Significance of Malaria and Impact of DDT - Essay Example

?Malaria and DDT There are several diseases that are common in warm and tropical environments. One such disease is malaria. Malaria is a contagious disease that affects humans, caused by a parasite known as Plasmodium, which is spread through the bites of the infected mosquitoes. The parasite usually multiplies in the liver of the human body and then infects the red blood cells. After the infected mosquito bites, the symptoms of malaria usually appear between ten to fifteen days. Malaria’s signs and symptoms include headache, fever, and vomiting. The disease is common in subtropical and tropical regions including a lot of Americas, Asia, and the Sub-Saharan Africa. Malaria is very common in these regions since they have reliable hot temperatures and large amounts of rainfall. Since mosquitos live in a warm environment with consistent temperatures, they breed continuously in the aforementioned areas. Significance of Malaria Malaria is one of the major contagious diseases in tropical environments and a huge public health disaster. It has been ranked the leading cause of death in the world where almost five million new cases are identified, with deaths of two point seven million annually according to Glaser and Knight (2007). Historically, malaria has infected humans since the creation of mankind. Malaria has not spared is victims despite of their status and position, the American President John Adams for example nearly succumbed to malaria while on a diplomatic mission in Amsterdam. It was until the nineteenth century that facts about the real cause of malaria became known. So far despite this knowledge, malaria continues to grossly affect the populations of south East Asia, sub-Saharan, and Latin America its victims manly comprising pregnant women and young children (McConnell, 2006). Malaria causing mosquitoes are known to breed in swamy areas or areas that have stagnant waters where they lay their eggs. The Plasmodium parasite apart from infecting humans, also affects reptiles, birds, rodents, chimpanzees and monkeys. Plasmodium enters the bloodstream and damages the red blood cells as well as affecting the spleen, kidney, liver, and other vital body organs. Malaria has other names like falcipurum malaria, quartan malaria, black water fever, plasmodium, and tertian malaria. Thus malaria parasites are transmitted by female anopheles mosquitoes (Capinera, 2008). Information on the economic workload of malaria is needed to focus interventions equitably and efficiently, and to establish investment in control and research of how to combat the disease. Treatment of malaria is costly its asociated expenses a burden to the victims. Many institutions use weak data to estimate indirect costs, which fail to account for seasonal variations, the difference between the marginal and average product of labour, and the means firms and households survive in response to the illness period. Impact of DDT There are several measures used in combating malaria including use of insecticides, mosquito nets and medication that fight the disease. One product that has been used for a long to in fighting malaria is DDT (Dichlorodiphenyltrichloroethane). DDT is a synthetic pesticide invented in 1874. DDT opens sodium ion paths in the neurons of insects enabling them to fire suddenly which results to eventual deaths spasms. However, in humans it affects the health through endocrine disruption or genotoxicity. Genotoxic substances are recognized to be potentially carcinogenic or mutagenic, particularly those capable of causing genetic mutation and of contributing to the growth of swellings as noted by Miller and Spoolman (2008). DDT may be directly genotoxic, although it may also make enzymes generate other genotoxic intermediates. It is also an endocrine disruptor in that it act as an ant androgen. According to Roberts and Tren (2010), the remains of DDT on the walls of the houses can change the transmission mode of mosquitoes. The non contact repellant action of DDT remains can stop a malaria mosquito from entering the house. In spite of the repellant action, if the mosquito enters, then the contact irritant action may cause it to leave before making any bite. If the contact irritant action fails, then contact toxicity might still leads to the death of the mosquito, after prolonged contact with DDT treated surfaces. There are various modern insecticides which might be applied as a substitute for DDT, although they are expensive and do not have long residual action. The common re-spraying of chemicals with a short residual activity known as DDT alternatives is not a cheap method of malaria control in remote areas. As developing countries are avoiding house spraying plans, they have slowly reverted to the situations of unpreventable rural malaria that was there before mid 1940s. Currently, the basic relationship of rural people with malaria, and the expense of using house spraying to prevent mosquitoes in rural areas is an old idea that needs to be re-invented. The notion that malaria should be prevented by combining many methods of mosquito control such as integrated vector control (IVC), as opposed to applying DDT to the walls is considered incorrect by certain quarters. As a matter of fact, IVC methods are not considered as applicable and affordable approaches to the control of malaria. DDT is deadly to a wide range of animals and insects but less lethal to mammals. The scientific thinning mechanism is not entirely recognized, although there is a