FILE - In this Jan. 10, 2012 file photo, a man rides an electric bike crossing a street shrouded by haze in Beijing. A senior Chinese environmental official told foreign embassies on Tuesday, June 5, 2012 to stop publishing their own reports on air quality in China, a clear reference to a popular U.S. Embassy Twitter feed that tracks pollution in smoggy Beijing. (AP Photo/Andy Wong, File)Andy Wong/The Associated Press
A senior Chinese official demanded on Tuesday that foreign embassies stop issuing air-pollution readings, saying it was against the law and diplomatic conventions. It was a pointed criticism of a closely watched U.S. embassy index.
The level of air pollution in China's capital varies, depending on the wind, but a cocktail of smokestack emissions, vehicle exhaust, dust and aerosols often blankets the city in a pungent, beige shroud for days on end. Many residents dismiss the common official readings of "slight" pollution in Beijing as grossly understated.
The U.S. embassy has installed a monitoring point on its roof which releases hourly air-quality data via a widely followed Twitter feed. While China tightened air-pollution monitoring standards in January, the official reading and the U.S. embassy reading can often be far apart.
Chinese experts have criticized the single U.S. embassy monitoring point as "unscientific." Deputy Environment Minister Wu Xiaoqing went a step further, saying such readings were illegal and should stop, though he did not directly name the United States.