It is an honest question. Is the poison bad for others or only because a pregnant woman or the foetus are exceptionally weak to it?

If it is, why and how do people still live there?

Again, I'm guessing that pregnancy is probably a health condition where everything is under stress, and drinking toxin laced tap water doesn't help.

But lots of people do live there, and from albeit biased observation, they seem happy enough just drinking beer and wine (and maybe bottled water).

I'd say it's probably a red flag for non-pregnant folks too.