Lead poisoning has occasionally surfaced in health news due to toys containing lead. Lead toxicity has generally decreased in the U.S. since the 1970’s when lead was removed from house paints and in the 1990’s when lead-containing gasoline was banned. However, more than 4% of children in the U.S. have lead poisoning at any given time.
Lead is a naturally occurring metal found in our Earth’s crust. Its chemical symbol is Pb, from the Latin “plumbum.” Our English word “plumbing” comes from this Latin root. Lead is easily malleable and was used at one time to make lead pipes. Use of lead for water plumbing dates back to before the Roman Empire. Some believe lead toxicity may have contributed to the fall of the empire.
Today, lead is used commercially in the production of batteries, ammunition, and as X-ray shielding. In the United States, it is no longer used in paints and gasoline due to health concerns.
Lead can enter our bodies through both the respiratory system and the gastrointestinal tract. Lead dust can be produced during production of lead-containing products. The effects of lead on our bodies are the same whether we breathe it in or swallow it. When it gets into the blood stream by one of these portals, it will be deposited in the bones and other organs.
Lead ions can interfere with certain enzymes in the body. Though lead can affect almost any organ or body system, the signs and symptoms of lead poisoning are seen mainly in three systems: the brain and nerves, the blood, and the gastrointestinal tract.
Children who ingest lead may be more susceptible to brain and nerve damage. This is because nerves are actively growing in the young. Poisoning can lead to brain swelling, loss of insulation around nerve cells (demyelinization), and nerve cell death. In adults, there may be nerve inflammation, paralysis, lethargy, difficulty walking, seizures, and coma. Long-term exposure in any individual can affect intelligence and mental performance.
In the blood, lead can interfere with the proper incorporation of iron within the red blood cells. In individuals with lead poisoning, the red blood cells become small and fragile. This can lead to anemia. In the gastrointestinal tract, acute lead poisoning can cause abdominal pain, spasms, and rigidity. This has been commonly called “lead colic.”
Unfortunately, the symptoms of lead poisoning are rather vague. One has to have a high index of suspicion for the possibility of lead poisoning in order to catch it early. The CDC recommends a blood test for lead levels in children around 2 years of age. Older children who may be at higher risk for lead exposure should also be checked.
This includes individuals who live in houses or apartments built before 1978, especially those who are remodeling; also, those who live in areas where lead poisoning has been identified.
Treatment of lead poisoning starts with removing the source of lead from the environment. Chelating agents are then administered to the patient. These are medicines that bind with the lead so that it can be excreted from the body.
Finally, the U.S. Consumer Product Safety Commission has a wealth of information on lead poisoning and toy recalls due to high lead content. This information can be accessed via the web at http://www.cpsc.gov and http://www.recalls.gov or by calling 1-800-638-CPSC.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.