This is a good article to read, if you wish to have facts rather than hysteria.
“Results from screening samples of milk taken in the past week in Spokane, Washington, and in San Luis Obispo County, California, detected radioactive iodine, or iodine-131, at a level 5,000 times lower than the limit set by the U.S. Food and Drug Administration, officials said.
At that level, a person would have to drink 1,000 liters of milk to receive the same amount of radiation as a chest X-ray, said Dr. James Cox, radiation oncologist at Houston’s MD Anderson Cancer Center.
The I-131 isotope has a very short half-life of about eight days, the EPA said, so the level detected in milk and milk products is expected to drop relatively quickly.
“The good news about iodine is, it has a short half-life,” said Curran. “It doesn’t dwell in any biologic system, be it an adult, a child, a cow, for any significant period of time, and at those levels there’s no evidence that there’s any medical significance.””