Slashdot Log In
DDT or Malaria -- Which is Worse?
Posted by
Cliff
on Thu May 11, 2006 08:59 PM
from the a-choice-between-two-evils dept.
from the a-choice-between-two-evils dept.
Assassin bug wonders: "Although the topic of malaria has been discussed on Slashdot, DDT use has not. After having banned DDT (C14H9Cl5)" in 2004, Tanzania has reversed their ban on DDT use. What is the Slashdot community's opinion regarding the use of DDT for mosquito control versus genetically modified mosquitoes?"
"Key facts to consider:
- Insects have developed resistance, for every tactic that has been used against them (including biological control, crop rotation, and various chemicals)
- Although the direct effects of DDT on humans might be benign, the effects on wildlife and the environment are well documented
- In some countries, such as India, popluations of DDT-resistant mosquitoes exist
- The fitness (i.e., reproductive success in the wild) of mutant mosquitoes is not well understood."
Related Stories
[+]
Science: Genetically Engineered Malaria-Resistant Mosquito 35 comments
David_Bloom writes "According to this Yahoo! News article, a team of German and American genenetic engineering experts have successfully created a malaria-resistant mosquito. Sounds good, but the scientists are still unsure about how to actually apply this to the world's large mosquito population."
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
Full
Abbreviated
Hidden
Loading... please wait.
DDT (Score:3, Informative)
The alleged environmental impact was when the use was ultra-widespread, like dusting crops.
DDT is effective at fighting malaria in much of the world, applying just around the home, but chemical manufacturing companies largely stopped making it after it got a bad name from the environmental concerns.
Re:DDT (Score:5, Informative)
You mean like after it decimated the ecosystem on Borneo, forcing 14,000 cats to be parachuted in to stop the population from dying of bubonic plague and typhus.
Alleged? Alleged? C'mon. This is well documented. DDT doesn't kill humans, but it sure does screw with a lot of other animals. It can be used intelligently, but it can also be used stupidly, too.
It's not even clear that when it's used intelligently that it's cost effective to do so. USAID doesn't believe that it is.
Parent
Link to Harvard about Borneo (Score:5, Informative)
Click on the top link about borneo on this Harvard Page [harvard.edu]
Parent
Re:Link to Harvard about Borneo (Score:3, Informative)
Note that the author of the cat drop was a little too dismissive of the dangers of the rats (he seemed to be more concerned by the fact that they were nibbling people's toenails and eating transistor radios) but hey, he's a reporter. Can't blame him for that.
Still, though, I really recommend the Charlotte Pomerantz book [amazon.com]. It's a well-written children's book which
Re:DDT (Score:3, Funny)
Not to derail your very good point, but
Parachuting 14,000 cats? If anotehr poster hadn't already posted corroborating links I'd be disbelieving you right about now.
Man. The sheer visual of 14,000 feline paratroopers just gives me the giggles.
Re:DDT (Score:4, Interesting)
2) There were no outbreaks of plague or typhus. Every instance you find of someone saying this is someone retelling a trumped up story they heard. The cats were dropped because there was FEAR an outbreak would occur. It didn't.
3) The insect control measures in Borneo are today considered to have been a great success. The problem of malaria went away. Thousands of children lived who might otherwise have died, and as I mentioned, there was no outbreak of plague or typhus.
4) Sorry, I just don't take USAID's position on DDT seriously. They have in the past shown themselves to be tools of of the anti-DDT environmental lobby.
Parent
Re:DDT (Score:3, Funny)
Re:DDT (Score:3, Insightful)
Re:DDT (Score:3, Informative)
Having read several articles about this very topic, it's been mentioned that none of the alternatives are either as effective as DDT, or, just as important for poor african nations, as inexpensive and easy to produce. The whole 'sticking around' thing is very usefull for mosquito suppression.
Nobody's supporting the wide-area spraying that went on in the US before the ban, where some states seemed determined to hit every square foot. They're talking abou
Rachael Carson = Bad Science (Score:4, Informative)
Re:Rachael Carson = Knew what she was talking bout (Score:4, Interesting)
-Rachel Carson, Silent Spring
Note the last sentence. It seems she KNEW that in some cases, not using DDT would amount in a LARGE amount of damage, and in these cases, using DDT would be unavoidable. Spray as little as you possible can seems to be common sense, but may not be to the uneducated.
