Because of its low cost and physical properties, lead has been used in a wide variety of products such as paint, gasoline, ceramics, batteries, and cosmetics. Research has shown that children are particularly vulnerable to the health effects of lead, including deficits in attention span, adaptability, learning, and memory, as well as increases in aggression and other behavioral problems. Even low levels of lead exposure can result in decreased performance on intelligence tests. Lead exposure in adults is associated with an increased risk of high blood pressure, impaired kidney function, fertility problems, and cataracts.
Research conducted by NIEHS-supported scientists over the past 30 years delineating these effects has led to regulatory standards to reduce or eliminate lead from many consumer products including paint, gasoline, soldered food cans, and plumbing, and a corresponding decrease in average blood lead levels in the general population. In addition, clinical trials sponsored by NIEHS showed that treatment with chelating agents like succimer could significantly lower blood lead levels in children with moderate to severe lead exposure.
These interventions have produced an overall decrease in blood lead levels in the general population. Results from the National Health and Nutrition Examination Survey show that blood lead levels have dropped from 12.8 to 2.8 micrograms per deciliter, an average of 78% for persons of all ages. There has been an 87% reduction in the total number of children with blood lead levels greater than 15 micrograms per deciliter, from 3 million in 1984 to 393,000 in 1994.
The banning of lead from consumer products and the subsequent reduction in lead exposure has had an enormous impact on children’s health. The drop in blood lead levels has resulted in significantly fewer diagnoses of lead-related deficits in learning and behavior, along with an estimated average improvement of four points on standard intelligence tests. According to the Centers for Disease Control and Prevention, this small difference translates into an increase of $56,000 in lifetime earning potential for each child in the United States.