It then builds up in fish. For this reason, older fish have higher levels of mercury than younger fish. Small amounts of mercury can harm a brain starting to form or grow. That is why unborn and nursing babies, and young children are most at risk. Too much mercury can affect behavior and learning.
Mercury can harm older children and adults, but it takes larger amounts.
It may cause numbness in hands and feet or changes in vision. The Safe Eating Guidelines identify limits to protect everyone. Some Maine waters are polluted, requiring additional limits to eating fish. Fish caught in some Maine waters have high levels of PCBs, Dioxins or DDT in them. These chemicals can cause cancer and other health effects.