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HEALTH-LATIN AMERICA:
Much-Maligned DDT
Still Has Supporters
Diego
Cevallos* - Tierramérica
MEXICO CITY, (IPS) - DDT is one
of the 12 substances known as
persistent organic pollutants
that the international community
has targeted for urgent
elimination. But this
insecticide, which before
falling out of favour prevented
millions of deaths and inspired
a Nobel Prize, may yet have a
long life ahead of it.
For many countries, DDT (dichloro-diphenyl-trichloroethane)
is still an ''effective and
affordable'' weapon against
malaria, according to United
Nations agencies.
Malaria is transmitted through
mosquito bites, infecting 300
million people worldwide each
year, and killing more than a
million people, especially in
Africa.
Latin America feels the impact
of the disease as well. More
than a third of the region's
population lives in at-risk
zones, and each year 1.4 million
people, mostly children, are
infected. According to figures
from the Pan-American Health
Organisation (PAHO), more than
105 million dollars are spent
annually to combat malaria.
Some observers attribute the
devastating effect of malaria to
the limitations imposed by
governments and
environmentalists on the use of
DDT, a broad-spectrum
insecticide, patented in 1937 by
Swiss chemist Paul Mueller.
The effectiveness and
long-lasting properties of DDT
prevented massive crop losses
and staved off hunger in
developing countries, so much so
that Mueller won the 1948 Nobel
Prize in Medicine.
But the world was put on guard
against DDT in the 1970s when
some studies suggested that it
is carcinogenic, leads to
premature births, contaminates
food and causes neurological,
respiratory and cardiovascular
harm to the human body.
Other insecticides were
developed and marketed, but all
were more expensive.
''No study is conclusive about
the harmful effects of DDT, but
based on the precautionary
principle and the apparent
pressure from some big companies
that produce insecticides (that
compete with DDT) it was agreed
to limit its use,'' Américo
Rodríguez, a scientist with
Mexico's Malaria Research
Centre, told Tierramérica.
DDT ended up on the list
included in the Stockholm
Convention on Persistent Organic
Pollutants (POPs), an
international instrument signed
in 2001 to restrict and
eliminate the use of 12
substances worldwide. POPs have
a strong tendency to accumulate
in the fatty tissue of animals
and spread throughout the food
chain.
The Convention authorises DDT
use exclusively for fighting the
vectors of diseases, under the
guidelines of the World Health
Organisation.
The countries that signed the
Stockholm Convention must decide
if this should continue to be
the case. They have a chance to
take up the matter this week, as
representatives are gathered in
the Uruguayan Atlantic resort of
Punta del Este through May 6.
The United Nations Environment
Programme (UNEP), the driving
force behind the Convention,
called for caution on the DDT
question.
UNEP documents drawn up for the
purpose of the Uruguay meeting
indicate that the participants
could conclude that ''until
safe, affordable and effective
alternatives are in place,
governments can continue using
DDT to protect their citizens
from malaria -- a major killer
in many tropical regions.''
UNEP executive director Klaus
Toepfer has weighed in on the
issue as well, saying that
unless more ambitious
investments are made in the
search for better vaccines
against the malaria parasite and
better pesticides and methods
for fighting against the vector
mosquitoes, it will be many
years before DDT is completely
eliminated.
Every year a total of 7,500
tonnes of DDT are sprayed on the
interior walls of homes. It is a
relatively cheap and effective
way to repel and kill the
mosquitoes that transmit
malaria.
In Latin America, several
countries consider DDT their
best weapon against a potential
epidemic. Ecuador, for example,
will ask the Convention this
week in Punta del Este that the
insecticide not be eliminated
from the market -- at least for
now.
Ecuador wants to be able to
utilise DDT ''at least in the
next few years,'' until the
country's officials and
scientists are able to develop
integral alternatives to combat
malaria, Ricardo Tapia,
coordinator of the POPs project
financed by the UN, told
Tierramérica.
In the Andean nation, which
reported 52,000 malaria cases in
2003, DDT has not been used
since 1990, but the authorities
don't want to lose the option to
do so if a true health emergency
were to occur.
In 2001, Venezuela and Costa
Rica had requested authorisation
from the UN to continue using
DDT in controlling malaria
mosquitoes. Brazil, however,
requested permission to use it
in the production of dicofol, a
pesticide applied in citrus
groves.
So far this year, Venezuela has
recorded 11,000 malaria cases,
but the environmental health
director at the Venezuelan
Health Ministry, Jesús Toro,
said in a conversation with
Tierramérica that his country
halted DDT use in 1994, and will
not be seeking authorisation to
renew use.
However, reports from UNEP and
from the non-governmental
RAP-AL, a Latin American
pesticide alternative action
network, indicate that the
substance was indeed used in
Venezuela in recent years.
Guatemala, meanwhile, is
resoundingly opposed to
application of the insecticide.
''The use of DDT should not be
permitted,'' Rodolfo Zeissing,
head of the Guatemalan Health
Ministry's malaria programme,
said in a Tierramérica
interview.
''Guatemala's position is
against DDT use because it is
harmful to the environment due
to the persistence of its
residues in the soil for many
years. This leads to
contamination throughout the
food chain, through soil, the
grass consumed by cattle, milk
from cows and human breast
milk,'' he said.
In this Central American
country, where more than 14,000
cases of malaria were reported,
DDT has not been used since the
1970s, according to official
sources, But NGOs say there is
evidence in Guatemala, as in
many other countries in the
region, of agricultural
application of the pesticide,
obtained as contraband.
Some 14,500 tonnes of the
insecticide are being stored in
precarious conditions in
Guatemala, which leads some to
fear an accident that would
release the toxin. Zeissing
notes that support from experts
and from PAHO is necessary to
eliminate DDT from his country.
Most Latin American and
Caribbean governments state that
in their efforts to fight
malaria they follow the
recommendations of international
experts, applying a set of
measures that include
alternative insecticides to DDT,
sanitation supports, case
follow-up, mosquito netting,
community efforts and timely
medical attention.
But in the opinion of David
Reyes, the RAP-AL representative
in Ecuador, that is not
necessarily true. There are
cases in which health
authorities are fighting the
malaria vectors using
ineffective means, he said.
The impact on human health of
alternative pesticides could be
serious if there are not
sufficient safety controls.
''Sometimes they fumigate right
over the people. It's an
outrage,'' said Reyes.
(* With reporting by Juan Carlos
Frías in Ecuador, Humberto
Márquez in Venezuela and Jorge
A. Grochembake in Guatemala.
Originally published Apr. 30 by
Latin American newspapers that
are part of the Tierramérica
network. Tierramérica is a
specialised news service
produced by IPS with the backing
of the United Nations
Development Programme and the
United Nations Environment
Programme.)
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