> I can’t find anything indicating there’s any difference in bioavailability between hot and cold water, or that it’s a concern at all.
Bioavailability of lead salts (like that form when you have a lot of hot water, metallic lead, and other contaminants in a tank for a long time) is higher than of metallic lead.
Similarly, bioavailability of dissolved lead is higher than that of metallic lead particulate. The mechanism we're discussing is metallic lead particulate sitting in water heaters and dissolving.
> I strongly suspect the people who say you shouldn’t drink hot water are just parroting something that may be entirely mumbo jumbo, or may be true in some instances for homes with older plumbing but not anymore.
I suspect the people who say you shouldn't drink hot water have looked at the grody water that comes out when you drain a heater that's sat for a long time and see all the sediment and yuckies that accumulate at the bottom.
I suspect so too and again, their thinking is obviously incorrect. Those sediments and yuckies were all taken out of the hot water supply, but passed right through to the faucet on the cold side.
Every time I drain my water heater, I dumped a bunch of sediment and yuckies down the drain that otherwise would have been in me, if I were drinking from the hot side rather than the cold.
The logic you’re describing is like looking at a gross filter you’re replacing and saying “look at all this junk in the filter, I’m never filtering my drinking water again!”
Filters look gross when you replace them for the exact same reason that hot water tank is full of sediment. It removed them.
> I suspect so too and again, their thinking is obviously incorrect.
That crap usually sits in the bottom of the water heater but it can become less safe with time (e.g. forming lead salts or dissolving lead, as mentioned, or grow legionella cultures). It can also get stirred up and you can get a whole bunch more of it all at once.
It also doesn't all come from the input supply; a lot of it comes from the hot water heater itself corroding over time.
Bioavailability of lead salts (like that form when you have a lot of hot water, metallic lead, and other contaminants in a tank for a long time) is higher than of metallic lead.
Similarly, bioavailability of dissolved lead is higher than that of metallic lead particulate. The mechanism we're discussing is metallic lead particulate sitting in water heaters and dissolving.
> I strongly suspect the people who say you shouldn’t drink hot water are just parroting something that may be entirely mumbo jumbo, or may be true in some instances for homes with older plumbing but not anymore.
I suspect the people who say you shouldn't drink hot water have looked at the grody water that comes out when you drain a heater that's sat for a long time and see all the sediment and yuckies that accumulate at the bottom.