Irradiated mail
Encyclopedia
Irradiated mail is mail
that has been deliberately exposed to radiation
, typically in an effort to disinfect it. The most notable instance of mail irradiation occurred in response to the 2001 anthrax attacks
; the level of radiation chosen to kill anthrax spores was so high that it often changed the physical appearance of the mail.
The United States Postal Service
began to irradiate mail in November 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 continuous wave electron beam accelerator built by IBA Industrial, to irradiate the mail. A few facilities were planning to use cobalt-60
sources, though it is unclear whether this was ever done.
s, photographic film
, biological
samples, food
, medicines, and electronic 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 some plastics 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 cover
s through the mail. A number of auction
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.
Mail
Mail, or post, is a system for transporting letters and other tangible objects: written documents, typically enclosed in envelopes, and also small packages are delivered to destinations around the world. Anything sent through the postal system is called mail or post.In principle, a postal service...
that has been deliberately exposed to radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...
, typically in an effort to disinfect it. The most notable instance of mail irradiation occurred in response to the 2001 anthrax attacks
2001 anthrax attacks
The 2001 anthrax attacks in the United States, also known as Amerithrax from its Federal Bureau of Investigation case name, occurred over the course of several weeks beginning on Tuesday, September 18, 2001, one week after the September 11 attacks. Letters containing anthrax spores were mailed to...
; the level of radiation chosen to kill anthrax spores was so high that it often changed the physical appearance of the mail.
The United States Postal Service
United States Postal Service
The United States Postal Service is an independent agency of the United States government responsible for providing postal service in the United States...
began to irradiate mail in November 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
Bridgeport, New Jersey
Bridgeport is an unincorporated area within Logan Township, located in Gloucester County, New Jersey. The area is served as United States Postal Service ZIP Code 08014....
, operated by Sterigenics International, uses a Rhodotron continuous wave electron beam accelerator built by IBA Industrial, to irradiate the mail. A few facilities were planning to use cobalt-60
Cobalt-60
Cobalt-60, , is a synthetic radioactive isotope of cobalt. Due to its half-life of 5.27 years, is not found in nature. It is produced artificially by neutron activation of . decays by beta decay to the stable isotope nickel-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 seedSeed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...
s, photographic film
Photographic film
Photographic film is a sheet of plastic coated with an emulsion containing light-sensitive silver halide salts with variable crystal sizes that determine the sensitivity, contrast and resolution of the film...
, biological
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
samples, food
Food
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals...
, medicines, and electronic 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 some plastics have bubbled or melted.
Irradiation's effects on paper caused some alarm in the philatelic
Philately
Philately is the study of stamps and postal history and other related items. Philately involves more than just stamp collecting, which does not necessarily involve the study of stamps. It is possible to be a philatelist without owning any stamps...
world, which sends large numbers of rare postage stamp
Postage stamp
A postage stamp is a small piece of paper that is purchased and displayed on an item of mail as evidence of payment of postage. Typically, stamps are made from special paper, with a national designation and denomination on the face, and a gum adhesive on the reverse side...
s and cover
Cover (philately)
In philately, the term cover pertains to the outside of an envelope or package with an address, typically with postage stamps that have been cancelled and is a term generally used among stamp and postal history collectors. The term does not include the contents of the letter or package, although...
s through the mail. A number of auction
Auction
An auction is a process of buying and selling goods or services by offering them up for bid, taking bids, and then selling the item to the highest bidder...
houses stopped sending material through the mail, and Linn's Stamp News
Linn's Stamp News
Linn's Stamp News an American publication, is the largest weekly newspaper for stamp collectors, with a paid circulation of just over 46,000 Circulation peaked at almost 92,000 in 1978 and has declined ever since because fewer new collectors are subscribing to replace those who subscribed in the...
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.