Should Dichlorodiphenyltrichloroethane be Banned Worldwide - Essay Example

Should DDT be banned worldwide? This paper aims at exploring various effects of using DDT for elimination of the infection diseases. The points of view presented in the popular press and in the academic sources will be discussed. The opinion of experts supporting banning of DDT and their opponents will be analyzed. The language and the distinctive features of popular press and academic sources will be examined. The conclusion about the possibility of DDT’s utilization will be made. Should DDT be banned worldwide? I am going to discuss the question about the necessity of the restriction and banning of DDT worldwide. The utilization of this substance as the insecticide started in 1940th. For the next 30 years, DDT helped to fight malaria and typhus, as well as was used in agriculture against pests. However, the growing concerns about environmental impact of DDT lead to its banning in many countries. The other reason to put it into the blacklist of forbidden substances was the fact that insects became resistant to DDT. The DDT issue became controversial. Experts divided into two groups. The advocates of DDT claim that there is no need to ban this substance because it is still effective against vectors of malaria. The opponents suppose that insecticides less harmful for the environment should be used to fight malaria. The complex of economic, planning, medical measures will be the most effective tool against this disease. Each part has its own arguments. I am going to examine the opinion of both sides presented in the popular sources and in the scientific literature. I chose five articles on the websites and at the online version of the Scientific American. I also analyzed information presented in the university press books and the official reports about DDT. Both types of sources present the opinion of the defenders of DDT and their opponents. I will start my analysis from the opinion of DDT’s defenders. To understand their point of view, the main facts of the DDT history have to be discussed. DDT was first synthesized in 1874. It is colorless, odorless and tasteless substance. DDT is insoluble in water, but fats, oils and organic solvents can dissolve it. The insecticidal action of DDT was discovered by Paul Hermann Muller in 1939 (ScienceHeroes.com 1, 2009). Since that time DDT became widely used in Europe, Asia and America. DDT opens sodium ions channels in neurons of insects. It leads to spasms and death of the insects like mosquitos and bugs. DDT can be used for the variety of species. It fights both pests and vectors of diseases (Ayres, J.G. et al. 285, 2010). Many pesticides are used before DDT. However, these substances were dangerous both for the human and for the insects. The main reason why DDT became widely used was its safety. It is not harmful for the human, especially at the proper utilization. For more than 60 years of its exposure in different places only a few cases of accidental poisoning were registered. As DDT is not dissolved in water, it can be safely used in the forms of dust or powder. The dose that does not cause harmful effect for the human is 6 mg/kg. The dose that does not cause death due to the accidental or intentional ingestion is 285 mg/kg. The other pesticides may cause poisoning at lower doses (Ayres, J.G. et al. 285, 2010). The first success of DDT application was obtained during World War II. During the military companies, many soldiers died from disease like typhus, yellow fever or malaria. These diseases were spread by insects (vectors). According to the WHO estimation, about 25 million people were saved (Dikshith 136, 2011). After the war, DDT become available for the agricultural use. Its utilization helped bring under control and totally eliminate malaria in Europe and North America. For example, malaria cases decreased on the 33 % in South America between 1942 and 1946. In 1948, there was not registered malaria-related deaths in Italy. The number of newly diagnosed malaria cases decreased after DDT was sprayed in Kanara district (India) from 50,000 people to about 1,500 per year in the late 1940th. According to another statistical data, the number of malaria cases fell from about 75 million in 1951 to 50,000 in 1961 in India. When DDT spraying was used in Sri Lanka in 1946, 3 million new cases of malaria were being registered every year. The number of cases dropped to 7,300 ten years later. In 1964, only 29 Sri Lankans had malaria (Discoverthenetworks.org 7, 2008). In every place where DDT was used in significant quantities, the incidence of malaria decreased significantly. The success in killing the vectors of infectious disease was outstanding. In May 1955 the World Health Organization started a Global Malaria Eradication Campaign (GMEC). The campaign was mostly oriented on the use of DDT. Before 1961, malaria was removed from North America, southern Europe, the Caribbean, and most parts of eastern and southern Asia. In South Africa, the spraying of DDT during 18 months resulted in decreasing of malaria