Lead Poisoning

Exposure to lead in housing poses a significant health risk to young children. Lead is a heavy metal used in many materials and products. When absorbed into the body, it is highly toxic to many organs and systems and seriously hinders the body’s neurological development. Lead is most harmful to children under age six because it is easily absorbed into their growing bodies and interferes with the developing brain and other organs and systems. Pregnant women and women of child-bearing age are also at increased risk, because lead ingested by the mother can cross the placenta and affect the unborn fetus.

Lead poisoning causes irreversible health effects and there is no cure for lead poisoning. At very low levels of exposure in children, lead causes reduced IQ and attention span, hyperactivity, impaired growth, reading and learning disabilities, hearing loss, insomnia, and a range of other health, intellectual, and behavioral problems. At low levels, lead poisoning may not present identifiable symptoms, and a blood test is the only way to know if a child is poisoned. At very high levels of exposure, which are now very rare in the U.S., lead poisoning can cause mental retardation, coma, convulsions, and even death.

As lead poisoning rates have declined nationally, the disparities of this disease have increased. In some communities, the rate of exposure is about five times the national average, which is estimated at 1.6 percent of children aged 1-5. In the U.S., children from poor families are more likely to be poisoned than those from higher income families. African-American children are also at increased risk, when compared with both Hispanic and white children.

National health experts agree that exposure to lead-contaminated dust from deteriorated lead-based paint in older homes is the primary pathway for lead exposure in young children. Lead dust settles quickly, is difficult to clean up, and is invisible to the naked eye. Young children usually are poisoned through normal hand-to-mouth activity, as lead dust settles on their toys and the floor. Children may also be seriously poisoned by eating lead-based paint chips, but this is relatively rare.

Soil in the vicinity of the home can also be contaminated by flaking exterior lead-based paint, previous deposits of leaded gasoline, and exterior sandblasting. In yards where soil is contaminated with lead, children can become exposed to harmful levels of the heavy metal when they get their hands dirty and place their fingers or a dirty or dusty toy in their mouths during normal play activity. Lead-contaminated soil and dust can also be tracked into homes on shoes or by pets or can be blown in through open windows and doors. Vegetables grown in lead-contaminated soil may absorb lead and poison children and adults.

Drinking water may become contaminated with lead from pipes or solder when water corrodes them. Less common sources include workplace exposures to lead where workers may receive doses well above those experienced by the general population. Exposed workers may carry lead particles home on their clothing, shoes, or hair, putting family members at risk. Those who work in construction, demolition, painting, with batteries, in radiator repair shops, lead factories, or with a hobby that involves lead are often exposed to lead. Rare sources of exposure include food and drink stored in leaded crystal, lead-soldered cans, or lead-glazed ceramicware; home remedies and cosmetics that are popular in some cultures; and some consumer products.

Except for severely poisoned children, there is no medical treatment for this disease. While drug therapy can reduce high levels of lead in the body, it does not undo the harm caused to developing organs and systems. A blood lead test is the only way to determine if a child has lead poisoning. The U.S. Centers for Disease Control and Prevention (CDC) defines a blood lead level of 10 µg/dl as a level of concern, indicating that steps should be taken to reduce ongoing lead exposure. Recent research has found adverse health effects, including learning disabilities, at much lower levels of exposure.

Most health department lead poisoning prevention programs postpone action to address lead-based paint hazards until after a child has been identified as lead poisoned. In effect, children are used to detect lead hazards in their homes. Over the past decade, emphasis has shifted to primary prevention to prevent and control lead hazards in housing before a child’s health is harmed.

Sources and Additional Information:

National Safety Council – nsc.org/library/facts/lead.htm

U.S. Centers for Disease Control and Prevention, Third National Report on Human Exposure to Environmental Chemicals (July 2005) – www.cdc.gov/exposurereport/metals/pdf/lead.pdf

U.S. Department of Housing and Urban Development Office of Healthy Homes and Lead Hazard Control – www.hud.gov/offices/lead/

U.S. Environmental Protection Agency – www.epa.gov/lead/