DDT treatment?(10 posts)
Does everyone know the story of DDT? Apparently one of its uses was to control bedbugs, before it was banned. The ban has mainly to do with agricultural spraying, using much much higher doses, and mixed with toxic solvents, than indoor spraying, at very low dosages with water as the solvent. It also turns out that DDT is more effective than pyrethroids, the standard bedbug pesticide, and is not shown to be harmful to human beings, despite now many studies. All of this has come to light because of debates over anti-malaria spraying in Africa, where DDT would be very effective and perfectly safe. But I wonder, given the rise in infestations in the US, if it isn't time to reconsider the ban. I found a fair amount of this information through the following article, which is about malarial mosquitoes, but seems like it would apply to bedbugs. http://www.washingtonmonthly.com/features/2003/0303.gourevitch.html
Anybody know what chemicals the city sprays with when they spray for West Nile Virus?
Not DDT, that's for sure. I don't think it's coming back any time soon.
Mosquito control is usually handled at the local level, so different cities choose different methods. I did a quick look at the EPA website. The larvicides used for mosquitos don't overlap with anything I've read about bedbugs. http://www.epa.gov/pesticides/health/mosquitoes/larvicides4mosquitoes.htm
The adulticides include organophosphates (malathion and naled) and synthetic pyrethroids (permethrin, resmethrin, sumithirn.)
For those interested in DDT, I happened to read an interesting article yesterday. Can't link it but you could look it up. He author makes some interesting comments about anti-DDT bias in the scientific community and at the UN. I am not saying I think there is a bias, that is what the author said. Don't want to make a political comment !
Last Chance for DDT
By ROGER BATE
Wall Street Journal
November 5, 2007; Page A19
Yes, I have now done a fair bit of research into this whole question. Bate is one of the most consistent advocates for DDT usage. And from what I can tell, there is indeed very strong anti-DDT prejudice, not just in the scientific community, but in society as a whole. It was so thoroughly demonized, on the basis of weak and confused evidence, in the late 1960s and early 1970s, that everyone sees it as the signature, evil 'artificial' chemical. It's a flashpoint for broader fears. Comparing a chemical to DDT, is a bit like comparing a contemporary civil war to the holocaust. As you all know, once you get bedbugs, you get obsessed with things, and I've gone and read all the scientific studies out on DDT, and it turns out it is very very safe for human beings - probably more so than pyrethroids. They used to spray all the WWII soldiers with DDT before attacking pacific islands, to protect them from yellow fever - which was more dangerous than the Japanese. They also sprayed all the Jews in the camps, when they liberated them, to delouse them. If DDT were that toxic to humans, it would have been pretty clear. Anyhow, would be nice if EPA loosened the rules, because it is by far the most effective tool against bedbugs - better and cheaper than pyrethroids. Indeed, DDT is so cheap to produce it is effectively free. Anyhow, this is besides the point because it will never happen here; too many people would panic I think, despite the fact that the bedbugs have returned!
Well, I do agree that it will never happen in the US. DDT for malaria control is a very different issue, as millions or people die from the disease every year and the prophylactics can be difficult to maintain for the long term.
Anyway, did you read the news posted on the blog today? There is an article from the Columbus Dispatch in which an expert says that, in countries where DDT was used for bedbug control, they eventually developed resistance. So while it could be helpful in the immediate epidemic even DDT might not be a long-term solution.
NYC sprayed malathion for West Nile when WNV first appeared, but I don't know what it's spraying now.
DDT killed a lot of things for a long time, but when mosquitoes developed resistance to it, it wasn't really worth the cost in terms of dead fish, birds and other living things we generally value.
There is absolutely no way DDT will ever be back on the US market. The reason why it was done away with is because of the residual activity and the magnification in the food chain. It takes a long time to break down which is why, at one point, it may have been effective against bed bugs but because of this exposure to humans is a concern and more so exposure to non-targets (animals, birds, etc...). The next argument is to license it for indoor usage but with the stigma it's not happening.
Also, I've heard of people testing DDT on BB's and ones that are resistant to pyrethrins showed high levels of resistance against DDT. It's not going to help as much as people want to think.
I don't know much about ddt but I saw on a .gov site somewhere that in the 20's and 30's in some states if an apartment building was infested they would evacuate and seal the building and then treat heavily weekly with ddt for six weeks before allowing the landlords to repopulate the buildings. I think you are right that it's probably down for the count as regards bedbugs in this country but it's a pretty interesting conversation. Later... cos
DDT may be safe for humans, but I think the reason it was banned had little to do with human health but rather the effect of DDT building up in the food chain. The classic example is eagles eggs being produced without shells (meaning no more live baby eagles in affected populations).
However, I have only read a few studies on either side, so I am not an expert by any stretch. I must admit the alluring tale of magic DDT that will kill all bedbugs is tremendously appealing... but reports of eventual resistance has the discouraging ring of truth.
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