Abstract
Dichlorodiphenyl trichloroehane (DDT) is an organic toxin that has insecticidal qualities. The following sections present arguments both for and against the ban of DDT worldwide. DDT is in fact, the pesticide to which the mosquitoes have developed the fastest resistance. Bed nets cannot eradicate malaria. However, it is widely believed that DDT works only by killing mosquitoes with its toxicity. There are claims that DDT leads to algae death. Alongside, it is DDT that comes to the rescue of poor people against malaria. Thus, it is a paradox in the context of banning DDT.
Introduction
Dichlorodiphenyl trichloroehane (DDT) is an organic toxin that has insecticidal qualities. Apart from being used as an insecticide in saving agricultural crops, it has also proved to be pretty effective in combating malaria. However, several studies have indicated the harmful effects of the pesticide both on ecology as well as environment. These concerns have forced the U.S Environmental Protection Agency to prohibit the extensive use of DDT in the year 1972. Gradually, other developed countries have also followed suit. Since then, more than 38 countries have either totally banned or reduced the usage of DDT. Of these, about 26 countries have completely stopped the use of DDT and in the remaining ones, its use is restricted (Boughton 2010).
This paper focuses on the issue that has assumed global importance because of its far-reaching consequences and has triggered an environmental debate- the banning of DDT worldwide. While some experts are of the opinion that the use of DDT should be prohibited globally, others are totally opposed to the move. This paper presents both sides of the argument and derives a possible conclusion by assimilating the different points of view.
Background
The credit for the discovery of the DDT goes to the famous scientist Paul Mueller who has been the first to observe its insecticidal qualities in the year 1939. The presence of certain chemicals in DDT has been able to reinforce the view that this substance would prove to be highly effective in countering certain deadly diseases.
DDT was first used during the World War II to arrest the rapid proliferation of typhus which is a disease caused by the body lice in Naples, Italy. Its instant success reinforced its effectiveness. During this period and even in the years following the World War II, it proved highly beneficial in safeguarding the human lives against malaria and other diseases borne by mosquitoes. In fact, the miraculous effect of DDT in saving the lives of millions of people fetched Paul Mueller the Nobel Prize for Medicine and Physiology in the year 1948 (Boughton 2010).
The use of DDT became highly popular not only because of its insecticidal qualities. The fact that it appeared to be less harmful to the users as compared to the pesticides used earlier like arsenic, cyanide, copper-sulphate, nicotine etc. made it a more viable option.
However, it was a documentary filmed by Rachel Carson titled “Silent Spring” (1961) that raised serious concerns regarding the harmful effects of DDT on ecology as well as environment. In the documentary, Carson captured the “footage of children at a picnic being engulfed in a cloud of DDT” (Oreskes 2010). Carson drew attention to the fact that the bioconcentration of the substance in the food chain caused serious reproductive failures in the higher animals. This, in turn, would disrupt the ecological balance.
Based on the concerns raised by the documentary, the Science Advisory Committee of the President recommended total elimination of the use of DDT over a short period of time. From 1957 onwards, restrictions were being imposed by the U.S government on the uses of DDT which finally culminated in the prohibition of its usage by the Environmental Protection Agency in 1972.
The United States has further strengthened its drive against DDT by signing the Stockholm Convention on Persistent Organic Pollutants (POP) along with 90 other nations on 24th May, 2001. The main aim of this treaty is to halt the use of DDT as well as all the other chemicals belonging to the same group. However, these resolutions have been met with strong opposition by certain environmentalists.
The following sections present arguments both for and against the ban of DDT worldwide. A senior researcher at the Worldwatch Institute, Anne Platt McGinn argues in favour of the move. On the other hand, Donald R. Roberts resists the campaign against DDT.
Reasons favouring the worldwide ban of DDT
Anne Platt McGinn raises concerns over the re-emergence of malaria in the last couple of decades that is gradually assuming a greater magnitude. Cases of malaria have been reported more in certain African nations which are more prone to this disease because of their geographical location. However, there are not many options available to combat the disease on a larger scale. Hence, reliance on the use of DDT persists.
She is against the use of DDT in any form because of its adverse ecological and environmental impact. DDT is called a persistent pesticide as it remains poisonous for a long time before breaking down into less poisonous substances. “Its impact can be judged from the fact that even to this day, it is one of the most common pesticides detected in the milk of nursing mothers” (Boughton 2010).
Moreover, it is fat-soluble, meaning that it easily accumulates in the fat of the animal instead of being excreted from the body. Naturally, when that animal is ingested by another animal, DDT also enters the body of that animal. In this way, the pesticide moves up the food chain. “Not only this, it also leads to the increased concentration of DDT in the higher animals” (Boughton 2010). Prolonged intake of this substance gives rise to certain physiological abnormalities in animals which disrupts the food chain and endangers human lives.
