Thank you for the opportunity to provide this testimony to you today regarding the effect of elevated lead levels and lead poisoning. My name is Dr. Muriel Wolf. I am an Associate Professor of Pediatrics at George Washington University Medical School, and Attending in Pediatrics and Cardiology and Senior Pediatrician at Children's National Medical Center in Washington, DC. I have taken care of children with elevated lead levels and lead poisoning for over 30 years.
Fortunately, the health care landscape has changed significantly since the 1970s when we admitted over 100 children per year with elevated lead levels of over 60 mcg/dl. Now, we admit fewer than 5 children per year with elevated lead levels at this number.
The problem of lead in the water in the District of Columbia has alerted all of us about the possibility of elevated blood lead levels. But as of this writing, there is no strong evidence that the lead in the water has caused any serious elevation of blood lead levels.
While the issue of lead in the District water supply is an important one, let it not be lost that most elevated lead levels in children are due to lead paint in old houses. Children exposed to an environment where there is peeling or flaking lead paint are at risk for elevated blood lead levels. Small amounts of lead paint chips or dust can cause blood lead levels to become elevated. Because of the presence of lead paint in old houses, the Centers for Disease Control (CDC) has recommended in cities where more than 20 percent of the houses were built before 1970, children should be tested for elevated blood lead at age one, and then again at 2 years of age. In DC, over 50 percent of the housing was built before 1970. Accordingly, all District children should have blood lead tests at 1 and 2.
Lead can cause significant health problems. Currently the acceptable blood lead level according to CDC guidelines is 9mcg/dl or less. Very high blood lead levels (over 50 to 60 mcg/dl) may cause serious health problems such as marked learning disability and mental retardation. Even higher blood lead levels can be associated with brain swelling and seizures. Elevated blood lead levels may cause significant anemia and kidney damage.
Children with blood lead levels above 20 mcg/dl may have learning disabilities and attention deficit disorder problems, and hearing and growth may even be affected. More recent studies have shown that even mild elevations of blood lead levels between 10 and 20 mcg/dl may minimally lower the IQ by 1 to 3 points.
The goal is to prevent elevated blood lead level, and currently those elevated levels almost always come from exposure to lead paint and dust. Homes with lead paint should be screened for lead hazards where there is peeling and flaking paint. Windows and doors should be wiped with high phosphate soap. Floors should be. wet-mopped rather than vacuumed so that the lead in the dust is not spread throughout the room. Children and adults should frequently wash their hands to prevent environmental exposure to lead dust. Finally, the paint causing the problem should be sealed or removed.
Lead paint remains the most serious source of lead problems at this time. But lead in the water is a significant issue as well -- especially if the CDC decides to lower the acceptable level of lead for children. Lead in the water may contribute to elevated lead levels, but nobody knows for sure. It has not been shown so far in DC to be the cause of elevated lead levels beyond the 10 mcg/dl level. Of the 14 patients identified in the District with elevated lead levels above 10 mcg/dl, all lived in environments where there was lead paint and tested positive on dust wipes.
Current research reported in the New England Journal of Medicine in April 2003 suggested that lead levels of 5-9 mcg/dl can indeed lower IQ by 5-7 points. If this research can be corroborated by other studies, then we should be significantly concerned that lead in the water in the District of Columbia may be contributing to elevated lead levels.
It is appropriate to study the issue of lead in the water in the District of Columbia, but the lead found in housing is the major problem at the