The expert investigation report concludes that cadmium can be found in cocoa and chocolate due to its presence in soils, either through natural or man-made sources, where cocoa is cultivated and harvested in the tropics. Cocoa plants take up cadmium from soils via their roots and deposit it in the nibs (center) of cocoa beans. Reducing cadmium levels without compromising taste characteristics will require blending low and high cadmium beans in the short-term, and changes to soil composition or cocoa genetics over time, especially in the Latin America and Caribbean regions where fine flavored cocoa is grown and cadmium levels in soils tend to be higher.

In contrast, lead is not taken up through the roots of cocoa plants. Instead, lead from many sources including soil, dust, and deposition from power plants around the world, adheres to the outer shells of cocoa beans after they are extracted from the pods. The beans are naturally coated with a sticky cacao pulp known as “baba” or “mucilage” which allows lead to cling to the beans while they are being fermented and dried in the open in the tropical countries where they are grown. The experts found that, where feasible, minimizing soil contact and the potential for aerial deposition at these stages of the harvesting process, and optimizing contaminant removal during subsequent bean cleaning, roasting, and shell removal (as many chocolate manufacturers already do), should help reduce lead levels in finished products.