cases on 80 %. The same measures in Ecuador lead to decreasing of malaria by 60 percent. Malaria fell by 90 percent in Madagascar. It was the real success. DDT use reached 80 million kilograms in 1962. According to the estimation made at this period DDT prevented 500 million human deaths, due to malaria (Discoverthenetworks.org 9, 2008). Now developed countries overcame malaria and other inflectional diseases carried by insects. Why tropical Africa did not get the same results? Why they still fight against malaria? There were a few reasons. African countries almost had no infrastructures capable of spreading DDT in an effective and comprehensive way. African mosquitoes and malaria parasites differed slightly from the species on other continents. They were more resistant to the pesticide campaigns. But even under such circumstances several successful results were obtained. For example, the pilot project was started in the Kigezi district (Uganda). DDT was sprayed twice per year and it permitted to remove malaria from the region. Some experts suppose that constant use of DDT would successfully remove malaria from every region of the world, including Africa (Discoverthenetworks.org 10, 2008). However, DDT was banned in many countries since 1970th. The triggering event was the book of Rachel Carson published in 1962 (ScienceHeroes.com 8, 2009). The reasons was not the danger for the human health, but the ecological means. It claimed that due DDT action bird’s egg shells were thinning, as well as other negative consequences occurred. Created ecological movement insisted on banning of DDT and succeed. Rachel Carson’s book and her arguments for banning of DDT are proven to be exaggerated (Foss 72, 2011). The thinning eggshells was caused due to the exposure of high doses of DDT. The prediction that DDT use results in 100 % of cancer was not proved by the studies. The poisoning with DDT was due to its misuse (Bate 2, 2008). The arguments were based on the carefully chosen incidents and on the citing of the precautionary principle. However, environmentalists forgot about African children died from malaria. The banning of DDT was criticized since it was adopted worldwide. It was connected with many cases of malaria’s reverse. For example, temporary total ban of DDT in South Africa lead to the increase of malaria (Dikshith 137, 2011). There is another sad statistics. According to one of the researches, the number of malaria’s cases in Sri Lanka dropped from 2.8 million cases in the 1940th to 17 cases in 1965 due to the spraying of DDT. Five years later the country stopped using DDT. The number of diseases increased to 2,500,000 (Junkscience.com 3, 2012). Madagascar stopped using DDT in the 1980th. It resulted in an epidemic of malaria, and more than 100,000 people died. The opinion of DDT’s defenders was expressed by one of the heroes of Michael Crichton’s novel State of Fear. This character calls banning DDT “arguably the greatest tragedy of the twentieth century” and that the ban “killed more than Hitler.” (ScienceHeroes.com 9, 2009). DDT remains probably the most useful insecticide that was ever used for public health. Even US used it several times after the banning in 1972. It was sprayed for killing plague-carrying fleas in Colorado, New Mexico and Nevada (Bate 13, 2008). In 1973, World Health Organization admitted that positive effect of DDT use overcomes negative consequences (Dikshith 137, 2011). DDT still is used for malaria control. DDT can be sprayed on walls inside the houses. Relatively small amount of the insecticide required. This measure repels mosquitos and does not causes damages for the environment. Some governments in developing countries, like Uganda, make a decision to spray this chemical despite the opposition from local business lobbies (Bate 13, 2008). Companies in China and India still produce DDT for their own public health programs and for export. Western company do not produce DDT for many years. Known chemical companies Bayer, Dow Chemical, Du Pont and BASF produce alternative products. They have incentives to see DDT banned (Bate 12, 2008). DDT’s alternatives cost more. They can be as harmful for the human health as DDT. There is no reason to use expensive means with the same harmful effect if we have cheap and effective chemical (Junkscience.com, 2012) Opponents of using DDT also have enough arguments. As this chemical is not dissolved in water, it is hard to remove it from the human or animal body. Once it enters into the body, this substance will be removed for years. The pesticide can be accumulated in body tissues, especially in breast milk. (Dikshith 187, 2013). Several proves that DDT causes harmful effect on the human health were found. Laboratory researches on animals showed the potential carcinogenicity of this chemical (Dikshith 187, 2011). The other health problems reported in the official documents are reduced fertility, genital birth defects, breast cancer, diabetes and damage to developing brains. Its metabolite, DDE, can block male hormones (Van den Berg 8, 2008). Opponents of DDT have own