Chuck

You are a master at throwing in red herrings! To start with, let's keep
ourselves to the issue and ignore your irrelevancies such as your
misinterpretation of the precautionary principle, genetically modified
food, DDT and your other soap box subjects (I'll come back to them later).

Scientific advances are either accidental (e.g., synthesis of urea
formaldehyde, discovery of the antibiotic effects of penicillin etc.),
which I'll ignore here, or the result of a process that starts with
hypothesis. This hypothesis is then put to test by experimentation,
tests and measurements until proof confirming or denying the hypothesis
is obtained, at which time, it becomes scientific fact. Nature, and
other respected scientific journals, have several sets of criteria to
determine what they publish (and I speak from experience here, as a
contributing editor to several journals). The full blown paper goes
through a long and severe peer review process and must be considered as
representing the thoughts of the best scientists in the world in their
respected fields. The subject may be hypothetical, just as much as
proven science, but it must be backed up by best knowledge and a logical
sequence of thought. Then there are short communications. These may or
may not be peer reviewed (usually only if they appear very
controversial). The next stage are news itams (and I suggest that your
item probably falls into this category), which are usually printed
verbatim, or are trimmed down to fit available space. These are never
peer reviewed and can represent fact, hypothesis or opinion. There are
also guest editorials which are generally a forum for opinion. Finally,
there are letters which complete the forum for opinion but may also
represent hypothesis or fact.

You obviously would wish such journals to publish only proven scientific
fact. In this case, the scientific world would be much poorer as it
would leave the founded hypothesis to be published in such popular
magazines as Scientific American, New Scientist or, God forbid, Popular
Science.

I'll go back to Molina and Rowland's landmark hypothesis. If Nature had
not published this in 1974, as a full paper, then it is probable that
the whole process leading to the Montreal Protocol and the establishment
of the scientific proof that chlorine atoms knocked off covalent bonds
of some organic molecules reaching 8-50 km altitude, 14 years later
would, at the best, been delayed or at the worst, never happened. As it
is, it is still touch and go whether we will suffer undue undesirable
effects in the next few decades. I strongly recommend you read
"Protecting the Ozone Layer" by Andersen and Sarma (recently published).
This will give you an insight into the facts and processes from
hypothesis to proof, as well as the application of the precautionary
principle in a scientifico-political context.

-----------

OK: the precautionary principle. This is best illustrated by the
pharmaceutical industry. A new molecule must go through a whole series
of tests before it can be sold to the general public, a process that can
take many years. Why? Remember thalidomide? Even so, compromises are
made, for practical reasons, and new side-effects are occasionally
recorded after the drugs are marketed, but the process is a reasonable
application of the precautionary principle and probably filters out 99%
of the potential negative effects. A friend of mine contracted
trypanasomia (Rhodesian sleeping sickness) and required an arsenic-based
drug which saved his life. I remember reading the paper that was packed
with the capsules. I can't quote it verbatim but it listed the following
under contra-indications:
- severe permanent heart, liver and kidney lesions are possible
- considerable lesions to the cerebral cortex and other parts of the brain
- possible paralysis of the motor nerves
- modifications to the skin and hair
- death
- the medical profession will understand that these contra-indications
may be preferable to the certain outcome of death if the disease is not
treated.

I agree that this anecdote is a red herring, but is an illustration of
the lesser evil applied to the precautionary principle, as was the
Montreal Protocol, and as would be if species are saved from extinction
by man's mistaken belief that he has dominion over other living things.
I would much rather spend big bucks in saving species than, for example,
knocking the bejabers out of the Iraqis or the Palestinians, to resolve
nothing.

_______

As for GMOs, if any country wishes to apply the precautionary principle,
that is their right - or do you deny that? There is a BIG difference
between using GMOs in famine-stricken African countries and places like
the USA. What percentage of the total US diet is taken up by, say, GM
corn? 1%, 2%? What percentage of a starving African's diet would be?
90%, 95%? Do we know whether this is likely to have an effect, which has
not been foreseen? Similarly, do we know whether the introduction of a
massive quantity of sterile corn is likely to have an effect on the poor
native crops? I, personally, tend towards not being the sorcerer's
apprentice, but I'm not a farmer. I tend to minimise using x-icides in
my garden, especially on veggies, even if my aubergines have skin
lesions due to snails and I have a few grapes which are attacked by
fungus. But I must use insecticide on my peaches and nectarines during
the growing stage, if I am to have any fruit at all (thanks to DDT
killing the insects' natural predators, while rendering themselves
immune to the stuff).

---------------

This brings me to DDT. Rather than spend time, please let me quote
verbatim a message I sent to someone on this subject a few days ago:

QUOTE STARTS


I can't agree with you about the effect on other species: I have seen
this island's ecosystems totally changed during the time that the
anti-malarial action was taking place. I agree that it was probable that
the efforts made to eradicate the disease were probably exaggerated
(e.g., the spraying took place in places where malaria was not endemic,
such as in the mountains) and this caused more harm than good, but the
aim was TOTAL eradication. This meant that many predatory invertebrates
were killed as well as the mossies, so that resistant species of other
insects could develop. In the early 1950s, various species of the
insectivorous praying mantis were very common (probably at least 6
species and seen daily). Today, if I see half-a-dozen per year of just
one small species, this would be exceptional. Other species I see fewer
of are spiders, geckos, frogs, lizards and chameleons, all
insectivorous. This is not because of urban development, as I live in
the country with my garden backing onto several sq km of totally wild
government-owned forest and garrigue land with several biotopes. Re
frogs, I have made a mini-study of the Hyla arborea ssp savignii (spelt
wrong in the article ** in the list below), as we have inadvertently a
large colony of them actually in the garden and even on our patio. I've
also seen the Green Toad in our garden on occasion. I'm planning to
build an aquatic biotope to study the breeding habits of both species
better and increase their numbers in the hopes of reducing our
dependence on insecticides to control no-see'ums indoors and fruit pests
outdoors. Their tadpoles are particularly voracious! The adult Hyla is
not over effective, as they ignore small insects. Their favourite prey
seems to be small moths and similar-sized beasties and they will easily
eat one per hour, under favourable conditions. Geckos are also
interesting and go especially for the crane fly. I hope the aquatic
feature will also attract dragon and damsel flies. We occasionally see
them migrating, but I don't think there are any residents within a
couple of km or so from here.

