Lets not forget the 8 day half-life either. By the time it gets accumulated enough to be harmful the older stuff will be dropping off the backside. Add in production, shipping, processing, bottling, more shipping and sales times even more will have expired leaving a minute trace that would expire in the fridge or you within a couple-3 days.
Exactly -- This is what Nads refuses to grasp. Radioactive Iodine that has been released eight days ago is half as radioactive as stuff released today. Eight days from now its radioactivity will be 25% of the original dose. The decay is more or less binary ; newly released material has a radiation of 1/1 then it falls to 1/2, then 1/4, 1/8, 1/16, 1/32, 1/64 ,1/128 etc etc... So - the iodine that is just showing up now is already on its way to packing 1/4 of the radiation it originally did, and its particles spread over a much wider radius. As new stuff arrives, the existing stuff ceases to be any threat at all - its not going to 'collect' into anything meaningful.
Nads, your theory makes as much sense as a man trying to cool his neighborhood on a hot summer day by throwing a few ice cubes out his window every 20 minutes.