DDT Could Thwart West Nile Virus

West Nile virus has killed seven people in Louisiana this year, two in Mississippi and at least 145 people in six states have been infected. A 12-year-old Wisconsin boy died last week of mosquito-borne encephalitis.

The Centers for Disease Control and Prevention says West Nile virus is in the U.S. to stay. The virus may now be found in 37 states, including every state from Texas to the Atlantic.

CDC Director Julie Gerberding called West Nile virus an "emerging, infectious disease epidemic" that could be spread all the way to the Pacific Coast by birds and mosquitoes.

Louisiana has been monitoring the virus since 2000 and has one of the most active mosquito-control programs in the country -- and yet it is the state with the highest death toll.

It's time to bring back the insecticide DDT.

Currently used pesticides, such as malathion, resmethrin and sumithrin, can be effective in killing mosquitoes but are significantly limited since they don't persist in the environment after spraying.

DDT does. DDT lingers longer and so is more effective in mosquito control.

DDT's persistence, in fact, is often used as an argument against the insecticide. Though the Environmental Protection Agency banned DDT in 1972, three decades later residue of its byproducts may still be found in our bodies and the environment.

So what? No harm, no foul.

There's never been any credible evidence that the low levels of DDT residue in our bodies and the environment have caused any harm.

Even if concern exists over DDT residue persisting in the environment, limiting DDT use solely to mosquito control would ensure that any such buildup would be dramatically lower than in the past.

At the time the EPA banned DDT, approximately 12 million pounds of the insecticide were used annually. But almost 99 percent of that amount was used agriculturally to protect cotton, soybean and peanut crops. Only about 159,000 pounds -- a little more than one percent of the 12 million pounds -- was used for other reasons, including insect control.

So much less DDT would be used today -- if that is something you're worried about compared to potentially fatal mosquito bites.

Claims that mosquitoes eventually would develop resistance to DDT are off-base. While some mosquitoes may over time develop physiological mechanisms of resistance to DDT's lethal effects, it still provokes strong avoidance behavior so mosquitoes spend less time in areas where DDT has been applied. This still reduces mosquito-human contact.

DDT is also less toxic to humans than the alternative chemicals. That should be a boon to those who believe they are sickened by the spraying of the alternatives.

No doubt anti-chemical and environmental activists would wage war on any effort to bring DDT back. Rachel Carson's attack on DDT in her 1962 book Silent Spring, after all, was the springboard of success for modern environmentalism.

But the activists don't like any of the chemicals used currently either.

Tufts University anti-chemical activist-researcher Dr. Sheldon Krimsky said on ABC's World News Tonight, for example: "The chemicals have not been adequately tested for their human health effects. There's a lot of circumstantial evidence that they cause cancer in animal studies. They are hormone disrupters."

It's a lot of balderdash, but more to the point, what alternatives do the enviros offer?

A group called the Safer Pest Control Project is calling on municipalities to abandon insecticides in favor of so-called "ecological methods."

The SPCP wants to monitor mosquito populations by using traps and by checking ponds and sources of water for signs of mosquito larvae.

No problem. Just let me know which mud puddle is my responsibility.

The SPCP wants to eliminate breeding areas by draining areas of stagnant water and aerating ponds.

Perhaps the SPCP has missed the last 30 years of enviro-mania that has succeeded in labeling virtually every standing body of water a "wetland" subject to onerous federal permitting and regulation. By the time needed permits were obtained, mosquito season would be over.

My favorite SPCP recommendation for mosquito control is stocking ornamental ponds with mosquito larvae-eating fish -- but we need to make sure they don't "threaten the ecology of natural areas by competing with native species for food."

The SPCP is ambivalent about vegetable-based horticultural oils which are "effective in killing larvae in water and sinking egg rafts on the surface … [but] can kill beneficial organisms, including some mosquito predators."

"Ecological methods," it seems, is merely a euphemism for saying "Shoo!"

Judicious use of DDT won't harm people or the environment. It will, however, kill mosquitoes -- which is better than mosquitoes killing us.

Steven Milloy is the publisher of JunkScience.com , an adjunct scholar at the Cato Institute and the author of Junk Science Judo: Self-defense Against Health Scares and Scams (Cato Institute, 2001).