My last message was composed mainly out of my head (I checked the
molecular structure in a book). However, your reply incited me to do a
short 'Net search. There are thousands of articles on DDT, which I admit
seems to be quite a controversial subject (I had not realised it and
thank you for bringing this to my attention). I attach below a list of a
few that seem interesting, especially with regard to insect-resistance
to the substance (you gave me doubts in your message, but I see that it
is, in fact, so).

Having read le pour and le contre, please allow me to take a stand:
- DDT could be useful for eradicating *local* populations of
disease-bearing insects in undeveloped countries, provided that: a) it
is proven that the insects are not resistant to it; b) only the breeding
grounds of the insect are identified and treated; c) it be used as a
single, short-term (e.g., < 1 year) intensive blitz on the insect over a
maximum of 3 broods; d) that the blitz be supervised by scientifically
competent persons; e) other endemic species be avoided as much as
possible; f) every effort be made to avoid it entering into food chains;
g) any residual insect "colonies" be eliminated by other means.
- In the event of local malarial conditions, other means of control,
such as marsh drainage, should be applied simultaneously, provided that
there is no danger to other endemic protected species.
- I would be very opposed to its wide-scale use in any country, such as
was done in Cyprus in the 1950s.
- I would be opposed to its use on any long-term plan or in any other
conditions than above, especially in agriculture or to reduce
nuisance-value but harmless insects.
- I would be especially opposed to its use as a follow-up of a previous
blitz.
- I would be generally opposed to its use in developed countries, other
than for very exceptional emergency measures on a local scale.
- I would be very forcefully opposed, indeed, to its sale to the public
in any country. In fact, it would be ideal if each batch made were to be
accompanied by an expert in its use, until it had all been used under
his strict control!

I agree that there is no black or white in this subject (the same as I
am reluctantly forced to use other insecticides in the house and garden)
but I do believe that such a persistent insecticide that loses its
effectiveness and is known to cause harm should be used only under
strictly defined conditions. This would be analogous to the permitted
use of CFCs and other ozone-depleting chemicals under the Essential Uses
Exemption clauses of the Montreal Protocol, where 4 strict criteria must
be shown to apply before an Exemption is granted.

