Talk:DDT and the effects on malaria

[edit] Additional info

Category:Mosquito control has some info on DDT.

Also, here's some links from a discussion I had with a friend by email in 2005 - no time to arrange it neatly and put it in the article - perhaps someone else can? One of the most interesting things I learnt was that DDT has not been banned completely, but is used, usually in a limited way, in some countries.

My friend sent this link: Africa needs DDT, not "blah, blah, blah" - Pravda (Yes, the old Soviet propaganda machine!)

My response was: "After reading a couple of things... I think the argument for DDT has been overstated by some people, but it is still useful in certain, very specific applications (e.g. applying to the walls of houses - it lasts for months, and once the mosquitos develop resistance, the newer insecticides remain effective)."

[edit] Joe baker vs Donald Johnston

A pro-DDT newspaper article was written in 2005 by Joe Baker: Rachel Carson, mass murderer? A rebuttal to was published: "DDT has many drawbacks in trying to stop malaria", by Donald Johnston, The Spectrum, St. George, June 19, 2005 - this is no longer available online, except in the newspaper's archive, behind a paywall. It makes various claims that would be worth checking, so I've summarized them below. Joe Baker's responded with a rebuttal to the rebuttal - this is also available online, so I haven't bothered summarizing: DDT has saved millions of lives.

(Most likely Donald Johnston had a response to that as well, but I haven't gone looking... I think a more profitable next step is to check the facts directly, starting with Wikipedia's entry on DDT and checking the sources.)

Johnston says that:

DDT "is highly toxic to fish and aquatic invertebrates, a teratogen for amphibians, it accumulates to toxic levels in mammals and there is good reason to suspect that it damages the reproductive capacity of birds. In humans, it exerts acute toxic effects. Its metabolites persist in breast milk following cessation of environmental application and there is some evidence it affects mental development in children." (Interestingly, all his evidence for danger to humans is vague, e.g. "some evidence".)

He notes that it is classified as a "probable human carcinogen." (My emphasis.)

"Sri Lanka resumed DDT use following its initial cessation, and then switched to malathion in the early 1970s because DDT failed to stop a malarial epidemic. Why didn't it work? The mosquitoes became resistant."

Some do still use it. "The World Health Organization recommends its use for impoverished countries unable to purchase more expensive alternatives. Therein lies the true attraction. DDT is cheaper, not better,"

He disputes the statistics - "While Mr. Baker incomprehensibly put the incidence of malaria in Sri Lanka at 2.5 million cases annually, the reality is enlightening. The incidence actually peaked over the past quarter-century at 700,000 in 1987, and in 2003,after a 13-year decline, was 10,000with two fatalities nationwide. This success was achieved, absent DDT use, with intelligent public health measures - including insecticide treated bed-nets."

Note on the author: "Donald Johnston holds a PhD in genetics. He developed an interest in malaria while working in the tropics. He lives in Bloomington."

Then there's a blog post with a debate in the comments, including pro-DDT comments by tc: The Great DDT Hoax.

It seems to me that it's more complex than some hardline environmental skeptics will admit (and hardline greenies for that matter, I expect). However, I haven't noticed such unbalanced arguments in my quick look at AAEA's material; they seem to be much more honest, saying that yes, there's a negative impact, but it's small (I don't know if this is true) and it's less significant that the deaths of many people (hard to argue with that).

It should also be noted that there are other ways of reducing the risk of malaria. These should also be used. The GEM method strikes me as particularly clever. But malaria is such a deadly thing it warrants every technique we have, and I think limited use of DDT on indoor walls is probably very helpful, with very little environmental impact.

Another point to watch - one must be careful of stereotyping "greens" as only caring about the environment, and not about people. They do endorse alternatives, but generally do not intend to do so at the cost of a great loss of human life:

Even representatives from the WWF and Greenpeace were quoted in the New York Times on 8 January 2005 as saying that they would accept the use of DDT "if the alternative isn't working as they didn't in South Africa... if there's nothing else, and it's going to save lives, we're in favour of it. Nobody is dogmatic about it. (Pravda article, linked above)

Note also Rachel's Carson's comments endorsing limited use of insecticide - noting that limited rather than wasteful use would reduce problems of resistance. Like the economist Adam Smith, she's often portrayed as an ideologue, but appears to have been much more balanced. See this blog post: Rachel Carson: Vindicated!.

Coincidentally I got a very sad SMS two days ago from a good friend, saying that her sister back home in Sumatra had just died of malaria. Life is hard in places like that. --Chriswaterguy · talk 07:41, 28 October 2007 (PDT)