The DDT debate: balancing malaria control against environmental harm

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The chronology of DDT opposition

The reasons why DDT should be banned worldwide

The alternatives to DDT

In this work, we present a rigorous debate on why DDT should be banned world wide and better and sustainable strategies employed in managing the global malaria deaths and complications. This is conducted with a discussion on the effectiveness of non-DDT-based solutions as well as the suitable methods of implementing non-DDT-based solution to the malaria problem

The DDT debate is one of the most controversial debates in the contemporary society and academia that is seen to present a possible clash in views in the domain of science, technology as well as society in general (Easton,2005). This is because DDT a chemical for controlling the spread of malaria by the elimination of mosquitoes is noted to be effective it combating the spread of malaria worldwide while presenting a health dilemma in regard to its hazardous nature in an almost equal measure. In this paper we present the debate that its is ethical and appropriate to ban the substance in the face of science, technology and the society in general.

Background information

Malaria is a disease which affects the blood and is caused by a bite from the female anopheles mosquito. Davrouzou et al. (2011) indicated that the disease causes more than 2.7 million cases of death annually. Malaria has no known vaccine that can effectively be used to cure it. The only viable solution of managing malaria-related deaths is the eradication of the causative agent-mosquitoes.

Dichlorodiphenyltrichloroethane (DDT) was initially used as an insecticide by a scientist, Dr. Paul Herman Muller in 1939.It is worth noting that he was not the very first person to make the chemical. He was however the very first person to discover and use it as an insecticide. This was when he realized that DDT could kill insects and other sorts of bugs (Davis, 1971). The insecticide, DDT, was employed in the killing of various insects which cause diseases such as malaria, body lice as well as typhoid fever. The use of DDT as an insecticide helped in reducing the malarial infection cases in the United States as well as South Africa. The United States of American in 1951, considered malaria to be eradicated as a consequence of using DDT.

The chronology of DDT opposition

In 1962, an aquatic biologist by name of Rachel Carson created a public awareness on the dangers associated with the use of DDT in her famous book, Silent Spring (Carson,1962). In her book, she outlined several negative effects that DDT had in birds and aquatic life (fish). Her work indicated that DDT was the cause of poisoning witnessed in bald eagles, various fish species and other smaller animals as pointed out by Davis (1971).

Sooner or later, other environmentalists and lobby groups started to speak out in opposition of DDT usage.1967 saw several organization proceed to file law suits aimed at restricting the use of DDT. The usage of DDT was eventually limited in 1969. In 1970s, the Environmental Protection Agency (EPA) was established. In1972, the environmental watchdog placed a ban on the use of DDT (EPA,1975). This was as a consequence of the chilling allegation and claims contained in the controversial work of Rachel Carson in her book Silent Spring (Carson,1962). Carson argued that DDT was causing cancer in children while killing wildlife. This was however discovered to be false since reports as well as statistics indicated otherwise (EPA,1975).

The banning of DDT from agricultural use globally was under the Stockholm Convention. It is worth noting that its limited application in disease vector control persists to date and remains controversial (Kim,2007;Bill,2007).

Other than the Endangered Species Act, the ban of DDT by the U.S. is indicated by scientists as a main factor in the observed comeback of the previously endangered bald eagle, a bird of national stature in the U.S. (Stokstad,2007)

It is worth noting that DTT had for quite along time been considered to be a wonderful chemical from the time it started being used after World War II. The chemical became preferred in the fight against insects as a consequence of its high level of toxicity to the nervous system.It is a very strong nervous poison. The main advantage which was believed that it had at that time over the other chemicals is that it was harmless to humans. The implication was that it cloud be applied in the control of the insects without any form of a health backlash to humans. The chemical was sprayed on landing sites during World War II so as to prevent the Allied troops from being infested with lice and other insects.

The chemical was successfully employed in the control of the spread of other epidemics such as typhus-carrying lice. The chemical was also successfully employed in combating yellow fever, elephantiasis as well as typhus through the control of the insects that harbor these diseases. Easton (2005) pointed out that the most successful application of DDT was noted to be in the control of over sixty mosquito species that spread the malaria parasite.

DDT has always been employed in combination with other less effective measures such as draining of swamps. The chemical was used in developing and developed countries such as U.S., Europe, Australia and Japan in the eradication of malaria.

The use of DDT was indicated to be very effective in the eradication of malaria. For instance, in India and Sri Lanka, the chemical worked impressively. In India, it reduced the number of mortalities from 800,000 to nearly zero while in Sri Lanka it reduced the number of deaths from about 2.8 million to about 17 (Harrison,1978).

The alternatives to DDT

Prior to the adoption of DDT as an insecticide, malaria was eradicated successfully in the tropical regions by the removal as well as poisoning of their breeding grounds and the larva habitats. An example is the filling and the application of oil to stagnant water. The unfortunate thing is that these methods have rarely been applied in places such as Africa for along time (Killeen et al.,2002).

