What is mercury poisoning?

Mercury poisoning is a serious condition that can cause long-term, permanent damage to the human nervous system, digestive system, kidneys, and lungs. Mercury poisoning results from over-exposure to high levels of mercury. There are two main ways we are exposed to mercury. The first is through breathing mercury vapor. The second is by eating food and drinking water or other liquids that have been contaminated with methylmercury, a common mercury compound.