quote:
I have to disagree with what Peter has said here. It is a case of "Size does
not matter".

reply:

Well, I don't have a problem with disagreement. When I post, I do so in the
spirit of inquiry. I do not have the last word on any of this.

However, one must have perspective. If you are talking about PARTS PER
BILLION, you are talking about amounts that are undetectable by ordinary
means.

Finding 5 parts per billion is like looking for a particular family in
China. Finding a needle in a haystack would be easy compared to that. Of
course, some molecules are toxic in smaller amounts than others.

You can eat a teaspoonful of salt, but not of dioxin. Still, there is a
concentration at which dioxin is not dangerous, just as there is an amount
of salt which is poisonous to a human being.

There is also a word for inordinate fear of an item: superstition.
Perspective is what I am talking about, and to have that, one must be
informed. Millions of dollars are spent on determining the lethal doses of
these compunds (LD-50).


Peter Borst