DDT is in fact, the pesticide to which the mosquitoes have developed the fastest resistance. Hence, although it has been hailed as a miraculous substance in countering malaria initially, it has failed to be equally effective later.
In the light of the above facts, McGinn (2002) opines that the disease cannot be combated by restricting the mosquito population but by adopting measures that would lead to its total eradication. She insists on the use of ‘bed net’ which is “… a mosquito netting that is treated with an insecticide, usually a pyrethroid, and that is suspended over a person’s bed” (McGinn 2002). Bed nets cannot eradicate malaria. But, since the Anopheles mosquito that causes the disease attacks in the evening and at night, bed nets would give the necessary protection against mosquito bites. This would help in drastically reducing the recurrence of the disease. Furthermore, bed nets help in arresting the spread of infection and reducing anaemia.
However, it has been found that in most malaria-prone areas of Central and South Africa, bed nets are rarely used. Even the available ones are subject to high tax rates.
McGinn believes that initiatives taken in the form of effective campaigns can successfully address this issue.
She refers to the Roll Back Malaria (RBM) campaign which started in the year 1998. WHO has taken the initiative in collaboration with the World Bank, UNICEF and the UNDP (United Nations Developmental Plan) (Boughton 2010).
The RBM campaign reiterates the importance of effective strategies to be implemented at the household and community level to achieve desirable results (Boughton 2010).
The strategies to be implemented include:
- Encouraging extensive use of bed nets and eliminating the taxes imposed on it.
- Applying appropriate technologies as per the requirements of the given situation. E.g. proper maintenance of home and surroundings can yield favourable results.
- Utilizing the existing networks not only to create awareness regarding the disease but also to arrest its expansion.
- Realizing the need to work on an organizational basis to curb its rapid outgrowth. The problem can be mitigated by realizing that malaria is not merely a health problem, rather, it has serious social, economic, environmental, agricultural as well as urban implications.
According to McGinn, these strategies, if properly implemented, can provide enough justifications for eliminating the overall usage of DDT worldwide.
Reasons against the worldwide ban of DDT
Donald R. Roberts, on the other hand, voices his concerns against the steps taken to ban DDT globally. He presents a series of arguments opposing the move. According to him, malaria is basically a rural disease and the alternative methods adopted to curb the disease in towns may not prove beneficial in the rural areas. He refers to the U.S. Public Health Service manual to elucidate his point there “there has been no economically feasible method of carrying malaria control to the individual tenant farmer or sharecropper…the DDT residual spray to walls” (Roberts 2005).
He argues that the large-scale campaigning against the use of DDT is the result of misinterpretation of science. In other words, a gross failure to understand the way DDT works has resulted in this confusion. It is widely believed that DDT works only by killing mosquitoes with its toxicity. But, in actuality, it basically works as ‘a spatial spray’ rather than through its toxicity to mosquitoes. This possibly explains the spectacular success achieved by DDT in eradicating malaria not only in the United States but also in Europe, Sri Lanka as well as the Republic of China.
Roberts also disputes the predictions made by Rachel Carson which have no scientific basis. He argues that most of the claims made by Carson have proved to be wrong in the long run. However, inappropriate use of the substance can be a cause of concern for the wildlife but it is true for any chemical substance.
In fact, he refutes the four prominent claims made by Carson regarding the harmful effects of DDT by citing substantial evidences. Firstly, the fact that DDT “will cause the obliteration of higher tropic levels” (Roberts 2005) has proved to be wrong as to this day, there has been no extinction of species at the level. Moreover, it has also been found that the residual remains of the substance declined gradually after its use in agriculture has been restricted.
Secondly, the claim that DDT leads to algae death has also been negated by Roberts. “The places where the reported deaths of algae due to DDT have taken place have water concentrations of 500 parts per billion” (Boughton 2010). But, the fact remains that the saturation point of the substance under question is 1.2 parts per billion implying that it cannot penetrate water level beyond that.
Thirdly, the fact that DDT has caused the near extinction of the Bermuda petrel birds is considered a vague claim by Roberts as no substantial evidence exists to establish the claim. Moreover, the number of the Bermuda petrel birds has been found to decrease before the use of DDT has been restricted in agriculture and even after that.
Fourthly, Carson’s claim that DDT is responsible for the premature births of California sea lions has also been disputed by Roberts as there exists no evidence supporting the claim. Furthermore, the species has continued to flourish even during the time the chemical has had wide-spread application and even after that.
Roberts strongly criticizes the systematic campaigning initiated by some of the scientists against the use of DDT. The proposal to ban DDT worldwide is an explicit example of the gross misuse of science. He goes on to say that although millions of bucks are spent each year on theorizing the harmful effects of DDT, not much is done to prevent the recurrence of this deadly disease.