It IS known that DDT builds up in the tissues of organisms high up in food chains. Perhaps studies don't indicate that DDT directly causes any sort of harm, but I don't think having an organochlorine in ANY fleshy parts is a good thing.
Parent
Re:Rachael Carson = Knew what she was talking bout (Score:2, Flamebait)
Or do you just mean to say that faking Scientific results is okay as long as your heart is in the right place?
-Peter
Re:Rachael Carson = Knew what she was talking bout (Score:3, Insightful)
This is the first thing I've heard contrary to the "fact" that DDT causes thin shells.
It's not a question of ALL birds it about a small number of sensitive species.
"Anderson notes that DDT and DDE levels in nature have been falling for decades. Populations of bald eagles, peregrine falcons, ospreys, and brown pelicans have all bounced back. In 1969, researchers reported finding total DDT accumulations ranging fro
Spiked-online = dodgy quote?!? (Score:4, Insightful)
"DeWitt reported no significant difference in egg hatching between birds fed DDT and birds not fed DDT"
and then, one sentance later, this:
"DeWitt's report that DDT-fed pheasants hatched about 50 percent more eggs than 'control' pheasants."
Now, I don't know who DeWitt is, and I don't claim to be knowledgable about DDT, but these sound like contradictory statements to me!
Maybe spiked-online and/or DeWitt have a vested interest in DDT...
Parent
Re:Spiked-online = dodgy quote?!? (Score:2)
http://www.junkscience.com/ddtfaq.htm [junkscience.com]
Bald eagles were reportedly threatened with extinction in 1921 -- 25 years before widespread use of DDT.
[Van Name, WG. 1921. Ecology 2:76]
No significant correlation between DDE residues and shell thickness was reported in a large series of bald eagle eggs.
[Postupalsky, S. 1971. (DDE residues and shell thickness). Canadian Wildlife Service manuscript, April 8, 1971]
#
The bald eagle had vanished from New
Re:Rachael Carson = Bad Science (Score:2)
Look, DDT has uses. It can be useful under proper control. But we don't exactly have a good track record of handling these things. And DDT does destroy ecosystems. It has. That's fact. That's not bad science. It happened.
It's healthy to be skeptical of its use. History is littered with examples where we just tried to mildly affect an ecosystem and ended up demolish
Re:Rachael Carson = Bad Science (Score:2)
Yes, Silent Spring was wrong. But the complete devastation of the Borneo ecosystem was caused by DDT.
Re:Rachael Carson = Bad Science (Score:2)
It also kills caterpillars, and some reptiles and mammals too. Not humans, though, and not birds. But cats do die from it, for instance.
This will keep the pests away without killing them all, and therefore will not be so destructive to their ecosystem.
Right, I agree. Unfortunately DDT's main benefit was that it could be blindly sprayed cheaply and provide blanket protection against malaria.
This is insane. It destroys ecosystems and ends up causing far more harm than good.
But done in
Riiiiibit (Score:3, Funny)
It's true (Score:4, Insightful)
And DDT-hate on the part of international aid organizations (international aid is the entire health budget for some impoverished African countries) has led to countries refraining from using DDT.
Not using DDT kills poor Africans.
DDT is the cheapest, most effective way of protecting against the world's deadliest disease. Anti-malarial netting is somewhat effective, but simply does not compare to DDT.
Re:It's true (Score:3, Insightful)
The answer is never. Unless ALL malaria is wiped out in ALL organisms around the world, DDT will have to be continously used FOREVER to prevent malaria from breaking out.
This will eventually stop working. Som
Re:It's true (Score:2)
obviously the risk to the environment is a factor but i'm not willing to tell people they have to get sick and die because we don't want the jungle they live in/near contaminated with insecticides.
it should be their choice.
