More than one in 10 children sickened by contaminated milk still showed signs of kidney damage six months afterward, researchers have found, raising concerns about the long-term health effects brought by the country's massive food safety scandal.

At least six children died and nearly 300,000 children fell ill two years ago after consuming infant formula contaminated with the industrial chemical melamine in order to fool inspectors testing for protein.

The study's results point to the possibility that as many as 30,000 children could have suffered health complications for months after drinking the contaminated milk.

Researchers from Peking University studying ultrasound images of infants who fell ill in the 2008 contamination found that while most children in a rural Chinese area fully recovered, about 12 percent still showed kidney abnormalities six months later.

The research report was published in Monday's Canadian Medical Association Journal.

According to the report, the research was conducted in September 2008 in rural areas close to the manufacturer of Sanlu dairy products in Shijiazhuang, which was under the spotlight during the tainted-milk scandal.

The researchers conducted ultrasound screenings on 7,933 local children younger than 3 years old who had exposure to a high level of melamine in dairy products. They found that 48 were suffering from kidney stones, according to the report.

After six months, researchers found that renal abnormalities remained in 12 percent of the affected children.

"Our results suggest a need for further follow-up of affected children to evaluate the possible long-term impact on health, including renal function," said the report.

None of the researchers could be reached for comments Tuesday, as the school is still on winter vacation.

Parents of affected children also expressed worries about their children's long-term health and possible medical costs.

Guo Caihong from central China's Henan Province said her sick three-year-old girl is receiving no care now.

She said the girl had been suffering from kidney stones after drinking Sanlu milk for more than a year.

"I sent her to the hospital in August 2008, when a stone of 13mm was diagnosed in her right kidney. Then after receiving medical treatments in the hospital for about 22 days, my girl was ordered to go home. By then, the stone was still 6mm," Guo told China Daily.

Guo said she is worried about possible long-term impacts on her daughter's health.

"Now it seems nobody cares about my girl, though she has not fully recovered yet. What if problems occur in the future?"

Zhou Xiong, from Wuhan of central China's Hubei Province, is father to a 2-year-old son who has suffered from kidney problems since June 2008, allegedly caused by tainted Sanlu formula. He said that local hospitals will not admit the sick boy.

"The hospital just ordered my son to go home and drink water," he said.

Zhou said he hopes the government can come up with a treatment plan so that sick children like his son will be "insured" in case of any future health problems related to the tainted milk.

The two families were each offered 2,000 yuan (US$290), according to a compensation plan that was offered last year, but both of them turned the money down.

"It doesn't even cover the money spent on the formula, let alone what we've spent on medication," Guo said.

(China Daily February 24, 2010)