Defenders of the near global ban on DDT often hint that it actually saved the lives of millions of poor people because the pesticide was becoming ineffective due increasing resistance to it by mosquitoes.
A new study finds that one of DDT's main effects is not to kill mosquitoes, but to so irritate them so much that they do not even enter houses and huts that have been sprayed with it.
As Reuters reports:
Mosquitoes that carry malaria, dengue fever and yellow fever avoid homes that have been sprayed with DDT, researchers reported Wednesday.
The chemical not only repels the disease-carrying insects physically, but its irritant and toxic properties helps keep them away, the researchers reported in the Public Library of Science journal PLoS ONE.
They estimate that DDT spray reduced the risk of disease transmission by nearly three-quarters.
Malaria affects more 40 percent of the world's population, killing more than a million people every year, most of them young children.
DDT use has been discontinued in most countries because of fears the pesticide may cause cancer and because of its potential effects on animals such as birds.
But the World Health Organization last year recommended the use of DDT in places like Africa where malaria is still common, saying the benefits outweighed the risks.
Disclosure: I hate mosquitoes even if they do not carry malaria, dengue, or yellow fever. Despite my loathing for winged bloodsuckers, I am not in the pay of Big DDT nor any other pesticide company nor do I own any stocks in such companies.