Extra Crispy

Concerns surface over human food

The FDA says that 38 poultry farms in Indiana received contaminated feed from China in early February and fed it to poultry within days of receiving it. Thirty of the farms raise broiler chickens for people to eat. Eight farms raise chickens for breeding.

The FDA says all of the broilers believed to have been fed chicken contaminated with melamine have since been processed into food, and adds the likelihood of illness after eating those chicken is quote "very low."

When melamine first showed up in tainted pet food, it appeared that this might have been an isolated incident, but Chinese business officials have told The New York Times that melamine has been "routinely added" to various types of animal feed there for years. Why? To make buyers think that the protein levels were higher than they actually were, increasing market value.

So why did melamine suddenly start killing pets?

Scientists now say because it was combined with another chemical..

"I think we've identified what we feel is an important and likely underlying positive agent of why the animals are getting sick," said Alan Wildeman, from the University of Guelph.

Scientists from Canada and the U.S. believe they may have unlocked the mystery. They've learned that melamine combined with another contaminant found in the pet food, cyuranic acid, forms crystals in the kidneys.

"What we've done is experiments that show if you take cat urine and you add melamine to it and cyuranic acid, the crystals will form in the cat urine in a test tube as we're watching them, so it happens within a matter of hours," Wildeman said.

The crystals are suspected of killing the pets. The ASPCA has just seen a case that suggests that's exactly what happened.