Auburn, Oct. 24---As the number of anthrax outbreaks among U.S. Postal Service workers increases, the federal government has been exploring the option of using irradiation to cleanse mail of anthrax and other potentially fatal pathogens.

Will it work?

Yes, says one expert. But, she warns, implementing this technology will be costly, time-consuming and fraught with challenges.

"There are two basic ways that mail could be irradiated in order to rid it of such pathogens," says Dr. Jean Weese, an Alabama Cooperative Extension System food scientist. "One is the cobalt 60 method, while the other involves an electron beam."

Cobalt 60 is considered the most effective form of irradiation, she says, because it would allow an entire truckload of mail to be treated in a short time.

Even so, Weese says, there is one drawback associated with this procedure: Since it would cost too much to build cobalt-60 facilities at individual post offices, vast quantities of mail would have to be collected from different locations and transported to a centrally located irradiation plant.

"Postal employees would first have to collect the mail from a variety of mail drops – homes, businesses and local post offices – in order to carry it to the central plant for processing," Weese says. "This would undermine the whole purpose of limiting human contact with mail until it’s been irradiated."

An added complication, Weese says, are the costs involved in building irradiation plants and transporting mail to these facilities – costs that eventually would be reflected in substantially higher postage rates, she says.

Irradiation machinery using electronic beams would be a far less costly alternative, Weese says. The machines are small enough to be installed in individual post offices, thereby reducing the levels of human contact with untreated mail. But even this relatively cheaper technology has its share of drawbacks, she says.

Electron beams, for example, are only able to penetrate 1 or 2 inches deep and would be largely ineffective with larger mail parcels.

"The problem is that this technology is not as powerful as the cobalt-60 method because it doesn’t penetrate to the same depth," Weese says. "This means the mail would have to be exposed for a longer period of time in order for the anthrax spores to be destroyed."

There is the added problem associated with the spores’ physical makeup. Spores, because of their hard outer coating, are much more resistant to irradiation than vegetating cells such as E.coli – a factor also contributing to the need for longer periods of irradiation exposure.

There is also the challenge of eliminating postal workers’ exposure to mail prior to irradiation.

"For this to work properly, the whole postal routine will have to be reorganized," Weese says. "This could mean we have to deliver mail to a central mail drop so that it can be conveyed directly to the irradiation facility."

This ultimately could mean the end of home-mail pickup and similar forms of convenient service previously taken for granted, she says.

Unfortunately, disruptions of these kinds may be only the tip of the iceberg, Weese says, since the planning required to implement such a system will not be accomplished in days, months or even years.

Whatever the case, she says, the changes that likely will accompany this new system are yet another example of how even routine tasks such as mailing a letter have been permanently altered by the tragic events of Sept 11.

Irradiation already is used extensively to sanitize food and medical products, often in bulk or assembly line settings. While the procedure has drawn sharp criticism from some scientists, who claim its effect on food has not been fully established, the Centers for Disease Control and Prevention contends it is a safe and effective technology that can prevent many foodborne diseases.