Signs and treatment of chronic lead poisoning
Chronic lead poisoning is the most common form of intoxication with heavy metals. According to the WHO, lead is responsible for more than 600,000 cases of mental retardation in children, and a year from this poisoning about 140 thousand people die. 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 registered in children from one to five years, as well as among workers whose activities are associated with the use of lead and its compounds.
Lead refers to a group of heavy metals and is a polytropic poison, that is, upon ingestion it acts on several organs and systems. It causes:
- increased fatigue;
As a result of chronic intoxication lead develops:
- inability to intellectual activity;
- and kidney disease;
- the red blood cells are destroyed.
Lead is also a carcinogen.
Where lead is used
In ancient times, alchemists connected 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 learned to smelt. The industrial production of this metal-containing goods began in 1870 - they were lead paints. Lead compounds are used in paints and building mixtures to this day, this element is successfully used in electronics as solder, in printing, in the manufacture of crystal and glaze for ceramics, in non-ferrous and ferrous metallurgy, for protection from x-rays and radiation. Three quarters of the world's volume from the use of lead comes from the production of batteries. In the lead pollution of the environment, the largest contribution is made by non-ferrous metallurgy enterprises - more than 80% of emissions. Lead is accumulated in the soil, it can be contained in house dust, enter the body with water and food. The most dangerous is chronic poisoning in children.
According to the researchers, in contaminated cities, the risk of problems with schooling for this reason is about 40%, and about 9% of children need treatment!
Other causes of poisoning:
- getting lead compounds into the body due to the use of badly burned dishes with this glaze containing the metal;
- when using moonshine from the apparatus with parts made of lead;
- when working with lead felts and whites;
- when cutting by gas welding a metal coated with compounds of this metal;
- in old houses with lead pipes a source of poison can become a water pipe.
Acute poisoning happens rarely. This can happen if the child swallows pieces of lead paint, putty or, for example, a lead weight. In adults, acute occupational lead poisoning is possible as a result of industrial accidents.
Inorganic salts are absorbed when ingested and inhaled dust, organic compounds can penetrate the skin. When ingested through the mouth, about 10% of lead is absorbed into adults, and up to 40% in children. It is considered that for adults, when taking food, a safe dose is 150 mcg 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. The lethal dose is 10 grams.
When entering the blood, the metal binds to erythrocytes, then it is deposited in bones (up to 90%), where it is practically not active. From 10 to 20% of the element settles in soft tissues mainly in the kidneys, spleen, liver and brain. It is excreted mainly with feces and about 10% in urine. Lead is able to form persistent stores in the body. There it is in the form of an inactive compound - tribasic phosphate. Under some unfavorable conditions - other intoxications, alcohol, infectious diseases, mental trauma - he can re-enter the blood, causing re-poisoning.
It is excreted slowly from the body: the half-life period of blood and soft tissues is 30-40 days, of bones - up to 100 days.
By binding to disulfide groups of protein molecules, lead destroys enzyme systems, disrupts hemoglobin metabolism-anemia, kidney inflammation develop, the function of the heart, thyroid and liver suffers. In high concentrations, it damages the proteins of cellular structures, leading to their denaturation and cell death.
Very sensitive to intoxication with lead and its compounds are children. The growing organism quickly absorbs the poison, the nerve cells suffer greatly. In pregnant women, lead can affect fetal development, causing various neurological disorders.
The main symptoms of poisoning
When lead poisoning symptoms depend on the intensity of the disease. There are four degrees of Saturnism.
- Bearing is characterized by a lead edge - gray with a purple tint strip on the edge of the gums and teeth.
- An easy degree is manifested by disorders in the work of the autonomic nervous system (astheno-vegetative syndrome): weakness, fatigue, increased or decreased sweating, lethargy, increased muscle irritability, convulsions and sensitivity disorders in the extremities.
- With an average degree of poisoning, lead colic occurs-cramping abdominal pain, persistent constipation, blood pressure rises to 200 mm Hg. Art. and higher.
- Heavy degree. In addition to the above signs, there are violations from other organs and systems. The brain is a headache, memory disorder, dizziness, absent-mindedness. Peripheral nervous system - paralysis of the extensor muscles of the hand or foot, polyneuritis of the extremities. Anemia develops, an earthy pale skin color appears. There are chronic diseases of the kidneys, liver, cardiovascular system.
In severe cases, cerebral edema and renal insufficiency occur, convulsions, coma and death develop.
Middle and severe poisonings are not completely cured.
In children, lead is deposited in the growth zone of long tubular bones, which is clearly seen on x-rays and is a diagnostic sign. With lead poisoning, the signs in children are also based on the development of encephalopathy. Since the disease often occurs subclinically (without pronounced external signs), the danger lies primarily in the effect of poison on fast-growing brain cells. There are no external symptoms, but the development of the child slows down, the ability to learn decreases, selective speech disorders occur, behavioral responses and mental development slow down. The action of the poison on the brain is irreversible.
Treatment of lead poisoning
The diagnosis is based on clinical signs and the detection of lead in blood over 250 μg / l. Also in the study of urine, lead and protoporphyrin are detected. 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 cerebral edema and maintain 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.
At the expressed signs antidotnuju therapy spend within five days. If necessary, after 2-3 days, repeat the course. Symptomatically treated with anemia, disorders of the autonomic nervous system, remove lead colic. Lead poisoning has its consequences. Complete recovery, perhaps, only with a mild degree of poisoning.
Prophylaxis of lead poisoning
To prevent lead poisoning at work, measures are taken to improve ventilation in the shop, automate production processes, use personal protective equipment: respirators and overalls. Periodically monitor the level of lead in the blood.
In domestic conditions, for the prevention of poisoning, hands, children's toys, nipples are regularly washed, dusted from surfaces. If there is a suspicion of Saturnism, they investigate drinking water, paint inside the house and ceramic products.
Intoxication is more often chronic and develops as a result of the constant ingress of this metal into the body with polluted air, water or food. In children, the disease can occur without obvious signs, but the toxin will affect the brain, causing a violation of mental activity.