Blood lead levels as low as 10 μg/dl are associated with harmful effects on children's learning and behavior. Very high blood lead levels, exceeding 70 μg/dl, can cause serious health consequences, including seizures, coma and death. The percentage of children with elevated blood lead levels has dropped significantly over the years as leaded gasoline and lead solder used for canning food has been phased out. However, in 1997, the CDC estimated there are still 890,000 U.S. children with blood lead levels above 10 μg/dl. Lead-based paint remains the prevalent source of lead exposure for U.S. children.