Lead Poisoning

What Is It?

Lead, a metal used in manufacturing primarily because of its resistance to corrosion, is poisonous when inhaled or ingested by humans. It enters the bloodstream and is stored in the organs, tissues, bones and teeth. With increasing or prolonged exposure, this toxin can cause:

• Permanent damage to the central nervous system, especially the brain
• Developmental delays in children
• Behavioral changes in children
• Decreased production of red blood cells (anemia)
• Hearing problems
• Damage to the reproductive systems of men and women
• Kidney disease
• Convulsions (seizures)
• Coma

The leading source of exposure is lead-based paint, which remains in about 40 percent of U.S. houses, nearly all of them built before lead paint was outlawed for residential use in 1978. The main hazard is paint dust, which enters the air when old paint is scraped, sanded or begins to flake. Undisturbed lead paint in good condition usually is not a problem.

Other ways people can ingest or inhale lead include drinking water from pipes that are made of lead or use lead solder, using ceramic dishes made with lead, playing in lead-contaminated soil, using lead in hobbies or crafts such as stained-glass work, or consuming certain home remedies containing lead.

Children face the most serious risk because their developing systems absorb more lead. Young children, especially toddlers, also play on the floor and tend to put objects in their mouths that may be covered with lead dust. If lead paint is flaking, small children sometimes eat the sweet-tasting paint chips or chew on painted surfaces.

Adults who have high lead levels in their blood usually have been exposed in the workplace. Industries with high potential exposure include construction that involves welding, cutting, blasting or other disturbances of lead-painted surfaces; smelter operations; radiator repair shops; and firing ranges. Young children can be exposed to lead from parents who work in these areas and carry lead dust home with them on their clothes and shoes.

A woman with a history of lead poisoning can pass lead on to her fetus if she becomes pregnant, even if she no longer is exposed to lead. This occurs because more than 90 percent of lead may be stored in the bones and then released into the bloodstream years later.

Since lead was banned in gasoline and residential paint, average blood-lead levels have dropped dramatically in the United States. Nevertheless, the most recent estimate from the U.S. Centers for Disease Control and Prevention, using data collected from 1999 to 2000, is that 434,000 young children still had lead levels of at least 10 micrograms per deciliter, the maximum recommended level for children. Recent studies suggest that even lower levels may be harmful.