QUOTE ENDS

Best regards,

Brian

Charles Dolci wrote:
> Brian:
>
> You say that "Nature is not a magazine but a respected scientific journal"
> That may be the case, but how can it be worthy of respect when it prints a "news
> communication" like this. Things do not happen in a vacuum. Nature and other
> such "journals" know that the unsophisticated, popular media will grab stories
> like this, create issues and manufacture crises that are picked up by
> politicians and others who then make public policy, all based on nothing more
> than speculation by people who call themselves scientists. Then we end up with
> policies (such as "lead-free" as just one example) that are not based on science
> and, ultimately, are detrimental to the environment.
>
> But this article was not about opinion, it was not even about speculation. It's
> pure scare mongering. The "scientists" admitted they had no facts ("... lacks
> data on tropical forests ..." and "... unidentified or poorly studied plants
> ..." and "... no one's got around to checking if they qualify ..."). I am not a
> scientist, I have never claimed to be, but is it good science to hypothesize
> about things over which you have no facts? The only kind of science they seem to
> be practicing is "political science".  One would think that scientists who are
> speculating about some new idea or hypothesis that is so devoid of facts would
> engage in less advocacy and avoid scare tactics. Nowhere in the article does it
> say or imply that these scientists are offering up a hypothesis.
>
> You also state "Readers are able to draw their own conclusions ..."
> One would like to think so, but the gist of the article draws the conclusion for
> the reader. There is not a single fact or data point in the entire article that
> a careful reader could use to draw any kind of conclusion or form an opinion.
> (Well, I do go too far. There is one fact that is very obvious. These scientists
> want taxpayer money to do their research.)
>
> Regarding the "precautionary principle" I am all for the precautionary
> principle, I utilize it every day.  When driving when I come to the stop sign I
> come to a full stop and make sure that it is safe to proceed before I hit the
> accelerator. Before I drink milk directly from the carton I make sure my wife is
> not in the room to see me.  I am sure we all employ the precautionary principle
> in our daily lives, otherwise few of us would have survived to middle age.
>
> But there needs to be a rational basis to the precautionary principle, otherwise
> we would all still be hunter-gatherers, eating our meet uncooked and wearing
> animal hides.  If the EU council of ministers existed one million years ago,
> when man first learned to control fire, I am sure they would have banned fires
> because of the precautionary principle.
>
> Brian also says "If it is later shown that this was overkill, then the worst
> that has happened is that we have wasted some money." Unfortunately, it is not
> so simple or harmless as that. The illogical and irrational application of the
> precautionary principle, in a very real sense, is leading to the suffering and
> deaths of millions of people.
>
> This in today's news, from the AP:
>
> GENEVA -  The U.N. food agency is looking for a country to store thousands of
> tons of genetically modified corn that has been rejected by the Zambian
> government despite the country's deepening hunger crisis, a spokeswoman said
> Tuesday.
>
> "The authorities have officially asked us to remove from the country the food we
> have stored there which could contain GMOs," or genetically modified organisms,
> said Christiane Berthiaume, spokeswoman for the World Food Program.
>
> The crisis, which threatens 14.4 million people in six southern African
> countries, was blamed on poor weather and mismanagement in several of the
> affected countries. An estimated 2.9 million Zambians, nearly 30 percent of the
> population, are in danger of starvation in the coming months, officials say.
>
> Zambian President Levy Mwanawasa has referred to the food as "poison," but the
> United States, which donated it, argues that tens of millions of Americans eat
> genetically modified corn every day with no ill effects. Several U.N. agencies
> have declared the food safe.
>
> *****"
>
> Europe is banning GM fods because of the precautionary prinicple. It's one thing
> for the rich nations of Europe to be so picky about what they eat, they have
> alternatives. But not everyone is so lucky.
>
> Even more startling is the irrational application of the precautionary principle
> to the outright ban of DDT. According to all reports, since the ban on the use
> of DDT for all applications the number of cases of malaria and the subsequent
> deaths have skyrocketed. Malaria is responsible for about 500 million clinical
> cases of disease and about 2.7 million deaths a year, mostly those of children
> under five and pregnant women. In Sub-Saharan Africa alone, malaria destroys 70%
> more years of life than do all cancers in all developed countries combined. See
> attached. If more comprehensive data on the impact of the DDT ban on malaria is
> needed I can provide it (its a big *.pdf file and I don't want to litter
> everyone's mailboxes).
>
> Chuck Dolci
>
>
>
>
> *User-Agent: Mozilla/5.0 (Windows; U; Win98; en-GB; rv:1.0.1) Gecko/20020823
> Netscape/7.0
> *X-Accept-Language: en-gb, en
> *MIME-Version: 1.0
> *Content-Transfer-Encoding: 7bit
> *From: Brian Ellis <[log in to unmask]>
> *Subject: Re: [EN] Nature Magazine
> *X-To: Charles Dolci <[log in to unmask]>
> *X-cc: [log in to unmask]
> *To: [log in to unmask]
> *
> *Chuck
> *
> *I don't back you up either on your attack on this article or on the
> *medium carrying it.
> *
> *First of all, Nature is not a magazine but a respected scientific
> *journal. The whole process of establishing a scientific finding usually
> *starts with a hypothesis. For example, Molina and Rowlands published -
> *in this same journal, Nature - their startling theory that CFCs could
> *cause ozone-depletion in 1974, long before there was any scientific
> *observation to back up their hypothesis. Nevertheless, it did prove
> *true, scientifically confirmed by both modelling and empirical
> *observations. Notwithstanding, it was wisely acted upon by the
> *precautionary principle; even the Vienna Convention and the Montreal
> *Protocol were signed before we had the science. When the science did
> *arrive, it showed the situation was far worse than had been foreseen and
> *the Montreal Protocol had to be seriously tightened with a faster and
> *more draconian phase-out schedule.
> *
> *Secondly, this is a short news communication and has not been published
> *as a peer-reviewed paper. Notwithstanding, the conditional tense abounds
> *and it clearly demonstrates its hypothetical nature. Readers are able to
> *draw their own conclusions; you have drawn yours as a naysayer, while
> *others, like myself as ayesayers, may be alarmed. You are entitled to
> *your opinion, just as much as I am, but it certainly does not serve your
> *cause to be so vituperative against both the substance and the form of
> *the article.
> *
> *Thirdly, in this day and age, in cases like this, where there may be a
> *risk of irreversible damage, it has become usual to apply the
> *precautionary principle. That is to assume, if there are reasonable
> *grounds, the worst and to take strong measures to combat the supposed
> *"evil". If it is later shown that this was overkill, then the worst that
> *has happened is that we have wasted some money. OTOH, if the situation
> *is as bad, or worse, than has been painted, then that plant that may
> *save thousands from a painful and premature death (including perhaps
