I’ve read that cocoa processing involves drying the pods in the open air. Heavy metals in dust from nearby mines covers the surface of the pods, which are later ground up along with the cocoa.
The solution here seems simple enough: Don’t dry the pods in the open air. But the farmers don’t have a lot of extra money lying around that they can use to address this, and the market is (currently at least) still buying.
Oof. Folks had this same sort of outlook on lead contamination here in Missouri. Here's the problem: the farmers also live downwind of the lead pollution. They didn't poison the air. But now they're being expected to handle it.
The solution here seems simple enough: Don’t dry the pods in the open air. But the farmers don’t have a lot of extra money lying around that they can use to address this, and the market is (currently at least) still buying.