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A Toxic Substance--Lead
How are we exposed to lead?

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gh lead does not occur naturally in the body, everyone has acquired some lead in their body from the environment. Lead, which is found in batteries and paints and used to be in gasoline, interferes with red blood cell formation and causes irreversible mental retardation. The effects on mental development are especially severe in young children. Surveys indicate that about 2-4% of children have learning disabilities due to lead. Learning disabilities and hyperactivity can come from lead poisoning.  Click here and here to learn more about childhood lead poisoning.


How does lead make us sick?

Lead Element Abbreviation ImageAlthough the poisonous nature of lead has been known for many years, scientists are just now beginning to learn how lead acts. Lead binds in proteins that contain positively charged atoms, such as calcium and zinc. Both of these metals occur in certain proteins in the body. Proteins become folded, and those folds determine the physical properties of the proteins and their ability to function as receptors and enzymes. If the folding is changed, the function is changed. Zinc serves to stabilize the folding of proteins.

Lead can displace protein-bound zinc and thus change the protein folding. Lead binds seven times more strongly to zinc-based proteins than to calcium-based proteins. This is another reason to drink your milk. A diet that contains the right amounts of calcium, protein and iron, helps guard against lead poisoning.


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