> *yourself), may have been saved from extinction, to put it on an
> *emotional note. The problem is also that a single plant type is not an
> *isolated item, but a part of a biotope. Other species, such as fungi and
> *insects, may depend on it and these may be part of a much more important
> *food chain. Every single species that we lose, through the inconsiderate
> *action of man, whether deliberately or inadvertently, is a loss for the
> *whole world. I have personally witnessed how this island has been raped
> *over the last 50 years. It is estimated that about 40% of plant species
> *have disappeared, or nearly so, and probably as many animal species
> *(more, if you count insects). In some cases, the niche has become
> *occupied by more harmful species. Control of this necessitates the use
> *of more herbicides and insecticides that kill good and bad
> *indiscriminately and pollute our ecosystems.
> *
> *In other words, the terms of our short tenancy on our planet should
> *include "thou shalt not cause harm to living things that may thus be
> *endangered and thou shalt do everything in thy power to ensure that they
> *survive".
> *
> *That having been said, humans are not responsible for all extinctions
> *and I have little doubt that species die off from natural causes every
> *day. After all, you can hardly blame us for the dinosaurs! It is
> *probable that natural genetic mutations generate new species every day,
> *as well. Nature is a melting pot in constant movement. Humans do not
> *have the right to add or remove species from that pot or play at
> *sorcerers' apprentices.
> *
> *Best regards,
> *
> *Brian
> *
> *Charles Dolci wrote:
> *> I had always thought that Nature was a "Science magazine", but I guess I was
> *> wrong. Or maybe their definition of "science" is different than mine.
> *>
> *> Refer to an article at http://www.nature.com/nsu/021028/021028-11.html
> *> entitled "Dying plants double"
> *>
> *> New calculation of threatened species gives startling result.
> *> 1 November 2002
> *>
> *> HELEN PEARSON
> *>
> *> Nearly half of the world's plants could be close to extinction, scientists
> have
> *> warned.  The calculation triples previous estimates.
> *>
> *>>>>    "... could be close to extinction ..." THEN IT IS EQUALLY PLAUSIBLE
> THAT
> *>>>
> *> THEY COULD BE "FAR FROM EXTINCTION".
> *>
> *> The number of plants on the standard Red List of threatened plant species is
> a
> *> massive underestimate, say the botanists, because it lacks data on tropical
> *> forests.  When estimates from here are taken into account, the fraction of
> *> species under threat spirals from 13% to between 22% and 47%1.
> *>
> *>
> *>>>>    WHAT KIND OF PRECISION IS THIS ".. between 22% and 47%."?  MAYBE IT IS
> *>>>
> *> THE BEST THEY CAN DO GIVEN THEY "lack data on tropical forests" WELL, IF THEY
> *> LACK DATA ON TROPICAL FORESTS THEN HOW DO THEY KNOW THOSE FORESTS HAVE
> *> THREATENED PLANT SPECIES? IS IT NOT EQUALLY PLAUSIBLE THAT THE LIST OF
> *> THREATENED SPECIES IS MASSIVELY OVERESTIMATED?  AFTER ALL, THEY LACK DATA.
> *>
> *> Monitoring the environments most at risk would cost only US$100 per species
> per
> *> year - $12.1 million in total - says Nigel Pitman of Duke University in
> Durham,
> *> North Carolina, one of the report's authors.
> *>
> *> "We may be on the edge of a mass extinction of plants," says Pitman.  "We'd
> like
> *> to see a major investment for the world's threatened flora."
> *>
> *>
> *>>>>    THEN AGAIN WE MAY NOT BE. WHY DON'T THEY WAIT FOR SOME DATA BEFORE THEY
> *>>>
> *> PROCLAIM THE RAIN FORESTS DEAD.
> *>
> *> The figures are startling, and probably in the right ballpark, says botanist
> *> Michael Nee of the New York Botanical Garden.  Razing tropical forests for
> *> farming is thought to be a prime cause of species annihilation.  "There are
> too
> *> many people raping the landscape," says Nee.
> *>
> *>
> *>>>>    "... proabably in the right ballpark ..." AND "... thought to be a
> prime
> *>>>
> *> cause ..."  THIS PASSES FOR SCIENCE?
> *>
> *> Red or dead
> *>
> *> Species get put on the World Conservation Union (IUCN) Red List when they are
> *> formally identified as being close to extinction.  But this excludes
> *> unidentified or poorly studied plants.
> *>
> *>
> *>>>>    WELL, ONE WOULD HOPE SO, PARTICULARLY IF THEY ARE "unidentified".
> *>>>
> *>
> *> "There are thousands of plants in the tropics that deserve red-listing but no
> *> one's got around to checking if they qualify," says Pitman.
> *>
> *>
> *>>>>    WELL THEN HOW THE HELL DOES THIS ..... KNOW THEY DESERVE TO BE
> *>>>
> *> RED-LISTED? AFTER ALL, NO ONE CHECKED TO SEE IF THEY QUALIFY. AND THIS PASSES
> *> FOR SCIENCE?
> *>
> *> Working in tropical countries, Pitman and his colleague Peter Jorgensen found
> *> that the number of species unique to each country is a rough guide to the
> number
> *> that is threatened.
> *>
> *> Ecuador, for example, has 4,000 species that are found nowhere else.  Nearly
> *> 3,500 are under threat, because they often grow in small regions, where a
> *> landslide or fire can wipe them out.
> *>
> *>
> *>>>>    HMMMM. SINCE LANDSLIDES AND FIRES HAVE BEEN AROUND FOR MILLIONS OF
> *>>>
> *> YEARS, WITHOUT INTERVENTION FROM MAN, WHAT IS THE POINT? DO THEY WANT TO ADD
> *> THEM TO THE LIST BECAUSE A LANDSLIDE OR FIRE MIGHT SOMEDAY OCCUR? WHY DON'T
> THEY
> *> ADD ALL PLANT SPECIES TO THEIR LIST, AFTER ALL, IF A LARGE METEOR COLLIDED
> WITH
> *> EARTH THERE COULD BE MASSIVE PLANT EXTINCTIONS.
> *>
> *> To find the global proportion of plants under threat, Pitman and Jorgensen
> *> pooled the numbers of species unique to each country.  The exact number is
> hard
> *> to pin down because estimates of the number of plant species range between
> *> 310,000 and 422,000.
> *>
> *> "It's an interesting attempt to connect the dots of our picture of global
> plant
> *> extinctions," comments ecologist Hal Mooney of Stanford University in
> *> California.  "The numbers they calculate should add to growing concern about
> *> irreversible species loss."
> *>
> *>
> *>>>>    THE ONLY THING THAT SEEMS TO BE IRREVERSIBLY LOST IS HEALTHY SCIENTIFIC
> *>>>
> *> SKEPTICISM.
> *>
> *> AND THIS PASSES FOR SCIENCE??
> *>
> *> Chuck Dolci
> *>
> *>
> *>
>
>
> ------------------------------------------------------------------------
>
> Malaria Foundation International
> Global Networking Against Malaria
>
> OPEN LETTER TO DDT TREATY NEGOTIATORS
>
> 29 March 1999
>
> Dear [Diplomat],
>
> We are a group of scientists and doctors who are writing you on account
> of your participation in the ongoing treaty negotiations of the United
> Nations Environment Program (UNEP) aimed at eliminating Persistent
> Organic Pollutants, or POPs.
>
> You are no doubt aware that one of substances the POPs Treaty seeks to
> ban from future use is DDT, and that such a ban is supported by most
> wealthy Western countries and several environmental NGOs. However, you
> may not be aware that DDT is also a critical tool in the fight against
> malaria, which remains a terrible scourge of the developing world.
>
> As people who have dedicated our careers to health in the developing
> world, we wish your country to carefully scrutinize any treaty proposal
> which could aggravate the burden of malaria upon your citizens. Although
> we entirely agree that DDT should one day be eliminated because of its
> known environmental effects, we also believe that human life must not be
> endangered in reaching that goal.
>
> In our view, setting a deadline for the elimination of DDT -- whether
> that deadline is in 2007 or some other date -- unacceptably endangers
> health in countries with malaria. We simply cannot be sure when DDT will
> no longer be necessary for malaria control. Yet to act ethically, we