Re:It's true (Score:2, Insightful)
by the time DDT loses effectiveness we might have better treatme
Re:It's true (Score:4, Insightful)
Parent
Re:It's true (Score:2)
That takes research that isn't being done and especially money that isn't being spent. I heard a program on Science Friday that said that many strains of malaria are almost totally resistant against current drugs, in part because they are being misused. I think the comment was that there were many more drugs be
Re:It's true (Score:2)
We have a better cure for malaria. It's a combination of education, and pennicillin. The trouble is, it's not a simple fix. It requires a generation to transition to that solution, because people won't be educated enough to use antibiotics in a way that isn't harmful quickly enough. DDT use should be combined with economic progress and education.
In simpler terms, wealth cures malaria, and malaria prevents wealth. DDT breaks the chicken and egg cycle.
Re:It's true (Score:2)
Re:It's true (Score:2)
We have something better (Score:2, Interesting)
offtopic, but hey: (Score:2, Interesting)
Re:offtopic, but hey: (Score:2)
It's an entire story of the Borneo DDT disaster, told in rhyme. To quote:
Give me DDT.... (Score:2)
Wait... (Score:3, Funny)
100 things you should know about DDT (Score:4, Informative)
DDT! (Score:2)
[Not an original PDP-10 hacker, just a poseur.]
Astroturf (Score:2)
Dr. Lambert has made a hobby of following DDT opponents' crazy theories, as well as the anti-global-warming crowd, and the Big Money that makes both possible. For a compact overview of DDT falsehoods, check out DDT ban myth bingo [timlambert.org].
They used to spray it from trucks (Score:2)
either/or? (Score:4, Insightful)
I don't think it's a 1:1 comparison. Killing mosquitoes is analagous to killing terrorists...you don't stop them from breeding. A proper mosquito-control regimen involves maintaining healthy (warm summer) climate so dragonflies are healthy and eat the mosquito larvae the moment they pop out of the pond.
You should see a pond with dragonflies hovering...it looks like the Congratulations screen from a videogame. Each dragonfly takes a 10' radius, so a group of them has the whole pond on lockdown.
The effects on wildlife are NOT 'well documented' (Score:2, Troll)
DDR or Malaria, which is worse? (Score:2)
False Dichotomy (Score:3, Interesting)
Then there is Methoprene - a compound that is similar to an insect growth hormone. It targets specifically insect larvae and prevents them from reaching their next stage of development. Again, it can be used like any conventional insecticide, does not accumulate and is easily biodegradable and non-toxic to anything but insects. Has been successful in trials against mosquitoes as well.
So, why DDT?
old news (Score:3, Informative)
http://www.junkscience.com/ddtfaq.htm [junkscience.com]
Basically, 'Silent Spring' was based on test data that was wrong.
The birds whose eggs were shattering, had been raised on a diet containing less than 20% of the calcium they usually got. Duh. Low calcium = weak eggshells.
When the experiment was repeated with a proper diet, there was NO such finding, even in birds HEAVILY fed DDT.
Even the original authors of the experiment had, by 1971, turned their investigations more to PCBs, and discounted DDT as an issue with bird populations.
An administrative Judge ruled even at the time that DDT wasn't dangerous.
Nevertheless, the administrator of the then-new EPA ruled it would be universally banned...and then promptly went to work for the exact same anti-DDT enironmental lobbying group, after he left he EPA.
But I find that DNR staff, ecological speakers visiting schools, reporters, etc all have cheerfully and unquestioningly swallowed the Kool Aide on this because of its SEMINAL impact and justification of the environmental movement. To be fair, when confronted constructively about it, are rather shocked but eventually persuaded that there MIGHT be some doubt...which is a lot when you're attacking such a sacred cow. However, I have yet to see anyone subsequently change their presentation, curricula, or (effectively) beliefs.
Question that DDT might not be dangerous? That might make people wonder about the validity of the whole "movement", if they could be shown to be such easily-gulled rubes.
Heck, it might even make you think global warming is BS...but no, that MUST be true, right? Scientists say it is.
DDT or Malaria? (Score:5, Informative)
DDT is very cheap and effective in the spot you're applying it to. And therein lies the problem: it's almost too good. The step from using it where it is effective and safe to using where it has unwanted side effects has historically proven to be very short.
Lacking DDT, the industry has had to develop alternative approaches, such as IPM, which are more information and biology centric, and new materials which are more narrowly targetted and which break down in the environment in a more benign way. This requires more up front effort and investment, but in the end is probably more effective.
