week ago.