9327. Lead

Lead is a highly toxic heavy metal. Once it enters the body, it accumulates in nervous tissue, bone tissue, the kidneys, and the liver. Over time, it causes disorders of the nervous and immune systems, mental disorders, anemia, hypertension, and renal failure.

Determination of lead levels is used for diagnosis, assessment of the severity of intoxication, and selection of treatment for intoxication with this metal. It is best combined with complete blood count and biochemical blood tests, as well as urinalysis.

Household sources of lead entering the body include: elevated lead levels in the air of old buildings where lead-based paints were used; water and other liquids contaminated with lead (lead may enter from lead-containing plumbing solder and metal cookware); the use of ceramics with a high lead content; and vapors of leaded gasoline in the atmosphere.

Lead that enters the gastrointestinal tract is poorly absorbed, but lead that is inhaled with contaminated air is absorbed almost completely. Lead absorption is increased in cases of dietary deficiency of calcium, phosphorus, and iron. In the blood, the majority of lead is contained in erythrocytes and only about 5% is present in plasma, in the form of complexes with phosphates, proteins, and organic acids. Lead is excreted predominantly by the kidneys. When the level of exposure exceeds a certain threshold, lead begins to accumulate in the body, forming persistent depots, mainly in bone tissue.

The group at risk of increased lead exposure includes drivers, workers involved in auto body repair, workers in paint and coating production, and people living along highways. Prolonged exposure may cause saturnism. This is occupational lead poisoning characterized by the development of a “lead complexion” (an earthy-pale skin color), a lead line along the edges of the gums and lips, an increased risk of arterial hypertension, and worsening of the course of chronic kidney diseases. A characteristic symptom of chronic lead intoxication is anemia. Adverse environmental conditions pose the greatest danger to children during the period of active growth (3–12 years), which is characterized by a high level of element absorption. Prolongation of the pubertal period and neurological changes have been noted in children with subclinical levels of lead poisoning. Acute lead poisoning manifests as erythrocyte abnormalities, polyneuritis, lead encephalopathy, dyspepsia, and lead colic.

• For the diagnosis of lead poisoning.
• For the differential diagnosis of possible causes of chemical poisoning (with simultaneous determination of the levels of other toxic metals).
• For monitoring excessive exposure to lead in the human body in occupational settings.
• For assessing the effectiveness of treatment for saturnism.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: