Dan, I live in Africa. I lived in Zimbabwe for more than half my life. There's no denying that Malaria is a big problem. But DDT is definitely NOT the answer.
Other preventative measures are cheaper, and far less damaging. Wikipedia again: "The relative effectiveness of IRS (with DDT or alternative insecticides) versus other malaria control techniques (e.g. bednets or prompt access to anti-malarial drugs) varies greatly and is highly dependent on local conditions.[15] "A study by the World Health Organization released in January of 2008 found that mass distribution of insecticide-treated mosquito nets and artemisinin based drugs cut malaria deaths in half in Rwanda and Ethiopia, countries with very high malaria burdens. IRS with DDT was determined to not have played an important role in the reduction of mortality.[105] "Vietnam is an example of a country that has seen a continued decline in malaria cases after switching in 1991 from a poorly funded DDT-based campaign to a program based on prompt treatment, bednets, and the use of pyrethroid group insecticides. Deaths from malaria dropped by 97%.[106] "In Mexico, the use of a range of effective and affordable chemical and non-chemical strategies against malaria has been so successful that the Mexican DDT manufacturing plant ceased production voluntarily, due to lack of demand.[107] Furthermore, while the increased numbers of malaria victims since DDT usage fell out of favor would, at first glance, suggest a 1:1 correlation, many other factors are known to have contributed to the rise in cases. "A review of fourteen studies on the subject in sub-Saharan Africa, covering insecticide-treated nets, residual spraying, chemoprophylaxis for children, chemoprophylaxis or intermittent treatment for pregnant women, a hypothetical vaccine, and changing the first line drug for treatment, found decision making limited by the gross lack of information on the costs and effects of many interventions, the very small number of cost-effectiveness analyses available, the lack of evidence on the costs and effects of packages of measures, and the problems in generalizing or comparing studies that relate to specific settings and use different methodologies and outcome measures. The two cost-effectiveness estimates of DDT residual spraying examined were not found to provide an accurate estimate of the cost-effectiveness of DDT spraying; furthermore, the resulting estimates may not be good predictors of cost-effectiveness in current programmes.[108] "However, a study in Thailand found the cost per malaria case prevented of DDT spraying ($1.87 US) to be 21% greater than the cost per case prevented of lambdacyhalothrin-treated nets ($1.54 US),[109] at very least casting some doubt on the unexamined assumption that DDT was the most cost-effective measure to use in all cases. The director of Mexico's malaria control program finds similar results, declaring that it is 25% cheaper for Mexico to spray a house with synthetic pyrethroids than with DDT.[107] However, another study in South Africa found generally lower costs for DDT spraying than for impregnated nets.[110] Right, so we've established that DDT is not always effective, that it's often more expensive than other methods of preventing malaria, but most importantly that alternative treatments exist that don't cause cancer or riverfuls of dead fish. Martin's quote sums up my position: "Overselling a chemical's capacity to solve a problem can do irretrievable harm not only by raising false hopes but by delaying the use of more effective long-term methods. So let's drop the hyperbole and overblown rhetoric -- it's not what Africa needs. What's needed is a recognition of the problem's complexity and a willingness to use every available weapon to fight disease in an informed and rational way." >> Second, the hard bit. " ... done more to aid or more to harm ... ". This >> is >> the tricky part. Without a complete assessment of Walmart's entire impact >> on >> poor people (and in fact the whole ecosystem of humanity), it's nearly >> impossible to answer accurately. I'm in no position to have much of an >> opinion on this one. But then again, nor is anyone else, much. > >Actually, there are good data on this....I've read on this subject for >years. One good source is Kerry's former economic advisor >http://www.americanprogress.org/kf/walmart_progressive.pdf >One can also do very straightforward mathematical modeling that indicates >this general trend. Fair enough. I don't have the data. I've only been in a Walmart once. I have noticed that they're trying to go carbon-neutral, however. >Actually, I read fairly extensively on the subject for years before making >this post. I hadn't realized that it seems to have been an ongoing debate for some years. The answer seems painfully obvious to me, so why there should have been any debate on the subject at all, escapes me. >>you'd have seen that it is VERY nasty stuff. >Can you quantify VERY nasty stuff? One of my differences with many folks is >that I do not think we can go to a zero risk world. For example, I'd take a >med that cut my chances of a heart attack in half even if increased my >chances of cancer by 1%. But, I'm a research physicist who deals with >probability in a manner that I think differs from others. I'm a software architect, and the specific job I am working in involves computationally answering questions very much like this, trading off numbers against each other. I don't have any numbers in this case, sorry - I'm not a chemist / epidemiologist. What I do know is that these are hard sciences, and that they have advanced enormously in the past twenty years since the EPA's butt-covering statement of 1987: "The EPA, in 1987 , classified DDT as class B2, a probable human carcinogen based on "Observation of tumors (generally of the liver) in seven studies in various mouse strains and three studies in rats. DDT is structurally similar to other probable carcinogens, such as DDD and DDE." Regarding the human carcinogenicity data, they stated "The existing epidemiological data are inadequate. Autopsy studies relating tissue levels of DDT to cancer incidence have yielded conflicting results." [42] " You can bet your bottom dollar that today, epidemiological data are indeed adequate. >So, we probably have a small risk from DDT to humans that is small enough to >be hard to measure on one hand, and a known killer of millions per year >right now on the other. Indications are that the deaths due to DDT were >from very large doses/exposures...while simply returning to Africa for two >weeks resulted in Neli getting malaria. There are much better options that don't wreck the environment or cause cancer. I used to take antimalarials, when I was in Zim. It's no big deal. Malaria is fairly well understood. >Given this, if it was someone you loved, would you want their country to use >DDT in house spraying against malaria? Absolutely not! I'd rather they didn't go, or they simply got Malaria. Which is curable, as you might remember. Which liver cancer often isn't. Also, you would have to wipe out all or nearly all the mosquitoes. Have you any idea how big Africa is?? That's a heck of a lot of DDT, and a heck of a large environmental catastrophe. Regards, Curtis. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
