Narrator: This is Science Today. Lead poisoning was once thought to be on the decline in this country. But the problem is re-emerging in the nation's big urban areas due to lead waste from demolition of old buildings or sandblasting lead paint off steel structures. Donald Smith, an environmental toxicologist at the University of California, Santa Cruz, explains.
Smith: Because we've used lead for so long in a number of different industrial materials, including as an additive in gasoline. As a result of all those industrial activities and the use of lead as a combustion in cars, there's enormous amounts of lead, essentially stockpiled in the dust and soil of urban areas.
Narrator: Smith says the exposure level is higher in these areas where the soil is not landscaped and children play in the dirt and dust.
Smith: And the smartest thing an individual can do is just to be aware of where the child is playing. If there's a lot of exposed dirt on the outside of the house, in the parks and so on, is to try and keep the child's hands clean.
Narrator: And monitor their activity. For Science Today, I'm Larissa Branin.