Reversal Thinking About DDT Ban

Six years after the insect killer DDT was globally outlawed on grounds of environmental damage, two researchers say there are new reasons for doubting the chemical is harmful and are urging its use against malaria.

In a book which was launched recently, Donald Roberts, professor of tropical medicine at the U.S. military's Uniformed Services University of Health Sciences, and Richard Tren, head of lobby group Africa Fighting Malaria, argue that DDT is the only effective weapon against the deadly mosquito-borne parasite.

Environmental group Greenpeace defended the United Nations' aim of eventually eliminating DDT use worldwide and said evidence that it harms wildlife and human health was sound, even if not conclusive.

DDT's unprecedented power to kill insects won its inventor a Nobel prize in the 1940s and it was considered a wonder chemical until evidence emerged of its toxicity to wildlife and people, leading Western nations to ban it in the 1970s.

A treaty to forbid its use worldwide along with a dozen other industrial chemicals came into effect in 2004, but some countries like South Africa and Ethiopia still take advantage of tightly limited exemptions allowing indoor spraying.

Dichloro-diphenyl-trichloromethylmethane (DDT) has been blamed for birth defects in humans and threatening endangered birds such as the bald eagle by thinning their egg shells.

"There are an almost endless list of claims that DDT causes one kind of harm or another but ... with each claim, the evidence that the DDT is the cause is simply not there," Roberts told.