Copyright © Philip M. Parker, INSEAD. Terms of Use.
Definition: DDT |
DDTNoun1. An insecticide that is also toxic to animals and humans; banned in the United States since 1972. Source: WordNet 1.7.1 Copyright © 2001 by Princeton University. All rights reserved. |
| Domain | Definitions |
Computing | DDT /D-D-T/ n. [from the insecticide para-dichloro-diphenyl-trichloroethene] 1. Generic term for a program that assists in debugging other programs by showing individual machine instructions in a readable symbolic form and letting the user change them. In this sense the term DDT is now archaic, having been widely displaced by `debugger' or names of individual programs like `adb', `sdb', `dbx', or `gdb'. 2. [ITS] Under MIT's fabled {ITS operating system, DDT (running under the alias HACTRN, a six-letterism for `Hack Translator') was also used as the shell or top level command language used to execute other programs. 3. Any one of several specific DDTs (sense 1) supported on early DEC hardware and CP/M. The PDP-10 Reference Handbook (1969) contained a footnote on the first page of the documentation for DDT that illuminates the origin of the term: Historical footnote: DDT was developed at MIT for the PDP-1 computer in 1961. At that time DDT stood for "DEC Debugging Tape". Since then, the idea of an on-line debugging program has propagated throughout the computer industry. DDT programs are now available for all DEC computers. Since media other than tape are now frequently used, the more descriptive name "Dynamic Debugging Technique" has been adopted, retaining the DDT abbreviation. Confusion between DDT-10 and another well known pesticide, dichloro-diphenyl-trichloroethane (C14-H9-Cl5) should be minimal since each attacks a different, and apparently mutually exclusive, class of bugs. (The `tape' referred to was, incidentally, not magnetic but paper.) Sadly, this quotation was removed from later editions of the handbook after the suits took over and DEC became much more `businesslike'. The history above is known to many old-time hackers. But there's more: Peter Samson, compiler of the original TMRC lexicon, reports that he named `DDT' after a similar tool on the TX-0 computer, the direct ancestor of the PDP-1 built at MIT's Lincoln Lab in 1957. The debugger on that ground-breaking machine (the first transistorized computer) rejoiced in the name FLIT (FLexowriter Interrogation Tape). Source: Jargon File. |
Agriculture | The abbreviated name of a chlorinated hydrocarbon insecticide, dichloro-diphenyl-trichloromethane. It is persistent in the environment and biomagnifies in birds of prey. The Environmental Protection Agency canceled U.S. registration of virtually all but emergency uses of DDT in 1972. (references) |
Environment | The first chlorinated hydrocarbon insecticide chemical name: Dichloro-Diphenyl-Trichloroethane). It has a half-life of 15 years and can collect in fatty tissues of certain animals. EPA banned registration and interstate sale of DDT for virtually all but emergency uses in the United States in 1972 because of its persistence in the environment and accumulation in the food chain. (references) |
Source: compiled by the editor from various references; see credits. | |
(From Wikipedia, the free Encyclopedia)
Chemical structure:
DDT is created by the reaction of trichloromethanal with chlorobenzene (C6H5Cl). Trade or other names for DDT include Anofex, Cesarex, Chlorophenothane, Dedelo, p,p'-DDT, Dichlorodiphenyltrichloroethane, Dinocide, Didimac, Digmar, ENT 1506, Genitox, Guesapon, Guesarol, Gexarex, Gyron, Hildit, Ixodex, Kopsol, Neocid, OMS 16, Micro DDT 75, Pentachlorin, Rukseam, R50 and Zerdane.
DDT is persistent in the environment, with a reported half life of between 2-15 years and is immobile in most soils. Routes of loss and degradation include runoff, volatilization, photolysis and biodegradation (aerobic and anaerobic). These processes generally occur only very slowly. Breakdown products in the soil environment are DDE (1,1-dichloro-2,2-bis(p-dichlorodiphenyl)ethylene) and DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane), which are also highly persistent and have similar chemical and physical properties.