> must know, with the greatest of certainty, that DDT is unnecessary
> before we ban it.
>
> Despite our oppostion to a deadline, we agree humanity must find and
> implement alternatives to DDT as quickly as possible. To be
> satisfactory, these alternatives must be: (1) equally effective, (2)
> equally inexpensive, and (3) able to replace DDT wherever it is now used
> or may be needed in the future for malaria control. This will require
> scientific and technical resources that developing countries lack, but
> which Western countries can offer.
>
> We therefore advocate eliminating DDT in two phases. Phase one would
> immediately ban DDT use in agriculture, but would make an exception for
> the life-saving use of DDT in malaria control. Phase two would extend
> the ban to public health uses of DDT, but ONLY if Western countries
> research and successfully implement effective, affordable alternatives
> to replace DDT. This two-phase plan, we emphasize, does NOT rule out a
> DDT ban, but makes it contingent on Western countries funding global
> efforts to research, develop and deliver satisfactory alternatives to
> control malaria.
>
> As a negotiator of the POPs Treaty, we believe it is helpful for you to
> understand the science and politics of DDT and malaria. In this letter,
> we explain why we believe DDT is a legitimate tool of malaria control,
> and why a two-phase ban is justified. It is our wish that you find this
> information useful in pressuring developed states to negotiate a POPs
> Treaty that respects both the environment and human health.
>
>
>
> Why do we need to worry about malaria in eliminating DDT?
>
> Malaria is responsible for about 500 million clinical cases of disease
> and about 2.7 million deaths a year, mostly those of children under five
> and pregnant women. In Sub-Saharan Africa alone, malaria destroys 70%
> more years of life than do all cancers in all developed countries
> combined. It therefore follows that even a tiny loss in the efficiency
> of a national malaria control program, occasioned by the loss of DDT or
> otherwise, would result in a tremendous number of additional deaths from
> the disease.
>
> Malaria is a serious infection of Plasmodium parasites, which are spread
> by the bite of Anopheles mosquitoes. For this reason, nearly all malaria
> control strategies target either the parasite or the mosquito in some
> way. This is easier said than done. There are no fewer than four species
> of Plasmodium that infect people, each with thousands of genetic
> variants, and about thirty-five different species of
> malaria-transmitting mosquitoes. It is the complex diversity of the
> parasites, the mosquitoes, the local ecologies, socio-economic
> conditions, and human responses to disease that conspire to make malaria
> notoriously hard to control. As a result, there is no single
> prescription, not even DDT, which can successfully control malaria in
> all locales.
>
> Yet DDT is still a very useful tool for malaria control in some places.
> Once or twice a year, DDT is applied to the interior walls only of a
> house. No spraying is done outdoors. Wall spraying is sufficient because
> mosquitoes tend to feed at night, when people are also indoors. If a
> mosquito is "DDT sensitive", the small amount of DDT it absorbs through
> its feet when it lands on a sprayed wall will kill it within a few
> minutes. If a mosquito is "DDT resistant", it will not die, but will be
> irritated by the DDT and fly outside. This irritant effect means that
> DDT continues to be moderately effective even in locales where DDT
> resistance is considered widespread. In either case, whether DDT kills
> or irritates the mosquito, the opportunity for the mosquito to bite a
> person with malaria and carry the infection to another person is lost.
>
> World Health Organization scientists have called indoor house spraying
> "the most easily applicable large-scale transmission control measure"
> for malaria. DDT is often the insecticide of choice because it is both
> very cheap and effective. Data from the Pan-American Health Organization
> show that where South American countries stopped spraying houses with
> DDT, their rates of malaria increased, often dramatically. Conversely,
> the single country to increase DDT house spraying (Ecuador) was also the
> only one to significantly reduce its rate of malaria (by 61% overall).
>
> But leaving aside its effectiveness, what makes DDT attractive is its
> very low cost. Although exact data on cost per life saved are lacking,
> there is no doubt that indoor house spraying is among the most
> cost-effective malaria control strategies. For countries with small
> health budgets and worsening malaria problems, there may be few, if any,
> practical alternatives, which may be a reason to immediately increase
> rather than eliminate DDT use. Thus, any treaty to ban DDT must be
> weighed very carefully, as against the uncertain cost of other
> strategies to control malaria, and the loss of human lives if these
> strategies are too expensive to be implemented.
>
>
>
> Isn?t DDT so dangerous to health that it outweighs any benefit in
> malaria control?
>
> There is no doubt that there are health risks associated with DDT use.
> For this reason, some condemn DDT outright. This is inappropriate,
> because the relevant question is not whether DDT can pose health risks
> (it can), but whether these risks outweigh the tremendous public health
> benefits of DDT for malaria control (they do not).
>
> Of all the criticisms one can make about DDT for which there is
> evidence, the worst is that it possibly causes cancer. This is the
> conclusion of the International Agency for Research on Cancer (a branch
> of the WHO), which classifies DDT in the lowest category of substances
> for which there is a definable cancer risk: DDT is "possibly
> carcinogenic to humans". The IARC rates DDT as being "possibly
> carcinogenic" because it found that there was sufficient evidence of
> risk in animals, but inadequate evidence in humans.
>
> While it sounds worrisome that DDT is "possibly carcinogenic", we
> emphasize that this risk must be balanced against the public health
> benefits. It is only if the health risks of DDT outweigh the benefits of
> DDT for malaria control that we should consider not using it. Balancing
> health risks and benefits like this is not unusual. For instance,
> several prescription drugs are classified by the IARC as "possibly
> carcinogenic", "probably carcinogenic", and even "carcinogenic in
> humans" ? but these drugs are still used to treat life-threatening
> diseases because the health benefits of a cure far outweigh the cancer
> risk . The same is true of DDT.
>
> Another possible risk of DDT is that it may shorten the duration of
> lactation in women. This is the view of one group of scientists who
> found that DDE (a product of DDT decay in the environment) reduced
> lactation time in Mexican women. As of today, this conclusion has yet to
> be confirmed by a second or third group of scientists, as is necessary
> to have confidence in this result. This is especially so because
> experiments in rats contradict the human studies, and fail to show that
> DDE affects lactation time.
>
> But even if DDT shortens lactation time, this too must balanced against
> the benefits of DDT for malaria control. The same scientists who found
> reduced lactation in Mexican women also noted an "absence of any
> apparent effect on the health of the children" . That is, either DDT
> made no difference to childhood health, or made so little difference
> that the scientists overlooked it. Such a risk is insignificant
> alongside the 2 million childhood deaths caused by malaria yearly.
>
> Finally, some critics, notably the World Wildlife Fund (WWF), suggest
