mercury is what type of metal

Get the MERCURY Out!
The Effects of Mercury on the Nervous System

What is Mercury?
Mercury is a metal that has been used in products such as light bulbs, batteries, paint and thermometers. Although quite useful, mercury is also poisonous and can contaminate the environment if it is not disposed of properly. There are several forms of mercury:
Elemental (metallic) mercury: shiny, silver, odorless liquid used in thermometers. It is absorbed by the body through vapors.

Organic mercury: mercury combined with carbon. Methyl mercury is a common form of organic mercury. These forms of mercury are soluble in lipids and cross the blood brain barrier and placenta easily. Organic mercury is absorbed through the digestive tract and also through vapors.

Inorganic mercury: mercury combined with non-carbon substances. Mercury salts are one kind of inorganic mercury. Inorganic mercury is usually a white powder or crystals. This form of mercury has been used in medicines. Mercuric nitrate was used by the felt-hat industry in the process of curing felt. People in the felt-hat industry sometimes showed signs of mercury poisoning and came down with "Mad-Hatter" syndrome. This is where the phrase "mad as a hatter" originated and was the basis for the "Mad Hatter" character in Lewis Carroll's book Alice in Wonderland.
Different types of mercury affect people in different ways. Organic mercury is more dangerous than inorganic mercury, but many inorganic mercury compounds can be converted to the organic type.

Where is Mercury Found?

Mercury is a natural material found in the earth. Some mercury vapors are given off during volcanic eruptions.

Mercury is a by-product of coal-burning power plants. Mercury is released into the air, then it falls back to the earth.

Mercury is used by mining operations to separate gold from impurities in ore.

Mercury is used during the manufacture of various products. For example, before 1990, mercury was added to paint.
How Are People Exposed to Mercury?
Breathe mercury fumes.

Eat food (especially fish) or drink water that has been contaminated by mercury. Mercury is absorbed by fish through their gills. Mercury also makes its way up the food chain when fish eat plankton or smaller fish that are already contaminated. Fish that are commonly found with high levels of mercury include shark, swordfish and large tuna. The United States Food and Drug Administration has set a limit on the amount of mercury (1 part per million) that cannot be exceeded in fish intended for human consumption.

Absorb mercury through the skin. Glass thermometers contain mercury that should be cleaned up properly (see below).

Eat objects that contain mercury. For example, small children may eat batteries that contain mercury. Broken high power lights and long fluorescent tubes can also contain mercury. Small amounts of mercury from these sources may be ingested accidentally.
Mercury levels within a person's body can be measured in blood, urine and hair samples. The normal level of mercury for someone who has not been exposed to mercury is about 2 ppm (hair) or 3-4 ug/dl of blood or 25 ug/l or urine. When levels get to about 50 ppm (hair), people may start to experience nerve damage. Because hair continues to grow, it can be used to document when and how much a person has been exposed to mercury.
How Does Mercury Affect the Nervous System?
Methyl mercury targets and kills neurons in specific areas of the nervous system including the:
Visual cortex
Cerebellum
Dorsal root ganglia


Several mechanisms have been proposed to explain how mercury kills neurons:

Protein inhibition
Disruption of mitochondria function
Direct affect on ion exchange in a neuron
Disruption of neurotransmitters
Destruction of the structural framework of neurons
Methylmercury is especially dangerous to developing babies. This form of mercury is highly toxic and can cross the placenta and the blood-brain barrier. Mercury is concentrated in the brain of the developing fetus because the metal is absorbed quickly and is not excreted efficiently. Children exposed to mercury may be born with symptoms resembling cerebral palsy, spasticity and other movement abnormalities, convulsions, visual problems and abnormal reflexes. The brains of children who have died as a result of mercury poisoning show neuron loss in the cerebellum and throughout the cerebral cortex. Mercury also appears to affect brain development by preventing neurons from finding their appropriate place in the brain. Human Brain
32 week old fetus

What is Mercury?
Mercury is a metal that has been used in products such as light bulbs, batteries, paint and thermometers. Although quite useful, mercury is also poisonous and can contaminate the environment if it is not disposed of properly. There are several forms of mercury:
Elemental (metallic) mercury: shiny, silver, odorless liquid used in thermometers. It is absorbed by the body through vapors.