Lead poisoning

Lead poisoning refers to the accumulation of lead in body tissues. The lead is built up in the body when a person swallows or inhales it.

The lead exposure can damage the brain, the nerves and many other parts of the body. Lead poisoning is more common in children.

There are two different forms of lead poisoning:

• Acute lead poisoning: When a large amount of lead is absorbed in a short period. It is rare.
• Chronic lead poisoning: When small amounts of lead are absorbed over a long period. Chronic poisoning is more common in children.

Before knowing how harmful lead could be, it was widely used in several products. Some of them are no longer produced, but they can still be found in houses:

The main sources of lead nowadays are:

• Lead-based paint: Walls and floors painted with dyes that contain lead are still frequent in older homes. There can be found also in old painted furniture. Children may eat paint chips from older homes or suck contaminated walls or furniture (lead-based paints were banned in the U.S. for residential use in 1978).
• Pipes: Water pipes in old houses were built with lead. The exposition to lead was due to water consumption. Some newer copper pipes was still weld with lead.
• Leaded gasoline: This type of gasoline, that are not used nowadays, contains lead. In the USA, leaded gasoline was banned in 1996. However, some dust and soil can still be contaminated with lead from emissions of leaded gasoline.
• Folk medicines: Some folk medicines such as Azarcon and Greta used for indigestion or traditional cosmetics like kohl (made by grinding stibnite) contain large amounts of lead.
• Old toys or jewelry.
• Pottery or stained glass may contain lead.

It is believed that 1 in 40 children ages 1-5 years have blood lead levels over the recommend rate.

Excessive lead may affect to multiple body systems and be linked to high blood pressure.

Lead exposure during pregnancy may have an impact on the developing brain. Lead accumulation may also have impact on infants and young children. It increases the probability of suffering lower IQs, slowed growth, behavioral disorders or hearing loss.

Lead poisoning may include nonspecific symptoms such as:

• Weakness
• Irritability
• Weight loss
• Vomiting
• Headaches
• Abdominal pain

In case of an acute lead poisoning, with a large amount of lead in the body, the symptoms may include severe abdominal pain, diarrhea, seizures, coma and even the death.

The best way to diagnose lead poisoning is to test the level of lead in the blood. A value over 5 µgr/dl is considered enough evidence for adverse health effects in children and adults.

The first step in treating lead poisoning is to avoid further contact with lead (remove or change lead pipes, lead-based paints, etc.). This work should be carried out by professionals with special training (do not do it yourself).

If blood levels of lead are high enough, chelation therapy may also be prescribed. Chelation agents bind to the lead and help the body pass it in urine at a faster rate. The most used for this purpose are:

• Edetate calcium disodium (EDTA calcium) given intravenously.
• BAL (British Antilewisite o dimercaprol). It is also given intravenously.
• Succimer (Dimercaptosuccinic acid or DMSA). It is taken by mouth. It is usually sold under the trade name Chemet.
• D-Penicillamine taken by mouth.

If acute lead poisoning reaches the stage of seizures and coma, there is a high risk of permanent brain damage or death.

The long-term effects of lower levels of lead can also be permanent and severe. However, if chronic lead poisoning is caught early, these negative effects can be limited.