Mothra, note that the FDA's standard for iodine-131 in milk is much, much higher than the EPA's maximum contamination level, based on the assumption that the milk consumption will be short-term. The pertinent update:

The FDA's Derived Intervention Level for iodine-131 in milk is 4700 picoCuries per liter. The EPA's MCL for iodine-131 is 3 picoCuries per liter.

"There are a few reasons that EPA's MCL for I-131 drinking water is different than FDA's DIL for I-131 in any given food," said FDA spokesman Siobhan Delancy by email. "One of them is that EPA assumes a 70 year time period for exposure, so the MCLs are basically for continual, ongoing intake. They are meant to be as low as reasonably achievable while the DILs are meant to assure that no one will reach a specific dose that would warrant protective actions as a result of an event."