Published in the Asbury Park Press
By JEAN MIKLE
TOMS RIVER BUREAU
DOVER TOWNSHIP -- If thermal treatment is used to clean up some of the pollution sources at the former Ciba-Geigy Corp. Superfund site, dioxin emissions from the treatment process should pose no threat to public health, federal environmental officials said last night.
Responding to questions raised by audience members at a March forum on thermal treatment, the federal Environmental Protection Agency brought two experts on dioxin to last night's session at the Holiday Inn.
Paul R. de Percin, a chemical engineer at the EPA's National Risk Management Research Laboratory, based in Cincinnati, said emissions tests made at other cleanup projects that used thermal desorption units showed emissions far below federal standards. Any dioxin emissions would come from the thermal desorption process; there are no dioxins at the Ciba site.
Thermal desorption units heat soil to temperatures between 500 and 1,200 degrees Fahrenheit to vaporize and remove contaminants. The technology, which is effective at removing organic pollutants from soils, is one of several treatment techniques being considered to clean up more than a dozen contaminated sites, as well as 35,000 drums of waste on Ciba's property off Route 37.
"We know how to operate and design the system so it won't form dioxin," de Percin said. ". . . You get very, very low numbers."
But results at previous sites did not reassure several members of the audience, who have previously questioned the lack of emissions testing during the cleanup several years ago at Dover's Reich Farm Superfund site, off Route 9.
"Stack tests," or tests of air emissions in the stack of a thermal desorption unit, were not done at Reich Farm, which was cleaned up several years ago.
Linda L. Gillick, who chairs the Citizens Action Committee on Childhood Cancer Cluster, questioned why stack tests were not done during the farm cleanup.
Romona Pezzella, EPA's remedial project manager for the Ciba site, said that although she could not answer that question, the EPA will do a trial burn with a stack test if thermal desorption is chosen as a remedy.
Dwain Winters, who heads the EPA's Dioxin Policy Project, said the vast majority of dioxins are absorbed through ingesting foods like meat, dairy products and fish, since the chemical tends to accumulate in fatty tissue.
Winters said that studies have shown that small increases or decreases in exposure to dioxin over short periods of time do not affect someone's risk of developing cancer or other symptoms connected to dioxin exposure.
"Inhalation is a very inefficient method of exposure," Winters said.
Township resident Scott Minnich asked Winters for more concrete information about what is likely to happen if thermal desorption is used at the Ciba site.
"I'd like to know how much more dioxin I am likely to inhale," he said. Winters said he could not be more specific now, but that information will be included in an assessment made by EPA if thermal desorption is one of the treatment methods chosen.
Source: Asbury Park Press
Published: August 6, 1999
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