Lead poisoning: signs and symptoms, causes, treatment, prognosis

general information

Lead poisoning (plumbism, saturnism) is a type of metal intoxication caused by the ingress of lead into the body. The brain is most sensitive. Poisoning can occur as a result of the ingestion of lead paint and the use of imported lead-glazed tableware. Very high blood lead levels can cause personality changes, headaches, loss of sensitivity, weakness, metallic taste in the mouth, loss of coordination when walking, problems with digestion and anemia. The diagnosis is based on symptoms and blood test results. Testing your home's drinking water, ceramics, and paint for lead can help identify potential sources of lead poisoning. Treatment consists in eliminating the factors of poisoning and in removing lead from the body.

Banning the use of paint containing lead pigments (in the USA in 1978) and leaded gasoline (in the USA in 1986, by 2011. worldwide, except for 6 developing countries) has led to the fact that lead poisoning has become much less common.

Causes and risk factors

Lead poisoning usually occurs directly by ingesting (swallowing) the metal. Usually in the following cases:

• with children living in old houses with peeling lead paint or lead pipes;
• during home renovation, when a large amount of lead in the form of paint particles removed from surfaces prepared for painting appears in the air of the room being repaired. Small children often pull chipped paint into their mouths, especially during renovations, and this can be enough to trigger symptoms of lead poisoning. Lead pipes used in plumbing and sewerage tanks can leach lead into water, which then flows to the faucet.

There are other sources of lead poisoning:

• Lead is also found in some glazes. Ceramic jugs, cups and plates covered with this glaze can release metal, especially if they come into contact with acidic substances (such as fruits, cola, tomatoes, wine, and cider).
• Possible sources are moonshine and traditional medicines with high levels of lead.
• Occasionally, third-party items containing lead (such as bullets, curtain hooks, or fishing weights) will enter the stomach or tissues. Bullets hitting certain soft tissues can increase the concentration of lead in the blood, but this process takes many years.
• Occupational lead intoxication can occur during the manufacture and disposal of batteries, when bronzing, making brass, glass, cutting pipes, brazing and welding, smelting ore or working with ceramics or pigments.
• Some folk cosmetics and imported herbal preparations and medicinal plants contain lead and cause local outbreaks of lead poisoning in high-density areas immigrants.
• Breathing leaded gasoline vapors (where it is still produced) with the intent of intoxication to the brain can lead to lead poisoning.

Lead affects various parts of the body, including the brain, nerves, kidneys, liver, blood, digestive tract and genitals. Children are especially vulnerable to poisoning, since lead causes the greatest damage to the developing nervous system.

If the concentration of lead in the blood remains high for several days, the victim usually develops symptoms of sudden brain damage (encephalopathy). A lower concentration of lead in the blood for a longer time sometimes causes persistent mental retardation.

Do you know that…

Children living in older homes should be screened for lead poisoning, even if they are asymptomatic.

Signs and symptoms

In many cases of mild lead poisoning, there are no symptoms. If symptoms do occur, they usually take at least a few weeks to develop. Occasionally, periodic flare-ups of symptoms occur.

Typically, symptoms of lead poisoning include personality changes, headaches, numbness, weakness, a metallic taste in the mouth, loss of coordination when walking, poor appetite, vomiting, constipation, cramping abdominal pain, bone or joint pain, high blood pressure, and anemia. Asymptomatic kidney damage often develops.

• Small children exposed to lead may become moody, and the time they could devote to one lesson or spend in the game, can be gradually reduced over several weeks. Then, sudden encephalopathy may occur, which worsens over the next few days and leads to constant severe vomiting; lack of coordination and difficulty walking; disorientation; and, finally, seizures and coma. Chronic lead poisoning in children can cause mental retardation, seizure disorders, aggressive behavior disorders, developmental regression, chronic abdominal pain and anemia.
• In adults who have to work with lead, symptoms (such as personality changes, headaches, pain in abdominal and nerve damage with numbness and loss of sensation in the arms and legs) develop after a few weeks or later. In adults, there may also be a loss of sex drive, infertility, in men - erectile dysfunction (impotence). Encephalopathy is rare in adults.
• Children and adults can develop anemia.
• If leaded gasoline fumes are inhaled in children and adults, the usual symptoms of lead poisoning may be accompanied by symptoms of psychosis.

