Heavy Metals Found in the Human Liver

There are two types of heavy metals: beneficial and toxic. Toxic metals are dangerous in even small amounts. Beneficial metals are important to the health and function of the human body. However, in large amounts, even these metals can be dangerous. One of the most important functions of the liver is to remove dangerous substances from the body. Therefore, it is not surprising that there are many heavy metals found in the human liver.

Arsenic

• According to the Agency for Toxic Substances and Disease Registry (ATSDR), arsenic is the most common cause of heavy metal poisoning in adults. Arsenic is found in water all over the world. This often leads to seafood contamination. Arsenic is released into the environment through glass and chemical manufacturing; as well as zinc, copper, and lead smelting. It is also found in rat poisons, fungicides, and paints.

Cadmium

• A by-product of mining and smelting of zinc and lead, cadmium is another toxic metal frequently found in the liver. Cadmium is found in insecticides, fertilizers and fungicides. This agricultural usage transfers cadmium into the soil, and from soil to ground water. Other sources of cadmium are: paint pigments, cigarettes, PVC plastics, and nickel-cadmium batteries.

Copper

• Copper is a beneficial heavy metal that aids in the building of important enzymes in the body. However, excess copper can be very dangerous. Wilson's disease is an inherited disorder in which the liver stores excess copper instead of excreting it into the bile. People with Wilson's disease may have tremors, difficulty with swallowing and speaking, brain damage or hepatitis.

Iron

• Iron is another beneficial metal that can be extremely toxic in large amounts. Therefore, young children should not be given iron dietary supplements. Iron should be acquired through normal diet in young children. Iron deficiency is very dangerous as well, so balanced nutrition is crucial for maintaining appropriate iron levels. Hemochromatosis is an inherited disorder that causes excess iron to be stored in the liver. Hemochromatosis affects 1 million people in the United States and can be fatal. However, the disorder is treatable through bloodletting.

Lead

• Lead is the leading cause of metal toxicity in children. According to the Merck Manual, chronic lead poisoning in children may cause mental retardation, aggressive behavior disorders, seizure disorders, anemia, chronic abdominal pain and developmental regression. Many homes built before 1940 still contain lead in paint and plumbing materials. Other sources of lead include PVC plastics and pesticides.

Mercury

• The ASTDR considers mercury the third-most-dangerous heavy metal, after arsenic and lead. Mercury is found naturally in the environment, but it is also released into the air by industrial pollution. This atmospheric mercury then mixes with rain, contaminating drinking water and fish. Mercury poisoning can cause long-term damage to the brain, kidneys and nervous system.

Zinc

• Zinc is another beneficial metal found in the liver. Zinc is crucial in the formation of more than 100 enzymes, including components of DNA and RNA. Excess zinc can be inhaled in the form of zinc oxide fumes or ingested by drinking acidic substances from zinc-lined containers. Zinc excess can be fatal and may cause copper depletion, which can result in anemia.