Irradiated mail is

mail The mail or post is a system for physically transporting postcards, letter (message), letters, and parcel (package), parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid ...

that has been deliberately exposed to

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

, typically in an effort to

disinfect A disinfectant is a chemical substance or compound used to inactivate or destroy microorganisms on inert surfaces. Disinfection does not necessarily kill all microorganisms, especially resistant bacterial spores; it is less effective than ste ...

it. The most notable instance of mail irradiation in the US occurred in response to the

2001 anthrax attacks The 2001 anthrax attacks, also known as Amerithrax (a portmanteau of "America" and "anthrax", from its FBI case name), occurred in the United States over the course of several weeks beginning on September 18, 2001, one week after the September 11 ...

; 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 The United States Postal Service (USPS), also known as the Post Office, U.S. Mail, or Postal Service, is an independent agency of the executive branch of the United States federal government responsible for providing postal service in the U ...

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 is a census-designated place{ (CDP) and unincorporated community that is part of Logan Township, in Gloucester County, in the U.S. state of New Jersey. At the 2020 United States census, the population of the CDP was 389. in the 20 ...

, 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 (60Co) is a synthetic radioactive isotope of cobalt with a half-life of 5.2713 years. It is produced artificially in nuclear reactors. Deliberate industrial production depends on neutron activation of bulk samples of the monoisoto ...

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 A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

photographic film Photographic film is a strip or sheet of transparent film base coated on one side with a gelatin photographic emulsion, emulsion containing microscopically small light-sensitive silver halide crystals. The sizes and other characteristics of th ...

biological Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary in ...

samples,

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...

medicines A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and rel ...

, and

electronic equipment The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification a ...

. In the process of irradiation, mail is exposed to extreme heat. Paper is weakened and may appear to have been aged, with discoloration (e.g., yellowing), and brittleness. Pages may break, crumble, or fuse to other pages. Documents bound with glue may have loose pages. The printing on pages may be distorted or offset onto adjacent pages. If tape is affixed to address labels, the address may be illegible. Irradiation's effects on paper caused some alarm in the

philatelic Philately (; ) is the study of postage stamps and postal history. It also refers to the collection and appreciation of stamps and other philatelic products. Philately involves more than just stamp collecting or the study of postage; it is possi ...

world, which sends large numbers of rare

postage stamp A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to customers who pay postage (the cost involved in moving, insuring, or registering mail), who then affix the stamp to the fa ...

s and

cover Cover or covers may refer to: Packaging * Another name for a lid * Cover (philately), generic term for envelope or package * Album cover, the front of the packaging * Book cover or magazine cover ** Book design ** Back cover copy, part of co ...

s through the mail. A number of

auction An auction is usually a process of buying and selling goods or services by offering them up for bids, taking bids, and then selling the item to the highest bidder or buying the item from the lowest bidder. Some exceptions to this definition ex ...

houses stopped sending material through the mail, and ''

Linn's Stamp News ''Linn's Stamp News'' is an American weekly magazine for stamp collectors. It is published by Amos Media Co., which also publishes the Scott ''Standard Postage Stamp Catalogue'', the Scott ''Specialized Catalogue of United States Stamps and Co ...

'' 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, including all mail directed to the White House, Congress, and the Library of Congress.

In popular media

In the TV show NCIS's "SWAK" episode, an envelope with a suspicious powder is delivered to their office and opened - blowing into one of the agent's faces. While they're taking cleansing showers, they discuss that all mail to federal facilities is irradiated by the post office, and they specifically mention Bridgeport, NJ

References

External links

US Environmental Protection agency:Irradiated Mail

{{DEFAULTSORT:Irradiated Mail Radioactivity Postal systems 2001 anthrax attacks