China Probes 'Mystery' Kidney Stones in Children

China is baffled by a "drastic" rise in the number of infants falling ill with kidney stones in the wake of a tainted milk scandal which killed six children from kidney complications and made hundreds of thousands ill.

China sentenced two people to death last month for their part in producing or selling milk adulterated with melamine, an industrial compound used to cheat nutrition tests. Nearly 300,000 children fell ill with kidney stones and other kidney-related illnesses from drinking the tainted milk last year.

But a recent rash of kidney complaints in children with apparently no link to drinking milk tainted with melamine had puzzled Chinese health experts and prompted a new investigation, the China Daily said on Thursday, citing the Health Ministry.

"We're trying to find out why the number of kidney ailments among babies has risen drastically ... it could be related to feeding habits or families' living environment," the paper quoted Ma Yangchen, a Health Ministry spokesman, as saying.

Chinese quality authorities this week said milk formula produced by Dumex, a unit of France's Danone, was free of melamine after dozens of parents complained that their children had developed kidney stones.

The paper quoted a survey in China's northwestern Gansu province saying that 5.6 percent of children with kidney stones had not drunk any milk formula at all.

Kidney stones are common among adults and diet has been linked to people who are susceptible, but they rarely develop in young children.

The melamine scandal was the latest in a string of food safety failures that have blighted the "made in China" brand in recent years.