What is mercury?
Mercury or quicksilver is the only common metal which is a liquid at ordinary temperatures.
It is found in a variety of household products, such as thermometers and fluorescent light bulbs; it also occurs naturally in the environment and can be released into the air through industrial pollution.
What is methylmercury?
Mercury in the air, where in contact with streams and oceans, turns into methylmercury in the water.
Fish absorb it as they feed, building it up in their systems. It accumulates more in some types of fish and shellfish than others, depending on what they eat.
How is it harmful to humans?
The Environmental Protection Agency (EPA) in the United States has classified methylmercury as a neurotoxin, which can be harmful to young children and the unborn whose mothers eat contaminated fish and shellfish.
Exposure to methylmercury can harm the brain and nervous system of a foetus or child, affecting cognitive thinking, memory, attention, language and fine motor and visual-spatial skills. It can also cause personality changes, nervousness, trembling and dementia.
Source: AVA and EPA