Endosulfan: Another
Organochlorine Pesticide
Charlene Hurst
Physical & Chemical Properties
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Color: beige
Physical State:
crystalline-waxy solid
Melting Point: 106 C
Density: 1.735 g/mL
Lipophilic
Beta form converts to
alpha at high temps.
http://www.inchem.org/documents/ehc/ehc/E40_2.gif
Applications & History
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First introduced 1956, called
Thiodan®
Organochlorine pesticide mainly for
tobacco and fruits
Used for control of over 100 insects
Production in US stopped after
1982
Still used in chemical formulations
in the US as a wettable powder and
emulsifier for wood preservation,
home gardening, agriculture
1967 40 million fish in Rhine died
from exposure
USGS
Chemistry
2 stereo isomers: alpha and beta
 Break down to: diol, sulfate, lactone,
ether, hydroether
 Half life from 1-6 months in water to 2
years in soil
 Degraded in water to endosulfan diol, in
soil to endosulfan sulfate
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Environmental entry
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Some agricultural runoff
Accidental spills
Volatized into the atmosphere, transported
No natural occurrence
Detected: atmosphere, soil, sediment, surface
water, rain water, food items
Synergism with other toxicants? (ex. Dieldrin)
Organismal Entry
Inhalation
 Absorption through skin
 Orally
 Target sites within body: fatty tissues, liver,
kidneys
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Toxic Effects
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Mammals less susceptible than aquatic animals, most
toxic for fish
Residue levels peak in fish within 7days to 2 weeks
- rainbow trout LC50 =1ppb in 48hrs.
- Striped bass LC50= 0.10 ppb in 96hrs.
Inhibited spermatogenesis, deformed intestinal cells,
degradation of testes
Decrease in growth, egg production, oxygen
consumption, red blood cell count
Neurotoxicity: convulsions, decreases neurotransmitter
levels, prevents binding
Behavioral changes in fish
Mode of Action
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Metablized by both hydrolysis and oxidation
Diol metabolite by chemical hydrolysis (pH influenced)
Sulfate metabolite by oxidation(P450Prevents GABA
from opening chloride channels for hyperpolarization
Inhibits Na, K and Mg dependent ATPase in brain.
Causes changes in Na and K levels, decreases in Ca
and Mg levels in brain
Results in repetitive nerve discharges
Detoxification
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Organisms can increase
growth rates to reduce
the amount of substance
in the body
Excretion: mostly in
feces, small amounts in
urine
Filtration of water
Bacterial microorganisms
Selenium treatment
(Kumar et. al, 2007)
References
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Brown, A.W.A. 1978. Ecology of Pesticides. John Wiley and Sons: New York.
Department of Health and Human Services: Agency for Toxic Substances and Disease
Registryhttp://www.atsdr.cdc.gov/toxprofiles/tp41.pdf. 2000.
Edwards, C.A. Ed. 1973. Environmental pollution by pesticides. Plenum Press. London and New
York.
Kullman, S.W. and F. Matsumara. 1995. Metabolic pathways Utilized by Phaenerochaete
chrysosporium for degradation of the cyclodiene pesticide endosulfan. Applied and Environmental
Microbiology, 1996.
Kumar, M., C. V. Lakshimi and S. Khanna. 2007. Biodegradation and bioremediation of endosulfan
contaminated soil. Bioresource Technology 99 (2008): 3116-3122.
Navqi, S. M. and C. Vaishonavi. Bioaccumulative potential and toxicity of endosulfan insecticide to
non-target animals.
Rehman, S. 1996. Endosulfan toxicity and its reduction by selenium: a behavorial, hematological and
peroxidative stress evaluation. Internet Journal of Toxicology 3 (1).
United States Geological Survey. Pesticides in Stream Sediment and aquatic biota: current
understanding of distribution and major influences. United States Geological Survey Fact Sheet.
http://water.usgs.gov/nawqa
Wade, M.G., D. Desaulniers, K. Leingartner and W. G. Foster. 1997. Interactions between endosulfan
and dieldrin on estrogen-mediated processes in vitro and in vivo. Reproductive Technology 11, (6):
791-798.
Yuquan, L., K. Morimoto, T. Takeshita, T. Takekeuchi and T. Saito. 2000. Genotoxic effects of αendosulfan and β-endosulfan on human HepG2 cells. Environmental Health Perspectives, 106
(6):559-561.