Claims about DDT
Introduction
Here I try to isolate and itemize claims that come up in the “DDT debate”. I then list the main overall positions I see on the topic, and which of these claims one must take to believe these positions.
Claims
- DDT has been banned for pesticide use in many (malaria-endemic) countries.
- DDT has been banned for use in malaria control in many (malaria-endemic) countries.
- Widespread resistance to DDT by mosquitoes exists.
- Conditional on (3), the resistance is caused mainly by DDT’s agricultural use, rather than its mosquito insecticide use.
- DDT use against mosquitoes has significantly waned.
- The cost of manufacture of DDT has increased.
- In Africa, “no comprehensive effort has ever been made to control or eradicate malaria” (quote from Palmer).
Main positions
Bate claims (5):
As these publications pointed out, although DDT was granted an exemption for public health in the Stockholm treaty and the World Health Organisation (WHO) approved its use for malaria control, no aid agency was purchasing it and some, such as the World Bank and the US government, were actively discouraging its use.
In the same article Bate does not touch on (3).
As far as I can tell, Palmer accepts (1), rejects (2), accepts (3), doesn’t care about (4), accepts (5), accepts (6), and accepts (7).
To claim that the lack of use of DDT has “killed millions”, I think one must accept (5) to start, but also reject (3) and (7), and maybe also reject (6) because one must believe the cost of DDT is still small enough. Rejecting (3) and (6) roughly corresponds to the idea that “DDT is still an effective way to combat malaria”.
TODO: check for conjunction fallacy fallacy (unpacking fallacy) later.
See also
References
- “The ban of DDT did not cause millions to die from malaria” by Michael Palmer
- “Rehabilitating Carson” by Quiggin and Lambert
- “DDT works” by Roger Bate