BOISE - A study concluded last year indicates that the number of children in 2013 with blood lead levels above 10 micrograms per deciliter in the Bunker Hill 21-square-mile EPA Superfund cleanup area was 2 percent.

That's down from 57 percent in 1989 - the study released by the Panhandle Health District in November shows.

On Wednesday, Idaho Department of Environmental Quality Director Curt Fransen touted Superfund cleanup efforts to state lawmakers, saying the blood lead levels for children living in the Superfund site in Shoshone County now are "consistent with national averages."

"It (the cleanup) has been successful and the blood lead data back that up," Fransen said in an interview.

Addressing the Idaho Legislature's joint budget committee, Fransen said the study conducted last summer illustrates that the blood lead levels of children within the Superfund site, commonly known as "the box," have steadily declined since the cleanup began during the 1980s.

"Blood lead levels in children in the area known as the box, the 21-square-mile area right around Kellogg, the city of Kellogg, were once among the highest blood lead levels ever recorded in the country," Fransen said.

Fransen also said that study illustrates the environmental cleanup progress that has been made in the box and the Coeur d'Alene Basin - where contaminated soil in many cases has been replaced with clean soil.

"Over the course of the cleanup, blood lead levels in children in that area have dropped to levels consistent with national averages," Fransen said. "A significant sampling effort this past summer confirmed that the blood lead levels of children in the box remain within national averages, and demonstrate that the cleanup activities have been successful and that the locally based and implemented institutional control program run by the Panhandle Health District is effectively maintaining the progress that has been made."

Metallurgical contaminants from a century's worth of mining in the Silver Valley include lead, arsenic, zinc, and cadmium, said Fransen, and added the human health aspects of the Superfund cleanup have concluded.