DDT and Malaria

DDT is the single best agent ever created to repel or kill mosquitoes, yet because of unsubstantiated claims about the hazards of its use, we stopped using it in America and numerous countries followed suit. Perhaps it's time to weigh the pros and cons once more:

In Sri Lanka, malaria is transmitted by the female Anopheles culcifacies mosquito. The species breeds in rock pools and rice fields, and is a fairly efficient vector of the disease. Historically, the primary method of malaria control has been to spray indoor walls with DDT. It's an efficient way to kill the bugs, given their habit of resting on walls, and only tiny amounts are needed.
More importantly, studies show that mosquitoes are reluctant to enter a DDT-treated building, which means it offers a far cheaper alternative to prophylactic drugs or bed nets. Use of DDT in Sri Lanka cut malaria rates here from 3m cases a year in the 1940s to fewer than 50 in 1963.
Since then, environmental pressures against DDT have forced it to be abandoned, first in Western countries and then in most other parts of the world. Although it was obvious that it was the massive use of DDT in farming, not the small amounts used in public-health applications, that caused the environmental problems, the issue of scale was ignored by policymakers.

Environmentalists have the enviable position of rarely being questioned about claims they make. Is DDT 100% safe? No. Is any insecticide? Again, no. But the benefits of using DDT far exceed the potential downside.