A rocklike substance used in driveways and roadbeds already has made residents in north Pinellas and south Pasco counties uneasy because it emits elevated levels of radiation.
More tests this month will reveal what concentrations of heavy metals and other contaminants reside in the slag, a byproduct of phosphorus processing.
Residents turned their attention to the material this summer after several homeowners had slag on their property tested for radium-226. They suspected the slag came from the former Stauffer Chemical plant, now a federal Superfund site at the county line.
After the state's Bureau of Radiation Control, a division of the Department of Health, discovered elevated levels of radiation coming from the slag, residents demanded to know what the substance was made of.
They'll get their answers some time next month after about 20 slag samples have been analyzed by the Florida Department of Environmental Protection, said environmental specialist George Heuler.
Heuler may begin taking the samples as early as next week. He will explain the process to residents at a meeting at 7:30 p.m. Nov. 13 at the Tarpon Springs Community Center, 400 S Walton Ave.
Heuler said he plans to start with properties already tested by the Bureau of Radiation Control and then fan out so he has equal representation from areas in Tarpon Springs and Holiday.
"I think when this study is completed, we'll be able to say comfortably where it's safe, and if it isn't, we'll be able to take the next step," Heuler said.
Heuler said he suggested the testing after getting lots of calls from residents worried that their families are being exposed to high concentrations of chemicals because the slag was used near their homes, schools or workplaces.
The U.S. Environmental Protection Agency, which is overseeing the cleanup at the Stauffer site, issued a statement supporting the tests. It also announced that the Bureau of Radiation Control will test radiation levels inside homes and businesses upon request.
The bureau found elevated levels of radiation in several roads and at least one driveway and behind the bleachers at Sisler Field, an athletic complex in Tarpon Springs. But none was high enough to warrant further outdoor testing, said environmental administrator Harlan Keaton.
Heuler said his tests will examine the levels of lead, arsenic, cadmium, chromium, phosphorus and other heavy metals found in slag. If any of those contaminants is found to be too high, the DEP will measure its chances of leaching out of the slag, Heuler said.
If a substance could leach into nearby water supplies, the DEP will recommend a way to stop it, such as capping a slag driveway with asphalt, he said.
The federal Agency of Toxic Substances and Disease Registry in Atlanta also is interested in the levels of radiation and contaminants in the slag, said Southeast regional representative Carl Blair.
The organization, which investigates the health hazards associated with Superfund sites, will look at how easily people are exposed to those substances, he said.
If exposure is great, the agency may recommend an epidemiological study, an extensive look at the health of those living or working near the slag over the years.
The results of the slag testing will be sent to the EPA close to the end of the year. But the EPA has little to do with any contamination away from the Stauffer site because, so far, there is no concrete proof the slag comes from the old chemical plant, said Maxwell Kimpson, who is overseeing the cleanup for the EPA.
Residents who want Stauffer to take responsibility for any off-site contamination have accused the EPA of hurrying to clean up the Superfund site without taking their concerns about slag and other contaminants seriously.
The Agency of Toxic Substances and Disease Registry, part of the Centers for Disease Control and Prevention, is funded by the EPA. But Blair said researchers there operate without interference from those working on other aspects of the cleanup.
"We won't be satisfied until we look at every possible exposure scenario," Blair said. "We don't care how long it takes or how much it costs."