News & Media Opinion Pieces Bring Back DDT?

Bring Back DDT?

There are many interesting means by which humankind acts to ravage biodiversity.The following example is taken from a recent book “The climate change challenge and the failure of democracy”, Shearman and Smith, Praeger, Westport, Connecticut, London

“…the arrival and spread in the United States of the West Nile virus will be described. This virus is normally confined to parts of Asia and Africa. Mosquitoes transmit the virus from birds to humans, resulting in encephalitis, an often fatal inflammation of the brain. In the summer of 1999 birds at the Bronx Zoo in New York died inexplicably. Then humans began to die from encephalitis. The diagnosis of the problem was very slow because Ronald Reagan, believing in small government, had severely reduced funding of the public health service and it had never recovered. However when it was realized that West Nile virus had succeeded in evading the U.S. quarantine service, there was official panic in New York City Hall.

 It was decided to eradicate the mosquitoes of New York, and the U.S. Air Force was used to spray pyrethroid insecticide over much of the city. No one felt it was important to note that Hurricane Floyd was roaring up the U.S. coastline, and it was soon bucketing rain onto New York and washing the insecticide into drains. Within a week the lobster industry of Long Island Sound, worth hundreds of millions of dollars, was completely destroyed and hundreds of fishermen were out of work. It was overlooked that the mosquito and the lobster are related arthropods and both highly susceptible to the insecticide. West Nile virus spread across the United States and has caused over 600 deaths, high morbidity, and large health costs.”

Eight years later, the disease is increasing exponentially in the US and is now found in birds in 39 states. Hundreds of human deaths are recorded The Center for Disease Control in the US suggests preventative measures–Wear clothes that expose little skin; use insect repellent;stay indoors during peak mosquito hours (dusk to dawn); and “get rid of mosquito breeding sites” by removing standing water and installing and maintaining screens. Sound familiar? Yes these are the simple measures to control the malaria-carrying mosquito.

Dr Henry Miller, a physician, fellow at the Hoover Institution, and an official at the NIH and FDA from 1977-1994 writes in the Wall Street Journal online on August 17 “To control mosquitoes that carry West Nile virus, the pesticide would need to be used extensively– and it should be. DDT should be made available, immediately, for both indoor and outdoor mosquito control in the U.S.; and the government should oppose international strictures on the pesticide. Federal officials should also educate local authorities and citizens about its safety and potential importance. Right now, most of what people hear is the reflexively anti-pesticide drumbeat of the environmental movement.”

Miller’s argument is based upon a ban that resulted from its extensive use in farming and that a more judicious use in the 1970’s could have been maintained. He says:-

“In the absence of a vaccine (for West Nile), eliminating the carrier — the mosquito — should be the key to preventing an epidemic. But in 1972, on the basis of data on toxicity to fish and migrating birds (but not to humans), the Environmental Protection Agency banned virtually all uses of DDT, an inexpensive and effective pesticide once widely deployed in the U.S. to kill disease-carrying insects. The effectiveness and relative safety of DDT was underplayed, as was the distinction between the large-scale use of the chemical in agriculture and more limited application for controlling carriers of human disease. There is a world of difference between applying large amounts of it in the environment — as American farmers did before it was banned — and using it carefully and sparingly to fight mosquitoes and other disease-carrying insects. A basic principle of toxicology is that the dose makes the poison”.

No-where in the article in the Wall Street Journal do we read about the steadily increasing accumulation of DDT in the environment and in most animals and humans, or that DDT is a persistent organic pollutant with cancer risks (reviewed on this site recently). Perhaps a significant problem with the ban on DDT is that its toxicity was researched and promoted by environmentalists. Dr Miller exposes his feelings by writing “Of course, spraying any pesticide — let alone DDT — has been greeted by hysteria from environmental activists, who have attacked the killing of mosquitoes as “disrupting the food chain.” To many in public life environmentalists are still ‘closet Marxists’ or ‘reds under the bed’ . This is why Doctors for the Environment Australia has traction in putting environmental isues in context for we are primarily doctors of medicine and qualify in the minds of some as civilised.

David Shearman
The views expressed are my own