I’m pretty much used to right-wingers and libertarians being wrong about, well, almost everything. So when I read this over-the-top editorial at Tech Central about DDT, I was pretty confident that a little research would show me that environmental groups are right to oppose DDT use in Africa.
But in this case the Tech Central op-ed is right. DDT is far, far more effective than any of the alternatives for preventing the spread of malaria, especially to children.
Of course, Tech Central wouldn’t be Tech Central if the piece didn’t get significant facts wrong. For instance, many of the groups it claims oppose DDT use are actually neutral on the subject, or even support DDT use to combat maleria (the World Health Organization supports DDT use, for example). As usual, right-wingers feel free to simply make up lies about groups they dislike, knowing that no other right-winger will call them on it.
But on the main point they’re correct; DDT is essential. From The Christian Science Monitor:
The US Agency for International Development is pushing bed nets as an alternative to DDT spraying. Are they insane? Let’s say it was your child, and you’re offered two alternatives to prevent the child from catching this often-fatal disease. One solution works by spraying the walls, which keeps the disease-carrying mosquitoes out of the house. The other solution works by depending on your child to stay obediantly in bed all night and hoping no mosquitos bite during the day.
No American parent would find bed nets an acceptable alternative in that circumstance – not even for a moment. USAID should be ashamed for suggesting it. (Some of USAID’s other anti-malaria programs are more worthwhile).
Like environmentalists, I’m disturbed by all the unknowns about DDT’s effects on humans. But fighting the theoretical harms of DDT should take a back seat to fighting the very real harms of malaria.
Someday, an alternative to DDT that’s as effective may be developed. Until that time, household DDT use in areas facing malaria should not only be “not forbidden,” it should be encouraged and generously funded.
Link to the Tech Central article via The Fifty-Minute Hour. Also, this BBC article has a decent summary of the DDT/malaria issue..
Amp,
Reading Rachel Carson’s “Silent Spring” when I was about 12 years old was the beginning of my environmental consciousness.
From what I’m remembering, the problem with DDT is not its immediate effect on humans, but on the ecosystem. Birds and other animals that ingest bugs sprayed with DDT often die. I don’t know what the answer is, and whether DDT is a matter of lesser-of-evils, but I think especially in areas that are environmentally sensitive, we need to proceed with caution and use DDT very selectively.
While I’ve never seen any evidence that DDT did *not* thin eggshells, and my understanding is that the eggshells of avian apex predators have thickened since the disappearence of DDT in the US, I think the rest of the article is right. I am an environmentalist, but not so extreme that I would advocate the death of people to save that of animals. Usually, when you heat that people will die when an area is protected to protect the spotted eagle or piping plover, it is complete crap. But malaria is a nasty vicious disease that is still strong in most of the world. If DDT use saves lives, it is worth it, especially since South Africa seems to be taking a responsible view of its use – spraying walls, not marshes. You learn something new every day.
Most of the species worst affected by DDT are either high altitude (like the Condor) or high-latitude (like the falcons) nesters. Since very few people get Malaria, or other insect-borne diseases, outside the tropics, using DDT outside the tropics is contraindicated. However, in the tropics, large numbers of people die due to Malaria. Using DDT – carefully – is the best alternative these people have, when they are allowed to have it.
Does anybody have any studies on the effects of DDT on tropical nesting raptors? I never heard anything about this stuff affecting broad-winged hawks, who migrate through the tropics, or the forest-falcons and other low-latitude raptors.
Duct Tape!
The problem with DDT was always with its profligate use. Some African countries have shown that it can be used judiciously and to good effect. Having lived in West Africa and having had a bout of malaria (very minor) I am in favour of any mostly safe program that would reduce its incidence. I have seen what it does and its not pretty.
hm, my boss is a doc and a public health expert, and i thought i recall xeroxing a medical journal article for him that said something about clinical studies indicating carcinogenic properties of DDT, as well as birth defects…this is now questionable? new evidence available? let me do some research and get back to y’all, i could be muddled but the pseudo-memory nags.
here’s the article summary:
Nonmalarial infant deaths and DDT use for malaria control.
Chen A, Rogan WJ.
National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709, USA.
