WASHINGTON — The federal government began widespread testing of the human food supply last week to look for traces of the same contaminant that forced the recall of millions of cans of pet food.
The contaminant, melamine, was also found in several pigs in California and North Carolina that were fed tainted pet food, forcing the quarantine of some animals in both states. Some of the pigs that ate contaminated pet food in California were eaten by consumers who purchased them directly from the farms, according to the California Department of Food and Agriculture. The state said the health risk from such consumption was “minimal,” however.
The Food and Drug Administration was scheduled by the end of last week to begin testing a range of products for human consumption that could contain melamine-contaminated ingredients from China. The ingredients include wheat gluten, corn gluten, corn meal, soy protein and rice bran. The ingredients can be used in a variety of products, including energy bars, pizza dough, protein shakes and other products, according to reports.
“Over the next few weeks, this assignment may expand in size and scope to include other products and other types of proteins as we learn more about this,” said Dr. David Acheson of the FDA's Center for Food Safety and Applied Nutrition in a press conference last week.
The testing is a “proactive” measure, he said, pointing out that none of the contaminated ingredients were known to have been used in the manufacture of foods for humans.
“We believe that it is very important to further raise awareness about food protection and food defense, and that is one of the reasons we are undertaking this assignment,” he said.
Melamine was identified as a contaminant in ingredients used to make pet food that may have killed or sickened several cats and dogs in the U.S. Scraps from the pet food, which the FDA said was shipped to the livestock feed suppliers before the contaminant was identified, were also used in the pig feed that was sent to the farms in California and North Carolina, officials said.
In addition, the FDA said it believed that hogs in South Carolina had been fed contaminated feed and that the feed had also been sent to a poultry farm in Missouri and to hog farms in several other states.
Steve Lyle, a spokesman for the California Department of Food and Agriculture, Sacramento, told SN that 45 individual consumers had purchased pigs that had eaten contaminated food. The pigs were sold at “custom slaughterhouses” that butcher the animals for pig roasts or to meet specific religious requirements.
“It does not appear that any of this product or animal got into the commercial food supply,” he told SN, noting that he believes the situation has been contained in his state. “In California, we think we've got it pretty well-established that it was one pet food manufacturer distributing scraps to one farm.”
Steve Larsen, director of pork safety for the National Pork Board, Des Moines, Iowa, told SN last week that melamine might not be absorbed into the meat of the pigs, minimizing the risk to humans.
“We know that melamine is not fat soluble, so it is most likely broken down in the liver and secreted through the kidneys and the urine,” he said. “So there is a chance that it is not accumulated in the tissues of these animals.”
It was not clear what the risk to humans might be of consumption of other products containing melamine. According to reports, the substance is not a known carcinogen, although it is not permitted for use in food products because it has been known to cause kidney problems and other ailments in some animals.
The pet food recall began March 16 when Menu Foods, a maker of store-brand pet foods, recalled some of its moist pet food products that contained wheat gluten imported from China. The recall has since been expanded to other several other pet food brands. Melamine, a chemical used in the manufacture of plastics and fertilizers, was discovered as a contaminant in the wheat gluten about two weeks after the recall began.
Soon afterward, rice protein concentrate imported from China and also used in pet food was also discovered to have been tainted with melamine. Other similar chemicals have since been found in some pet food ingredients imported from China.
The FDA said it suspects that melamine and the other chemicals might have been intentionally added to the ingredients to create an impression that the products had higher protein content.