Arsenic is a medicine in small enough doses.

So is mercury. It's used as a preservative in injections for babies and
young children - at higher levels than allowed for adults ...

I'm not arguing for or against, just saying that pharmaceutical uses aren't
a reason for saying that something is safe. Oxygen is necessary for life yet
poisonous in some concentrations.

There are indeed some irrational oppositions to waste products, nothing is
without risk ...

Mary