Environmental officers blamed a Sinopec refinery for a cloud of foul-smelling chemicals that affected many parts of Shanghai on Sunday.
The Shanghai Environmental Protection Bureau said yesterday initial investigations found that the stench was caused by a leak of sulphides, including hydrogen sulphide, at the Sinopec Shanghai Gaoqiao Petrochemical refinery.
Air-quality checks found hydrogen sulphide levels were eight times higher than the prescribed limit, the bureau said, adding that the leak had been stopped.
'The aforementioned substance will, in relatively low concentrations, cause physical discomfort to humans, [but] short-term exposure does not affect human health,' it said. 'Persons responsible for the accident will be seriously dealt with.'
Residents complained of dizziness and nausea, but the municipal health bureau had received no reports of residents falling ill, the Shanghai Daily reported.
The environmental bureau said it conducted a 'rapid investigation' after its hotline received complaints on Sunday afternoon from residents of Pudong, Yangpu, Hongkou, Zhabei and Xuhui districts - covering most of the east and centre of the city.
