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Avoid customary weakness by re-introducing DDT for malaria
2008-04-07 09:37:11
By PETER TINDWA
The world over, efforts are being made to eliminate the use of Dichloro Diphenyl Tricholoroethane (DDT).
Question: Currently, there have been global efforts to get rid of the application of DDT.
Among non-governmental organizations taking part in the elimination of DDT is AGENDA. Briefly, can you say something regarding the global efforts?
Answer: Dichloro diphenyl tricholoroethane (DDT) is one of the 12 initial persistent organic pollutants (POPs) targeted for elimination by the Stockholm Convention on POPs, which was adopted in May, 2001 and entered into force in May, 2004.
All East African Community (EAC) member countries are parties to the Convention.
Kenya, Tanzania and Uganda as signatory parties to the Stockhom Convention on POPs have to develop or review legislation that would lead to domestication of the treaty and have effective implementation at the country level.
POPs are toxic chemicals that remain intact in the environment for long periods (several decades).
Q: How are they distributed?
A: They are widely distributed through the air and water, accumulate in the fatty tissue of living organisms and can thus, be passed along the food chain and are highly toxic to animals and humans.
These can also pass from mothers to their new borns and therefore, continue to harm different generations.
Q: Could you disclose their effects to humans?
A: Exposure to these toxins has been shown to increase the risk of cancer, hormonal imbalances, neurological disorders, infertility, diabetes, impotence and a weakened immune system, interfere with normal infant and child development.
Due to these detrimental effects to human health and the environment, DDT was banned in the United States of America (USA) and other developed countries in early 1970`s after being used for among other purposes malaria control programmes.
It was used to control malaria parasite carrying mosquitoes in a number of countries.
Tanzania and several other developing countries banned the chemical between early and mid 1990`s although there was no effective monitoring to make sure it was really stopped from use.
However, there is campaign to introduce DDT back as a silver bullet solution to malaria in Africa.
Q: Why NGOs, including yours are against any move to re-introduce the use of DDT in East Africa, especially in Tanzania?
A: Well, Tanzania has already stated its intention to re-introduce DDT for that purpose.
The advocates for DDT re-introduction say that ``malaria is killing people in Africa, but environmentalists care more about saving birds and are blocking the use of DDT to save people.
DDT wiped out malaria in the US., but is now being denied to Africans.
DDT is the best way to fight malaria. There are no health effects from DDT exposure and its use should be widespread.
The only accurate part of this story is that malaria does kill millions of people in Africa every year, a preventable public health tragedy of catastrophic proportions. The rest of the story is false.
cases where mosquitoes have not yet developed resistance, it won`t solve the malaria health crisis.
Technical expertise and better malaria control methods already exist in Africa. It`s only resources and political will that are lacking.
Public health experts, government experts and environment a lists around the world support the approach to DDT taken by the Stockholm Convention on POPs.
The treaty allows DDT exemptions for malaria control in countries that request it.
This approach recognizes that in some cases, DDT can be an effective temporary tool for malaria control.
Most importantly, the treaty also mobilizes desperately needed funds for malaria control and prevention, with an emphasis on safer, more effective alternatives and strategies that don`t further jeopardize the health of current and future generations.
When DDT was banned in the USA in early 1970\'s both health and environmental impacts were considered and more is known today about its effects.
DDT is classified by USA and international authorities as a probable human carcinogen.
Also reproductive disorders associated with DDT are well documented in animal studies meaning that it can equally affect human given its persistence nature and characteristic to bio-accumulate and bio-concentrate up the food chain.
One recent study clearly documented neurological effects-including developmental delays among babies and toddlers exposed to DDT in the womb.
Studies have also linked exposure to reduced breast milk production among nursing women, and USA researchers have found that the DDT breakdown product, DDE, can increase risks of premature delivery and reduced infant birth weights.
DDT and its breakdown products have also been found in human blood and breast milk in dozens of studies around the world.
The problem with DDT which has led to its failure is resistance among malaria-carrying mosquitoes.
Resistance was identified in Africa as early as 1955 and by 1972 nineteen species of mosquito worldwide were resistant to DDT.
Q: Could you tell the public why DDT gets its way in countries where it has been banned?
A: Due to lack of effective and close customs surveillance, which has been made worse by free trade agreements, there is a risk that when DDT is allowed for malaria control, it will find its ways to the farmers, who will go back to using the pesticide illegally.
Poor farmers would opt for the use of DDT because it is cheap, effective and can be easily smuggled from malaria control centres.
