Heavy Metals in Chocolate - does craft chocolate contain cadmium and lead?

It's back in a the news - a new study has found, again, that there are concerningly high levels of cadmium and lead in mass market chocolate.
Cocoa Runners' own craft chocolate expert Spencer Hyman answers some questions - should we be worried? Is there cadmium or lead in craft chocolate too? Is it all just a big fuss over nothing?
You can read Spencer's full answers here: cocoarunners.c...