The DDT Ban Controversy

Yolanda Lukovinyova

What is DDT Anyway?

• Organochlorine insecticide • First synthesized in 1877• 1948 Dr. Paul Müller was awarded

the Nobel Prize for its insecticide properties

• Extensively used during WWII to control typhus and malaria

• Banned in the US in 1972

DDT Chemical Information

DDT DichlorodiphenyltrichloroethaneMolecular

FormulaC14H9Cl5

Molecular Weight

354.49

Melting point 108.5°C

Boiling Point 260 °C

Solubility (H2O) < 1 mg/mL @ 21 °C

Why did the US ban DDT?

• The public outcry based on the book, Silent Spring by Rachel Carson published in 1962

• Scientific studies showed that DDT was carcinogenic

• Scientific studies showed that DDT caused thinning egg shells in birds

• Toxicity data acquired about DDT

Worldwide Ban Controversy

• UN had to decide if a worldwide ban by 2004 should be implemented

• The ban was to be imposed on 12 toxic chemicals known as the Dirty Dozen.

• DDT is part of the Dirty Dozen

Worldwide Ban Cont’d

• Proponents evidence:– Scientific studies done to show DDT is

carcinogenic– Scientific studies showing egg shell thinning

in various bird populations as a result of DDT

– DDT is so stable it takes many years to decompose

– DDT accumulates in fatty tissue of animals– Precautionary principle

Worldwide Ban Cont’d

• Opponents evidence:– Banning DDT would kill millions of people

because it helps control malaria, typhus and other diseases

– Many of the scientific studies were flawed– No human has ever died from DDT– Bans should not be based on

precautionary principles, rather on science

DDT should not be banned because…

• Prevents diseases • Good insecticide• Science proving DDT to be

carcinogenic and bad for the environment is flawed

• Politics controlled the US decision to ban DDT, not factual science.

DDT is an insecticide

• Very effective towards disease carrying mosquitoes

• Used heavily after 1945 in the agriculture industryCheapest

insecticide available

Cheapest insecticide available

DDT prevents diseases

• Can be used to kill disease-bearing lice

• DDT can be used as a repellant– Sprayed on walls of buildings to repel

insects– Diseases insects can carry are

malaria, sleeping sickness, and yellow fever

DDT flawed science

• Carcinogenic studies– In 1969 study of mice, it was shown

that the DDT sprayed mice developed tumors.

– Reality was that the mice food was carcinogenic

– After the study was redone without carcinogenic food, no mouse formed a tumor

DDT flawed science cont’d

• Eggshell thinning evidence– 1968 studies reported high DDT

concentrations in the eggs of raptors•Resulting in thinning egg shells•Decline in population

– Reality was that the population declined before the use of DDT and after it had been banned

– Researchers admitted to the fact that the egg extracts studied had little or no DDT

DDT Flawed Science Cont’d

• Another study, done with quails showed a thinning egg shell problem– Quail diet in the study did not have

enough calcium – If there is not enough calcium in the

diet, egg shells naturally thin

DDT and Politics

• US ban was based on politics• 1972, Judge Sweeney listened to 7

months of testimony about DDT and determined it not to be a carcinogenic hazard to man or animals

• 2 months later, EPA head declared that DDT was a potential human carcinogen and should be banned

Conclusion

• DDT should not be banned worldwide because of the lack of scientific evidence.

• Not allowing the use of DDT would kill millions of people around the world

• I prefer dead mosquitoes over dead children.

Sources Cited

• “Biomagnification: how DDT becomes concentrated as it passes through a food chain.” Biomagnification. June 13, 2002. http://www.ultranet.com/~jkimball/BiologyPages/D/DDTandTrophicLevels.html

• ChemFinder. June 13, 2002. http://www.chemfinder.com

• Dinan, Frank J. and Bieron, Joseph F. “To Spray or Not to Spray: A Debate Over Malaria and DDT.” To Spray or Not to Spray: A Debate Over Malaria and DDT- Case Study Collection. June 13, 2002. http://ublib.buffalo.edu/libraries/projects/cases/ddt/ddt.htm

Sources Cited Cont’d

• Milloy, Steven. “At Risk from the Pesticide Myth.” Junkscience.com—At Risk from the Pesticide Myth. June 10, 2002. http://www.junkscience.com/foxnews/fn072800.htm

• “Extoxnet Pesticide Information Profile—DDT.” EXTOXNET PIP – DDT. June 13, 2002. http://ace.orst.edu/cgi-bin/mfs/01/pips/ddt.htm

• “Facts versus Fears: DDT”. Facts versus fears – DDT. June 13, 2002. http://www.altgreen.com.au/chemicals/ddt.html

Sources Cited Cont’d

• Katz, Harry. “DDT and Chlordane Killed by Politics, Not Science.” PCT Online >> Article >> DDT and Chlordane Killed by Politics, Not Science. June 13, 2002. http://www.pctonline.com/articles/article.asp?Id=216&SubCatID=36&CatID=9

• Many images are from Microsoft’s online clipart library.

• Mosquito. June 14, 2002. seth-swims.ohdrats.com/ sounds/ wav/ mosquito.wav

• Sound Aerosol Spray Can. June 14, 2002. kumori.free.fr/ aerosol.wav

• Virtual Zoo. June 12, 2002. http://students.cs.byu.edu/~ik7/virtualzoo/