> that DDT may disrupt hormones in the human body and adversely affect our
> immune and nervous systems. But the scientific evidence of such harm is
> scanty, if there is any harm at all. WWF itself admits that "the
> magnitude of immune suppression...is largely unknown", and that "direct
> effects to humans [nervous system] are difficult to assess".
>
> It would be ironic indeed if in running from the bogeyman of these
> speculative health risks, we banned DDT and ran directly into the
> familiar and deadly hands of malaria. Wisdom demands that one first
> study and prove that risks of hormonal disruption outweigh the benefits
> of malaria control. Until this is done, the only sensible conclusion is
> that all the health risks of DDT are outweighed by the concrete,
> demonstrable health benefits of DDT use in malaria control.
>
>
>
> Why is DDT being attacked as a health risk?
>
> The question of DDT?s impact on human health is controversial because of
> the impact of DDT on wildlife. In their effort to bring about a total
> ban on DDT, it is unfortunate that some environmentalists have
> exaggerated the health risks of DDT.
>
> A report distributed by World Wildlife Fund at the POPs Treaty
> negotiations shows how the science of DDT and health can be
> misrepresented in the endeavour to protect wildlife. The report appears
> well researched and credible, in part because it cites a long list of
> scientific studies. But when one reads these studies, it becomes clear
> that WWF has inaccurately conveyed the conclusions of some studies to
> discredit DDT. This can be surprisingly blatant. Consider this quote
> from the WWF report:
>
> "Some studies have found correlations between higher concentrations of
> DDT and DDE and women who had developed breast cancer, while others have
> not."
>
> To back the first part of this statement, WWF cites two studies which it
> alleges demonstrate a correlation between these substances and breast
> cancer. However, when one turns to the more recent of these studies, the
> scientists actually conclude just the opposite. In their own words:
>
> "[The] lack of association between exposure to organochlorines [i.e.
> DDE] and breast cancer was present regardless of length of follow-up,
> year of diagnosis, or the case patient?s menopausal and
> estrogen-receptor status. CONCLUSION: The data do not support the
> hypothesis that exposure to DDE and PCBs increases risk of breast cancer."
>
> In essence, WWF has cited a study that says "there is no association
> between DDE and breast cancer", as support for its position that DDE
> creates a risk for breast cancer. Needless to say, this is
> scientifically misleading, and dreadfully wrong.
>
> WWF also misleads by concealing the fact that a much greater number of
> studies contradict its position than support it, and that study after
> study finds no risk of breast cancer associated with DDT or DDE
> exposure. WWF cites only a single negative study, but at least five
> studies reached this conclusion in 1997 alone. This supposed breast
> cancer risk fails to be materialize even in areas where DDT is used for
> malaria control, as the authors of a recent study from Vietnam conclude:
>
> "[Our] results suggest that recent and past exposure to p,p?-DDT does
> not play an important role in the [cause] of breast cancer among women
> living in a country with a tropical climate where insecticide use for
> mosquito control is common."
>
> Thus, considering the many studies that have been done on the question,
> it is doubtful that there is any association between DDT exposure and
> the risk of breast cancer.
>
> In summary, we would advise developing countries to be skeptical of
> claims that DDT is destroying the health of their people. Sweeping aside
> the unfortunate scientific misrepresentations, at worst there are small
> health risks, and very large health benefits to DDT house spraying. We
> therefore have no doubt that it would be a terrible error to eliminate
> DDT, which probably saves hundreds of thousands of lives a year from
> malaria.
>
>
>
> What about the environmental dangers of DDT on wildlife?
>
> It cannot be seriously disputed that DDT has devastated some wildlife
> populations, such as birds of prey. The effects of agricultural DDT
> overuse in the 1950s and 1960s on these populations are reversing only
> now. We agree this is a good reason to eventually eliminate DDT.
> However, the urgency with which DDT is eliminated in public health uses
> must not be an overreaction to the mistakes of agriculture, given the
> small amount of DDT that indoor house spraying requires.
>
> The environmental impact of DDT use in agriculture and malaria control
> are not at all comparable. Indoor house spraying needs 2 g/m2 of DDT
> once or twice a year, or about 470 g for a large house. Quite a lot of
> this DDT will remain indoors and never enter the environment. By
> contrast, a single 40 hectare field of cotton requires 795 kg of DDT per
> growing season ? as much as 1700 times as much DDT, sprayed directly
> into the environment. Spraying all the high-risk houses in a small
> country like Guyana is estimated to require only as much DDT as for a 4
> km2 cotton field.
>
> Plainly, it is the agricultural uses of DDT which are a major
> environmental danger and which must be immediately banned. There is far
> less urgency in banning public health uses of DDT. Although this should
> eventually be done, we can safely postpone doing so until satisfactory
> alternatives to DDT are found and implemented. To do otherwise, or to
> tie DDT elimination to an deadline that may pass without implementation
> of alternatives, is to endanger the health of the developing world for
> an environmental goal.
>
>
>
> What are the alternatives to DDT and indoor spraying, and are they
> practical?
>
> Suppose that DDT were banned today and it became necessary to adopt
> alternative strategies for malaria control. We would find, broadly
> speaking, that we had two choices:
>
> (1) continue house spraying, but use insecticides other than DDT; or
>
> (2) abandon house spraying of insecticides altogether in favor of
> non-chemical malaria control strategies.
>
> Having said this, not all alternatives are equally attractive as DDT. We
> would therefore need to ask three questions:
>
> (1) Is the alternative equally affordable as DDT house spraying?
>
> (2) Is the alternative equally effective as DDT house spraying?
>
> (3) Is the alternative equally safe as DDT for human health?
>
> Of course, we would want to reject unsafe alternatives. We would also
> want alternatives to prevent the same number of deadly or disabling
> malaria cases per dollar spent. In short, we would want safe
> alternatives that are equally cost-effective as DDT. Cost-effectiveness
> is supremely critical to developing countries that have very little
> money to spend on malaria control.
>
> With this to guide us, we can now consider some alternatives.
>
>
>
> (1)?Alternative insecticides
>
> Leaving aside DDT, there are three families of insecticides used in
> malaria control: the carbamates, the organophosphates, and the
> pyrethroids. The first two are dangerous to handle and require special
> protective equipment that is not widely available in developing
> countries, so they are not practical alternatives. That leaves only the
> pyrethroids to substitute for DDT, although some worry that they are
> hazardous to health as well.
>
> At this time, there is reason to be enthusiastic about the pyrethroids.
> Like DDT, pyrethroids require little protective equipment and are safe
> in ordinary use. There is, however, controversy as to their
> cost-effectiveness. Although pyrethroids cost very much more per kilo
