Facts About Lead Poisoning
Lead provides no known biological benefit to humans. Lead can produce adverse effects on virtually every system in the body; it can damage the kidneys, the nervous system, the reproductive system, and cause high blood pressure. It is especially harmful to the developing brains of fetuses and young children.
There may be no lower threshold for some of the adverse effects of lead in children. In addition, the harm that lead causes to children increases as their blood lead levels increase.
Blood lead levels (BLLs) as low as 10 micrograms/deciliter (ug/dL) are associated with harmful effects on children's learning and behavior. We should try to prevent the occurrence of blood lead levels of 10 ug/dL and above in children. Very high blood lead levels cause devastating health consequences including seizures, coma and death.
Children with venous blood lead levels of 20 ug/dL or above or with venous BLLs in the range of 15 to 19 ug/dL over a period of at least three months need a doctor's care.
Elevated BLLs in children are a major preventable health problem that affects children's mental and physical health. The higher a child's BLL and the longer it persists, the greater the chance that the child will be affected. Elevated blood lead levels can result in:
- Learning disabilities;
- Behavioral problems;
- Mental retardation;
- At extremely high levels (70 ug/dL or higher), seizures, coma and even death.
Prevention of Childhood Lead Poisoning
Significant progress has been made in the United States in reducing overall rates of childhood lead exposure through comprehensive prevention strategies, including:
Environmental Prevention Strategies
- Environmental standards that removed lead from gasoline, paint and plumbing.
- Water treatment and removing lead solder from food cans.
- Reducing lead-based paint hazards in children's homes.
- Physician education.
- Family and community education.
Remaining Sources of Lead Exposure
Despite progress, major exposure sources still exist:
- Lead-based paint in older homes that is deteriorating, creating dust and paint chips easily ingested by young children.
- Lead-based paint in homes that is disturbed during renovation or remodeling.
- Lead-based paint in homes that is exposed on a surface easily chewed by a young child (such as a window sill).
- Lead-contaminated soil.
Other potential sources of lead exposure in some areas are:
- Operating or abandoned industrial sites and smelters. Although lead pollution has been greatly reduced, some soil and dust contamination can still result.
- Occupations and hobbies. Children can be exposed to lead-contaminated dust on parents' clothes.
- Use of lead-containing ceramics for cooking, eating or drinking.
- Use of traditional home remedies or cosmetics that contain lead.
The Current Situation
Between 83 percent and 86 percent of all homes built before 1978 in the United States have lead-based paint in them. The older the house, the more likely it is to contain lead-based paint and to have a higher concentration of lead in the paint. Houses built before 1950 pose the greatest hazard to children because they are much more likely to contain lead-based paint than newer houses.
Average BLLs in the United States have fallen dramatically since the 1970s. Whereas in 1976-1980 the average BLL in children was 15ug/dL, in 1991-1994, the average was 2.7ug/dL.
However, some populations of children continue to be disproportionately exposed to lead. In general, children who live in older housing are more likely to have elevated blood lead levels than the population of U.S. children as a whole. According to a national survey, from 1991-1994:
- 21.9 percent of black children ages 1 to 5 who were living in older housing had elevated blood lead levels (10ug/dL or higher)
- 16.4 percent of poor children living in older housing had elevated blood lead levels.
- 11.5 percent of children living in older housing in large urban areas (population of 1,000,000 or greater) had elevated blood lead levels.
- 4.4 percent of all children had elevated blood lead levels.
Depending on the severity of a child's BLL, follow-up treatment can include:
- Family education about preventing future contact with lead sources.
- Environmental investigation and lead hazard reduction or abatement.
- Medical treatment, such as chelation therapy.