Shanghai authorities are under increasing pressure to release detailed information about tests on water in the Huangpu River, from which more than 10,000 dead pigs have been retrieved.
Officials from the water, environmental protection, health and agricultural authorities will meet today to discuss possible publication of test results.
Shanghai's municipal government has insisted water quality in the Huangpu River, which provides water to more than a fifth of the city's residents, has not been affected by the dead pigs.
It said the nine measures of water quality - including turbidity, ammonia-nitrogen level, coli bacillus level and chemical oxygen demand - had tested as normal, without giving specific figures.
Tests for six kinds of virus and five kinds of bacterium, all related to pig diseases, had also been carried out since the first reports of dead pigs in the river at the start of this month. All the tests had so far proved negative.
The authorities said tap water from water plants in the city's Songjiang, Jinshan, Minhang and Fengxian districts, which took water from the river, had met national standards.
"Recently we have received a large number of inquiries from university students and other residents from those four districts asking for concrete information about the water tests," an official from the municipal water authority's inquiries hotline said.
"When I told them that according to the government's publicity regulation, we are required to reply to their inquiries within 15 working days, they became enraged and sometimes scolded me and my colleagues."
Ma Jun , director of the Beijing-based Institute of Public and Environmental Affairs, said Shanghai's government should let the public know more "specific and comprehensive" information about the water tests, rather than giving them vague assurances that there was no problem.
"The public tend to ask why the water quality in the Huangpu River, where so many dead pigs were floating, hasn't deteriorated," Ma said.
"In the circumstances, the authorities should release more details and should do it more frequently."
He also suggested that independent institutions should be invited to conduct water tests to ease public concerns.