A spectacular closing ceremony brought the 2008 Beijing Olympics to a close at the weekend, but officials monitoring the air quality in Olympic cities warned residents against giving a huge sigh of relief. "While the air quality in Beijing has improved, there are still large quantities of particulates and sulphur dioxide in the air in both Beijing and Shanghai" warned Fei Changxiao, the diminutive head of China's Air Quality Inspectorate. "Therefore it is important to avoid deep sighs to ensure healthy lungs."

"Jiayou pollution control measures, Jiayou Zhongguo" he added.