Air Date: Week of October 5, 2001

Living on Earth's Diane Toomey reports on an Institute of Medicine finding on a possible link between a vaccine preservative and childhood disorders such as autism.

Transcript

CURWOOD: Coming up, growing tobacco may be hazardous to your health. First, this environmental Health Note with Diane Toomey.

TOOMEY: In recent years, there's been growing concern that disorders such as attention deficit syndrome and autism may be linked to childhood vaccinations. A mercury-based preservative called thimerosal, used in some vaccines, has been a particular concern. Mercury is a known neuro-toxin, but there's been little study on how low doses of the type of mercury used in thimerosal might affect brain development. Now, a recent report from the Institute of Medicine, a branch of the National Academies, says there's no evidence thimerosal has a hand in causing neurological damage. But the report did caution that since mercury accumulates in the body, it is medically plausible, although unproven, that thimerosal exposure could increase the risk of disorders such as autism.

In addition, some children may be unusually vulnerable to mercury exposure because of their genetic make-up. Two years ago, phase-out of children's vaccines containing thimerosal began, although there was a small number of dosages still on the shelf that contain the preservation. As a precaution, the report recommends using non-thimerosal vaccines. But if they're not available, the report emphasizes that the risk from preventable childhood illnesses far outweighs any possible risks from thimerosal. And children should continue to be vaccinated. That's this week's Health Update. I'm Diane Toomey.

CURWOOD: And you're listening to Living on Earth.