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