Lead

Type: Periodic Element
Periodic Element: (Pb)
RDA:Not established.

Importance- To Body:
Lead has no confirmed biological role. High levels of calcium and iron tend to provide some protection from lead poisoning; low levels cause increased susceptibility.
Distribution- In Body:
Lead enters the body via inhalation, ingestion, or skin absorption. Almost all inhaled lead is absorbed into the body; for ingestion, the rate is 20–70%, with children absorbing a higher percentage than adults.
Excess Effects:
Lead Poisoning, most ingested lead is absorbed into the bloodstream. The primary cause of its toxicity is its predilection for interfering with the proper functioning of enzymes. By mimicking calcium, lead can cross the blood-brain barrier. It degrades the myelin sheaths of neurons, reduces their numbers, interferes with neurotransmission routes, and decreases neuronal growth.

Deficiency Effects:
None Listed
Sources Food:
Fruit and vegetables can be contaminated by high levels of lead in the soils they were grown in. Soil can be contaminated through particulate accumulation from lead in pipes, lead paint, and residual emissions from leaded gasoline.
Sources Environmental/Geographic:
Elevated concentrations of lead persist in soils and sediments in post-industrial and urban areas with industrial emissions. Poisoning typically results from ingestion of food or water contaminated with lead, and less commonly after accidental ingestion of contaminated soil, dust, or lead-based paint. Seawater products can contain lead if affected by nearby industrial waters.
Supplement Information:
Treatment for lead poisoning normally involves the administration of dimercaprol and succimer.[242] Acute cases may require the use of disodium calcium edetate, the calcium chelate, and the disodium salt of ethylenediaminetetraacetic acid (EDTA). It has a greater affinity for lead than calcium, with the result that lead chelate is formed by exchange and excreted in the urine, leaving behind harmless calcium.