[sarah180]

You do this with a proper understanding of statistical power, and you report "no conclusion" when you don't have studies of adequate power. This is not actually a terribly difficult problem with a proper understanding of Bayesian statistics, it just doesn't lead to good headlines, because a lot of the time the answer is "the study couldn't really provide an answer."

[sjeohp]

I'm not saying you're wrong but doesn't that inherently favour the side claiming "there is no problem because you can't prove there's a problem." Until by the time someone can prove there's a problem we already have a generation with lead poisoning or a collapsed ecosystem or whatever it may be.