China worries about long-term effects of bad milk

"I'm really worried. Consequences of this could last a lifetime," said Fan Xinjia as she cradled her young son in her arms while waiting to return the milk powder at the Sanlu Group headquarters in the northern Chinese city of Shijiazhuang.

"In today's China you can only have one child, so you have to think about what's best for them. But this milk problem could ruin the rest of his life," she added, fanning herself in the hot midday sun.

Hundreds of children have been diagnosed with kidney stones after drinking powdered milk made by the Sanlu Group and tainted with melamine. The toxic chemical takes on the appearance of protein and can fool testers to thinking that the milk product has a higher nutritional content than it actually has.

Scientists however warned that removing kidney stones of the affected babies will not be the end of the story.

"Even after removing large stones, there may still be small stones in the renal tubules in the kidneys, they may cause damage later and overall renal function may be affected," said Wong Kar-yin, a consultant pediatrician at the Queen Mary Hospital in Hong Kong, told Reuters.

"They must be monitored in the long term to ensure that their renal function will not be impaired."

LONG TERM IMPACT
Melamine is an industrial chemical and there is little scientific literature documenting its harm in humans. But in animal tests, it has been linked to kidney stones and damage to the reproductive system.

Associate professor Peter Dingle, an environmental toxicologist at Murdoch University in Perth, Australia, believes melamine may cause damage to the immune system too.

"Formaldehyde, a derivative of melamine, is known to cause respiratory problems in mice. It is a known carcinogen in mice, and if you have been exposed to it for a long period of time, that is a serious concern," Dingle told Reuters.

"It also affects the immune system and anyone who has been exposed to it gets more vulnerable to flu, viruses, bacterial infections and it affects several organs throughout the body."

"Everyday we are exposed to toxins in the air, lead, toxic chemicals and our bodies are constantly breaking them down and getting rid of them. If our immune systems are compromised ... you can't break these (toxins) down," he said.

Some parents were worried if their children may end up malnutritioned - a condition which would make them vulnerable to all sorts of infections later on.

At Shijiazhuang's main children's hospital, parents lined up anxiously with their children waiting to register them at a tent for a medical check-up.

"I'm nervous," said one woman, who asked not to be identified. "What will I do if this stunts my daughter's growth?"

Wong said the children could be malnourished if the formula milk had been their only source of food but he said he has seen no evidence of this from news clips and press photographs of affected children.