Lead poisoning occurs when a person swallows or inhales lead in any form, damaging the brain, nerves, and many other parts of the body. Acute lead poisoning, which is relatively rare, occurs when a large amount of lead is taken into the body all at once. Chronic lead poisoning, which is a common problem inchildren, occurs when small amounts of lead are taken in over a longer period.
Lead can damage almost every system in the human body, and it can also causehigh blood pressure. It is particularly harmful to the developing brain of unborn babies and young children. The higher the level of lead in a child's body, the more serious the problems, which can include slowed reflexes, learningproblems and even mental retardation. At very high levels, lead poisoning can cause seizures, coma, and death.
About one out of every six children in the United States has a high level oflead in the blood, according to the Agency for Toxic Substances and Disease Registry. Many of these children are exposed to lead through peeling paint inolder homes. Others are exposed through dust or soil that has been contaminated by old paint or past emissions of leaded gasoline. Since children betweenthe ages of 12-36 months tend to put things in their mouths, they are more likely than older children to take in lead. Pregnant women who come into contact with lead can pass it along to their unborn babies.
More than 80% of American homes built before 1978 have lead-based paint. Theolder the home, the more likely it is to contain lead paint, and the higher the concentration of lead in the paint is apt to be. Some homes also have leadin the water pipes or plumbing. In addition, people may have lead in the paint, dust, or soil around their homes or in their drinking water without knowing it, since lead can't be seen, smelled, or tasted. Because lead doesn't break down naturally, it can continue to cause problems until it is removed. Lead-based paint is the most common source of exposure among preschoolers. Children may eat paint chips from older homes that have fallen into disrepair or chew on painted surfaces. In addition, paint may be disturbed during remodeling. Pollution from operating or abandoned industrial sites can find its way into the soil.
Other sources of lead poisoning include:
- Drinking water. Exposure maycome from lead water pipes, found in many homes built before 1930. Even newer copper pipes may have lead solder, and some new homes have brass faucets and fittings that can leach lead.
- Jobs and hobbies. A number of activities can expose participants to lead, such as making pottery or stained glass, refinishing furniture, doing home repairs, or using indoor firing ranges. When adults take part in such activities, they may inadvertently expose children to lead residue that is on their clothing or on scrap materials.
- Food. Imported food cans often have lead solder, and lead is found in leadedcrystal glassware and some imported or old ceramic dishes. In addition, foodmay be contaminated by lead in the water or soil.
- Folk medicines. Certain folk medicines (for example, alarcon, alkohl, azarcon, bali goli, coral, ghasard, greta, liga, pay-loo-ah, and rueda) and traditional cosmetics (such as kohl) contain large amounts of lead.
Chronic lead poisoning may lead to learning disabilities, hyperactivity, mental retardation, slowed growth, hearing loss, or headaches. In adults, lead poisoning can cause high blood pressure, digestive problems, nerve disorders, severe abdominal pain, diarrhea, nausea and vomiting, weakness, seizures and coma.
A high level of lead in the blood can be detected with a simple blood test. In fact, testing is the only way to know for sure if children without symptomshave been exposed to lead, since they can appear healthy even after long-term damage occurs. The Centers for Disease Control recommends testing all children at 12 months of age and, if possible, again at 24 months. Testing shouldstart at 6 months for children at risk for lead poisoning. Based on these test results and a child's risk factors, the doctor will then decide whether andhow often further testing is needed. In some states, more frequent testing is required by law.
Children are at risk if they:
- Live in or regularly visit a house builtbefore 1978 in which chipped or peeling paint is present or where remodelingis underway.
- Have a brother or sister, housemate, or playmate who has been diagnosed with lead poisoning.
- Live with an adult whose jobor hobby involves exposure to lead.
- Live near an active lead smelter, battery-recycling plant, or other industry that can create lead pollution.
Adults may be at risk if they own glazed pottery or make stained glass, or are involved in renovating an old house which may be contaminated with lead.
The first step in treating lead poisoning is to avoid further contact with lead. For adults, this usually means making changes at work or in hobbies. Forchildren, it means finding and removing sources of lead in the home. In moststates, the public health department can help identify lead sources in the home. A professional with special training should remove lead paint. Scraping or sanding lead paint creates large amounts of dust that can poison people inthe home and that may linger long after the work is completed. In addition, heating lead paint can release lead into the air. For these reasons, lead paint should only be removed by someone who knows how to do the job safely and has the equipment to clean up thoroughly. Occupants (especially children and pregnant women) should leave the home until the cleanup is finished.
If blood levels of lead are high enough, the doctor may also prescribe chelation therapy, a type of treatment using chemicals that bind to the lead and help the body pass it in urine at a faster rate. There are four chemical agentsthat may be used for this purpose, either alone or in combination: Edetate calcium disodium, dimercaprol, succimer, and penicillamine. (Although many doctors prescribe penicillamine for lead poisoning, this use of the drug has notbeen approved by the Food and Drug Administration.)
Changes in diet are no substitute for medical treatment. However, getting enough calcium, zinc, and protein may help reduce the amount of lead the body absorbs. Iron is also important.
If acute lead poisoning reaches the stage of seizures and coma, there is a high risk of death. Even if the person survives, there is a good chance of permanent brain damage. The long-term effects of lower levels of lead can also bepermanent and severe. However, if chronic lead poisoning is caught early, these negative effects can be limited by reducing future exposure to lead and getting proper medical treatment.
To prevent lead poisoning:
- Play areas should be as clean and dust-free as possible.
- Pacifiers and bottles should be washed after they fallon the floor; stuffed animals and toys should be washed often.
- Children should wash hands before meals and at bedtime.
- Floors, windowsills and other chewable surfaces (such as cribs) should be washed twice a weekwith a solution of powdered dishwasher detergent in warm water.
- Bushes should be planted next to an older home with painted exterior walls to keep children at a distance.
- Grass or another ground cover should be planted in soil that is likely to be contaminated, such as soil around a homebuilt before 1960 or located near a major highway.
- Household tap water should be tested for lead.
- Water from the cold-water tap only should be used for drinking, cooking, and making baby formula, since hot water islikely to contain higher levels of lead. The more time water has been sitting in the pipes, the more lead it may contain.
- People who work withlead should change clothes before going home.
- Food should not be stored in open cans (especially imported cans).
- Food should not be stored or served in pottery meant for decorative use.