- Irradiated mail
Irradiated mail is
mail that has been deliberately exposed toradiation , typically in an effort todisinfect it. The most notable instance of mail irradiation occurred in response to the2001 anthrax attacks ; the level of radiation chosen to kill anthrax spores was so high that it often changed the physical appearance of the mail, in some cases spectacularly so.The
United States Postal Service began to irradiate mail inNovember 2001 , in response to the discovery of large-scale contamination at several of its facilities that handled the letters that were sent in the attacks.A facility in
Bridgeport, New Jersey , operated by Sterigenics International, uses a Rhodotron(TM) continous wave electron beam accelerator built by IBA Industrial, to irradiate the mail. A few facilities were planning to usecobalt-60 sources, though it is unclear whether this was ever done.Effect on mail
The USPS warned that a number of products could be adversely affected, such as
seed s,photographic film , biological samples,food ,medicines , andelectronic equipment . In addition, a number of papers and plastics have been observed to react badly to the irradiation; paper may become grayed and fragile, and someplastics have bubbled or melted.Irradiation's effects on paper caused some alarm in the philatelic world, which sends large numbers of rare
postage stamp s and covers through the mail. A number ofauction houses stopped sending material through the mail, and "Linn's Stamp News " regularly featured reports on stamps and covers that had been ruined by irradiation.Although at one time the USPS expected to irradiate all mail, it later scaled back to just treating mail sent to government offices.
External links
* [http://www.epa.gov/radiation/sources/mail_irrad.html US Environmental Protection agency:Irradiated Mail]
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