Lead (Pb) in blood.

Among heavy toxic metals, lead is the most frequent cause of poisoning. It is widely used in industry and is found in small amounts in the environment. For many years it has been used in the manufacture of paints, water pipes, pesticides, and tin cans. Its content is elevated in old dilapidated houses and in the areas surrounding many industrial plants.

The degree of harm and severity of symptoms depends on the metal dose and duration of exposure, the age of the person, his nutritional status, and the presence of concomitant diseases and pathologies. For example, people with malnutrition and iron deficiency have significantly increased intestinal absorption of lead. Children and pregnant women are most susceptible to the toxic effects of this metal.

Lead is able to penetrate through the placenta from the mother into the foetus, which can not only affect the formation of organs and tissues of the child but also contribute to miscarriage or premature birth. Lead accumulates mainly in bones and is eliminated from the body very slowly.

Acute poisoning is rare and is manifested by encephalopathy, severe abdominal pain, vomiting, stool disorders, convulsions, and in some cases ends in coma and even death. Chronic lead exposure can be asymptomatic for a long time. Its signs may include pale grey skin colour, a dark border around the edges of the gums, weakness, nausea, fatigue, weight loss, anaemia, headaches, stomach cramps, and kidney, nervous, and sexual system dysfunctions.

The concentration of lead in the blood correlates with its content in the whole organism. It can be used to determine the severity of poisoning and to decide on treatment tactics and prescription of antidotes, and to assess the effectiveness of therapy.