It was first synthesized in 1873, and its insecticidal properties were discovered by the Swiss scientist Paul Hermann Müller in 1942 who was awarded the 1948 Nobel Prize in Physiology and Medicine for his efforts. DDT is the best known of a number of chlorine-containing pesticides used in the 1940s and 1950s. It was extensively used during World War II among Allied troops and certain civilian populations to control insect typhus and malaria vectors; entire cities in Italy were dusted to control the typhus carried by lice. DDT was then extensively used as an agricultural insecticide after 1945. In the 1950s doses of DDT and other insecticides had to be doubled or trebled as resistant insect strains developed, and evidence began to grow that the chemical was concentrated in the food chain. The compound is stable and concentrates in fatty tissue, reaching dangerous levels in carnivores high in the food chain. It is also excreted in milk.
In 1962 Rachel Carson's book Silent Spring was published. The book argued that pesticides, and especially DDT, were poisoning both wildlife and the environment and also endangering human health. The book received little support from the mainstream scientific community. Nonetheless, the public reaction to Silent Spring launched the modern environmental movement, and DDT became a prime target of the growing anti-chemical and anti-pesticide movements during the 1960s.
DDT was first banned from use in Norway and Sweden in 1970, and the United Kingdom in 1984. The EPA's first administrator, William Ruckelshaus, defying his science advisors, announced a ban in 1972 on virtually all uses of DDT in America, where it is classified in EPA Toxicity Class II. It is still used in other (primarily tropical) countries where mosquito-borne malaria is a larger health problem than DDT's potential toxicity.
DDT was banned in the 1970s in a climate of public mistrust of the scientific and industrial community, following such fiascos as Agent Orange, Three Mile Island, Love Canal, and use of the hormone DES. In understanding the public policy landscape that led to the ban, it is important to realize that there were essentially no restrictions on pesticide manufacture and use during the 1940s and 1950s. This led to impure products, little knowledge of any risks on the part of the pesticide users, overapplication, and near total disregard for any long-term environmental damage that might occur.
In this light, it is not surprising the DDT was overapplied, and its accumulation in the soil and in sensitive watersheds has been rigorously documented. There is little question that DDT accumulation in the environment led to the precipitous decline in raptor populations starting around 1960, with many birds including the bald eagle having been listed on the endangered species list for this reason alone. DDT accumulates through the food chain, with apex predators such as raptors having a higher concentration of the chemical than other animals sharing the same environment.
When present at comparatively low levels in birds, DDT causes the birds to lay eggs with thin shells. Prior to the ban, raptors accumulated enough DDT in their bodies to lay eggs with thin, membraneous shells that would break before hatching. In time, populations declined.
DDT is not particularly toxic to people, compared to other widely used pesticides. Some studies show that if DDT were used responsibly with the regulatory oversight present today, its safety would be comparable to other widely used insecticides. [1]
Because of DDT's singular effectiveness in the control of the mosquito, which vectors malaria, it is still used in many countries throughout the world where malaria has proven difficult to control. Use of DDT to control mosquitoes is primarily done inside buildings and through inclusion in household products and selective spraying; this greatly reduces the risk of strong environmental impact.
DDT is an organochlorine. Some organochlorines have been shown to have weak estrogenic activity, that is, they are chemically similar enough to estrogen to trigger hormonal responses in contaminated animals. This sort of activity has been observed in DDT in laboratory studies involving mouse and rat test subjects, but available epidemiological evidence does not indicate that these effects have occurred in humans as a result of DDT exposure.
Studies of alligators in Florida swamps have found extensive oestrogenation due to high levels of DDT exposure. Many male crocodiles in the area have deformed genitalia and feminised bodily features, while their eggs are showing high rates of infertility and abnormal fetal development. Some researchers believe that this is echoed in the human population. Fertility studies in Scandanavia (not entirely sure which country), where DDT was widely used to control pests, have found that the average male sperm count has dropped by almost 50% since DDT started to be used, while there is an increased rate of certain cancers of the reproductive organs compared to former years.
Controversy remains in some scientific circles over DDT's actual toxicity, however. Some scientists have protested that the laboratory animal studies done in 1969 (and which led to the banning of DDT in much of the developed world) which showed that DDT caused an increase in liver cancer was inconsistent with observations in the wild, given that DDT had been used widely during the preceding three decades with no increase in liver cancer in any of the human populations among whom it had been sprayed. When the World Health Organization investigated the 1969 mouse study, they found that both experimental and control groups had developed a surprising number of tumors. Further investigation revealed that the food fed to both groups were moldy and contained aflatoxin, a carcinogen. When the tests were repeated using uncontaminated foods, neither group developed abnormal numbers of tumors.
