Researchers used a special tool to study how earthworms absorb and store cadmium (Cd) from contaminated soil. They found that when exposed to Cd, earthworms accumulated the highest amounts of Cd in their nephridia, a specific organ responsible for waste excretion. The Cd was mostly concentrated in the area between the nephridiopore and first loop, as well as in the urinary vasiculus. In contrast, lower levels of Cd were found in the body wall of the worms.