Outbreak renews debate over DDT

By Timothy Hurley
Advertiser Staff Writer

Ken Hall remembers well the fun he and his playmates had as kids running through the streets during the routine DDT mosquito control foggings that were part of life in Hawai'i during the 1960s.

The state Department of Health has conducted mosquito fogging in Hawai'i previously, as shown in this photo, believed taken in the 1940s. Department of Health photo

At least two things have changed since those days: DDT has been banned, and Hall, 50, now directs the crews fighting the mosquitoes responsible for spreading dengue fever.

He's the manager of the Vector Control Branch of the state Department of Health.

DDT — dichlorodi-phenyltrichloroethane — was a powerful agent that helped quell the last dengue fever epidemic in Hawai'i and was a regular component of Island mosquito control until it was banned by the federal government in the early 1970s.

The state's first dengue outbreak in more than 50 years has prompted some individuals to suggest that DDT be enlisted to fight mosquitoes once again.

Alan S. Lloyd is one of them. The retired Hawaiian Electric Co. engineer remembers the DDT spraying for the dengue fever epidemic as a child in Honolulu during World War II, and he believes it's time to once again bring out "the ultimate tool.''

A growing number of tropical-disease scientists are advocating the judicious use of DDT, Lloyd points out.

"The governor says we have a full court press on the problem. That is not correct unless we turn this thing off now by using what worked 55 years ago,'' Lloyd said. "If the state DOH can nip this in the bud with their politically correct chemicals, that's fine. But if not, they should start using DDT again.''

The effectiveness of DDT as an insecticide was discovered by Swiss chemist Paul Hermann Muller in 1939. DDT became widely known toward the end of World War II. Wherever this pesticide was used, insect-borne diseases, especially typhus, were essentially eradicated.

Muller won the Nobel Prize in 1948 for his work with DDT. Soon thereafter, the pesticide became available worldwide and was successfully used to eradicate malaria in Europe and the United States and to significantly lower its incidence in many other areas.

The inexpensive, broad-spectrum insecticide became the agent of choice for ridding farmlands of pests, neighborhoods of mosquitoes, and homes of spiders and other creepy-crawlies.

In Hawai'i, it was used extensively for night operations with fogging machines mounted on trucks. The foggings occurred on a regular rotating schedule across O'ahu from just after sundown to midnight, and it was common for children to run joyously through the fog.

"We tried to forewarn each community, but the kids would all run through the fog thinking it was a lot of fun,'' said George Komatsu, a former Vector Control Branch employee who became manager in the mid-'80s and early '90s before retiring.

Then came Rachel Carson, a naturalist and marine biologist at the Woods Hole Marine Biological Laboratories, whose book "Silent Spring'' called attention to the effects of DDT on the eggs of raptor birds and seashore life.

DDT was eventually banned in the United States and in many other countries in the 1970s because of its damaging effects on the environment.

The pesticide, however, continues to be used today in limited quantities in the battle against malaria. The countries that continue to use DDT do so primarily because they cannot afford reliable alternatives or do not have the capacity to develop them.

According to Hall, there are plenty of safe and reliable alternatives for fighting the dengue fever mosquitoes in Hawai'i.

One of them is the insecticide now being used: Permanone, a permethrin-based compound authorized by the Environmental Protection Agency. At the levels used in Hawai'i, Permanone is described as having low vertebrate toxicity and the ability to evaporate quickly.

For DDT to be used in Hawai'i again, the federal government would have to rescind its ban or make an exception. No one believes that's about to happen.

"Even if we did have the option to use it, I don't know if we would,'' Hall said.

Indeed, the very thought of spraying DDT again in Hawai'i is enough to induce nightmares in people such as Carl Berg Jr., a former state Department of Health water quality specialist and City College of New York professor.

The self-described "environmental activist'' who lives on Kaua'i doesn't believe any chemicals — including Permanone — should be sprayed into the environment.

Berg fears that the insecticide will not only enter the food chain but also knock off predators that feed on the mosquitoes.

"I'm afraid they'll end up having to spray even more,'' he said.

David Morens, a National Institutes of Health medical epidemiologist and former University of Hawai'i researcher, said using DDT or any legal alternative is merely one item in the arsenal of weapons against an epidemic.

And it may not even be the most important one, according to Morens.

Source reduction — or getting rid of mosquito-breeding sites — is the most effective way to battle dengue fever, he said.

Turning over containers that hold water where mosquito larvae might be found also was an important factor in turning back the World War II outbreak in Hawai'i.

Morens, who studied dengue fever while at UH-Manoa in the 1980s, said he remains surprised that Hawai'i is suffering from a dengue outbreak.

More than 10 years ago, when Clark Air Base in the Philippines was being shut down and a lot of military traffic was heading to Hawai'i, there was an emergency meeting of health officials to assess Hawai'i's risk of a dengue outbreak. The conclusion of the discussion among a group of some 20 officials, he said, was that the risk was low.

The assessment was based partly on the high standard of living in Hawai'i. People here generally aren't as intimate with mosquitoes as they are in poorer countries where squalid living conditions are the norm.

Today, Morens said, with a dengue fever epidemic raging across the Pacific, Hawai'i faces the same threat that existed when Clark shut down. Perhaps, Morens said, a decline in support for the state's public health infrastructure may have played a role in dengue's gaining a foothold.

Hall said government money for vector control in Hawai'i has decreased by more than 40 percent in the last decade. But he maintains the decrease in resources has nothing to do with the current episode.

However, if the outbreak fans out across the islands, his department may be in trouble, he said.

Komatsu agrees.

"Oh. my, it's going to be a horrendous problem,'' he said.