After elimination of external exposure to lead, the intensity of some symptoms may decrease, but if exposure is resumed, it increases again.

Diagnostics

Diagnostics include:

• analysis of blood lead levels.

The diagnosis of lead toxicity is based on symptoms and blood tests. Adults who work with lead need frequent blood tests. Children living in areas with a predominance of old houses, where there is a lot of crumbling lead paint, need to have blood tests for lead. In children, signs of lead poisoning are often seen on x-rays of the bones and abdomen.

Treatment

Treatment includes:

• cessation of lead exposure;
• intestinal lavage (bowel lavage);
• chelation therapy and mineral supplements.

Treatment consists of eliminating the factors of lead poisoning and removing lead from the body. If an abdominal x-ray shows that the child has swallowed peeled lead paint, he is given a special solution polyethylene glycol (by mouth or through a tube passed into the stomach) and the stomach and intestines are washed (a process called intestinal lavage).

To remove lead from the body, the victim is prescribed drugs that bind the metal (chelation therapy) and excrete it in the urine. All drugs that remove lead from the body work slowly and have serious side effects.

Suksimer is one of the drugs used in chelation therapy. In case of mild poisoning, the victim is given oral succimer. More severe lead poisoning is treated in the hospital with injections of chelating drugs such as dimercaprol, succimer, and calcium edetate disodium salt. Since chelating drugs also remove useful minerals from the body - zinc, copper and iron - mineral supplements are often prescribed to the victim.

In many children with encephalopathy, persistent brain damage to one degree or another remains after treatment. Kidney damage can also be irreversible.

Prophylaxis

Measures to reduce the risk of household poisoning include regular cleaning, for example:

• hand washing;
• washing children's toys and pacifiers;
• cleaning of household surfaces;
• weekly wiping with a damp cloth on windowsills that may have traces of lead.

Peeling lead paint must be removed and painted over. Larger indoor renovations that remove all lead paint can lead to more lead contamination of the home, so it is best to leave it to a professional. Commercial tap water filters remove almost all lead from drinking water.

Adults who come into contact with lead dust during work should:

• use proper protective equipment;
• change clothes and shoes before going home;
• take a shower before going to bed.

Forecast

Reversibility.

The prognosis depends on the extent and duration of lead exposure. The effects of lead on the physiology of the kidneys and blood are usually reversible; there is no effect on the central nervous system. Although peripheral effects in adults often resolve after cessation of lead exposure, the data indicate that most of the exposure of the child's central nervous system to lead irreversible. Thus, children with lead poisoning can have adverse health, cognitive and behavioral consequences that accompany them in adulthood.

Encephalopathy.

Lead encephalopathy is a medical emergency and causes permanent brain damage in 70–80% of affected children, even those who receive the best treatment. The mortality rate among poisoned people who develop cerebral damage is about 25%, and among those who survived and who by the time chelation therapy was started, there were already symptoms of lead encephalopathy, about 40% have persistent neurological problems, such as cerebral paralysis.

Long term consequences.

Lead exposure can also shorten life expectancy and have long-term health effects. It has been found that mortality rates from various causes are higher in people with elevated blood lead levels; these include cancer, stroke and heart diseaseas well as the overall mortality rate from all causes. Lead is considered a possible human carcinogen based on animal studies. Evidence also suggests that age-related mental decline and psychiatric symptoms correlate with lead exposure. Cumulative exposure over an extended period may have a more important impact on some aspects of health than recent exposure. Some health effects, such as high blood pressure, pose a significant risk only with prolonged exposure to lead (more than one year). In addition, the neurological effects of lead exposure have been shown to exacerbate and persist in low-income children as compared to those with higher economic status.