Abstract
In 1972, the United States government banned the use of DDT after the awful discovery of the effects of this insecticide on the environment. The United States government raised concerns over the toxicity of this insecticide stating that the concentration of the drug in animal tissues, thus end up harming the animals in the process. A report carried out on the issue indicates that this insecticide had contributed to the extinction of birds and the thinning of eggs. However, the WHO released a statement on the issue stating that DDT is a useful drug especially for the control of malaria. According to their position statement, the WHO recognizes the health concerns associated with DDT but explains the efficacy of the drug in preventing the spread of malaria. The toxicity of the insecticide still remains an issue of concern for most health practitioners and environmentalists, and for that reason, is the subject of this paper.
Introduction
Dichlorodiphenyltrichloroethane, commonly known as DDT is a synthetic insecticide that has been associated with the control of diseases such as malaria and typhus. From the introduction of the insecticide in early 1870s, the insecticide has received a fair share of controversies and has been the subject of debate in the United States and the rest of the world. The position statement by the World Health Organization (WHO) argues for the approval of the use of this drug, but, only as an indoor residual spray for the control of malaria (WHO, 2007). The WHO supports the use of the drug as it is currently owing to the absence of alternatives to perform similar functions as the drug, i.e. preventing vector-borne diseases.
The position statement explains the efficiency of the drug in relation to its residual abilities that in turn limits human-vector contact. The WHO recognizes the effects of the insecticide on the environment, and supports chemical safety (WHO, 2007). Consequently, the WHO advices users of the insecticide from ingesting the drug or allowing contact with the skin. The statement explains that long-term toxicity of the insecticide is possible, especially since the insecticide ends up accumulating in human and animal tissues. However, the statement explains how the insecticide has been used to combat vectors such as malaria, and the resistance of the drug upon application. The WHO recognizes that other insecticides have been used as alternatives to DDT, and they are show support for the synthesis of such drugs. However, the statement also recognizes that most of the drugs used are less effective than DDT and can, therefore, not be used for treatment of Malaria (WHO, 2007). Consequently, until other alternatives are developed for effective and efficient control of malaria, the WHO maintains that, the insecticide should not be banned from use in households. Accordingly, the WHO does not agree to the use of less effective drugs just based on the idea that the insecticide has effects of the larger environment. They argue that doing this will not only lead to a malaria epidemic; it will also weaken human capacity.
This paper presents an evaluation of WHO’s position statement on the use of DDT in malaria vector control. The paper explains the toxicology issues associated with the use of DDT, while illustrating the types of toxicology data and the four phases of disposition of toxic compound. Conclusively, the paper provides a recommendation on whether the WHO should approve the use of DDT in controlling malaria.
Phases of Toxic Disposition
There are four phases involved in the disposition of a toxic compounds from the environment, into the body and out to the environment again. These phases include absorption, distribution, metabolism, and excretion. Absorption refers to the passage of chemicals from the environment across membranes and in the case of DDT, can occur through the skin or orally (HSDB, 2009). Distribution refers to the transfer of the chemical throughout the body and the storage of these chemicals in the body. Metabolism refers to the chemicals ability to replicate within the body and the effects of the chemical in the body. Lastly, excretion refers to the process through which these chemicals are eliminated from the body into the physical environment. These phases can be used to assess the toxicity of DDT in that they will provide information about the residual effects of DDT upon its use. Researchers will have the ability to understand the effects of DDT in the human body and the environment.
Exposure and Response Associated with DDT
Exposure to DDT occurs in two main forms, which include occupational exposure and accidental exposure (HSDB, 2009). Occupational exposure refers to a form of exposure resulting from extended contact with the insecticides. Occupational exposure only occurs through the skin, or inhalation. Contrastingly, accidental exposure occurs through ingestion, and it is less frequent than occupational exposure. The types of accidental exposures associated with DDT range from, acute exposure to sub-chronic exposure. These types of exposure mainly occur because the use of DDT requires users to apply the insecticide on surfaces, usually lasts for a long period. Acute exposure refers to exposure that occurs in day or less, whereas, sub-acute exposure refers to exposure that has occurred in 1 month or less. Chronic exposure refers to exposure to DDT for more than three months, and this is the most fatal form of exposure that has lead to the possible extinction of birds and other plants (HSDB, 2009). Some of the responses associated with DDT include eye irritation, and irritation when in contact with the skin.
Recommendation
Vector control has been a health issue for most especially those from poorer countries and regions. Millions of people have been dying from Malaria in Africa, and the position statement by the WHO reflects sound integrity on the issue of malaria eradication. The studies carried out on the effect of the insecticide on humans and animals illustrated that the effect on human beings was much lesser than the effect of the drug on animals. This means that, as humans, we should not worry about the effects of DDT because it only poses a threat when used wrongly.
Currently, there is no alternative DDT that is as effective as the drug. This was proved through the South African incident where the discontinuation of use led to an immediate reappearance of malaria in the community. Accordingly, the WHO should continue approving the use of DDT to prevent such an occurrence. However, the use of the drug should be carefully monitored and controlled, and reports should be created to illustrate the progression of insecticide use in relation to effects and treatment. These reports will act as reviews on DDT safety, and will be used to develop other policies in relation to DDT use.
In support for the use of DDT, the WHO should advice users of these insecticides on how to use the insecticide safely. They should provide guidelines concerning safe use of DDT and should establish standard operating procedures to be followed by spray operators. Most importantly, the WHO should provide the necessary resources to all affected countries to ensure that appropriate measures are taken.
However, the use of the insecticides should only be approved until other equally effective and efficient alternatives are developed. Once these alternatives have been created, then the WHO will cannot justify their approval for the use of DDT. Therefore, the WHO should continue to approve the use of DDT to combat malaria especially in endemic regions. However, this recommendation is only because there are no alternatives to the insecticide that are effective and efficient as DDT.
References
Hazardous Substances Data Bank (2009). DDT. Retrieved from: http://toxnet.nlm.nih.gov/cgi-
bin/sis/search/f?./temp/~i4n63D:1
World Health Organization (2007). The Use of DDT in Malaria Vector Control: WHO Position
Statement. Retrieved From: http://whqlibdoc.who.int/hq/2007/WHO_HTM_GMP_2007_eng.pdf
