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Subject:Re: Re Cost of conservation


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From: Charlie Bell [EMAIL PROTECTED]
Date: Mon, 07 May 2007 19:26:07 +1000
To: [email protected]
Subject: Re: Re Cost of conservation



On 05/05/2007, at 4:05 AM, Dan Minette wrote:



>> Indeed, Gautam made a good argument here that environmental policy and
>> environmentalist claims is a major contributor to the death of 1
>> million/year due to malaria.  The US used DDT as part of its  
>> elimination of
>> malaria.  No human deaths were attributed to DDT.

>That isn't why it stopped being used, Dan. Two reasons - first it  
>persistent in the food chain and the long term ecological  
>implications were regarded as untenable, but second, and this is  
>something that non-biologists seem to have a lot of difficulty really  
>comprehending, mosquitoes got resistant to it. Its efficacy was  
>already dropping. Just as the malaria parasite has become resistant  
>to most of the reliable drugs, the _Anopheles_ mosquitoes became  
>resistant to several of the cheap reliable insecticides.

>DT is used still, in impregnated nets. That's the only place it  
>eally has in the current antimalarial arsenal.


Maybe the specificity of my statement wasn't clear.  The points you made
with respect to resistance to DDT is not unknown to me....I'd be surprised
if it didn't happen.  "Carpet bombing" use of insecticides does create
those sort of problems.  I also have no arguement with worries about the
effects of such use on the environment.  

But, I was talking about resistance to a specific type of
program....spraying of walls.  If you look at a South Africa program on the
World Banks site:

http://web.worldbank.org/WBSITE/EXTERNAL/COUNTRIES/AFRICAEXT/SOUTHAFRICAEXTN
/0,,contentMDK:21266668~menuPK:368095~pagePK:2865066~piPK:2865079~theSitePK:
368057,00.html

http://tinyurl.com/2nr6t5

you will see my suggestion as one of three parts of a comprehensive
program.  This has a marginally high chance of promoting DDT-resistant
mosquitos, but I think we agree that it's not much compared to the
widespread, indiscriminate use that leads to resistance. 

One notes an important difference between South Africa and African
countries that do not use this type of program....South Africa is the most
prosperous Sub-Sahara African country.  (Nigeria has a lot of oil revenue,
but not a good ecconomy).  As a result, it is far more likely to take
actions in the interests of its own people than countries dependent on aid
from foreign government and NGOs.  

As an aside, this article indicates that at least some NGOs are changing
their viewpoints....and signing onto programs like the one that I've been
reccomending.  That's a very hopeful sign....and I hope that 10 years from
now we can talk about the problem with a knee-jerk reaction against
anything involving DDT being a past problem, with malaria deaths reduced to
a fraction of what they are now.  

So, from my perspective, I see three general viewpoints on this issue.  One
was that held, say, 50 years ago, which was focused on the immediate
positive reaction to using chemical insecticieds....and generally being if
a little is good, more is better.  The second is a focus on the dangers of
the use, with the only acceptable level of use being zero.

The third is an understanding of cost/benefits.  You have presented very
solid arguements against case 1...and I do not have any conflict with those
points.  My arguement is that a subset of environmentalists by giving false
and misleading information, are contributing to the problems with malaria. 
I tried to chose my words carefully, and I think _ontributing to_ captures
the nature of the problem.  I also gave references to statements that I see
as problematic.

What I'm arguing for is a hard nosed cost/benefit analysis.  I don't see
that in the POP site that I quoted.  The fact that there are problems with
using DDT doesn't make overstating the risks valid.  It's the mirror image
of "if a little is good, a lot is better" falacy: "if a lot is bad, any is
bad." 

I don't place you in the third camp...and I don't see myself at all in the
first.  Your arguement seems to accept DDT impregnated mosquito nets as a
worthwhile...and a reasonable tradeoff.  I'm adding indoor spraying as a
useful step...and do not endorse widespread outdoor spraying, let alone
carpet bombing spraying....with development of DDT resistant mosquitoes as
the main reason for my opposition to widespread outdoor use. 

Where we seem to differ is on the validity/value of indoor wall spraying. 
I don't see the problem with this, and have seen persuasive arguements for
the usefulness of such spraying.  The only arguement that I see against
this is the fear that it would be the camel's nose under the tent. So, my
question is: if the amount of DDT is actually limited to the amount needed
for wall spraying, are there any significant dangers to this use? And if
there are, do they outweigh the benefits?

Dan M.



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