I'm sorry Peter, I have deleted your original message so I can't quote from it. I think you said that "they" trust scientists to measure one part per million but don't trust them to do something else. I just associated myself (and perhaps even my "brigade") with the "they" that you were talking about. I don't know what a EPA and FDA are so can't comment. I think that people with high expectations are prone to being biased. Politicians are typical of this group but they are perhaps more devious. There was quite a high profile case about the honesty of scientists in Britain some years ago. I can't remember the poor man's name but he was crucified for saying what he thought about GM potatoes. Perhaps he was just a brave scientist - perhaps naive - who knows. Harry