This will hastening the development of resistant mosquito populations, extend its impact to a larger human population and likely to denial of agricultural products to the world markets taking in mind residual effect of DDT on the produce.
Although there are claims that indoor spraying of DDT (sprayed on the walls inside homes) is harmless, the truth is completely its reverse. When it is sprayed the risk of exposure is very high.
Researchers in Mexico and South Africa found elevated levels of DDT in the blood of those living where DDT was used to control malaria and breastfed children in those areas received more DDT than the amount considered ``safe`` by the World Health Organization (WHO) and the U.N. Food and Agricultural Organization (FAO).
Evidence also shows that long-lasting residues from DDT house spraying seep into nearby waterways, creating additional pathways of exposure.
For example, elevated DDT levels have been found in cow`s milk in indoor DDT treatment areas.
In many countries, this adds to exposure from old stockpiles of DDT that are not properly contained or controlled.
FAO estimates that there are more than 100,000 tons of obsolete pesticide stockpiles in Africa, mostly older chemicals such as DDT.
Tanzania, however, has more than 350 sites with more than 1,200 tons of obsolete pesticides and veterinary drugs of which DDT makes large portion of the obsolete stocks.
From the effects associated with DDT use, we have to compare with some environmental and health consequences in Tanzania.
Recently, the Cancer Institute of Tanzania reported higher rate of increase in cancer cases from 1970`s also reports of decrease in fertility and immunity which can be associated with such toxic chemicals like DDT.
When we consider increase in malaria incidences, we have to as well consider effects of climate change, poor urban and house planning, change of life styles that provide for conducive breeding areas for mosquitoes and exposure to them, not only because we have stopped using DDT.
Consider breast feeding to the children. We all know that mothers` milk provides long protection to the young. How long the mothers` breast feed their children to provide for that protection?
There is a tendency among mothers nowadays to shorten the recommended breast feeding duration and frequency for babies and substitute with instant milk.
This means they subject their children to malaria and other diseases by denying them the natural protection from mother\'s milk.
Q: The advocates for re-introduction of DDT assert that millions of people will die without DDT. What is the truth as far as their argument is concerned?
A: The truth is that currently millions of people are dying and will continue to die, if there are no effective malaria control programmes.
The public health community learned long ago not to rely on any single solution in fighting this deadly disease, with failed reliance on DDT providing the original lesson.
Fortunately, experiences from some countries have shown that effective malaria control is possible and that it requires a real commitment of resources, integrated strategies and community participation.
There are several effective alternative success stories that have reduced malaria incidences without DDT.
In Mexico for example, they have succeeded in adopting an integrated approach to preventing and combating malaria which can be emulated by other countries.
The country (Mexico) was a major producer of DDT from the 1950s until 2000, when it completely eliminated its use.
It currently implements an integrated malaria control programme that includes community participation in cleaning out gutters and other sources of water where mosquitoes can breed as well as volunteer work to raise awareness of the disease and preventive medications.
The integral approach involving community participation is not simply a matter of replacing one chemical with another, but rather of developing a comprehensive strategy.
The integrated approach combines: Early detection of malaria cases and prompt medical treatment, community participation in notification of malaria cases and cleaning of streams and other sites where mosquitoes breed as well as low-volume chemical control with pyrethroid pesticides.
Other programmes may include efforts to cut down on mosquito breeding sites by draining swamps and protect the population by building well screened houses.
The World Wildlife Fund (WWF) has documented success where non-chemical approaches were demonstrated to be cost-effective such as the use of fish that eat the larvae of the mosquitoes that spread the disease.
Vietnam reduced malaria deaths by 97% and malaria cases by 59% when they switched in 1991 from trying to eradicate malaria using DDT to a DDT free malaria control program involving distribution of drugs and mosquito nets along with widespread health education organized with village leaders.
A program in the central region of Kenya is focusing on reducing malaria by working with the rice-growing community to improve water management, use livestock as bait, introduce biological controls and distribute mosquito nets in affected areas.
There are also alternative chemicals that can be used to fumigate homes like natural pyrethroid pesticides, which are considered ``non-persistent`` chemicals, meaning that they break down easily.
On the other hand we would be promoting pyrethrum market to our farmers and contribute to poverty reduction.
Clearly, what Tanzania and other countries fighting malaria need now is strong support for effective solutions, not more reliance on DDT. If we are serious about fighting malaria, what we need is realistic long-term funding for community-based control strategies combined with improved housing, basic sanitation and effective policies to fight poverty.
Therefore, it is very important for Tanzania to put in place an unambiguous policy on DDT and guidelines based on the demands of the Stockholm Convention for all signatory parties to the Convention.
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