by Brooke Rogers| CBS11

NORTH TEXAS (CBS11) – The Food and Drug Administration is warning about a common test that may be delivering false negative results.

Children can contract lead poisoning from toys, dirt, paint, even the water in pipes.

For Stefania Motisi, the potential for lead poisoning worries her.

“I think about it all the time. It’s a dangerous thing. Horrible,” says the mother of 17-month-old Alena.

So the news that millions of lead poisoning tests could be compromised made this mom’s list – and many others – a little longer.

The FDA says Magellan Diagnostics’ LeadCare analyzers may have given false negatives. The tests in question: venous, or tests drawn from a patient’s arm, before May 17, 2017.

Pediatrician Julie Linderman says if your child is under 6 and had a negative venous test, as opposed to a finger prick, he or she should be retested.

“A false negative then could mean that your child does have some degree of lead toxicity, and it’s been missed,” Dr. Linderman says. “It can affect the brain. It can lead to ADHD symptoms, behavioral and growth problems.”

The Center for Disease Control estimates that children in 4 million households are exposed to high lead levels. No level is safe for a child.

“The last thing we want to do is subject a child to any type of testing where the results are not reliable,” says Dr. Linderman. “It’s unfortunate, but at the same time, at least this error was discovered with those devices.”

For Motisi, that will mean more questions for her pediatrician at Alena’s next checkup and more tests for lead poisoning, if necessary.

“If I had to, I’ll do it again, just to put my mind at ease,” she says.

If your child was given a finger prick test and it was negative, he or she does not need to be retested, according to the FDA.