The survey hit Chinese shares particularly hard, with the country's Shanghai Composite Index tumbling 2.6 percent to 2, 184.54 and the Shenzhen Composite Index falling 2.7 percent to 923.42.
Fury erupted online at the news, particularly in the wake of other recent pollution scandals, including the discovery of rotting pig carcasses floating in Shanghai's water supply and the choking levels of air quality Beijing experienced earlier this year.