It is worth noting that the effective of Indoor Residual Spraying (IRS) with DDT or any other suitable alternative when compared with other control techniques for malaria ( such as impregnated bed nets as well as improved access to anti-malarial drugs) shows great variation and is dependent on the specific local conditions (Sadasivaiah, et al.,2007)

A study by the World Health Organization revealed that the mass distribution of the impregnated mosquito nets (insecticide treated) as well as artemisinin-based drugs led to a reduction in the number of deaths in Ethiopia and Rwanda, two countries which had a high level of malaria burden. The use of Indoor Residual Spraying (IRS) with DDT is noted to have not played a role in the reduction of mortality in these countries (WHO, 2008; Brown,2008)

Vietnam is also noted to be enjoying a decline in the number of malaria cases a fact which has resulted in a 97% reduction in the mortality rate after they abolished the use of DDT in their anti-malarial campaign to a program which is based on the prompt treatment, pyrethroid based insecticides as well as bed nets (WHO,2000).

In Mexico, there has been the adoption of affordable and yet effective chemical as well as non-chemical strategies for the control of malaria and their success leas to the shut down of various DDT manufacturing plants in Mexico due to a general lack of demand for DDT (IPEN,2008).

Discussions

Even though there has been a general increase in the number of malaria mortalities as a consequence of DDT ban, several other factors are noted to have played part in the rise in the number of cases. Goodman and Mills (1999) reviewed 14 studies on the effectiveness of malaria in sub-Saharan Africa that discussed insecticide-treated nets, chemoprophylaxis for the young children, residual spraying, intermittent treatment of the expectant mothers, hypothetical vaccine as well as changing frontline drug treatment. Their work indicated that the general lack of information lead to poor decision making on the cost as well as the outcomes of various interventions. Their work indicated that there is little data on the cost-effectiveness' of the various malaria control techniques. Lack of evidence on the effects as well as costs of the packages of measure were pointed out. The work indicated that the cost-effectiveness estimates of spraying DDT were never accurate and the obtained estimates were never good predictots of the level of cost-effectiveness of the existing programs.

Another study carried out in Thailand indicated that the cost per case of malaria prevention by means of DDT spraying method was 21% more than the cost per case of the prevented malaria by means of lambda-cyhalothrin -- treated nets (Kamolratanakul, et al.,2001).This cast a lot of doubt on the proposition that DDT is the most cost-effective method of preventing malaria. Similar results were obtained in Mexico when then director of Mexico's control program for malaria declared that it is close to twenty five percent cheaper to spray houses with pyrethroid-based sprays as opposed to DDT base ones.

As suggested by Corin and Weaver (2005), amore comprehensive approach of evaluating the cost-effectiveness as well as efficacy of a given malarial control program is multifactorial . This is because it should not just measure cost in monetary terms but also the total number of saved lives and the level of ecological damage as well as effects on human health. Corin and Weaver (2005) pointed out that the detriment nature of DDT to the environment and human health exceeds the beneficial decline in the cases of malaria. The benefits are noted just to be higher in an epidemic scenario.

Barat (2006) compared a total of four highly successful malarial control programs in Brazil, Vietnam, Eritrea and India indicated that non-of the programs endorsed a given single strategy. They however mentioned the various success factors that included; conducive conditions in a country, a targeted and yet technical approach that employed a package of highly effective tools, good leadership, community involvement, control of finances, decentralized form of implementation, technical as well a programmatic support from various a partner agencies a s well as adequate financing.

Curtis (2009) indicated that mosquitoes which are resistant to DDT are generally susceptible to the synthetic and natural pyrethroids.

Recommendation

For the sake of sustainability, it is better to ban DDT since it might save life today and harm lives tomorrow due to that fact that it acculturates in the body and then gets transmitted along the food chain. It is necessary for the cheaper and more effective alternatives to be promoted and adopted at the individual, organizational and national level. This means that people must learn how to live with malaria rather than how to eradicate it totally since that is close to impossible.

Governments must therefore encourage the non-DDT-based malarial control strategies by;

Doing away with the taxes as well as tariffs levied on bed nets, pesticides as well as antimalarial drugs. The government must also emphasize on the adoption of appropriate and effective technologies such as the use of affordable and culturally acceptable plants to repel Anopheles mosquitoes.

Conclusion

DDT usage should be banned worldwide due to its bad effects on human and the environment (fish and birds). However, in emergency situations such as a malarial epidemic, it can be used in controlled amounts as suggested by McGinn (2002). Malaria is a terrible disease which can wipe an entire generation if not well controlled. It is therefore the role of everyone in the community to work towards ensuring that the global malarial epidemic is eliminated of means of affordable and yet sustainable solutions '