SHANGHAI, March 12 (Xinhua) -- The number of dead pigs collected from Shanghai's Huangpu River has increased to 5,916, Shanghai authorities announced Tuesday.
Workers have been busy collecting the corpses of floating pigs since Friday, and municipal authorities have said the corpses will be disposed of safely.
However, many corpses remain in the river. On Tuesday morning, 20 dead pigs were collected within 10 minutes, most of which had already started to decompose.
'It's common to find one or two dead pigs in the water, but too many corpses were found this time,' said Gao Dongsheng, a worker who has been collecting the dead swine since Friday.
Tags pinned to the ears of the pigs for tracing purposes indicate that they may have come from the upper reaches of the Huangpu River in Jiaxing City, east China's Zhejiang Province. The tags, however, only indicate the animals' birthplace.
Laboratory tests found porcine circovirus, a virus that can spread among pigs but not to human beings, in one water sample taken from the Huangpu River. All other tests showed no signs of irregular contaminants or disease, according to sources with the municipal agricultural commission.
The river is a major source of drinking water for Shanghai, an eastern metropolis of 23 million people.
The city's water quality has not been affected and is safe for human consumption, a local water supply company said.
'The dead pigs will float to the area near the Songpu Bridge, one of the major water intakes of the Huangpu River, if they are not collected in time,' said Chen Zhenlou, a deputy to the National People's Congress and a professor with the College of Resources and Environmental Science, East China Normal University.
An automatic water quality monitoring network should be built to constantly check for changes in relevant indicators, Chen added.