Natures Nightmare: A study of the chemistry of

Natures Nightmare: A study of the chemistry of

Natures Nightmare: A study of the
chemistry of DDT and its effects on the
Scott Zeglin
environment.
Abstract
Synthesis of DDT
DDT

Dichlorodiphenyltrichloroethane,
commonly known as DDT, is a powerful
insecticide that combats the vectors of
human disease and crop pests. DDT was
first used in World War II to combat
infectious disease in humans, but its
main use was as a pesticide until the
EPA banned it in 1973. Problems with
DDT arose when it was discovered that
the compound is stable and fat soluble,
which means that it accumulates in
animal fat tissue and becomes more and
more concentrated in the offspring of
infected species. It is useful to
understand why DDT is such a powerful
insecticide, but also why its half-life in
animals is so long (8 years). By
analyzing the chemical make-up of this
compound, improvements might be
possible to make the compound nonsoluble in fat or accumulating in animals,
while still maintaining its lethal effects
towards pests.

Introduction

After World War II, DDT was the most
commonly used pesticide in the world,
since it seemed to eradicate all unwanted
insects, and left all other organisms alone.
DDT is an organochlorine that undergoes
biomagnification as it accumulates
through the food chain, which means that
higher concentrations of the chemical will
be found in animals at the top of the food
chain, but there is no evidence that DDT
harms humans in any way. The
mechanism and synthesis of DDT was
studied to understand why it is such a good
insecticide, but what properties allow it to
be so harmful to non-target organisms.

Cl
Cl

Cl

Cl

H

+

O

OH

+

Cl

OH

O

OH

Cl

O S O

Cl

H

H

+

O

S

Cl

-

Cl
O

+

H

C h lo ro b e n z e n e
-H S O

O

OH

4

-

Cl
Cl

Cl
Cl

H
+ H
Cl O

+

H

Cl

Cl

Cl

H
Cl

O

Cl
H

+

H
Cl
H

Cl

O

Cl

H

H

Cl

H

Cl

Cl

Cl

Cl

Cl

+
Cl

H

Cl

Cl
Cl

H
-H

Cl

Cl

+

The main reason DDT accumulates
as it moves up the food chain is
because it is hardly metabolized or
excreted. This is because DDT is a
lipophile, meaning that DDT binds to
lipids, such as fat in animals. This
solubility in fat, coupled with the
stability provided by the anchoring of
chlorobenzene groups at each end of
the compound give a highly stable
compound almost incapable of being
metabolized in the animal body.
DDT poses a great risk to animals
at the top of the food chain. However,
by understanding the chemistry
behind why DDT is such an effective
insecticide allowed chemists to
develop alternatives such as dieldrin
and methoxychlor. These alternatives
are typically more expensive than
DDT and are not typically as effective.
However, some of the better
alternatives are more environmentally
friendly, eliminating this nightmare
from nature.

Conclusion

+

-H 2O

Cl

Biomagnification

H
Cl

Cl

Mechanism
DDT can be synthesized from two starting products,
Trichloroacetaldehyde and chlorobenzene. The reaction
between these two starting materials occurs primarily in
the para position of chlorobenzene, yielding an
intermediate alcohol, which in the presence of acid,
readily forms a second carbocation with another
chlorobenzene.

Acknowledgement
s

Kimball, John. (2003). [online], available HTTP:
http://users.rcn.com/jkimball.ma.ultranet/BiologyP
ages/I/Insecticides.html
Wikipedia, The Free Online Dictionary. (2000 or
later). [online], available HTTP:
http://en.wikipedia.org/wiki/DDT
Williamson, K.L. Macroscale and Microscale
Organic
Experiments, 2nd edition. 1994:
Houghton Mifflin,
Boston.

Recently Viewed Presentations

  • West Vigo High School

    West Vigo High School

    West Vigo High School Literacy Strategies In-service Four Square, KWL, Cloze, SQR3 Word of the Week, Zoom In - Zoom Out April 12 and 13, 2005
  • Service Styles - Chef Nick Boland

    Service Styles - Chef Nick Boland

    Service Styles Classical French Most elegant and elaborate style. ... table in a clockwise direction Not all food is prepared in the kitchen Food may be prepared or plated tableside using a gueridon General rules of French service Plates prepared...
  • Hickory Ridge High School - Cabarrus County Schools

    Hickory Ridge High School - Cabarrus County Schools

    High school credits earned while in Middle School (Math I, Math II, or EES) count towards graduation but not towards GPA. Know your child's counselor. HRHS Counselors see students based on last name: A - E Ms. Cathy Eveland. ......
  • The Effects of ELND005 (Scyllo-inositol) on Emergence of New ...

    The Effects of ELND005 (Scyllo-inositol) on Emergence of New ...

    Serves on scientific advisory boards of major Pharmaceutical companies including Elan Pharmaceuticals. He has also received lecture fees and his Institute has received research support grants from various Pharmaceutical/Biotech companies and foundations including Elan. ... KM Analysis: Kaplan ...
  • Acceleration Due to Gravity

    Acceleration Due to Gravity

    Acceleration Due to Gravity. In physics, a uniformly accelerated motion in a vertical line is called free fall. Every object on the earth experiences a common force: the force due to gravity. This force is always directed toward the center...
  • C STRUCTURE OF A ROUTER S 4 6

    C STRUCTURE OF A ROUTER S 4 6

    Explain routing using your street/highway analogy PowerPoint Presentation PowerPoint Presentation Explain RIP in Simple English PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation PowerPoint Presentation ...
  • Multi-tiered AI - Lehigh CSE

    Multi-tiered AI - Lehigh CSE

    Arial Times New Roman Wingdings 宋体 Tahoma Axis Multi-tiered AI Multi-tiered AI Multi-Tiered AI Framework Situational Projects The MTAIF Class Architecture Slide 6 Slide 7 US Army Soldier AI Squad AI Platoon AI Company AI, Brigade AI, Division AI, Army...
  • Japanese Manufacturing FDI and International Production and ...

    Japanese Manufacturing FDI and International Production and ...

    Changing Business Environment Weakening of stable shareholders Occurrence of hostile M&As Occurrence of bankruptcy and worker dismissal Loss of production skills, caused by the overseas shift of production Changing Economic Situations End of catch-up Strict enforcement of intellectual property rights...