Consider one common traditional use of DDT: Fogging to kill adult mosquito populations. The mosquito has to encounter the DDT on the wing or land in a place where there was residual toxic effect. Since the mosquito could be literally anywhere, this means you must saturate an entire area surrounding human habitations by fogging it. In the old days, you waited for a nuisance problem or a disease outbreak, and then fogged everything you could reach and hoped you were in time to stop human transmission. I've talked to public health researchers who believe that most such efforts tend to be undertaken after the actual problem has past. Or if you were proctive, you might try to treat preventatively, killing not only mosquitoes (you never get them all), but beneficial insects as well.
Today, if you can manage it, you find the aquatic habitat in which mosquito larvae hatch and develop, and if you can't drain it (e.g. artificial containers like abandoned machinery), you treat it with a narrowly targeted larvicidal material. BTI and Baccillus sphaericus for example, are endotoxic crystals that only act in aquatic larvae with high pH guts -- midges and mosquitoes mainly. If the mosquitoes have pupated, you treat with a material which forms a film on the water, blocking their breathing tubes; in the old days we used diesel oil, now we have specially formulated oils and even alcohols that form monomolecular films.
However, this involves knowing where the habitat is, which is information-centric problem. You need trained inspectors in the field who know what to look for and what to use. Even fogging operations are much more sophisticated; you don't just spray and pray. You have a trapping program to monitor adult populations so you don't end up fogging the wrong places. The technology involved for trapping is mostly rudimentary , but you need trained users who can sort and identify mosquitoes by species. Not all mosquitoes bite people or carry disease after all. Furthermore you'd be surprised how many untrained people mistake other insects such as crane flies for mosquitoes.
But it remains thrue, for the developed world Information + Biological Knowledge + Specific action pesticides = Control with fewer side effects.
With respect to human and animal health, there is little threat to human health from direct exposure to DDT in the concenrations that are effective. The established problem with DDT is bioaccumulation: the concentrations of DDT and chemical products of DDT break down are amplified as they go up the food chain. In certain key applications, such as house interior treatments, this is not a concern however, so it should be possible to use DDT this way.
In places like Africa, DDT used in domestic treatments would be a tremendous boon. The forms of Malaria that infect humans, unlike many other mosquito borne diseases such as the various encephalitis agents, don't have a natural animal reservoir. It spreads from person to person. Personally, I can imagine Malaria being eradicated, like smallpox, and domestic DDT treatments could play a part in this, if its use could be monitored and controlled.
I've been involved with equipping teams to go to Africa for malaria surveillance and for house treatments. One of the problems you face is that in many poor areas, theft is rife. I've had guys tell me they have
Re:DDT or Malaria? (Score:3, Informative)
Mostly correct, except you forgot to mention that DDT is actually in use in malaria prevention right now [globalpolicy.org] in 22 countries. Most of these countries are in Africa, but I'd appreciate it if you'd attempt to distinguish between individual countries and the second largest continent on the planet, since malaria is simply not a big problem in large areas of Africa such as Algeria (11th largest country by area in the world). And to the Steve Milloy fans, fears of creating DDT resistant strains of mosquitos are not
Re:DDT Use (Score:5, Informative)
Parent
Re:DDT Use (Score:2)
Re:DDT Use (Score:3, Interesting)
Her point (about antibiotics and mosquito control) was that we should try to domesticate of microbal advisaries. If you can produce a strain of a disease that has a short, mild infec
Re:DDT Use (Score:3, Informative)
You are a little off here.
The problem is that the use of non-bleach clearers are creating bacteria that are resistant to anything but bleach based cleaners.
Bleach is the best thing around to kill bacteria the way it works is to disolve the skin wall, no way to build up a resistance to that.
Sterilized Mosquitoes (Score:2)
Crichton's State of Confusion (Score:2, Informative)
As for his DDT stuff -- it's complete rubbish. In the 60s the World Health Organization tried to eradicate malaria by spraying DDT and failed. There are several reasons why it failed, but one of them was the indiscriminate use of DDT in agriculture, which was a very effectiv