According to him, the need of the hour is the realization that chemicals, however expensive or strong these might be, cannot prevent the recurrence of malaria. What can stop its recurrence is a protective screening. Malaria cannot be eradicated from the roots by the use of chemicals. The human beings need to be protected against the mosquitoes attacking and biting them. In the cities and towns, many people can afford to use effective protective measures in the form of air-conditioning, extensive screening of doors and windows etc. But, this is not the case in rural areas where people are basically much poorer. It is DDT that comes to the rescue of these poor people (Boughton 2010).
The chemical provides effective screening to these people to eliminate the recurrence of this disease and many others. Since the rural poor cannot afford effective physical screening used by their counterparts in towns and cities, they need to access a chemical like DDT that can provide the much required chemical screening against mosquitoes.
Roberts concludes by saying that the ill-effects of the enormous pressure created to ban DDT worldwide has already begun to show. Various data reveal the gradual increase in the number of people being attacked or killed by this disease. The situation is going to get worse day by day if authorities persist with their unfounded claim to ban the global use of DDT.
Conclusion
The arguments presented both for and against the worldwide banning of the use of DDT are not the individual arguments of Anne Platt McGinn and Donald R. Roberts. They represent the point of view of a large number of environmentalists either favouring or opposing the move.
The debate revolving round this issue has metamorphosed as a major environmental issue. The environmentalists find themselves facing a paradoxical situation. On the one hand, safeguarding human lives can endanger the lives of other species and harm the natural resources. On the other hand, ensuring the safety of other species as well as natural resources can lead to possible ignorance of the human needs. Thus, the priorities need to be set right and steps need to be taken with due consideration to the plausible risks.
The problem with malaria is that it has already become resistant to certain standard drugs. A more viable option has not yet been discovered. It is true that there are various ways to prevent the outburst of the disease like swamps can be treated to prevent possible breeding of mosquitoes, bed nets can be used extensively and fish may be introduced to destroy the mosquito larvae etc. However, these options do not eliminate the need to use chemicals.
In this context, reference may be made to one of the observations made by Robert I. Rose, an arthropod biotechnologist working with the Animal and Plant Health Inspection Service of the U.S Department of Agriculture, “Pesticides have a role in public health as part of sustainable integrated mosquito management” (Rose 2001).
The need of the hour is to develop a chemical substance that would lead to gradual elimination of the mosquito parasite and total eradication of the deadly disease. However, this has proved to be highly challenging as the mosquito parasite has developed resistance and irritability to a large number of chemicals. Efforts are now on to create ‘genetically engineered mosquitoes’ that would either be incapable of sustaining the malaria parasite or of infecting human beings.
These efforts would take a long time and need to be time tested to ensure their effectiveness and viability. In the meantime, a consolidated effort should be made to address the immediate scenario. As opined by Nicholas J. White (2006), “rather than wait for a perfect solution, we should recognize that present tools-including DDT-are effective enough now that there is no excuse to avoid them” (White 2006).
Malaria has definitely re-emerged into one of the deadly diseases claiming millions of lives every year. Children and pregnant women are more prone to this disease. The recurrence of malaria is also seen in areas that earlier have been declared malaria-free. The urgency of the situation becomes more pronounced in the light of global warming. Global warming has expanded the geographical area of the mosquitoes and has made them more potent since mosquitoes flourish in warm and temperate zones.
In the light of the above observations, it makes much of a sense to continue the usage of DDT as a spatial repellent to combat the disease until some better option is made available. This is because nothing can justify the huge and recurrent loss of human life.
Last but not the least; it is true that no chemical can claim to be without some adverse effects to ecology and environment. The same applies to DDT. But, the above discussion brings to the forefront the idea that many of the negative claims are to be investigated further to be established. Unless there is enough evidence to substantiate the claims, there is no point in raising a lot of hue and cry over the plausible negative consequences. This is because these possible negativities create a lot of panic and intimidation among the common people (Boughton 2010). Furthermore, it influences their point of view and leaves the common people baffled. The irony of the situation is that in the long run, it is the human beings who would be the worst affected.
Reference list
Boughton, C., 2010. The Effect of DDT: Measures needed. Emerging Infectious Diseases, 16 (6), pp.265-78.
McGinn, A., 2002. Malaria, Mosquitoes, and DDT: The toxic war against a global disease. In: T. Easton, ed. 2002. Taking Sides – clashing views in Science, Technology and Society. New York: Worldwatch Institute. Ch.9.
Oreskes, N., 2010. Merchants of Doubt: How a Handful of Scientists Obscured the Truth on Issues from Tobacco Smoke to Global Warming. San Francisco, CA: Bloomsbury Press.
Roberts, D., 2005. U.S. Senate Committee on Environment & Public Works Hearing Statements. Web.
Rose, R., 2001. Pesticides and public health: integrated methods of mosquito management. Emerging Infectious Diseases, 7 (1), pp. 17–23.
White, N., 2006. Malaria — Time to Act. The New England Journal of Medicine, 355 (19):1956-1957.