Comment by jerf | Hacker News Reader

Comment by jerf | Hacker News Reader

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Broadly speaking, I would consider the burden of proof to be on those who say that things in concentrations measured in small numbers of parts per billion are really bad and worth panicking over. It may be, it can not be ruled out, but the list of things that you routinely consume, that you can't help but consume, at similar concentrations would blow your mind.

Heck, a complete rundown of every microorganism you just ingested the last time you took a breath would blow your mind. (Mine too. I'd love to see it.)

The world is a dirty, dirty place, and always has been. You aren't a wilting flower, you are the product of billions of generations of organisms that survived, all of which except maybe the last three generations lived in a radically dirtier world than you do. I'm really not that worried about ppb pharmaceuticals in my water; if I'm going to go that route I'm going to finger my food for things like hormones and antibiotics long before my water.

http://www.usatoday.com/news/nation/2008-03-10-drugs-tap-wat...

""" Troubled by drugs discovered in European waters, poisons expert and biologist Francesco Pomati set up an experiment: He exposed developing human kidney cells to a mixture of 13 drugs at levels mimicking those found in Italian rivers.

There were drugs to fight high cholesterol and blood pressure, seizures and depression, pain and infection, and cancer, all in tiny amounts.

The result: The pharmaceutical blend slowed cell growth by up to a third suggesting that scant amounts may exert powerful effects, said Pomati, who works at the University of New South Wales in Sydney, Australia. """

Unfortunately (and I mean that, I wish this style worked better than it does because it is so easy compared to real experiments), that style of experiment is well known for producing useless results.

Think about it; if the water was that poisonous, such that 1/3 of our celluar growth was being eliminated, we wouldn't be speculating about whether our water was killing us, we'd know and long since have taken some sort of action. The strength of the real signal is bounded by the fact that we have millions upon millions upon millions of real people consuming these things every day. Reality always trumps both theory and experiment, and don't ever listen to anybody who forgets that. An experiment that shows an enormous signal, which we can observe in the real world can not possibly be occurring, is far more likely to be a flawed-beyond-usefulness experiment than a real reason for concern.

It is, however, a great way to get in the news.

You get the same problem when some people discover that X causes cancer, except that if you take their results seriously you end up with (metaphorically) 245% of the population dying of cancer X by the time they are 30. Except we don't. Hidden dangers can only be so dangerous.

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