Plan to irradiate mail spurs debate

Experts discuss effects on range of items Postal Service ships

War On Terrorism

The Nation


The decision by the U.S. Postal Service to try using electron beams to kill harmful organisms in the mail prompted a debate yesterday among experts about the possible impact on everything from shipped eyeglasses to cookies.

Postal officials said yesterday that the service had started sanitizing mail to the government at an Ohio plant. But they said the service would not start routinely sterilizing mail until tests ensured there was no significant damage to mailed goods or health hazard to employees. They said the procedure would be done initially only on mail that appeared suspect.

As companies scrambled to offer systems to the postal service and to private companies trying to cut the risk of anthrax assaults, experts said the technology had potential, but they urged caution.

"Any time you generalize and say something is a cure-all for everything that ails you, you will overstep the technical limits and end up with egg on your face," said Dr. Irwin A. Taub, an expert on food irradiation and a former senior research scientist for the Army Soldier Systems Center in Natick, Mass.

The technology, known as ion beam sterilization, uses a particle accelerator to produce beams of electrons, which are then fired through mail. The electrons disrupt the DNA of any living things they encounter, killing them.

Taub and other experts said they doubted that the process could be used on cartons or other bulky mail because the electrons would not penetrate deeply enough.

Experts generally agreed that foods sent through the mail would not be affected. No radiation or significant heat is generated in the process, which is already widely used to sterilize bandages, food containers, spices, surgical supplies and food for astronauts and the Army.

But the electrons that penetrate material to kill bacteria and spores could also destroy electronic circuits and data on floppy disks, and they could alter the inks in photographs, officials at some companies that build or operate sterilizing equipment said.

Brad Stone, a spokesman for the Food and Drug Administration, said his agency and the postal service were discussing ways to avoid having mailed prescription drugs go through the devices. "There'll be a system to ensure they won't be adversely affected," Stone said. The technique could also change some materials in unpredictable ways. For example, electrons can bounce around inside minerals, including gemstones and glass, in ways that change the color of the material.

Topaz is routinely modified commercially from clear to blue through ion beam sterilization, though at greater energy levels than those proposed for sanitizing the mail. Mineralogists said similar reactions could occur in glass at the energy levels being considered by companies competing for postal contracts.

Gerry Kreienkamp, a spokesman for the Postal Service, emphasized that the service was still in the early stages of deciding how to handle the new risk and the technologies chosen to reduce it.

"We'll have to test this and make sure it works within our system," Kreienkamp said.

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