Complete Cleanup Unlikely
There is no practical way to kill or remove every bit of anthrax from contaminated buildings, experts told Congress Thursday.
“We will never remove every spore,” said Dr. James Baker Jr., a professor of medicine at the University of Michigan and a military researcher on ways to neutralize biological weapons.
“There will be no assurance of total safety.”
In testimony before the House Science Committee investigating ways to remove anthrax contamination from federal buildings, Baker spoke of the effort to clean the Hart Senate Office Building.
“You will not sterilize that building no matter what you do,” he said.
“Like it or not, we are entering into a research project. What we are doing on the Hart building is an experiment that we need to learn from.”
Dr. Charles Haas, a professor of environmental engineering at Drexel University, said an absolute cleanup of anthrax contaminated buildings is impractical.
Instead, he urged that experts establish what is an acceptable risk and clean the buildings to that point.
“There is no absolutely safe level,” he said. “We need to educate the public that we cannot make everything sterile. There will always be residual risk. The question is what should we shoot for in the cleanup.”
The experts said that science does not know how many spores of anthrax could be considered a normal, natural part of the background. Anthrax is common in many parts of the nation, and it would not be surprising if there were natural levels in buildings.
Haas said the decision about safe levels should not be left to scientists alone, noting that “an acceptable risk level is a public policy issue.”
The experts said that the government response to the anthrax-by-mail crisis has lacked a central focus and that there has been poor communication about the risks.
“People will deal with the risks if they understand,” said Baker, “if you tell people what the rational risk is and that they will be supported if there is a problem.”
“The government needs to develop a clear way of assessing risks in a building,” said Dr. Lynn Goldman, a professor of environmental health sciences at Johns Hopkins Bloomberg School of Public Health. “We have not seen that type of framework.”
Manuel Barbeito, a retired biological cleanup expert at the U.S. Army Biological Warfare Laboratories at Ft. Detrick, Md., supervised the cleanup of a building containing labs, offices and more than a million cubic feet of space.
He said trace bacteria remained after an exhaustive cleaning but that federal researchers were able to continue working there.