Now be fair goomboogo, there is more than me with concerns, I have 13 tanks on my property but wouldn't use tank water unless as MHB stated I got the water analysed.
But you have to admit the lengths home brewers go to, to keep chemicals out, is the plastic HDPE, even though those who 'no chill go over the 74 degrees C into a plastic drum, best not use brass fittings and taps because of the lead content, some won't even use aluminium pots, and a recent thread about using water out of the hot water service for brewing!
Yet it warms the cockles of the heart that we happily make and ingest ethanol, which is metabalised into acetaldehyde and that is a group 1 carcinogen, we are quite happy to run the risk of cardiovascular and liver disease along with damage to our nervous system and accept that we will possibly also gain weight, leading to other ailments.
I might take up smoking, my grandparents smoked all their lives and they are in their nineties now, so there cant be anything wrong with that.