> than DDT, one uses less of them to spray a house. Taking this into
> account, a recent World Health Organization study estimated pyrethroids
> cost over three times as much as DDT in actual use. On the other hand,
> one study from Brazil suggests that pyrethroids can equal or surpass DDT
> for cost-effectiveness in house spraying. All in all, the evidence is
> unclear.
>
> However, even if pyrethroid house spraying were comparably
> cost-effective as DDT in one or a few cases, this does not mean that it
> will be in all cases, or that DDT is no longer needed. The problem, as
> always, is the tremendous diversity of malaria ? four Plasmodium
> species; thirty-five species of malaria-transmitting mosquitoes; and
> different local conditions everywhere ? a diversity so great that it is
> dangerous to say, after only a few studies, that pyrethroids can always
> substitute for DDT?s remarkable cost-effectiveness. For instance, if we
> ban DDT, what would we use in locales where mosquitoes are resistant to
> pyrethroids? Alternating between DDT and pyrethroids can avoid this
> resistance in the first place. In short, it would be absolutely
> imprudent to have only the single arrow of pyrethroids in our quiver to
> fight malaria.
>
> The diversity of malaria also requires that we be cautious with
> pyrethroid-based metho other than indoor house spraying. Scientists have
> tried hanging pyrethroid-dipped cloths over doors and windows, or
> soaking mosquito bednets in pyrethroids. Sometimes these strategies are
> comparably cost-effective as DDT house spraying. But again, success
> depends on the local ecology, mosquitoes, and socio-economic factors.
> Take pyrethroid-dipped bednets: these can dramatically reduce childhood
> deaths from malaria. But how can nets ever work in areas where people
> are too poor to buy nets (at $5-10 each); how can a net help where the
> local climate makes it unbearably hot to sleep under a net?
>
> While we believe the pyrethroids could one day largely substitute for
> DDT, we are not prepared to gamble with human lives by abandoning DDT
> outright. The diversity of malaria demands that we maintain an equal
> diversity of control strategies to fight the disease. If the world
> banned DDT today and later found that pyrethroids were sometimes, but
> not always, equally cost-effective or useful, the cost of this "mistake"
> in human lives would be too awful to contemplate.
>
>
>
> (2)?Alternatives other than insecticides
>
> Insecticides are not the only way to control malaria. Drugs, vaccines
> and environmental modifications can work to varying degrees. As always,
> which strategies work best depends on the local features of the disease.
>
> The difficulty with these options again is cost-effectiveness. Decades
> ago, a very inexpensive drug known as chloroquine was used, often
> together with DDT, in national campaigns against malaria. Today,
> chloroquine is increasingly ineffective throughout the world, and the
> replacement drugs are too expensive for many people in developing
> countries. Improving this situation will require a major, new
> committment from technologically developed countries. Not one major
> western pharmaceutical company is researching drugs for malaria, and the
> world?s most productive malaria drug laboratory (belonging to the US
> Army) is having its budget cut. In short, the future of malaria drugs
> remains questionable so long as developed countries do little to support
> drug research.
>
> Vaccines are even less promising in the foreseeable future. Despite what
> the press sometimes reports, there is no commercial malaria vaccine. A
> few vaccines have been tried in humans, but they all have severe
> limitations: they only work against malaria strains of a particular
> region (a global vaccine doesn?t exist); and they protect only about 30%
> of those vaccinated from disease, for a year or two at most. Technology
> has a very long way to go before vaccines are practical tools of malaria
> control, and at the current, poor level of research funding, developed
> countries are barely advancing vaccine technology. Even if scientists
> tomorrow discovered a cheap, effective vaccine that gave lifelong
> protection (a huge "if") on past experience it would take a decade, or
> decades, to vaccinate people worldwide.
>
> Finally, there is environmental control for malaria. World Wildlife Fund
> advocates planting trees to dry out wet areas, and introducing fish that
> eat mosquitoes, among other ideas. Environmental controls are probably
> best suited to areas where malaria transmission is moderate -- but much
> of Africa, Asia and South America is not like this. Where people receive
> hundreds of infected mosquito bites yearly, or the wet season brings
> great monsoons, environmental controls are likely to be overwhelmed. And
> even where they work, environmental controls can be very expensive.
> Thus, while environmental controls deserve more research, they cannot
> presently substitute for DDT.
>
>
>
> CONCLUSIONS AND RECOMMENDATIONS
>
> Today, there are no alternatives that can substitute for DDT in all
> cases. This is because of the diversity of the disease. There is no
> doubt that some alternatives can substitute in some areas, or even
> improve on DDT in other areas, but we cannot be sure that if we ban DDT
> there will always be an effective and affordable alternative. Yet there
> are good environmental reasons to eliminate DDT as soon as possible. The
> essential matter, therefore, is to test and implement alternatives
> before a DDT ban comes into force. Otherwise, we are gambling with human
> lives.
>
> Developing countries should consider that Western countries have an
> ethical duty to research and implement these alternatives. A 1996 study
> put total global spending on malaria research at only $84 million. For
> the price of only a single Stealth Bomber (the United States has
> twenty), the global malaria research budget could be sustained for two
> decades -- an interval in which over 50 million people will die from the
> disease. Other Western countries are equally guilty of neglecting
> malaria research.
>
> If Western countries do not commit the resources to test pyrethroids,
> develop malaria vaccines, distribute drugs, or provide the tropical
> world with bednets, why should they dictate the terms of a DDT ban?
> Western countries want a DDT ban because DDT is transported by
> atmospheric phenomena to northern latitudes, and it is there that the
> environmental problems are most serious. They should, accordingly, pay
> for it. We recommend that African countries reject any firm timeline to
> ban DDT, whether in 2007 or at a later date, unless given guaranteed
> funding to develop and implement alternatives to DDT for public health.
> Funding under the POPs Treaty should support research and control
> efforts in developed and developing countries alike, and should include:
>
> 1.?Biomedical research to develop drugs and vaccines.
>
> 2.?Development aid to make future drugs or vaccines affordable in the
> developing world.
>
> 3.?Development aid to finance alternatives such as pyrethroids or bednets.
>
> 4.?Technical aid to train health workers in the safe handling and use of
> alternatives such as pyrethroids.
>
> 5.?Clinical research and disease surveillance to prove that whatever
> alternatives a country adopts in place of DDT are equally effective.
>
> It will take all these steps to conquer malaria and ban DDT safely.
> Please demand this in the POPs Treaty negotiations.
>
> We wish you the best of luck in defending your country?s interests in
> the POPs Treaty negotiations, and hope our information has been helpful.
> We would also be very glad to hear from you, and to work with you on
