Earlier quoted context omitted.
The point is that "detectable" says more about the instrument than anything else. If there's no science that says "one atom of lead anywhere in your body is bad", then saying "detectable" is meaningless. I mean, if you said "we found a detectable number of bullets in half of children", now that would be bad.
> If there's no science that says "one atom of lead anywhere in your body is bad", then saying "detectable" is meaningless. It would be meaningless on that case too. Also meaningless is saying that 2% of the kids have a high level of lead, without saying what "high" means.
Oh, that's simple - it's defined as above the 98th percentile.
(I kid, I hope...)