This is scientific American 60 second science. I'm Dina Feinmaren. Got a minute?

A small but growing market exists on the internet for human breast milk.

Now a study finds that buyers should

really beware. Some purveyors of breast milk appear to be adulterating the

product with cow's milk. Such bovine contamination is more than just a scam. It can be a health risk for infants

who are allergic to or intolerant of cow's milk. The study, the first document this milk

fraud, is in the journal Pediatrics.

Researchers purchased 102 samples of supposed human breast milk online.

Tests found that 10 of these samples had enough bovine DNA to indicate that at least 10% of the milk in the sample actually came from cows.

Human milk is an ideal source of nutrients for infants, when it's safe.

Prior studies on breast milk purchased online have revealed dangerous amounts of bacterial growth that make it unsuitable for infant consumption.

Since no one typically screens these internet sold milk products for

pathogens or other contamination, it's up to consumers to protect themselves.

Some human milk banks do voluntarily screen their products, so it's best to check with local departments of health to find safe products.

Thanks for the minute. For Scientific American 60 Second Science, I'm Dina Feinmer.