It's found everywhere. They've detected DHMO even in the deepest parts of the ocean, and it's been estimated that every single human being alive has at least some of it in their bloodstream. We're fucked.
It turns out it is toxic to humans in large doses, but despite that it is still widely used by industry because it is such a cheap, abundant and potent solvent.
You think dihydrogen monoxide is bad HOH is right there beside it. On average globally around 1000 people a day die as a direct result of HOH exposure. It's estimated to be a contributing factor in around 7% of all deaths. HOH is also impossible to get away from, it's used to make tires, soap, explosives, I couldn't possibly name everything it's in. It's even worse for kids, HOH kills more children than adults per capita. Regulators aren't even talking about it, because it's so ubiquitous it would crush our economy removing it entirely. So we just accept that it kills 320,000 people a year.
I hear that every single person who drowned with the Titanic was later found to have elevated concentrations of dihydrogen monoxide in their bodies. Coincidence? I think not.