Unlike those other things, which are external contaminants that find their way in due to non-sanitary processing conditions, cadmium and lead in chocolate come

Unlike those other things, which are external contaminants that find their way in due to non-sanitary processing conditions, cadmium and lead in chocolate come from the soil the cocoa trees grow in, and end up in the beans themselves, in a way that is effectively impossible to extract from them. Also, from what I've read in other sources, the higher the cocoa content in chocolate, the higher the mineral content (including these "bad minerals") in the chocolate. And also — frustratingly — the soil that has these soil minerals, is also the soil that imparts what people generally consider to be more interesting/tasty terroir into the chocolate. The single-source, ethical, sustainable chocolate? Highest heavy-metal content.