Beijing shrouded in a cloud of pollution.<br/> <br />The city, notorious for bad air quality, saw levels far above hazardous conditions over the weekend on an index that measures particulate matter in the air.<br/> <br />A level of 300 is considered dangerous, while the World Health Organization recommends a daily level of no more than 20.<br/> <br />Beijing's air reached 755 over the weekend.<br/> <br />Greenpeace said the pollution was the worst ever recorded in the capital -- largely due to cars and the burning of coal to keep warm in an unusually cold winter.<br/> <br />Dissident artist Ai Weiwei joined outcry over the crisis on Saturday, posting photographs of himself wearing a gas mask on his Twitter page.<br/> <br />(SOUNDBITE) (Mandarin) CHINESE ARTIST AI WEIWEI SAYING:<br/> <br />"I felt really helpless, and the only thing I could do was find a way to express it. I bought the gas mask and wore it on my face to send two messages: one was to let people know how disgusting the situation in Beijing is, the second was to say that every person has the ability to save themselves."<br/> <br />State media reported dramatic increases in patients visiting hospitals with respiratory complaints.<br/> <br />China's cautious media has been unusually bold on the issue, calling on the government to take urgent action to address air quality.
