Structural Biochemistry/Poor Metals

The Poor Metals are:

• Aluminium (Al)
• Gallium (Ga)
• Indium (In)
• Thallium (Tl)
• Tin (Sn)
• Lead (Pb)
• Bismuth (Bi)

The poor metals are located in the p-block, and are the most electronegative but least reactive[1] of all the metals. They are softer than the transition metals, but cannot be classified as metalloids. [2]

Aluminum

The third most abundant element on the earth, it is a light, strong metal that has several types of alloys. One of its alloys is duraluminum, which is stronger than pure aluminum and resistant to corrosion, contains other elements such as copper, manganese, magnesium, and silicon. It is used for airplane construction and electrical wires.

Aluminum is harmful to the body since it it damages all types of tissues. It is considered a protoplasmic poison, meaning that a healthy cell will be damaged or killed as a result of exposure to the aluminum, and a neurotoxin. There has been evidence that accumulation of aluminum can contribute to the cause of Alzheimer's disease. Some research has shown that degeneration of nervous tissue from aluminum in animals are similar to the way the brain degenerates in Alzheimer's disease. Experimentation from Toronto University have shown that Alzheimer's disease patients that were given treatment for the removal of aluminum showed a decrease in the rate of degeneration.

At the molecular level, aluminum sticks to phosphates of our DNA. Other toxic metals such as mercury and lead stick to the phosphates as well, but the biological system has sticky chelators that remove the toxic metals and send it to the kidney to be detoxified. What makes aluminum a toxin is the fact that it cannot be easily removed from the phosphate, even with chelators. Once it sticks to the phosphate of the DNA, it will stay there until the cell dies.

Some symptoms of aluminum poisoning include forgetfulness, inability to concentrate and even dementia.

Galium

Gallium becomes a liquid at a low melting point of 29.8°C. It is a blue-gray metal that can expand upon freezing. Gallium is useful as a semiconductor and has similar properties as aluminum.

Lead

Lead is virtually ubiquitous in the environment as a result of its natural occurrence and its industrial use. Potential symptoms of overexposure to lead are anorexia, abdominal pain, colic, anemia, paralysis of wrists or ankles, kidney disease, and hypotension. Exposure to lead occasionally produces clearcut, progressive mental deterioration in children. Very low concentrations of lead interfere with the activity of δ-aminolevulinate dehydratase, and ferrochelatase during the biosynthesis of heme[1].

References

Goodman, Louis S, and Alfred Goodman Gilman. The Pharmacological Basis of Therapeutics. 7th ed. New York, N.Y.: Macmillan, 1985.

http://www.pspinformation.com/nutrition/minerals/aluminum.shtml