Disinfected mail or fumigated 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 had some form of

disinfection 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 ...

fumigation Fumigation is a method of pest control or the removal of harmful microorganisms by completely filling an area with gaseous pesticides, or fumigants, to suffocate or poison the pests within. It is used to control pests in buildings (structural ...

applied to it by postal authorities, with the intention of preventing the spread of

epidemic An epidemic (from Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of hosts in a given population within a short period of time. For example, in meningococcal infection ...

s via letters sent from infected areas. The usual practice was to puncture the envelope with small holes, often in a grid pattern, or to snip off one or more corners, in order to let the fumigation gases in. In addition, a special

postal marking A postal marking is any kind of annotation applied to a letter by a postal service. The most common types are postmarks and cancellations; almost every letter will have those. Less common types include forwarding addresses, routing annotati ...

may note the disinfection process. The process did not necessarily have a scientific basis; the practice dates from before an understanding of the cause of contagious diseases, and the fumigant was as likely to be based on folklore. For instance, in the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...

Mediterranean ports such as

Venice Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...

would smoke received covers or douse them with

vinegar Vinegar () is an aqueous solution of diluted acetic acid and trace compounds that may include flavorings. Vinegar typically contains from 5% to 18% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting ...

. The

cholera Cholera () is an infection of the small intestine by some Strain (biology), strains of the Bacteria, bacterium ''Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea last ...

pandemic A pandemic ( ) is an epidemic of an infectious disease that has a sudden increase in cases and spreads across a large region, for instance multiple continents or worldwide, affecting a substantial number of individuals. Widespread endemic (epi ...

s of the early 19th century led to widespread treatment of mail, although the concern had died down by the 1840s. Mail from the tropics, particularly

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

, was treated against yellow fever. Following the 1898 war in Cuba, the US military government in occupation instigated several policies to reduce the endemic yellow fever problem including disinfection of mail. In the 20th century some mail was heat-treated to prevent the spread of

smallpox Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus '' Orthopoxvirus''. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (W ...

. Most countries have instituted mail fumigation at one point or another, and investigation of the specific incidents is an active area for

postal history Postal history is the study of postal systems and how they operate and, or, the study of the use of postage stamps and Cover (philately), covers and associated postal artifacts illustrating historical episodes in the development of postal system ...

; the Disinfected Mail Study Circle publishes about 100 pages of original research each year in its journal ''Pratique''. An instance of double disinfection took place in 1900 with the fumigation with

sulphur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a colorless gas with a pungent smell that is responsible for the odor of burnt matches. It is r ...

of mail from the leper settlement of the island of Molokai and the mail was further fumigated with formaldehyde when it was received in Honolulu. However no instance of infection of post office employee was recorded even though they had handled such non-disinfected leper mail for years.

Irradiated mail 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 in the US occurred in response to the 2001 anthrax attacks; the level of radiation chosen ...

is a form of disinfected mail adopted in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, in response to the

2001 anthrax attacks The 2001 anthrax attacks, also known as Amerithrax (a portmanteau of "United States, 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 th ...

References

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External links

Bibliography of disinfected mail

Disinfected Mail Study Circle
Postal history Philatelic terminology