The following are excerpts from the United States Department of Housing and Urban Development (HUD) Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing:
According to the Centers for Disease Control and Prevention, childhood lead poisoning is "the most common environmental disease of young children." Lead is highly toxic and affects virtually every system of the body. At low levels lead's neurotoxic effects have the greatest impact on children's developing brains and nervous systems, causing reductions in IQ, decreased attention span, reading and learning disabilities, hyperactivity and behavioral problems.
The foremost cause of childhood lead poisoning in the United States today is ingestion of lead-based paint and the accompanying contaminated dust and soil found in or around older houses. The Department of Housing and Urban Development (HUD) estimates that three-quarters of pre-1980 housing units contain some lead-based paint. Fully 90 percent of privately owned units built before 1940, 80 percent of units built between 1940 and 1959, and 62 percent of units built between 1960 and 1979 contain some lead-based paint.
The belief that in order to be poisoned children must eat lead-based paint chips is unfounded. The most common cause of poisoning is the ingestion--through hand-to-mouth transmission of lead-contaminated surface dust. Leaded dust is generated as lead-based paint deteriorates over time, is damaged by moisture, abraded on friction surfaces and impact surfaces, or distributed in the course of renovations, repair or abatement projects. Lead contaminated dust may be so fine that it cannot be seen by the naked eye and can be difficult to clean up.