The Wall Street Journal‘s editorial page continues to exhibit signs of hysteria that can only be described as DDT poisoning. DDT has poisoned their view of what to do about malaria. (The article is now available by paid subscription.)
Malaria is a nasty disease that kills more than a million people every year. It is particularly brutal in attacking infants and pregnant women.
Malaria continues to rage because western nations with the resources to fight the disease spent their money on other things in the past 40 years, because the nations most affected lack the governmental adequacy or financial resources and willpower to mount effective campaigns against the disease, but mostly because malaria is a tough disease to fight.
Malaria is spread by several different species of mosquito, some of which have habits or constitutions which make mosquito eradication programs much less effective. Human malaria is really four different parasites, some of which have acquired resistance to the drugs used to fight it. The HIV/AIDS epidemics in tropical nations have not helped matters: What used to be minor cases of malaria now kill thousands who have compromised immune systems because of HIV/AIDS.
Hospitals in far too many nations are overwhelmed with malaria patients, and unable to provide care for many who could be saved. Most of those who die every year could live, with better distribution of health care, and with better prevention.
A few people have been afflicted with what can only be described as a different problem: DDT poisoning. Their views of malaria and what we need to do to fight the disease are poisoned by their anti-science political views. For at least five years there has been a nasty, persistent campaign to impugn “environmentalists” and Rachel Carson, claiming that DDT is the answer to all the world’s malaria woes. Though DDT has been available to fight malaria since 1946, these people complain that bans on spraying crops have discouraged the use of DDT against malaria, fatally.
Below the fold I’ll fisk the short piece from yesterday’s WSJ. It’s difficult to keep ahead of hoaxers, though — today they’ve got another call for DDT use, this time to fight West Nile Virus. Ironically, West Nile is most deadly against several species of bird, some of which are acutely subject to death by DDT.
My comments will be in bold type, in blue.
The Uses of DDT
Last year, the World Health Organization reversed a 25-year-old policy and recommended using the pesticide DDT to fight malaria in the Third World. A new study published in the public health journal, PLoS ONE, provides more evidence that the decision was long overdue.
See a more careful analysis of the PLoSstudy here — the study has little new, and it has some problems in its research design that suggest the excitement about the study is misplaced. One should also be alert when a press release extolling the study comes from an astro-turf lobbying group, a pseudo-science defending organization that has taken a partisan position in the discussion. One’s leg may be in danger of being pulled.
[WSJ said:] The U.S. and Europe solved their malaria problem a half-century ago by employing DDT, but the mosquito-borne disease remains endemic to the lowland tropics of South America, Asia and Africa, where each year a half-billion people are infected and more than a million die.
Beating malaria in the U.S. was not due to DDT. The U.S. lacks the species of mosquitoes that spread human malaria most effectively — our climate has been unfavorable to the mosquitoes. Even poor Americans generally can afford screens on their homes to keep mosquitoes out. Medical care in the U.S., even in the poorest states, was generally up to the job of treating malaria infections. I know of no study which provides any solid evidence that DDT plays a significant role in keeping malaria at bay in the U.S. Most of these arguments apply to Europe, too.
Note, too, that DDT has been in constant use in Mexico over the past sixty years. Malaria continues to vex Mexico — if DDT were a true panacea as the Journal claims, why hasn’t malaria been wiped out in Mexico?
[WSJ:] Despite those staggering numbers, radical environmental groups like the Pesticide Action Network continue to oppose use of the insecticide. One of their favorite arguments is that DDT is ineffective because mosquitoes can build resistance to the chemical’s toxic properties.
There is good reason to oppose the use of DDT. DDT is a poison, and it is uncontrollable once released in the wild. Among its most damaging properties, its breakdown products, like DDE, mimic the sex hormone estrogen. This is probably one of the key mechanisms by which DDE causes the thinning of eggshells among birds, but it also causes serious difficulties among many other species. In the past month, the Washington Post featured a story on fish in the Potomac River that have been deformed by such chemicals, endocrine disruptors — male fish laying eggs, fish of both genders unable to breed, and so on.