strong proof that DDE inhibits the integration of calcium carbonate from blood in the eggshells. Also, there is a proof that DDT destroys reproductive organs of the female, impairing eggshell quality. Human epidemiological research confirms that exposure to DDT is a risk factor for low and premature birth rate, and may impact a mother’s ability during breastfeeding. It is argued that the aforementioned effect may increase death of infants, offsetting its benefits in combating malaria. It has also been revealed that exposure to DDT might cause early weaning and preterm birth at amounts that would be required in the control of malaria. Data of also shows the possible disruption in quality of semen, gestation period, menstruation period, and lactation period due to the substance. Recent research demonstrates a connection between in utero exposures to DDT development of neurotoxicity in humans (Insel P et al 2010). For instance, a research carried at the University of California in 2006 found that children exposed while still lying in the womb are capable of developing problems. Ultimately, other studies have shown that even low levels of DDT in umbilical cord serum during birth are linked with decreased attention at infancy and decreased cognitive skills at four to five years of age. Benefits of DDT in Comparison to its Toxicity The Department of Agriculture in the United States, the federal agency chardged with the responsibility of controlling pesticides before the formation of the Environmental Protection Agency of the United States in 1970 started regulatory actions in the late 1950s to rule out the uses of DDT. This was the case due to increasing proof of declining effects of the pesticide in terms of its toxicological effects. There is widespread concern of the public over the dangers of the pesticide application and the need to use better methods of controlling pesticides. DDT has become characteristic of the toxics movement due to its adverse effects on the non-human environment (McKinney 2004). This has been demonstrated by the ecological research that bio accumulated DDT reproductive failure and thinning of eggshells in birds of prey. With such weak proofs of dangers to human health, one must choose either to ban or set the policy as a precaution. According to the National Research Council (1972), EPA issued an annulment order for DDT based on the unfavorable effects on the environment from its use, such as those to wildlife, and DDTs potential risk to human health, in 1992. Since then, research has improved a causal link between reproductive effects and DDT exposure is assumed. Currently, DDT is termed as a probable human carcinogen by the United States and global authorities. DDT is identified to be very persistent in the environment; it always accumulates in fatty tissues, and can move long distances in the upper environment. Because the use of DDT was stopped in the United States, its absorption in animals and environments has gone down but due to its perseverance, a residue from historical concern still exists. Given the organized documented adverse effects of health associated with DDTs toxic persistence and its properties, the international community has a common responsibility to avoid the use of this chemical and practice safe and perform good pest management practices at the community level to control insect borne disease such as malaria. Other epidemiologic proofs confirm that DDT exposure increases preterm delivery and reduces the gestation period. This increases the rate of infant deaths and therefore undoes any benefits on mortality rates from a reduction in malaria. Conclusion Malaria is a contagious disease of humans caused by a parasite known as plasmodium, which is spread through the bites of the infected mosquitoes. Malaria can rapidly disrupt the blood supply to important organs if not fully treated. Therefore, it can be controlled through effective treatment with artemisinin-based combination remedies; spraying with insecticide to prevent the vector mosquitoes; and use of insecticidal nets. On of the interventions used in the control of malaria is the use of DDT. DDT initially proved very efficient in the control of malaria causing mosquitoes but with time it has lost its popularity due a number of factors. Its efficience has reduced over time and its effects to the environment have remained a big minus to its disfavor. There are various modern insecticides which might be applied as a substitute for DDT, although they are expensive and do not have long residual action. DDT is deadly to a wide range of animals and insects but less lethal to mammals. The use of DDT has been criticised in that while it kills mosquitoes, it also increases the mortality rate of infants thereby undoing its good. DDT became characteristic of the toxics movement due to its adverse effects on the non- human environment. DDT however has been hailed for its effectiveness in terms of cost compared to several altermnative products. References Capinera J.L. (2008). Encyclopedia of entomology Gainesville: Springer. Press Knight. C & Glaser J (2007). Create impact with type, image & color - 160 pages London: Rockport Publishers. Press Garg. R, Jayakumar N, Paul .S (2009) Minimizing and Exploiting Leakage in VLSI Design London: Springer Insel P, Ross D, McMahon K, Bernstein M (2010) Nutrition 4th. Ed Jones & Bartlett Learning McKinney.E. (2004) Environmental Pollution Control Microbiology Kansus: CRC Press, McConnell T. H (2006). 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