Lead Poisoning

Lead poisoning occurs when a person swallows or breathes in lead, which can damage many parts of the body, especially in young children.

When Timmy turned one year old his parents bought a bigger house so that they would have more room for their family. Everyone in the family was excited about the move to the 75-year-old house, even though it would require quite a bit of work.

One of the first projects was to scrape off the old paint and replace it with lead-free paint. Timmy's dad made sure he cleaned up as he was working because he knew that chips of paint from homes this age often contain lead, which could be poisonous to Timmy if he put them in his mouth.

A few months later, Timmy's doctor tested his blood during a routine checkup and found a high level of lead. His parents had not known that Timmy could get lead poisoning from lead dust as well as paint chips. Luckily, the problem was caught and treated early.

Lead is a metal that has been mined for thousands of years. In the past, it was an ingredient in many everyday items found in or near homes, such as paint, gasoline, water pipes, and food cans. When a person swallows or breathes in lead, however, it can be highly poisonous. It is especially dangerous to children six years of age and younger, partly because the bodies of such young children are changing rapidly and partly because children in this age group tend to put objects in their mouths.

Lead is poisonous because it interferes with some of the body's basic activities. To some extent, the body cannot tell the difference between lead and calcium, a mineral that helps build strong bones. Like calcium, lead stays in the bloodstream for a few weeks. Then it is deposited in the bones, where it can stay for a lifetime. Even small amounts of lead can permanently harm children over time, leading to learning disabilities, behavior issues, decreased intelligence, and other problems. Large amounts of lead can cause seizures, unconsciousness, or even death.

There are many familiar items in people's everyday environment that can cause lead poisoning.

The most common way to get lead poisoning is through contact with lead in the form of dust. Lead can get into dust when old paint is scraped or sanded or when painted surfaces bump or rub together. This dust can then settle on objects that people touch or children put into their mouths.

Oil companies used to add lead to gasoline to improve performance. Leaded gasoline allowed lead particles to escape into the air through car exhaust systems. In 1978 the amount of lead allowed in gasoline in the United States was cut, and cars after that used lead-free gasoline. However, the soil around roads may still contain residue of lead from leaded gasoline. Lead can also get into soil when the outside paint on old buildings flakes or peels.

Lead was once widely used in household plumbing. This lead can get into water that flows through the pipes. The passage of the Safe Drinking Water Act (SDWA) in 1986, as amended, has limited the use of lead in public water systems and plumbing in the United States. However, the lead in old faucets, pipes, and solder used to connect pipes remained a problem. The amount of lead in water depends on the water's temperature (warm or hot water can contain more lead), the minerals and acid it contains, how long the water sits in the pipes, and the condition of the pipes.

Lead solder was once used to seal food cans. This lead could mix with the food inside the can. In 1995 the United States banned this use of lead solder, but it continued to be found in some imported cans.

Some other sources of lead are as follows:

Anyone of any age can be poisoned by lead. However, the risk is greatest among young children. In the United States, about 310,000 children who are one to five years old have a dangerously high level of lead in their blood. The following are some situations linked to increased risk in young children:

Lead poisoning is not easy to detect. Sometimes no symptoms occur, and at other times the symptoms look like those of other illnesses. Some of the possible early signs of lead poisoning in children are constant tiredness or overactivity, irritability, loss of appetite, weight loss, decreased attention span, trouble sleeping, and constipation.

High levels of lead can cause seizures * , unconsciousness, or even death in children. However, most cases of lead poisoning involve much lower levels of lead. Over time, though, even low levels of lead may cause permanent damage. At low levels, lead can cause problems such as learning disabilities, behavior issues, decreased intelligence, speech problems, decreased attention span, brain or nerve damage, poor coordination, kidney damage, decreased growth, and hearing loss.

Contact with lead is especially dangerous for children. However, it can be harmful for teenagers and adults as well. If a pregnant woman comes into contact with lead, it can raise her risk of illness during pregnancy. It can also cause problems, including brain damage or death, in her unborn baby. At high levels, lead in adults can cause problems such as infertility, high blood pressure, digestion problems, nerve disorders, memory problems, decreased attention span, and muscle and joint pain.

Often lead poisoning has few symptoms. The only way to know whether a person has lead poisoning is to get a blood test that measures the amount of lead in the blood. Children who are not at high risk are usually tested at one and two years of age. Children who are at high risk are usually tested every six months between the ages of six months and two years, then once a year until age six. A blood test can also be done at any time on anyone who has symptoms or may have been exposed to lead.

The first step in treatment is to avoid more contact with lead. Avoiding exposure means finding and removing any sources of lead in the home. The next step is to make any needed changes in diet. Children should eat at least three meals per day because they absorb less lead when they have food in their systems. Children also should eat plenty of foods high in iron and calcium, such as milk, cheese, fish, peanut butter, and raisins. When they do not get enough iron and calcium, their bodies mistake lead for these minerals, and more lead is absorbed and deposited in their tissues.

If blood levels of lead are high enough, the doctor may prescribe a drug that chelates (KEE-lates), or binds to, lead in the body. Once lead is bound up in this way, the body can remove it through urine or bowel movements. The drug used determines how it is administered: by injection in a vein, or by mouth.

The following tips can help prevent lead poisoning:

See also Environmental Diseases: Overview • Infertility • Learning Disabilities: Overview • Memory and Amnesia

* seizures (SEE-zhurs) are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.