"The bottom line is that arsenic is a heavy metal, like lead, and all heavy metals are dangerous and carcinogenic."

Gold, iron, tin are are all "heavy metals" and are certainly not carcinogenic or dangerous.

I remember from a video of Cody's Lab that metallic gold is safe, but oxidized gold is toxic. https://en.wikipedia.org/wiki/Gold#Toxicity But it's very difficult to oxidize gold, and even gold the salts try to go back to the metallic form, so most of the times it's not a problem.

Those are not considered heavy metals in toxicology.