Filed at 10:18 p.m. ET

ST. LOUIS (AP) -- More than a quarter of the children living close to the nation's largest lead smelter have elevated lead in their blood, state health officials said Tuesday in releasing a report they called an ``urgent public health hazard.''

In the 2,800-resident town of Herculaneum, 28 percent of children tested for elevated lead; In the part of town closest to the smelter, that number is about 45 percent, the report states.

The findings are the most comprehensive yet to gauge the extent of lead exposure in the home of the 110-year-old Doe Run Co. smelter, about 30 miles south of St. Louis on the Mississippi River.

The state Department of Health and Senior Services study, based on blood samples given voluntarily by 935 people last fall, found levels far above the national rate near 3 percent.

``This is extremely high,'' said Scott Clardy, a health department public health expert. ``This is far and away the highest rate I've seen anywhere, and it's the reason we declared the site an urgent public health hazard.''

Lead can cause brain damage in children; adults can develop anemia, kidney disease and high blood pressure. The EPA has not definitively tied any health problems to the smelter, though many residents say they are certain of a link.

Buyouts of homes could occur if the EPA agrees to designate Herculaneum a Superfund cleanup site, as requested by Rep. Dick Gephardt and Gov. Bob Holden. Their request is on hold to give Doe Run a chance to complete cleanup orders.

Families in Herculaneum are already asked to wash their hands frequently, leave shoes outside and wash children's toys if used outdoors.

Under EPA orders, Doe Run is spending millions of dollars to replace soil in residents' yards and reduce air pollution from its stacks by July.

While the company agrees with the report's recommendations, spokeswoman Barb Shepard said it still needs to review the findings closely and that some of the numbers either don't match up or are deceiving because small areas of high contamination are factored into averages.

Jack Warden, 40, who lives a quarter-mile from the smelter, said Doe Run has promised several times over the years to get lead pollution under control, and it has yet to happen.

``They say the science is greater now and things are going to change. To me, they are a proven liar,'' Warden said.

Regarding Tuesday's report, Warden said he had expected numbers that high.

``Everyone else wants to break out their study books,'' Warden said. ``To hell with the study books. Study time is over. It's time to act.''