> developing your country?s negotiating position on DDT. Please do not
> hesitate to write us if we may be of assistance.
>
> Sincerely,
>
> [Names of Signatories]
>
>
>
> REFERENCES
>
> World Health Organization, The World Health Report 1996 (WHO, Geneva,
> 1996), p. 47.
>
> World Bank data, as tabulated in World Development Report 1993:
> Investing in Health (Oxford University Press, Oxford, 1993), p. 216-9.
>
> Roberts, D. and Andre R.G. (1994), "Insecticide resistance issues in
> vector-borne disease control", American Journal of Tropical Medicine and
> Hygiene 50:21-34.
>
> J.A. Nájera, R.L. Kouznetov and C. Delacollette, Malaria Epidemics:
> Detection and Control, Forecasting and Prevention (World Health
> Organization, Division of Control of Tropical Diseases,
> WHO/MAL/98.1084/English), p. 39. The authors are referring to indoor
> house spraying generally.
>
> J. Mouchet et al. (1998), "Evolution of malaria in Africa for the past
> 40 years: impact of climatic and human factors", Journal of the American
> Mosquito Control Association 14(2):121-30; D. Roberts et al. (1997),
> "DDT, global strategies and a malaria control crisis in South America",
> Emerging Infectious Diseases 3(3):295-302, available at
> http://www.cdc.gov/ncidod/EID/vol3no3/roberts.htm
>
> Ibid.
>
> International Agency for Research on Cancer, World Health Organization,
> DDT and Associated Compounds, IARC Monographs volume 53 (1991). Updated
> conclusions (1997) appear on the internet at
> http://193.51.164.11/htdocs/Monographs/Vol53/04-DDT.HTM
>
> DDT is therefore less of a cancer risk than other POPs such as dioxin,
> which is "carcinogenic to humans", or PCB, which is "probably
> carcinogenic to humans".
>
> The following are examples of "possibly carcinogenic" drugs: Bleomycin
> (an anti-cancer drug), Metronidazole (an anti-parasitic drug), Phenytoin
> (an anti-convulsant); and Progestogen (a contraceptive). There are also
> "probably carcinogenic" drugs: Chloramphenicol (an antibiotic);
> Cisplatin (an anti-cancer drug). Finally, there drugs that are
> definitely "carcinogenic in humans": Chlorambucil (an anti-cancer drug);
> Ciclosporin (a drug for organ transplants); Methoxsalen (a skin drug).
>
> Gladen, B.C. and Rogan W.J. (1995), "DDE and shortened duration of
> lactation in a northern Mexican town", American Journal of Public Health
> 85(4):504-8.
>
> Kornbrust, D. et al. (1986), "Effects of
> 1,1-dichloro-2,2-bis[p-chlorophenyl]ethylene (DDE) on lactation in
> rats", Journal of Toxicology and Environmental Health 17(1):23-36.
>
> Rogan, W.J. et al. (1987), "Polychlorinated biphenyls (PCBs) and
> dichlorodiphenyl dichloroethene (DDE) in human milk: effects on growth,
> morbidity, and duration of lactation", American Journal of Public Health
> 77(10):1294-1297.
>
> World Wildlife Fund, Resolving the DDT Dilemma: Protecting Biodiversity
> and Human Health (Toronto and Washington DC, 1998), pp. 12-15.
>
> Ibid.
>
> Wolff, M.S. et al. (1993), "Blood levels of organochlorine residues and
> risk of breast cancer", Journal of the National Cancer Institute (USA),
> 85(8):648-52; Krieger, N, Wolff, M.S. et al. (1994), "Breast cancer and
> serum organochlorines: A prospective study among white, black and Asian
> women", Journal of the National Cancer Institute (USA), 86(8):589-99.
>
> Hunter, D.J. et al. (1997), "Plasma organochlorine levels and the risk
> of breast cancer", The New England Journal of Medicine, 337(18): 1253-1258.
>
> Longnecker, M.P. et al. (1997), "The human health effects of DDT and
> PCBs and an overview of organochlorines in public health", Annual Review
> of Public Health, 18:211-44; Lopez-Carrillo et al. (1997),
> "Dichlorodiphenyltrichloroethane serum levels and breast cancer risk: a
> case-control study from Mexico", Cancer Research, 57(17):3728-32; Van?t
> Veer P. et al. (1997), "DDT and postmenopausal breast cancer in Europe:
> case-control study", British Medical Journal, 315(7100):81-5; Schecter
> A. et al. [including M.S. Wolff] (1997), "Blood levels of DDT and breast
> cancer risk among women living in the north of Vietnam", Archives of
> Environmental Contamination and Toxicology, 33(4):453-6; Hunter D.J. et
> al. [including M.S. Wolff] (1997), "Plasma organochlorine levels and the
> risk of breast cancer", New England Journal of Medicine, 337(18):1253-8.
>
> See the study by Schechter et al, ibid.
>
> See Roberts, footnote 5 above. The comparison remains extreme even if
> one assumes a population density typical of a nation like Tanzania (33
> persons per square kilometer). In that case, 13.2 persons would occupy
> the same 40 hectares of this cotton field, making up perhaps three
> families in three homes. Spraying those homes would require about 1.4
> kilos of DDT; the cotton field still requires 560 times as much.
>
> Ibid.
>
> World Wildlife Fund report, footnote number 13 above, recommendation
> number 4, page 43.
>
> While DDT is manufactured in developing countries, pyrethroids are made
> only by multinational chemical companies. Pyrethroids therefore sell at
> higher prices, which could readily explain why Western chemical
> companies -- and their governments -- favour a DDT ban.
>
> J.A. Rosendaal (1997), "Vector control, methods for use by individuals
> and communities" (World Health Organization, Geneva).
>
> Charlwood, J.D. et al. (1995), "A field trial with Lambda-cyhalothrin
> for the intradomiciliary control of malaria transmitted by Anopheles
> darlingi root in Rondonia, Brazil", Acta Trop 60(1):3-13.
>
> J. Voorham (1997), "The use of wide-mesh gauze impregnated with
> lambda-cyhalothrin covering wall openings in huts as a vector control
> method in Suriname", Rev Saude Publica 31(1):9-14; Wu, N. et al. (1993),
> "Field evaluation of bednets impregnated with deltamethrin for malaria
> control", Southeast Asian Journal of Tropical Medicine and Public Health
> 24(4);664-71.
>
> Wirth, D.F. and J. Cattani, "Winning the war against malaria",
> Technology Review (Massachusetts Institute of Technology, August 1997).
>
> The preferred drug is now mefloquine (Lariam), which sells for about
> US$5 a treatment. Newer drugs, such as artemether, can cost about $15:
> M. Day (1997), "Is the African launch of a new malaria drug premature?",
> New Scientist (November 22, 1997), p. 18.
>
> National Academy of Sciences (USA), America?s Vital Interest in Global
> Health (1997), p. 36.
>
> The Walter Reed Army Institute of Research, which invented 3 of the 4
> leading malaria drugs since World War Two, now receives only $5 million
> a year from the US Government for malaria drug work.
>
> D. Kwiatkowski and K. Marsh (1997), "Development of a malaria vaccine",
> Lancet 350(9092):1696-701; Graves, P.M. (1998), "Comparison of the
> cost-effectiveness of vaccines and insecticide impregnation of mosquito
> nets for the prevention of malaria", Annals of Tropical Medicine and
> Parasitology 92(4):399-410.
>
> The United States Army and Navy, which have the leading malaria vaccine
> laboratories in the world, together spend only about $5 million a year
> on malaria vaccine research.
>
> The polio vaccine was discovered in the 1950s, yet global vaccination to
> eradicate polio only began in 1988 ? three decades later. The disease
> will not be eradicated before the year 2000.
>
> World Wildlife Fund report, footnote 13 above, pp. 27-28.
>
> There is little data on the cost of environmental control of malaria.
> The World Bank estimates environmental control of dengue fever, a
> mosquito-borne disease which is less virulent than malaria, costs
> several thousand dollars per year of life saved: World Development
> Report 1993 (Oxford University Press, 1993), page 62.
>
> The Wellcome Trust (1996), Malaria Research: An Audit of International
> Activity (Wellcome Trust, London).
>
>
>
>
>