Safety and prevention

Understanding lead poisoning

Introduction

Lead poisoning is the number one environmental health problem in the United States and affects many children in the greater New Haven region.

In many countries, including the U.S., lead is one of the most common sources of poisoning in children. Lead poisoning affects young children of all economic backgrounds. Children who are at risk often live in older homes where lead-based paint is not well maintained or where people renovate homes and do not follow necessary safety precautions.

According to the U.S. Centers for Disease Control and Prevention, almost a million children, age one to five, who were screened from 1991 to 1994 had elevated blood lead levels. Considering about 83 percent of the houses built before 1980 contain some lead-based paint, many more children are at risk for exposure to this toxic metal. Neurological damage from the lead can cause learning difficulties and other problems without the child or parent knowing it. All children should be screened for lead in their blood at least at one and two years of age. The good news is steps can be taken now to prevent or stop lead poisoning.

The Yale-New Haven Lead Program and Regional Treatment Center provides diagnosis and treatment of children with lead poisoning in their Lead Clinic at Yale-New Haven Children's Hospital. Educational services about lead poisoning are available at the program's Lead Resource Center. The Lead Safe Home provides alternative housing for families whose children are recovering from lead poisoning. For information call (203) 764-9106.

What is lead?
Lead is a heavy metal found naturally in the earth that has been used in many ways for hundreds of years. Lead was added to gasoline from the 1920s until it was phased out, beginning in the 1970s. Until the 1970s, lead was added to paint used in homes and for another decade it was used in solder to seal food cans and connect plumbing pipes. Because lead does not decompose or deteriorate, it does not go away but remains in homes, in the soil alongside roadways and in some water pipes.

What is lead poisoning?
Even though laws greatly reduced the amount of lead that now gets into our environment, lead is still a significant problem. When any home built before 1978 is renovated without appropriate precautions and lead paint is chipped, sanded or scraped, young children are placed at risk for lead poisoning.

Nearly all cases of childhood lead poisoning in the U.S. are caused by contact with deteriorating or disturbed lead-based paint, or dust or soil contaminated with lead.

When lead gets into the human body, usually through the mouth or the nose, it eventually enters the blood stream and collects in soft tissues of the body, such as the liver, kidneys and the brain. It also settles in the bones and teeth, where it is stored for many years. In young children, even small amounts of lead can damage the brain and the nervous system.

Studies have shown that children with elevated lead levels are at greater risk for learning problems, behavior problems and reduced intelligence. The longer a child is exposed to lead, the more likely it is he or she will have problems.

Young children at risk
Young children are especially vulnerable to lead poisoning because their rapidly developing nervous systems are particularly sensitive to the effects of lead. Due to their small size, children suffer more damage than an adult exposed to the same amount of lead. Lead is also absorbed more easily in children than adults.

In addition, the normal behavior of young children adds to the problem. Children naturally put toys, pacifiers and fingers in their mouths to learn, explore and comfort. They also crawl, play and basically live near the floor or ground where lead hazards tend to be worse. Sometimes a child will eat loose chips of lead paint out of curiosity or for its sweet taste, or chew on a toy contaminated with lead dust.

There are usually no physical symptoms until lead poisoning has become very serious. At very high levels, the brain swells, causing mental confusion, stumbling and speech difficulties. In the worst cases, lead poisoning can cause seizures, coma and even death. Today, these outcomes are rare because of better screening, earlier identification of children with lead poisoning and earlier intervention.

Pregnancy and lead poisoning
Any woman considering pregnancy who is concerned about lead should ask her doctor or nurse midwife about a lead test. Ideally, this test should be done before becoming pregnant. If there is any chance the mother was exposed to large levels of lead, a blood test for lead poisoning may be recommended. Lead in a mother's body can cross the placental barrier and enter the body of the growing fetus.

During pregnancy, hormone changes can cause lead stored for years in a woman's bones to be released into the blood. This lead probably won't affect the mother, but could pose risks for an unborn baby.

Babies exposed to lead in the uterus are more often born prematurely and smaller. Some studies suggest women exposed to lead may suffer more miscarriages. Others show that babies exposed to lead before birth may suffer effects similar to lead exposure after birth.

Screening for lead poisoning
In Connecticut, all children should be screened for lead poisoning at one and two years using a simple blood test. The test should be done earlier and more often on children who are suspected to have lead poisoning or have been exposed to lead. Your pediatrician or nurse practitioner can perform the test using a small blood sample taken from a finger. If that first test is above a certain level, a more accurate test is done using a blood sample from the arm.

Finding out your child has elevated levels of lead
The U.S. Centers for Disease Control and Prevention suggest the parent of a child with an elevated blood lead screening test should know the following, which your doctor or nurse practitioner can explain:

• The level of the blood lead test and what it means
• The potential adverse effects of an elevated blood lead test
• The sources of lead exposure and how they can be reduced
• How wet cleaning methods rather than dry sweeping reduces lead exposure
• The importance of follow-up blood lead testing
• When an environmental investigation is needed
• The dangers of improper removal of lead-based paint

For treatment information, see Yale-New Haven Lead Program and Regional Treatment Center.

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Reviewed: David Schonfeld, MD
Last revised: May 10, 2007 (dh)

Home page URL: http://www.ynhh.org

All information is intended for your general knowledge and is not a substitute for medical advice or treatment for specific medical conditions. You should seek prompt medical care for any specific health issues and consult your physician before starting a new fitness regimen.