Frequently Asked Questions About Iodine-131 Found in Milk

Is it safe to drink milk?

Yes. People do not need to stop drinking milk because of concerns about radiation at these low levels. The levels of Iodine-131 found in milk are extremely low, and many times less than the FDA intervention level.

What are the levels that would start to affect my thyroid?

The level of Iodine-131 that would affect thyroid health depends on many factors. The developing fetus, newborns, infants, and young children are particularly sensitive to iodine-131. The FDA’s level for intervention is conservative and provides a large safety margin to protect public health.

How long will there be traces of iodine-131 from Japan in milk?

Given the uncertainty related to the nuclear reactors in Japan, we don’t know how levels of Iodine-131 currently seen in milk may change over time. However, we do know that Iodine-131 becomes less radioactive quickly in the environment. We are continuing to monitor milk so that we know when levels go up or down.

Are there any groups of people that are especially sensitive to iodine-131?

The developing fetus, newborns, infants and young children are particularly sensitive to iodine-131. However, levels being measured now are still many times below the FDA intervention level, even for these groups.

Why does Iodine-131 collect in milk?

Airborne Iodine-131 that deposits on pastures may be consumed by dairy cows.  A portion of the Iodine-131 consumed by a cow would then be transferred into the cow’s milk.

Should I drink goat’s milk or other types of milk?

Historically, when cow’s milk has been affected by Iodine-131, so has goat’s milk.

What if I have thyroid disease? Would Iodine-131 affect me any differently?

The effects of Iodine-131 on health depend on many factors.  At this time, levels of Iodine-131 are still many times below the FDA intervention level.  If you have specific questions or concerns, contact your physician.

Page last reviewed: April 4, 2018
Content source: National Center for Environmental Health (NCEH), Emergency Management, Radiation, and Chemical Branch