Another 13 children were diagnosed with high blood lead levels in central Chinese city Chenzhou Tuesday, raising the total toll to 191, health authority said Wednesday.

Results of tests at two medical institutions in Chenzhou in Hunan Province over the past week showed that 191 of 423 people had excessive lead levels.

Forty-six, mostly children under 14 and from Haotang Town of Guiyang County, had lead levels so high that they were diagnosed as suffering from lead poisoning, said Chenzhou health bureau in a statement.

A total of 38 remained hospitalized, including three adults who demanded further checks despite normal blood lead levels.

The cases emerged about 10 months after 254 children were found with excessive levels of lead in their blood in the neighboring Jiahe County of Chenzhou in July last year.

As many as 309 factories were polluting the county in 2009.

Three lead plants in Chenzhou were held accountable for discharging lead contamination, which caused the poisoning, said Zhang Jiyao, deputy director of Chenzhou Environmental Protection Bureau.

The three plants had been leveled and the city would overhaul its mining industry and shut down more polluters, said Zhang.

The South China Environmental Supervision Center under the Ministry of Environmental Protection had dispatched a group to investigate the case Monday. Yu Qi, the group leader told Xinhua Wednesday an investigation was under way, but refused to give any further details.

Excessive amount of lead in the blood can cause damage to the digestive, nervous, and reproductive systems and cause stomachaches, anemia and convulsions.