statistics. About 60-80 grams is sprayed in each household every year in South Africa. The health state of people inside the homes, where DDT is sprayed, is not monitored. Only one researches results were published. In 2007, the study of male fertility was conducted in Limpopo (South Africa). It was found that men in the sprayed homes had extremely high levels of DDT in their blood. Their semen volume and sperm counts were at the low level (Cone 15, 2009). The use of DDT today differs greatly from its use in the past. It is sprayed in smaller amounts. However, it is sprayed on walls inside homes and other buildings. Inhabitants in Africa get more DDT than it was in the United States or Europe during the conducted campaigns. Additionally the insecticide is used in countries where the people are malnourished and poor. The possible immune diseases can increase their vulnerability to this chemical (Cone 20, 2009). There are also countries that fight malaria without using of DDT. For example, Mexico, the rest of Central America and parts of Africa used alternative methods. The main measures were the control of places where mosquitoes may live and the use bed nets with pyrethroid insecticides. But these actions give less results in South Africa (Cone 23, 2009). DDT is utilized against vectors of malaria. However their biology is different. There are no universal method to fight with mosquitos. For example, some species of mosquitoes breed in running water. It is not easy to control such insects. Another problem is that the programs of fight have to cover significant territories. As a rule, the existing infrastructure does not permit manage all parts of the country (Cone 25, 2009). The resistance to DDT is also the growing problem. Since the first use of the insecticide in 1946, experts reported about DDT resistance for more than 50 species of mosquitoes. For example, the resistance to DDT was detected in southern Greece in 1952. It was only 6 years after the spraying measures were used in agriculture and vector control. The resistance to DDT was observed in Central America, Southern Europe, the Middle East, and South and Southeast Asia. It was also reported about the rapid development of the resistance in Burkina Faso, Senegal and Togo. The main reason of the resistance to DDT was its wide use in agriculture in the past. Many species of mosquito that obtained resistance to DDT origin from the agricultural environments. The resistance to DDT can be also triggered further by other pesticides with the similar action. The main mechanism is ‘sodium channel’ mutation (Van den Berg 10, 2008). The use of DDT is not effective in case of growing resistance to the insecticide. Recently obtained data show that the cases of resistance to DDT are widely spread, especially in West and Central Africa. For example, Ethiopia, Uganda, Cameroon, Sudan, Zimbabwe and South Africa face this problem due to the previous wide use of this insecticide. In Asia, the problem of resistance is spread in India, China and Vietnam. Resistance and reduced susceptibility to DDT was also observed for the other species (for example, flies) (Van den Berg 10, 2008). It means that it will be necessary to find another means to fight malaria and other diseases transmitted be insects. DDT is not the only solution of the problem. Complex programs include chemotherapy (use of the pharmaceutical treatment), chemoprophylaxis (prophylactic use of the pharmaceuticals) and measures of the mosquito’s elimination without pesticides. These measure also include placing of homes away from the sites where mosquitos live. Drainage of swamp was used before the treatment with DDT. Biological control can also give good results. It foresees use of bacterial lavricides, predators eating larvae, repellents, fungi and nematodes (Laumann 16, 2009). These measures are environmentally friendly and can be more effective. The main reason for their further use is the growing resistance of mosquitos to DDT. Both sides have own arguments and present it in its own way. Academics sources and popular press use facts and numbers. However, academic sources present the results of the researches while popular press presents the opinion of the experts. Direct speech is widely used in the popular press. It can look like interview with the known expert (Cone 7 10 13, 2009). Academic sources present data in the form of tables and graphs. Every opinion of the expert other than the authors is referenced. You can find the source where this opinion was expressed in the references list. The language in the popular press differs from the language in the academic sources. As person that read the popular press is not the expert, the language use simple phrases. It uses words that effect on the imagination. Sometimes explanation are given to make reader more familiar with the topic. Academic sources use typical phrases that can be found in every scientific article or book. The material is presented without emotions. There are only facts and their estimation. The language in the popular is simpler and looks alive. The