Subject: Nations agree use of DDT to fight malaria exceeds risks------
Date: Wed, 10 Jan 2001 18:28:56 -0500
From: Stephen Tvedten <steve@getipm.com>
Organization: Get Set Inc. (www.getipm.com)
To: Paul Helliker <phelliker@cdpr.ca.gov>
Director, State
of California, Department of Pesticide Regulation
cc: Carol Browner browner.carol@epa.gov
Dear Mr. Helliker,
I thought you might like to read an article entitled: Nations agree use of DDT to fight malaria exceeds risks.
By JEAN LEBEL © Earth Times News Service
Canada and 121 other countries negotiated a landmark
anti-pollution treaty late last year, and bargained DDT right off the list of
immediately banned poisons. The treaty is all the better for that. DDT is a
widespread and pernicious menace, and must be banned completely. But not yet.
The insecticide DDT is one of the 12 nasty chemicals
addressed by the new global treaty on POPs or persistent organic pollutants.
The treaty, once in force, would subject most of these poisons to an immediate
ban. DDT was exempted, after long argument and only for the control of
malaria, until cheap, effective and safer alternatives can be developed.
Notwithstanding DDT's dreadful dangers, the POPs treaty
represents a fair compromise for the moment. What's needed now is well-funded
research, to find better strategies against malaria and the suffering it
causes.
DDT for agricultural use has been banned for years almost
everywhere and for powerful reasons. The chemical and its breakdown residues
(especially one known as DDE) have done proven damage to wildlife around the
world. Canada's bald eagle and peregrine falcon populations were ravaged by
DDT's damage to shells and embryos. There are disturbing possibilities that
DDT harms humans too with suspected links to breast cancer, liver cancer, and
disturbances to embryo development and reproduction.
Meanwhile, however, since the 1940s DDT has become the
weapon of choice against malaria. It is an affordable, readily supplied and
instantly lethal poison to the mosquitoes that carry the malaria-causing
protozoa. DDT application, typically on the inside walls of houses where the
disease is endemic, indisputably saves lives.
Some of the harms of DDT are proven. Other risks are
still insufficiently understood by scientists. All are insidious: The damage
can emerge years after DDT is introduced into the environment, and can appear
tens of thousands of kilometers away as airborne residues migrate across
hemispheres.
Considering the known and suspected dangers to human
health and the environment, it would be nice to be able to ban DDT
immediately. But banning it, without providing adequate alternatives, would be
ruinously unfair to those who suffer worst from malaria, the poor, in poor
countries.
In fact, malaria rates are already rising. Next year
alone, it is predicted, one million or more children will die of this single
disease. Infection rates have increased in part because of reduced
applications of DDT already, and in part because the parasitic protozoa and
mosquitoes quickly develop resistance to the drugs and chemicals used against
them. (This is another reason to find replacements for DDT: It can lose
effectiveness as mosquitoes produce new generations resistant to the spray.)
So it is true to say that DDT saves thousands of lives
every year. It is also true to say that the people who contract and die of
malaria are mostly poor. Cutting off supplies of DDT, without first providing
safe and efficient alternatives, would count as a real blunder and an
injustice.
And that is our dilemma. DDT is an environmental toxic
that honors no borders. Tissues of mammals in the Canadian Arctic, and of the
humans who eat them, show accumulated DDT metabolites that originated with DDT
sprays in the tropics. But in the malarial areas of Latin America, Africa and
Asia, people desperately need DDT as a matter of life and death.
How to escape the dilemma?
First, we have to rethink the supposed contradiction
between environmental protection and human health. A pollutant so violently
deadly to the natural environment cannot, in the end, be dismissed as benign
to human animal. If only as a precaution against a terrible future outcome, we
should consider human and environmental interests to be the same.
Second, we have to recognize malaria as a deeply complex
interaction between the parasite as cause, the mosquitoes as vectors, and
humans (we supply blood to the mosquito and our livers as breeding places for
the parasite). The best anti-malaria strategies will therefore address three
components: the human, the mosquito, and the environment in which the disease
persists.
Sprayed on walls, DDT works by killing mosquitoes on
contact. But there are alternatives, different chemicals, and different spray
technologies that apply chemicals with better effect at lower quantities. In
Mexico, for instance, Canadian supported research is experimenting with
chemicals called pyrethroids; new spraying techniques could bring pyrethroid
costs down to DDT levels, if environmental effects can be mitigated. In
Africa, success has been achieved in some communities by dipping bednets in
pyrethroids low-cost alternative in some cases, but one that needs active
community involvement.
Drugs work against malaria by killing the parasite in the
human host and by creating immunity. But again, protozoa soon breed
generations resistant to each new drug that comes along. And each new drug
tends to carry a higher price than the one before. One promising response, now
being tested, is the distribution of diagnostic "dipsticks" that
detect malarial infection instantly from a drop of blood and so direct
expensive drug therapy only to those who need it. An over-arching problem here
is that pharmaceutical firms are not much interested in researching new drugs
when most of the would-be customers are too poor to pay.
Environmental responses to the malaria challenge have
hardly been explored yet, but hold great promise. Example: A bacterium known
as Bti (for Bacillus thuringiensis var israelensis) eats mosquito larvae in
water. Easily propagated, harmless to humans and livestock, naturally
occurring, but it is altogether environment-friendly except to mosquitoes.
Researchers in Peru have developed a Bti kit for village distribution. Still,
cost is an obstacle to mass application.
Complex problems demand complex solutions. That's not a
welcome truth to policy-makers, or to single-issue advocates for DDT
abolition. All these strategies for mosquito control, drugs, environmental
approaches, with community participation need time and money to be tried and
succeed. In principle, that is what the new POPs treaty provides: time, and he
commitment of rich governments (including our own) to help finance the phasing
out of these globally destructive pollutants. Banning DDT must be part of that
effort. But not yet.
Jean Lebel, Ph.D., is an Environmental Health Specialist
in the Ecosystem Approaches to Human Health Program of Canada's International
Development Research Centre (IDRC). In the past 30 years, IDRC has contributed
more than $10 million to malaria-control research in developing countries.
Copyright © 2000 The Earth Times All
rights reserved.
Well Mr. Helliker,
It seems amazing to me, that after contaminating the entire earth with
DDT and other "registered" POISONS since 1942 (supposedly to
"control" mosquitoes and Malaria) to the extent that your
"registered" POISONS "can
appear tens of thousands of kilometers away as airborne 'residues'," so
much so that they and/or their metabolites are "normally" found in
all living tissue/blood - most people would eventually get the idea that your
"registered controls" are obviously not "effective"
because they are obviously NOT
working! The pests are obviously
immune or resistant and the poor people are STILL dying from Malaria! In addition your "cure" has a "few other
problems": "A pollutant
so violently deadly to the natural environment cannot, in the end, be
dismissed as benign to human animal."
If I may be so bold, "Isn't it time to try some safe and far more
effective (unregistered) alternatives? You
do not have to wait "until cheap, effective and safer alternatives can be
developed", unless you are waiting for the POISON "industry" to
develop more "registered" POISONS and not alternatives. If you are - then more innocent people will continue to die
and the earth will have more contamination and we will STILL have both the
mosquitoes and the Malaria!
Respectfully, Stephen
L. Tvedten
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