In 2001, after a five-year ban led to more than a ten-fold increase in malaria cases, South Africa permitted its use again. Uganda also began permiting its use in anti-malarial efforts despite a threat that its agricultural products to Europe would be banned as a result. One of the arguments against continuing its ban was that DDT was being used anyway in uncontrolled amounts.
Dr. Elizabeth Whelan, the president of the American Council on Science and Health claims that 60 million or more lives "have been needlessly lost since the ban on DDT took effect. ... It's a real tragedy that DDT has been so demonized over the years by activist organizations such as Environmental Defense and the regulatory bodies that they have duped." [1]
Whelan's estimates come from estimates that 2.5 million people die of malaria each year: mostly African children. According to the U.N. World Health Organization (WHO), malaria kills one child under the age of 5 every 30 seconds.
Environmentalists have responded to Whelean by pointing out that DDT has generally been banned only for agricultural use and remains widely used in malarial control, and by pointing out that the rise in malaria deaths can also be attributed to things like resistance to anti-malarial drugs.Properties
History
The banning of DDT
Support for using DDT
Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "DDT."
| The following table is compiled from various sources, across various languages. When English abbreviations or acronyms come from a non-English source, this is noted. | |||
| Entry | Source | Expression | Field |
ddt | English | Drop dead twice | N/A |
DDT | Greek | πίνακας περιγραφέα οριοθέτη | Computing, Post & Telecom |
Source: compiled by the editor, based on several corpora (additional references). | |||
Synonym: DDTSynonym: dichlorodiphenyltrichloroethane (n). (additional references) |
Crosswords: DDT |
| English words defined with "DDT": Muller ♦ Paul Hermann Muller. (references) |
| Specialty definitions using "DDT": Chlorinated hydrocarbons ♦ DDE ♦ PDP-7 ♦ TLAs. (references) |
| Non-English Usage: "DDT" is also a word in the following language with the English translation in parentheses. German (ddt). |
| Domain | Title |
Books | |
Source: compiled by the editor from various references; see credits. | |
| Subject | Topic | Quote |
Health | More and more strains of Anopheles mosquitoes were developing resistance to DDT and other insecticides. (references) | |
The pace of the battle accelerated rapidly when the insecticide DDT and the drug chloroquine were introduced during World War II. DDT was remarkably effective and could be sprayed on the walls of houses where adult Anopheles mosquitoes alight and rest after feeding. (references) | ||
The appearance and spread of insecticide-resistant mosquitoes as well as stricter environmental regulations now limit the effectiveness of the insecticide DDT, the mainstay of malaria eradication programs of the 1950s and 1960s. More recently, researchers have found that bednets soaked with other insecticides, which prevent mosquitoes from making contact with humans, significantly reduce malaria transmission. (references) | ||
Economic History | Azerbaijan | Soil throughout the region was contaminated by DDT and toxic defoliants used in cotton production during the Soviet era. (references) |
Armenia | Issues: soil pollution from toxic chemicals such as DDT; pollution of Hrazdan and Arax Rivers; the falling water level of Lake Sevan, a result of its use as a source for hydropower. (references) | |
Source: compiled by the editor from ICON Group International, Inc.; see credits. | ||
| "DDT" is generally used as a noun (proper) -- approximately 70.59% of the time. "DDT" is used about 34 times out of a sample of 100 million words spoken or written in English. Its rank is based on over 700,000 words used in the English language. Some parts-of-speech are not covered due to the samples used by the British National Corpus. (note: percents less than one-hundredth of one percent have been omitted) |
| Parts of Speech | Percent | Usage per 100 Million Words | Rank in English |
| Noun (proper) | 70.59% | 24 | 71,196 |
| Noun (singular) | 23.53% | 8 | 124,375 |
| Noun (common) | 5.88% | 2 | 245,945 |
| Total | 100.00% | 34 | N/A |
Source: compiled by the editor from several corpora; see credits.
