Mercury is a metal that is toxic to living organisms. It exists in several forms, some of which occur naturally in the environment.
Metallic or elemental mercury – an odorless, shiny, silver- white liquid – is commonly used in thermometers, barometers and fluorescent light bulbs. Metallic mercury is extremely dangerous. A few drops can generate enough fumes to contaminate the air in a room. Furthermore, skin contact with mercury can result in its absorption into the blood stream and potential health problems.
Mercury poisoning may include the following symptoms:
- Impairment of coordinated movements such as walking or writing
- Impaired speech, hearing and peripheral vision
- Mood swings and memory loss
- Muscle weakness
- Numbness and a “pins and needles” feeling in the hands, feet and sometimes around the mouth
- Skin rashes
Methylmercury, one of the metal’s forms, can attach to small particles in the soil or water. From there, methylmercury can enter and accumulate in the food chain. For example, small fish may eat food containing methylmercury particles, and some of those particles remain in their tissues. When larger fish eat those smaller fish, most of the methylmercury originally in the small fish is then stored in the larger fish. Methylmercury is found in both freshwater and saltwater fish and marine mammals.