Although dichlorodiphenyl trichloroethane (DDT) is being banned worldwide, countries in sub-Saharan Africa have sought exemptions for malaria control. Few studies show illness in children from the use of DDT, and the possibility of risks to them from DDT use has been minimized. However, plausible if inconclusive studies associate DDT with more preterm births and shorter duration of lactation, which raise the possibility that DDT does indeed have such toxicity. Assuming that these associations are causal, we estimated the increase in infant deaths that might result from DDT spraying. The estimated increases are of the same order of magnitude as the decreases from effective malaria control. Unintended consequences of DDT use need to be part of the discussion of modern vector control policy.
Publication Types:
Review
Review, Tutorial
PMID: 12967494 [PubMed – indexed for MEDLINE]
The treaty which proposes the banning of DDT world wide proposes phasing it out as other alternatives become available. Presumably, if no other alternatives ever become available, then DDT can continue being used indefinitely.
The netting which USAid is advocating is insecticidal netting. Presumably, the goal is to kill mosiquitos when they are attracted to the sleeping person, not merely to provide protection in the form of netting. Since the surface area of the netting is much less than the surface area of a house, even less insecticide would need to be used on the netting than the little that is used on the walls. While the drop in infection rates for the netting is lower (17-63% vs 75-90%) than for the wall spraying, it is possible that it is a method which could be improved upon. If the success rate could be brought up to the high end of the range consistently, this would be close to the level seen from wall spraying. If the netting could be used as the main part of a composite method (as USAid is advocating), then the composite method might well be able to match the success rate of the wall spraying method, while inflicting less damage on the environment. I don’t think that USAid should be castigated for attempting to develop such methods.
There was a great article in the New Yorker (in the last few years) about the guy who invented DDT, and the thing I learned from it is that the amount/concentration used in preventing malaria transmission is thousands of times less than the amount/concentration used as an herbicide (as it was in the US of Rachel Carson’s observation). In fact, I think that it is so low that it has been shown to have little or no environmental effect. And it requires only something like annual sprayings, which is amazing. We need to be able to separate radically different uses — it’s misunderstandings like this that lead to worries about fluoride treatment of water because of the possibility of fluorine poisoning (which involves different chemistry and orders-of-magnitude different concentrations). Let’s not throw the baby out with the bathwater, nor let Carson’s good actions create a deathly backlash across the globe . . .
Charles, I don’t find research into bed netting a bad thing, although I’m dubious that (bed netting + other componants) will ever be able to equal (DDT + other componants) as a malaria preventative, simply because bed netting doesn’t work when the person is not in bed.
But USAID doesn’t just fund research into use of bed nets as a possible, future replacement for DDT – if that’s all they were doing, I wouldn’t object (although I’d want them to fund DDT use, as well). But they’re also funding current projects to impliment nets as a replacement for DDT. And that’s irresponsible, in my view.
Amp, where are you getting that the inseciticidal netting only protects people while they are in bed? I may be missing something in one of your links, but if not, remember that it is insecticidal netting. Mosquitos killed by the netting are mosquitos which can’t bite you later no matter where you are. The insecticide sprayed on the walls doesn’t just protect you when you are inside the house, it protects you everywhere, because a large portion of the main malarial mosquitos hang out around the houses. Once they are killed by the DDT, they don’t wander away from the house anymore, so the population of malarial mosquitos goes down over a large area (this explains why the South Africans care that Mozambique doesn’t do its part in killing malarial mosquitos). The insecticidal bed netting would have the same effect, but is probably less effective because it covers a smaller area (although more effective than if the same piece of netting were hung on the wall, since sleeping people are an attractor for mosquitos).
Given that the difference between the best effectiveness of the netting (67% reduction in cases in some unnamed country) and of the resumption of DDT use in South Africa (75 % reduction in cases), it seems unreasonable to say that the usefulness of netting plus other methods could never match that of DDT.
I didn’t see anything that made clear why Mozambique refuses to use DDT. If USAid is not the main reason that Mozambique is not using DDT, then I don’t think it is irresponsible of USAid to be funding alternatives to DDT in countries that refuse to use DDT. If USAid is primarily responsible for Mozambique giving up the use of DDT as a protection against malaria, then I would agree that it was irresponsible of them to do so.
See the 01/09/2004 01:17 PM EST post at Quark Soup for arguments against DDT, most interestingly the issue of the development of resistant mosquito strains.
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