The Environmental Protection Agency and the Food and Drug Administration in the U.S. say that very low levels of radiation have turned up in a sample of milk from Washington. But federal officials say consumers should not worry. ...
B.C. nuclear chemist Kris Starosta told CBC News Tuesday that scientists also would be monitoring for the radioactive chemical cesium 137, which can persist in the environment for up to 30 years.
Iodine 131 tends to break down in a matter of weeks.
No point in reading the rest of this rubbish story from the CBC.
Iodine-131 does not "tend to break down in a matter of weeks," it has a half-life of exactly 8.0197 days.
As for "cesium 137 persisting in the environment for up to 30 year," that is sheer misinformation. This isotope has a half-life of 30.17 years, which means that several percent of any given amount will still be around after several hundred years.