The Occurrence, Fate, and Impact of DDT

1
The Occurrence, Fate, and Impact of DDT

• Albert Baramuli
• March 31st, 2006

2
History

• 4,4'-(2,2,2-trichloroethane -1,1-diyl)bis(chlorobe
  nzene) or dichloro-diphenyl-trichloroethane
• DDT was first synthesized in 1873 by Othmar
  Ziedler.
• In 1939, Paul Hermann Müllerr, a Swiss chemist
  discovered the insecticidal properties of DDT.
• DDT was developed as the first of the modern
  insecticides early in World War II. ( 1945)
• Between 1955 - 1969, World Health Assembly
  adopted a Global Malaria Eradication Campaign.

3
History

• By 1967, Malaria was eradicated in most developed
  countries and many subtropical Asian and Latin
  American countries.
• In 1962, American biologist Rachel Carson
  published the book Silent Spring.
• Sweden banned DDT in 1970, the USA in 1972, and
  the UK in 1986.
• In 2001, Stockholm Convention proposed a global
  ban on DDT and 11 other organic pollutants,
  effective starting May 2004.

4
Facts about DDT

• Technical Grade DDT contains (65-80) p,p-DDT,
  (15-21) o,p-DDT, (4) p,p-DDD
• In environment, DDT breaks down to p,p-DDE
• Half life of DDT 2 days in air, 2 15 yrs in
  soil
• Degradation by sunlight in air, by microorganism
  in soil.
• DDT, and especially DDE, build up in plants and
  in fatty tissues of fish, birds, and other
  animals (i.e. bioaccumulation)

5
Health Effects

• Toxic Effects
• - Animal carcinogenic
• - Human relatively safe
• Neurobehaviour
• - Poisoning headache, tremor, fatigue, etc.
• - Occupational Exposure Reduced verbal attn.,
  visuomotor speed, and sequencing
• Cancer
• - Breast, Pancreatic, Liver, Prostate,
  Testicular, Endometrial.
• - Lymphoma, Myeloma

6
Health Effects

• Reproductive Health
• - Semen volume quality, testosterone amount,
  sperm DNA damage
• - Reduce probability of pregnancy
• - Spontaneous abortion
• - Birth defects
• - Shorter lactation period
• Infant and Child Growth
• - Height
• - Mental and psychomotor development
• DNA Damage
• - Raised IgA and reduced IgG
• - Necrosis

7
Source of Exposure

• How might I be exposed to DDT ?
• Eating contaminated foods, such as root and leafy
  vegetable, fatty meat, fish, and poultry.
• Eating contaminated imported foods from countries
  that still allow the use of DDT to control pests.
  
• Breathing contaminated air or drinking
  contaminated water near waste sites and landfills
  that may contain higher levels of these
  chemicals.
• Infants fed on breast milk from mothers who have
  been exposed.
• Breathing or swallowing soil particles near waste
  sites or landfills that contain these chemicals.

8
Malaria in Africa

• Efficiency of DDT vector control depends on
• Coverage of spraying
• Mosquito Species
• Resistance to DDT
• Climate (rainfall, temperature, latitude)

9
Fight Against Malaria
In 1998, the WHO, World Bank, UNDP and UNICEF
conceived and partnered to create the Roll Back
Malaria movement Red insecticide treated bed
nest Blue insecticide residual spraying Green
both White - undetermined
10
Conclusion

• High exposure to DDT will affects the nervous
  system, shorter lactation period in women.
• Further test will still need to be conducted, to
  determine the benefits versus the health risks of
  using DDT
• Well coordinated efforts in combination with
  efficient health infrastructure should have
  better success in malaria control

11
References

1. Beard J. DDT and Human Health. Science of the
   Total Environment 2005 35578-89
2. Rogan WJ, Chen A. Health Risks and Benefits of
   DDT. Lancet 2005 366763-73
3. http//en.wikipedia.org/wiki/DDT
4. http//www.epa.gov/history/topics/ddt/01.htm
5. http//www.atsdr.cdc.gov/toxprofiles/phs35.html