Herbal Remedies

This is an example of why the what's the harm argument around herbal remedies is a problem for me:

http://consumerist.com/2010/02/morning-sickness-remedy-found-to-contain-lead-and-arsenic.html

I frequently talk with people who see no harm in using herbal supplements without really knowing much about the actually quality and quantity in the supplement. They say that if it doesn't work, it at least doesn't hurt right? Well as this link shows it can cause harm. Do you really want to ingest lead and arsenic, especially while pregnant? That is the harm. And on a nit picking note, this isn't really an herb, it is actually a mineral made up mostly of fossilized seashells, but it falls into that same loop hole category.