language of the academic sources is dry, uses typical phrases and special scientific terms. Popular press addresses to the average person while articles and reports in academic sources are addressed to the experts. Supporters of DDT use and their opponent give enough evidences. On my opinion, DDT should not be banned worldwide yet. Malaria kills millions people every year. Sometimes DDT is the last chance to save life of the human (especially children). Thus, this insecticide can be the last resort in the fight against malaria. The evidences that DDT is harmful for the environment and for the human health does not look solid. They flake on the face of deaths that could be prevented. The only reason that justifies the banning of DDT is growing resistance to this insecticide. It is the reason to use complex programs of fighting against malaria. The most suitable principle that can be used in DDT case is to compare risks and benefits. Sometimes it seems that we have to choose between big evil and less evil. Thus, the risks of using DDT have to be compared with its advantages in every case. The main idea that should not let that people die from malaria, and their health should not be at risk for any other reason. DDT should not be excludes from the list of possible means. However, it have to be used very carefully. Only the prevention of infection diseases and fight with vector is the reason to use DDT. We should take into account the growing resistance to this insecticide and possible risk of exposing to high doses. DDT is not the ultimate solution. As malaria is still not defeated such a solution is not found. I suppose that the complex programs will be the most effective in the fight against this disease. While the effective mean is not found DDT should not be banned, especially in Africa. References Ayres, J.G. et al. (2010). Environmental Medicine. Boca Raton, FL: CRC Press Bate, R. (2008, May 24). DDT works. Prospect. Retrieved July 1, 2014 from: http://www.prospectmagazine.co.uk/magazine/ddtworks/#.U7VcDrHy9qI Cone, M. (2009 May 4). Should DDT be used to combat malaria? Scientific American. Retrieved July 1, 2014 from: http://www.scientificamerican.com/article/ddt-use-to-combat-malaria/ Dikshith, T.S. (2011). Handbook of Chemicals and Safety. Boca Raton, FL: CRC Press Dikshith, T.S. (2011). Hazardous Chemicals: Safety Management and Global Regulations. Boca Raton, FL: CRC Press Discoverthenetworks.org. (2008). Malaria victims: how environmentalist ban on DDT caused 50 million deaths. Retrieved July 1, 2014 from: http://www.discoverthenetworks.org/viewSubCategory.asp?id=1259 Foss, J.E. (2011). Beyond Environmentalism: a Philosophy of Nature. Hoboken, NJ: John Wiley & Sons Junkscience.com. (2012). It was a mistake to ban DDT in 1972. Retrieved July 1, 2014 from: http://junkscience.com/2012/03/09/it-was-a-mistake-to-ban-ddt-in-1972/ Laumann, V. (2009). Environmental strategies to replace DDT and control malaria. Retrieved July 1, 2014 from: http://www.panna.org/sites/default/files/ddt_alternatives_PAN%20G_0.pdf ScienceHeroes.com. (2009). The DDT controversy. Retrieved July 1, 2014 from: http://www.scienceheroes.com/index.php?option=com_content&view=article&id=309&Itemid=263 Van den Berg, H. (2008). Global status of DDT and its alternatives for use in vector control to prevent disease. Retrieved July 1, 2014 from: http://www.pops.int/documents/ddt/Global%20status%20of%20DDT%20SSC%2020Oct08.pdf Bibliography Scholar: Ayres, J.G. et al. (2010). Environmental Medicine. Boca Raton, FL: CRC Press Dikshith, T.S. (2011). Handbook of Chemicals and Safety. Boca Raton, FL: CRC Press Dikshith, T.S. (2011). Hazardous Chemicals: Safety Management and Global Regulations. Boca Raton, FL: CRC Press Foss, J.E. (2011). Beyond Environmentalism: a Philosophy of Nature. Hoboken, NJ: John Wiley & Sons Laumann, V. (2009). Environmental strategies to replace DDT and control malaria. Retrieved July 1, 2014 from: http://www.panna.org/sites/default/files/ddt_alternatives_PAN%20G_0.pdf Van den Berg, H. (2008). Global status of DDT and its alternatives for use in vector control to prevent disease. Retrieved July 1, 2014 from: http://www.pops.int/documents/ddt/Global%20status%20of%20DDT%20SSC%2020Oct08.pdf Popular: Bate, R. (2008, May 24). DDT works. Prospect. Retrieved July 1, 2014 from: http://www.prospectmagazine.co.uk/magazine/ddtworks/#.U7VcDrHy9qI Cone, M. (2009 May 4). Should DDT be used to combat malaria? Scientific American. Retrieved July 1, 2014 from: http://www.scientificamerican.com/article/ddt-use-to-combat-malaria/ Discoverthenetworks.org. (2008). Malaria victims: how environmentalist ban on DDT caused 50 million deaths. Retrieved July 1, 2014 from: http://www.discoverthenetworks.org/viewSubCategory.asp?id=1259 Junkscience.com. (2012). It was a mistake to ban DDT in 1972. Retrieved July 1, 2014 from: http://junkscience.com/2012/03/09/it-was-a-mistake-to-ban-ddt-in-1972/ ScienceHeroes.com. (2009). The DDT controversy. Retrieved July 1, 2014 from: http://www.scienceheroes.com/index.php?option=com_content&view=article&id=309&Itemid=263 Read More