NEW YORK — The bedbugs moved into my house. I was itching all night long and after about five futile attempts to blast them with pyrethroids, one of the few allowable pesticides, I was ready for something stronger. Anything really.
Compared to other pesticides, pyrethroids are less toxic to humans and apparently less toxic to bedbugs too. (Thanks to our zeal for abusing anything new, bedbugs in New York City, where I live, are more than 200 times resistant to pyrethroids compared with Florida bedbugs, according to a recent study.) All I wanted was my exterminator to sneak me some DDT or another banned chemical. I considered organophosphates — the ones that have been linked to cognitive impairments among children.
My bedbug fiasco — costly and time-consuming — got me thinking about the global balancing act of pesticides versus disease. The real issue is not about those of us in the developed world annoyed with bedbugs and lice (we dealt with those too), but the rest of the world who have to weigh the pros and cons of pesticides versus killer infections.
Pesticides work because they are poisons. The goal is to concoct a chemical that hits bugs but nothing else. A microbiologist told me that his oncologist friends are in the same bind. They say they can kill every cancer cell but they’d kill the patient too. The trick — for the bugs and cancer — is all about targeting. We’re not there yet.
For most of us, raised in the post-"Silent Spring" era (Rachel Carson’s 1962 blockbuster book that outlined the abuse of pesticides and launched the environmental movement), DDT has become the Voldemort of chemicals — he whose name should not be ... spoken.
Yet this same drug was once considered a miracle weapon. After World War II, death camp survivors were drenched with the stuff to prevent typhus and our farmlands were showered with it to protect crops. It did the trick but we quickly learned it also killed birds and wildlife. To top it off, our abuse of it spurred resistance — something the experts warned about all along. DDT was banned in the U.S. in 1971. The chemical was labeled one of the so-called “dirty dozen” at the 1995 Stockholm Convention of Persistent Organic Pollutants slated for restriction, but not elimination. It was never banned globally.
The World Health Organization changed its tune a few years ago and started encouraging malaria-ravaged countries to use DDT indoors. The United States Agency for International Development, which for years did not fund DDT projects, started to sponsor a few of them here and there.
It’s important to remember that no one is talking about airplanes spraying pesticides the way we did half a century ago. They are talking about limited uses of chemicals inside certain homes with vulnerable mosquitoes — combined with a lot of other malaria-prevention techniques.
"Silent Spring," probably the most influential book ever written, “caused serious problems in terms of reluctance of people to use insecticides for public health value,” said Durland Fish, director of the Yale Institute for Biospheric Studies Center for EcoEpidemiology. To be sure, he said, we’ve made it very difficult for an honest use of pesticides. “There has been quite a bit of regulation, sometimes over-regulation of pesticides but some effort needs to be made to bring some rationale back to the whole story of pesticides.” He pointed to a U.S. Centers for Disease Control-funded Lyme disease study he did in Westchester County, N.Y., that showed that a single application of a commonly used insecticide reduced the risk of Lyme disease 97 percent but the county health department recommended against spraying.
This complicated global juggling (how much of the chemicals and where) has been played out in the press as fierce debates between environmentalists, who, rightly so, worry about the long-lasting impact of these poisons and public health experts, who, rightly so, worry about the millions of children dying from infectious diseases. In the real world, though, the issue is not so much about narrow-minded experts hollering at each other as it is about a network of do-gooders who have different sets of priorities. If you spend your life studying how high doses of organophosphates may impair children’s cognition, you’ll come into this debate with a different category of worries than if you take care of kids who are brain-damaged from malaria.
The environmentalists see the downside of chemicals. They read studies such as the recent ones in The Journal of Epidemiology suggesting that DDT exposure may increase rates of miscarriage or reduce fertility. A South Africa study suggested DDT affects sperm physiology.
Public Health officials focus on the immediate dangers of the mosquito-carrying diseases. Every day 2,200 Africans die from malaria, the vast majority are children younger than 5, according to the Global Fund to Fight AIDS, Tuberculosis and Malaria. Put another way, every 30 seconds, malaria kills one African child. Those who survive are often left weak — physically and mentally. It is a disease that is clobbering entire nations.
The real solution, according to the experts, is to do what I always nag my kids about: Use common sense, learn from mistakes and get along with the other players. That means that we have to look at the science, not the politics of pesticides and use them judiciously and only when needed.
We have to learn, for the first time, to use restraint when we discover a new poison for the bugs. Alternating a few chemicals in limited use will prolong resistance. And we have to realize that we’ll never control these diseases simply. These bugs are clever creatures, always one step ahead of us. If we want to make any advance, it will take a sustained, labor-intensive effort incorporating low doses of pesticides along with surveillance and prevention. For malaria, this also means impregnated bednets and good diagnostic techniques so we only treat people who truly have malaria.
And lastly, the environmentalists and the health folks should sit down together, a peace conference of sorts. Or, as Yale’s Fish said, “the public health funding agencies are not responsible for the environment and the Environmental Protection Agency is not responsible for health. We need to engage each other in outcomes so there won’t be conflicts.”
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