Lead is a heavy metal that plays no role in human physiology, so the ideal plasma level should be zero. At present it is practically impossible to find any person in whom blood lead levels are not detected.
The World Health Organization (WHO) defines intoxication as the lead poisoning values of more than 15 μg / dl. For the Center of Disease Control (CDC) the level of intoxication is greater or equal than 10 μg / dl.
Lead poisoning produces metabolic disorders directly related to its concentration. The alterations can lead to death and in varying degrees of deterioration of intellectual capacity, changes in behavior, blockage of hematopoiesis, renal toxicity and peripheral neuropathy. These alterations are more harmful in children.
How Long does it take to Die from Lead Poisoning?
Exposure to this metal produces metabolic disorders that are strictly related to its concentration in the body. The level of intoxication is greater or equal than 10 μg / dl, affecting all the body. If the lead poisoning is severe and not treated on time, it will cause death. This depends on a series of below mentioned factors.
Lead poisoning constitutes a serious public health problem, since it affects the most vulnerable population: children, workers and people of low socioeconomic status.
The absorption of lead occurs mainly in two ways:
The gastrointestinal route depends on age, diet, nutritional deficiencies. In the adult, it is estimated that 5% to 10% is absorbed at the gastrointestinal level. On the other hand, the child is 40% to 50% because of the attitude of the children to take everything to their mouths.
With respect to nutritional deficiencies, low in iron and calcium and rich in lipids-diets favor lead absorption.
The airway is the main one in the work environment; this is absorbed by approximately 90%. This route is of great importance in cities with a high concentration of automobiles and in proximity to metal-casting factories.
The distribution occurs in two compartments: the first is the skeletal system, which contains 80 to 95% of the body lead burden, with the average life in the bone being 20 to 30 years. In children it is deposited in the metaphysis of long bones, forming radiopaque deposits.
The second compartment is in the soft tissues such as the kidney, brain and liver, being in these the half-life of 20 to 30 days. In the blood it is found in blood red cells, this being the main compartment responsible for lead toxicity.
A noteworthy fact is that lead crosses the placenta, containing fetal blood 80 to 100% of the maternal lead.
The form of lead poisoning presentation of the symptoms can be acute or chronic. Acute lead poisoning is an infrequent presentation and may be due to ingestion of contaminated food or to massive inhalation of lead vapors.
In children, the most frequent form of lead poisoning presentation is acute encephalopathy, which can appear without prodromes or be preceded by abdominal cramping or behavior alterations. It is manifested by persistent vomiting, ataxia, intractable seizures, altered consciousness and coma. Mortality is approximately 25% and children who survive are left with neurological sequelae such as epilepsy, mental retardation, dystonia, optic atrophy and deafness. At the renal level, an acute failure occurs due to tubular damage and occasionally it presents as a “Fanconi syndrome”. At the gastrointestinal level, it can present with abdominal pain and intense vomiting, which can lead to “shock”.
Chronic Lead Poisoning: It is the most frequent form of presentation in both children and adults. The symptoms are nonspecific, mainly affecting the nervous, gastrointestinal, renal, hematopoietic and neuromuscular systems.
In the world, lead poisoning is considered a serious public health problem. It has great importance in the pediatric age since the harmful effects occur in the neurophysical development stage. This forces the pediatrician to keep in mind the existence of this intoxication, so it is essential a correct environmental history in children with clinical elements compatible with lead poisoning. Behavioral disorders, intellectual deficit, hyperactivity, school delay, renal pathology and anemia are the main alterations evidenced. The treatment must be directed by a multidisciplinary team.