| Hyphenated Usage | |
Beginning with "DDT": ddt-resistant. | |
| Source: compiled by the editor from various references; see credits. | |
| The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com. |
| Expression | Frequency per Day |
ddt | 286 |
ddt pesticide | 29 |
ddt insecticide | 9 |
ddt digest | 8 |
history of ddt | 7 |
ddt online | 6 |
ddt picture | 5 |
ddt structure | 4 |
effects of ddt | 4 |
ddt chemical | 4 |
| Source: compiled by the editor from various references; see credits. | |
| Language | Translations for "DDT"; alternative meanings/domain in parentheses. | |
Chinese | ddt杀虫剂. (various references) | |
Danish | syntetiske organiske insekticider med mangfoldige virkninger udgoer den gruppe af clorerede derivater, som inkluderer DDT( Dichlor-diphenyl-trichlor-ethan ), hexachlorcyclohexan-baserede insekticider og fosforsyreestere (hexachlorocyclohexane-based insecticides and phosphoric esters, multiple action synthetic organic insecticides constitue the group of chlorine der)vatives which include DDT ( dichlorodiphenyl-trichloro-ethane )). (various references) | |
Dutch | synthetische organische insecticiden met meervoudige werking zijn de groep van organische halogeenverbindingen zoals DDT (dichloordifenyltrichloorethaan), insecticiden op basis van hexachloorcyclohexaan, en fosforesters (hexachlorocyclohexane-based insecticides and phosphoric esters, multiple action synthetic organic insecticides constitue the group of chlorine der)vatives which include DDT ( dichlorodiphenyl-trichloro-ethane )), organische chemicaliën, zoals gechloreerde koolwaterstoffen, waartoe bijvoorbeeld DDT behoort, zijn slechts langzaam bio-afbreekbaar en leiden tot een hogere verontreinigingsgraad van het afvalwater (for example ) can only slowly decompose biologically and result in a high waste water content in rivers, organic chemicals such as chlorinated hydrocarbons ( one of which is DDT). (various references) | |
French | les produits organo-chimiques tels que les organo-chlorés ( dont le DDT fait partie p. ex. ) ne sont que lentement bio-dégradables et mènent une charge de pollution élevée des eaux résiduaires (organic chemicals such as chlorinated hydrocarbons ( one of which is DDT). (various references) | |
German | ddt. (various references) | |
Greek | τα συνθετικά οργανικά εντομοκτόνα πολλαπλής δράσης συνιστούν την ομάδα των χλωροπαραγώγων που συμπεριλαμβάνει το DDT(διχλωροδιφαινυλ-τριχ (hexachlorocyclohexane-based insecticides and phosphoric esters, multiple action synthetic organic insecticides constitue the group of chlorine der)vatives which include DDT ( dichlorodiphenyl-trichloro-ethane )). (various references) | |
Italian | imsetticidi ozganici sintetici ad azione multipla sono il gruppo dei cloroderivati al quale appartiene il DDT ( diclorodifeniltricloroetano ) , gli insetticidi a base di esaclorocicloesano e gli esteri fosforiei (hexachlorocyclohexane-based insecticides and phosphoric esters, multiple action synthetic organic insecticides constitue the group of chlorine der)vatives which include DDT ( dichlorodiphenyl-trichloro-ethane )). (various references) | |
Pig Latin | ddtay.(various references) | |
Portuguese | os produtos químicos orgânicos tais como os hidrocarbonetos clorados(de que faz parte,por exemplo,o DDT)só são lentamente dio-degradáveis e provocam uma poluição elevada nas águas residuais (for example ) can only slowly decompose biologically and result in a high waste water content in rivers, organic chemicals such as chlorinated hydrocarbons ( one of which is DDT). (various references) | |
Spanish | los productos químicos orgánicos tales como los organoclorados (de los que uno es el DDT, por ejemplo) son biodegradables sólo lentamente y dan lugar a una carga elevada de contaminación de las aguas residuales (for example ) can only slowly decompose biologically and result in a high waste water content in rivers, organic chemicals such as chlorinated hydrocarbons ( one of which is DDT). (various references) | |
| Source: compiled by the editor from various translation references. | ||
Scrabble® Enable2K-Verified Anagrams | |
| Words containing the letters "d-d-t" | |
+2 letters: dated, didst, doted, teddy, tided, toddy. | |
