Malaria and DDT: Dichlorodiphenyltrichloroethane

Malaria is a main cause of high morbidity and mortality rates. Some of the symptoms that typify the disease are fever, headaches, nausea and joint pains. It has been noted that it can result in yellow skin and seizures in severe cases. The disease causes over 0.5 million death on an annual basis, especially to young children, pregnant women and persons with poor immune systems. DDT was used to eliminate mosquitoes in breeding sites, but it has been shown that the insects have developed resistance against the chemical. Research has demonstrated that it harms both humans and wildlife. This paper addresses various issues with regard to DDT and malaria. However, it recommends that the use of DDT be banned.

Introduction

Environmental monitoring helps personnel in the field of environmental health to assess and mitigate negative impacts of various biological and chemical agents (Laureate Education, Inc., 2008). Malaria is a serious infectious disease that affects both humans and animals. Protozoans of the plasmodium species cause it (WHO, 2014). Several studies have confirmed that it is transmitted to humans and animals when infected Anopheles mosquitoes bite them. Dichlorodiphenyltrichloroethane (DDT) is a colorless and tasteless organochloride that is used to kill insects (EPA, 2014). Initially, it was included in many forms of aerosols, emulsifiable concentrates and smoke candles.

The large-scale use of DDT to control insects can be traced to the World War II when the chemical was utilized to control malaria and typhus in civilians and troops. After the war, many firms started to sell it commercially for applications as an agricultural pesticide. However, it was banned in 1972 after public outcry with regard to its confirmed negative impacts on humans and ecology (DDT: An introduction, n.d.). This paper focuses on discussing several aspects of malaria and DDT in the contemporary world.

Significance of malaria

The disease is a major public health challenge, especially in the developing countries in Africa (WHO, 2014). It is important to underscore that the etiology of the infection starts with the life cycle of Plasmodium. Asexual reproduction in the liver culminates in the production of gametocytes that could develop into either male or female gametes. Infection of the red blood cells results in manifestation of clinical signs and symptoms.

Malaria is typified by high morbidity and mortality rates in children and persons whose immune systems are compromised (WHO, 2014). In 2013, “it was estimated that the prevalence of the disease was 207 million cases” (WHO, 2014, par. 4). The relatively many cases of the infection indicate that at any given point in time, about 207 million persons were infected. The number of cases could also imply that malaria is characterized by high morbidity rates.

Morbidity refers to the number of people who have ill health at a time (WHO, 2014). In 2013, the mortality rate of the infection was found to be high. In fact, about 627,000 deaths were caused by malaria, which were found to have a range of 473,000 to 789,000 deaths. In Africa, it is confirmed that mortality rates have reduced an average of 49% since 2000 (WHO, 2014). It is essential to note that most cases of the disease occur in the sub-Sahara Africa.

Many scholars have demonstrated that persons and governments incur huge costs to treat malaria infections and implement prevention approaches. In fact, direct costs related to the disease are $12 billion on an annual basis. However, impacts of trends of economic growth are more than the $12 billion. Costs incurred by families include medication costs, travel expenses to and from healthcare facilities, lost days in the workplace, burial expenses, and expenses related to prevention measures. Costs that are incurred by governments are involved in staffing, purchasing of medications, public health prevention approaches, such as the use of bed nets and lost opportunities in relation to tourism and other economic ventures (WHO, 2014).

Impact of DDT

The use of DDT is aimed at killing mosquitoes that are the main agents of transmitting protozoans. The chemical works by initiating toxicity in the insects. Essentially, it is sprayed in areas that are shown to support mosquito breeding. In fact, a reduction in the number of female Anopheles mosquitoes is correlated with reduced prevalence and incidence rates of malaria. When the insecticide was adopted in the 1940s to control malaria, it showed very good results with regard to reduced mortality and morbidity rates. In countries such as Sri Lanka, the number of cases dropped to about 18 cases from 1,000,000 cases that were recorded before its use (Gething et al., 2010).

Currently, there are confirmed high rates of resistance on the use of DDT in indoor residual spray (IRS) due to continued agricultural use (Murray et al., 2012). The WHO recommends that nations need to confirm absence of resistance before they can embark on using it (WHO, 2014). Research shows that DDT’s effectiveness started to decline after 6 or 7 years after it was adopted for IRS (International Programme on Chemical Safety, 2014). Some of the alternative approaches that have been proposed to replace DDT are the use of bed nets and an insecticide known as malathion. Although the alternative pesticide is more effective, many households and nations across the world cannot maintain its use due to its exorbitant prices (Gething et al., 2010).

Scientific evidence and position statement

DDT has also been found to have negative health impacts on humans and wildlife, which could be demonstrated through analysis of previous three studies. One study focused on determining impacts of the chemical on male personnel who worked in an antimalarial campaign in Mexico. A sample of 2,033 workers was utilized. The researchers identified that workers who had more exposure rates to DDT showed increased chances of risk of birth defects.

However, no DDT exposure level was linked to spontaneous abortion and/or sex ratio (Salazar-García, Gallardo-Díaz, Cerón-Mireles, Loomis & Borja-Aburto, 2004). Another study concentrated on evaluating the effect of DDT on the development of breast cancer (Cohn, Wolff, Cirillo & Sholtz, 2007). The study was conducted in California. It involved the participation of women who were exposed to the chemical from 1959 to1967. The study showed that early exposures to the pesticide were correlated with increased chances of suffering from breast cancer (Cohn et al., 2007).

To determine the effects of DDT on wildlife, a study was conducted to assess the extent to the chemical and heavy metals negatively impact freshwater pearl mussel. The research was conducted in Europe due to relatively high levels of mussel (Hartmut & Gerstmann, 2007). It was established that DDT could act as an environmental pollutant, and remarkably reduce the population of mussel. The mechanism of action was confirmed to be via the metabolite of DDT that interfered with internal homeostatic events with regard to calcium (Hartmut & Gerstmann, 2007). Thus, it has been shown that the chemical is characterized by high rates of toxicity that negatively impact human beings and wildlife (International Programme on Chemical Safety, 2014). Beckvar, Dillon and Read (2005) have reported similar findings..

This paper recommends a ban on the use of DDT on the basis that there is adequate evidence on its levels of toxicity that interfere with people and wildlife. Although it is an effective insecticide, its continued use in farms has reduced its efficacy toward killing mosquitoes (Murray et al., 2012). A recommendation would be made to ban the chemical due to the fact its benefits in relation to the elimination of mosquitoes are minimal compared with levels of toxicity in the environment. It is clear that various organizations advocate for use of the insecticide while others argue against its use. However, advocates of the chemical should relook their stand, considering scientific evidence related to its negative impacts.

Conclusion

Malaria is a major cause of deaths and morbidity, but it mainly affects persons in sub-Sahara Africa. Although various approaches have been adopted to control the menace, it has high incidence and prevalence rates. DDT is an insecticide that was initially effective toward killing mosquitoes before the insects developed resistance. Alternative approaches to the control of malaria are safer because they rarely have toxicity levels associated with the use of DDT. It would be recommended that the chemical should be discontinued from use.

References

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Cohn, B. A., Wolff, M. S., Cirillo, P. M., & Sholtz, R. I. (2007). DDT and breast cancer in young women: new data on the significance of age at exposure. Environmental Health Perspectives, 115(10), 1406-1414.

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