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Dwight Causey. DDT and its Derivatives. DDT. DDE. DDD. Chemical Properties. History. First synthesized in 1874 Insecticidal properties discovered in 1939 by Paul Hermann Müller Won Noble Prize in Physiology and Medicine in 1948 - PowerPoint PPT Presentation
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Dwight Causey
DDT
DDE
DDD
Chemical PropertiesDDT DDE DDD
Molecular Weight
354.49 318.03 320.05
Appearance/ Physical State
Colorless Crystals, white powder
Crystalline Solid Colorless Crystals, white powder
Melting Point (oC)
109 89 109-110
Solubility (at 25oC)
0.025 mg/L 0.12 mg/L 0.090 mg/L
Log Kow 6.91 6.51 6.02
Log Koc 5.18 4.7 5.18
Henry’s Law constant
8.3x10-6 atm-m3/mol
2.5x10-5 atm-m3/mol
4.0x10-6 atm-m3/mol
History First synthesized in 1874 Insecticidal properties discovered in 1939 by
Paul Hermann MüllerWon Noble Prize in Physiology and Medicine in 1948
Used to control insect-borne diseases (i.e. malaria and typhus)
Peak of usage in 1962Registered for use on 334 agricultural commodities85,000 tons produced
Cumulative estimated world usage is 2 million tons
History Used in homes for
mothproofing and lice control
Still used today in developing countries to control malaria and lice
Silent Spring by Rachel Carson in 1962, questioned the widespread use of DDT
Mode of Entry into Water Indirectly
Agricultural runoff○ Binds strongly to soil and organic matter
Volatized into the atmosphere○ Redistributed through particulate matter
DirectlyWater pollution plants (sewer pipes to the
ocean)1,000,000 kg (~227 tons) from Montrose
Chemical Company to Palos Verdes shelf
Reactivity Slightly soluble in water Very lipophillic Physical Half-life: 2-15 years
Increases with timeSequestered in micropores
Biological Half-life: 8 years Biodegraded into DDE and DDD under
aerobic and anaerobic conditions, respectively
DDT Derivatives
DDE is the major metabolite Both resist to biodegradation in aerobic
and anaerobic conditions Very long half-lives in water Hydrolysis is a minor process in
degradation Photolysis of DDE is a major process
Half-life: 15-26 hours
DDD Toxicity
96 hour LC50:Glass shrimp: 2.4 µg/LRainbow trout: 70 µg/LLargemouth bass: 42 µg/LWalleye: 14 µg/L
48 hour LC50:Daphnid: 4.5 µg/L
DDE Toxicity
96 hour LC50:Rainbow trout: 32 µg/LAtlantic Salmon: 96 µg/LBluegill: 240 µg/L
Egg shell thinningMallard: 3 µg/gBrown pelican: 3 µg/g
Toxic Effects
Weak estrogenic activities In the brain:
Inhibition of ATP-based reactionsHepatic enzyme inductionDisruption of hormonal mechanisms
Inhibition of Na+/K+ ATPases in the gills Thinning of egg shells in raptors Reduction in cortisol production
Mode of Entry into Organisms Majority enters through food Some enters through absorption from
water through body surfaces (i.e. gills), not believed to be significant when compared to amount entering through food
Very Lipophillic, bioaccumulates Some organisms retain 90%+ of ΣDDT
in their food source
Molecular Mode of Interaction Egg shell thinning in Raptors, 2 possibilities:
DDE inhibits prostaglandin synthesis in the shell gland mucosa, limiting calcium and bicarbonate transport across the mucosa
Embryonic exposure alters shell gland carbonic anhydrase expression, causing eggshell thinning
In fish, no known molecular mechanism is knownBelieved to involve ATPases in the central nervous
system and gills In Insects, causes the irreversible opening of
voltage gated Na+ channels along the axon
Biochemical Metabolism and Breakdown DDT metabolized into DDE and DDD by
microorganisms Mixed-function oxidases may induce the
dechlorination of DDT to DDE in fishes In some mammals, DDE is converted to 2-
methylsulfonyl-DDE and 3-methylsulfonyl-DDEActed on by phase I CYP2B enzymesFollowed by conjugation with glutathione during
phase IIThen through the mercapturic acid pathway, 2-
SH-DDE and 3-SH-DDE are formed
Detoxification Up-regulation of CYP6G1 gene in
Drosophila melanogaster Secretion through urine, feces, semen, and
breast milk Clams shown to dechlorinate DDE to
DDMU under methanogenic or sulfidogenic conditions
Dried and ground seaweed has been shown to increase DDT biodegradation by 80% after 6 weeks, further degradation of DDD also seen
Bibliography Cal/Ecotox Toxicity Data for Brown Pelican (Pelecanus occidentalis) . Office of Environmental Health Hazard
Assessment. 1999. http://www.oehha.ca.gov/cal_ecotox/report/pelectox.pdf The Comparative Toxicogenomics Database. Mount Desert Island Biological Laboratory. 2008.
http://ctd.mdibl.org/ Denholm I, Devine GJ, Williamson MS (2002). Evolutionary genetics. Insecticide resistance on the move.
Science 297 (5590): 2222–3. Evans, D. H. (1987). The Fish Gill: Site of Action and Model for Toxic Effects of Environmental Pollutants.
Environmental Health Perspectives 71, 47-58. Hazardous Substances Data Bank. National Library of Medicine TOXNET System. 2008.
http://toxmap.nlm.nih.gov/toxmap/home/welcome.do Handbook of Acute Toxicity of Chemicals to Fish and Aquatic Invertebrates. U.S. Fish and Wildlife Services.
1980. Kantachote D., Naidu R., Williams B., McClure N., Megharaj M., Singleton I. (2004). Bioremediation of DDT-
contaminated soil: enhancement by seaweed addition. Journal of Chemical Technology & Biotechnology, 79 , 6, 632-638.
Lacroix M., Hontela A. (2003). The organochlorine o,p’-DDD disrupts the adrenal steroidogenic signaling pathway in rainbow trout (Oncorhynchus mykiss). Toxicology and Applied Pharmacology 190, 197-205.
O’Reilly A.O., Khambay B.P.S., Williamson M.S., Field L.M., Wallace B.A., Emyr Davies T.G. (2006). Modelling insecticide-binding sites in the voltage-gated sodium channel. Biochemical Journal, 396, 255-263.
U.S. Department of Health and Human Services. Toxicological Profile for DDT, DDE, and DDD. Agency for Toxic Substances and Disease Registry. 2002.
World Health Organization. DDT and its Derivatives – Environmental Aspects. Environmental Health Criteria 83. 1989. http://www.inchem.org/documents/ehc/ehc/ehc83.htm
World Health Organization. DDT and its Derivatives. Environmental Health Criteria 9. 1979. http://www.inchem.org/documents/ehc/ehc/ehc009.htm