Signs and treatment of chronic lead poisoning
Chronic lead poisoning is the most common type of heavy metal intoxication. According to WHO, lead is responsible for more than 600 thousand cases of mental retardation in children, and about 140 thousand people die from such poisoning in a year. This mainly occurs in the countries of Asia and the Eastern Mediterranean, but in Russia the problem of lead pollution of the environment is of no small importance.
The disease is more often recorded in children from one year to five years, as well as among workers, whose work involves the use of lead and its compounds.
Lead belongs to the group of heavy metals and is a polytropic poison, that is, when ingested, it acts on several organs and systems. He calls:
- increased fatigue;
As a result of chronic lead toxicity develops:
- inability to intellectual activity;
- and kidney disease;
- red blood cells are destroyed.
Lead is also a carcinogen.
Where lead is used
In antiquity, alchemists associated lead with the planet Saturn, so chronic poisoning with this metal is called Saturnism. Lead has been used by mankind since ancient times, it is one of the first metals that people have learned to smelt. Industrial production of goods containing this metal began in 1870 - these were lead paints. Lead compounds are used in paints and building mixtures to this day, this element has been successfully used in electronics as solder, in printing, in the manufacture of crystal and glaze for ceramics, in non-ferrous and ferrous metallurgy, to protect against X-rays and radiation. Three-quarters of the world's lead use comes from battery manufacturing. Non-ferrous metallurgy enterprises make the largest contribution to pollution of the environment - more than 80% of emissions. Lead accumulates in the soil, may be contained in household dust, enter the body with water and food. The most dangerous chronic poisoning in children.
According to the researchers, in polluted cities the risk of problems with schooling for this reason is about 40%, and about 9% of children need treatment!
Other causes of poisoning:
- ingress of lead compounds into the body due to the use of poorly baked dishes with glaze containing this metal;
- at the use of moonshine from the device with details from lead;
- when working with red lead and white;
- when cutting gas welding metal coated with compounds of this metal;
- in old homes with lead pipes, the source of poison can be running water.
Acute poisoning is rare. This can happen if a child swallows pieces of lead paint, putty, or, for example, lead weights. In adults, acute occupational lead poisoning is possible as a result of accidents at work.
Inorganic salts are absorbed when they enter the stomach and when dust is inhaled, organic compounds can penetrate the skin. On admission through the mouth, adults absorb about 10% of lead in adults, and up to 40% in children. It is believed that for adults, when taking food with a safe dose of 150 micrograms per day, although according to WHO there is no safe level of lead.
The toxic dose of lead for a person is 1–3 milligrams. Lethal dose is 10 grams.
When entering the blood, the metal binds to red blood cells, then it is deposited in the bones (up to 90%), where it is practically inactive. From 10 to 20% of the element is deposited in the soft tissues mainly in the kidneys, spleen, liver and brain. Excreted mainly with feces and about 10% with urine. Lead is able to form persistent depots in the body. There he is in the form of an inactive compound - tribasic phosphate. Under certain adverse conditions - other intoxications, alcohol, infectious diseases, mental trauma - it can re-enter the bloodstream, causing re-poisoning.
Excreted slowly from the body: the half-life from blood and soft tissues is 30–40 days, from bones - up to 100 days.
Binding to disulfide groups of protein molecules, lead destroys enzyme systems, disrupts the exchange of hemoglobin - anemia develops, kidney inflammation, heart, thyroid and liver function suffers. In high concentrations, it damages proteins in cellular structures, leading to their denaturation and cell death.
Children are very sensitive to intoxication with lead and its compounds. A growing organism absorbs poison more quickly, nerve cells suffer greatly. In pregnant women, lead can affect the development of the fetus, causing various neurological disorders.
Main symptoms of poisoning
For lead poisoning, symptoms depend on the intensity of the disease. There are four degrees of Saturnism.
- Lead rim is typical for carriage - a strip with a lilac shade of gray along the edge of the gums and teeth.
- A mild degree is manifested by abnormalities in the work of the autonomic nervous system (astheno-vegetative syndrome): weakness, fatigue, increased or decreased sweating, lethargy, increased excitability of muscles, convulsions and impaired sensitivity in the limbs.
- With a moderate degree of poisoning, lead colic occurs - cramping abdominal pain, persistent constipation, blood pressure rises to 200 mm Hg. st. and higher.
- Heavy degree. In addition to the signs described above, there are disturbances from other organs and systems. Brain - headache, memory disorder, dizziness, confusion. Peripheral nervous system - paralysis of the extensor muscles of the hand or foot, limb polyneuritis. Anemia develops, an earthy-pale skin color appears. There are chronic diseases of the kidneys, liver, cardiovascular system.
In severe cases, edema of the brain and renal failure occurs, seizures, coma and death develop.
Medium and severe poisonings are not completely cured.
In children, lead is deposited in the growth zone of long tubular bones, which can be clearly seen on X-rays and is a diagnostic sign. When lead poisoning, signs in children are also based on the development of encephalopathy. Since the disease often proceeds subclinically (without clearly expressed external signs), the danger lies primarily in the effect of the poison on fast-growing brain cells. There are no external symptoms, but the child’s development slows down, the ability to learn decreases, selective speech disorders occur, and behavioral and mental development slows down. The effect of poison on the brain is irreversible.
Lead poisoning treatment
The diagnosis is made on the basis of clinical signs and the detection of lead in the blood of more than 250 μg / l. Also in the study of urine detect lead and protoporphyrin. Treatment of lead poisoning begins with the elimination of the source of contamination, in acute and severe cases, the victim is hospitalized in a poison control center.
In the case of acute encephalopathy, measures are taken to reduce the swelling of the brain, support diuresis. Antidotes for lead poisoning are a number of complexing agents, mainly calcium salts of EDTA, D-penicillamine (Kuprimin) and Dimercaprol. They bind heavy metals and remove them from the body.
When there are signs of antidote therapy is carried out for five days. If necessary, the course is repeated after 2–3 days. Symptomatically treat anemia, disorders of the autonomic nervous system, relieve lead colic. Lead poisoning has its consequences. Full recovery, perhaps, only with a slight degree of poisoning.
Lead poisoning prevention
For the prevention of lead poisoning in the workplace they take measures to improve ventilation in the workshop, automate production processes, use personal protective equipment: respirators and overalls. Periodically monitor the level of lead in the blood.
In the domestic environment for the prevention of poisoning, they regularly wash their hands, children's toys, nipples, wipe dust from surfaces. If you suspect Saturnism - exploring drinking water, paint inside the house and ceramic products.
Intoxication is often chronic in nature and develops as a result of the constant ingress of this metal into the body with polluted air, water, or food. In this case, in children, the disease can proceed without clearly expressed signs, but the toxin will affect the brain, causing a mental disorder.