Personally, I suspect Piven has probably been duped by some alternative medicine people with hyper-sensitive tests. However, don't forget that he is in a contract dispute because he left a show before it was complete. He is well motivated to prove something. While I don't care what Jeremy does with his money or how he manages his health, I do care about the publicity and the credulous media reports. You simply cannot eat enough sushi to get poisoned like he is claiming (unless you are dipping it in an Hg sauce I suppose). We have enough real things to fear in our lives without this crap.
Sandy updates us on this topic on her blog: Junkfoodscience.com. She has some links to actual tests and an article by another favorite website of mine: Quackwatch. Here is a snippet:
Mercury fears have become as ubiquitous as mercury itself, it seems, and truly frightening people. Many victims are being led to believe that they have mercury poisoning through mercury tests that report “high” levels.Go here for the full article.