The researchers studied heavy metal pollution in the sediment of a severely polluted area of Lake Chaohu. They found that heavy metals like Hg and Cd accumulated mainly in the low-lying area near the bank. Most metals had low ecological risk, but Hg and Cd posed a high risk and likely came from the same sources. The upper sediment layers showed very high ecological risk due to Hg and Cd, while deeper layers still had moderate risk. Urgent action is needed to control pollution of Hg and Cd in the area.