Lead abounds in nature as it is distributed over the earth by reaching the environment for extraction from natural deposits. Lead enters metabolism and interferes with normal heme synthesis. It also acts on the nervous system, both centrally and peripherally. True lead poisoning can only occur with certain types of salts of the metal, so toxicity is not strictly related to the metal, but to the behavior of the ingested substance.
This type of poisoning can set in very insidiously with the appearance of symptoms when the lead content in the body becomes excessive. The main symptoms are abdominal pain, nerve palsy, metallic taste, and constipation. If lead has been ingested in the intestines an X-ray may show opacities.
Diagnosis and treatment
Lead poisoning can be recognized through the symptoms described above. Additional tests include assay of amino-levulinic acid dehydrase activity in erythrocytes. Acute poisoning requires supportive treatment to balance dehydration and electrolyte loss. Chronic poisoning, on the other hand, requires specific chelation-type therapy when symptoms are evident and blood levels are above 100 mL in adults and children.
Source: Vadecum of poisoning therapy by Roy Goulding