As judges and decision makers noted in 1972, because of the evidence pointing to DDT as the culprit poison, it would be unwise to act as if DDT were harmless without firm evidence that it is, in fact, harmless. DDT has been found not to be a serious acute toxin in humans, because most humans are more than 100 pounds. DDT has not been strongly linked to breast cancer. It must be held suspect in all other areas, considering the great success at recovery of species where DDT use has stopped.
We have 60 years of studies showing DDT kills songbirds, raptors, and bats, and prevents their successful breeding, wiping out succeeding generations. Some organizations want tight controls on the use of DDT. That is prudent, and the Wall Street Journal should not oppose prudence that saves lives.
DDT is also acutely toxic to birds that prey on mosquitoes, and to bats that prey on mosquitoes. Ironically, broadcast spraying of DDT can cause an increase in mosquitoes in the next generation, once all the predators are killed off.
Complicating these problems, DDT and its by-products are long-lived; they concentrate in fatty tissues of animals higher up the food chains, to levels that can be acutely toxic when the animals use the fats (such as when they migrate), or which can cause long-term damage later. DDT is known to cause cancers in rodents.
[WSJ:] According to the new study, however, that concern is misplaced. DDT continues to work as a repellent and irritant long after it’s no longer killing mosquitoes on contact. The researchers found that three out of five DDT-resistant mosquitoes avoided homes sprayed with the insecticide and reduced the risk of disease transmission by 73%.
Screens work well, too. Screens are not toxic. Screens don’t have to be re-applied. Bed nets are very effective, too. WSJ and other critics of Rachel Carson downplay common sense, cheap and constantly effective means to prevent malaria that don’t involve poisoning the environment. How odd.
Nor should we be misled to thinking that DDT is the best repellent. That issue was not studied in these experiments — and in fact, DDT was pitched against other pesticides known to have little if any repellent ability.
[WSJ:] Repeated studies have shown DDT to be safe for people and nature when sprayed indoors, yet other supposedly greener pesticides like alphacypermethrin have been touted as viable alternatives. Nevertheless, the latest research shows that DDT continues to be the most effective tool we have, as well as among the cheapest. “To date,” conclude the authors, “a truly efficacious DDT replacement has not been found.” Opponents of DDT are only ensuring more misery and death.
No one stands between WHO or governments in malaria-infected lands and the application of DDT. A couple of organizations officially oppose DDT applications, but they have no legal means to prevent it. More critically, money to conduct such spraying and the required education campaigns to go along with it (people don’t like it when government people show up to spray poisons in their homes) has been held in Washington, instead of being sent to Africa to be put to work. It would be absolute error to ascribe this odd frugality to the environmentalists who have undue sway in the Bush administration. If blame is to be established, let’s be fair and accurate in blaming.
DDT is legal to use, in limited indoor use, to kill mosquitoes and repel mosquitoes, to help control malaria. There is no ban on such use today. The strident Pesticide Action Network (PAN) does not have the ear of the Bush Administration, nor of WHO, and so it is silly to claim that they have somehow prevented the use of DDT against malaria.
Malaria defies simple solutions, however. The mosquitoes that carry the roughest forms of malaria parasites are not subject to DDT across the board — by habit, and in some cases, by genetic acquired-immunity, the mosquitoes get around DDT. DDT is absolutely ineffective against the malaria parasites themselves, some of which have acquired immunity to drugs used to treat the disease. Health care facilities in stricken nations need to be dramatically upgraded in order to treat the disease. Drug research programs need to find new pharmaceuticals to use, and find new ways of using current pharmaceuticals to prevent drug resistance. Spraying DDT does not build health care facilities nor make easier the diagnoses and treatment of the disease. DDT is not a panacea againast malaria.
To fight malaria, we need a lot more concern about the victims of malaria, how best to treat them and prevent infections in the future, and a lot less concern about how to bash people concerned about protecting the environment.