+3 letters: addict, adduct, darted, dauted, dawted, deduct, dented, didact, dieted, dinted, doated, doited, dotard, dotted, ducted, dunted, dusted, edited, oddest, oddity, outadd, outdid, tedded, tedder, tended, tiddly, tidied, toddle, traded. | |
+4 letters: adapted, addicts, addrest, adducts, adopted, athodyd, audited, baddest, betided, dadaist, dartled, dastard, datedly, daunted, deadest, debated, debited, debuted, deducts, delated, deleted, deltoid, demoted, denoted, dentoid, deputed, derated, detoxed, detrude, devoted, didacts, dighted, dilated, diluted, dirtied, distend, ditched, dittoed, donated, dotards, doubted, drafted, dratted, drifted, duetted, endited, faddist, haddest, hydatid, ideated, indited, iodated, katydid, lyddite, maddest, oddment, outadds, redated, reddest, saddest, sedated, staddle, steaded, stodged, studded, studdie, studied, tedders, teddies, tedding, thudded, tiddler, toadied, toddies, toddled, toddler, toddles, treaded, treddle, trended, trodden, trudged, twaddle, twiddle, twiddly, tzaddik, undated, updated. | |
+5 letters: abducted, addicted, addition, additive, additory, adducent, adducted, adductor, adjusted, admitted, adulated, advected, adverted, athodyds, attended, bedotted, bedstand, bedstead, budgeted, caudated, cheddite, coedited, credited, dadaists, damndest, dandiest, darndest, dastards, deadbeat, deadbolt, deadlift, dealated, deathbed, decadent, decanted, decedent, decocted, dedicate, deducted, deediest, defatted, defeated, defected, deflated, degusted, dehorted, dejected, delisted, deltoids, demasted, demented, demitted, dendrite, dentated, dentiled, denudate, departed, depicted, depleted, deported, deratted, desalted, deserted, desisted, despited, destined, detached, detailed, detained, detected, deterged, deterred, detested, deticked, detoured, detruded, detrudes, devested, deviated, dictated, didactic, didactyl, digested, directed, disputed, disrated, distends, dithered, diverted, divested, docketed, doctored, dodgiest, dotardly, dowdiest, downtrod, durndest, educated, extended, extruded, faddiest, faddists, fidgeted, giddiest, gladdest, gradated, hydatids, hydrated, indebted, indented, indicted, inducted, inedited, intended, intruded, katydids, lyddites, mandated, mediated, misdated, muddiest, nitrided, obtruded, obtunded, oddities, oddments, odontoid, outadded, outdared, outdated, outdodge, outmoded, oxidated, predated, quiddity, radiated, readdict, redacted, reedited, retarded, ruddiest, staddles, standard, steadied, stounded, straddle, stranded, stridden, studdies, studding, sturdied, tabarded, tendered, threaded, thudding, tiddlers, tideland, toddlers, toddling, traduced, treadled, treddled, treddles, trindled, trundled, tuxedoed, twaddled, twaddler, twaddles, tweedled, twiddled, twiddler, twiddles, undotted, unedited, untended, untidied, updarted. | |
| Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro. | |
Hexadecimal (or equivalents, 770AD-1900s) (references)44 44 54 |
| Leonardo da Vinci (1452-1519; backwards) (references)
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| American Sign Language (origins from 1620-1817 in Italy and, especially, France) (references)
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| Semaphore (1791, in France) (references)
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| Braille (1829, in France) (references)
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Morse Code (1836) (references)-.. -.. - |
| Dancing Men (Sir Arthur Conan Doyle, 1903) (references)
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Binary Code (1918-1938, probably earlier) (references)01000100 01000100 01010100 |
HTML Code (1990) (references)D D T |
ISO 10646 (1991-1993) (references)0044 0044 0054 |
| British Sign Language (Fingerspelling, BSL; 1992, British Deaf Association Dictionary of British Sign Language) (references)
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Encryption (beginner's substitution cypher): (references)383854 |
| 1. Definition 2. Synonyms 3. Crosswords 4. Usage: Commercial | 5. Images: Slideshow 6. Quotations: Non-fiction 7. Usage Frequency 8. Expressions | 9. Expressions: Internet 10. Translations: Modern 11. Abbreviations 12. Acronyms | 13. Anagrams 14. Orthography 15. Bibliography |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
