Here is a list. It is long. It was posted 04/23/11. Remember, ANY level above normal can harm your health.
One of this blogger's articles was disputed, here is his response: http://blog.alexanderhiggins.com/2011/04/07/higgins-responds-ubc-allegations-article-radiation-ca-drinking-water-rainwater-misleading-15014/
Lots of links below these articles.
In case you missed it, Jonas reported radioactive Jamba Juice in Washington state, contaminated with Americium.