[swayvil]

How does this obvious badness manifest, exactly?

I can drink water from a lead pipe all day and suffer not even a headache.

EDIT I'm serious. What is the obvious manifestation? Because the manifestations I've heard of aren't so obvious.

[__alexs]

If you do it for decades (or have low pH water?), you will slowly get dumber and probably get dementia or something.

[swayvil]

Yes. But that isn't obvious. I asked for obvious.

Obvious is "every time I do it I get a headache".