Thursday, November 11, 2010

DTT and Malaria

Richard Kamwi makes a number of claims in his article “Free the Fight Against Malaria” (November 8, 2010) published in The Wall Street Journal. The main argument he makes is that DDT should be reintroduced in an effort to decrease the spread of malaria. Kamwi (2010) makes this claim based on the idea that DDT is not harmful to the environment if used correctly, it is not harmful to humans, and that DDT is the only effective means of fighting malaria.

Whereas it may be true that if DDT is sprayed indoors its environmental impact may be limited, this assumes that all people will use it accordingly. Of particular concern is that if DDT is distributed in large quantities there is no guarantee that it will not be used outdoors to cull mosquito populations. The environmental damage that could occur as a result of such use is immense and is one of the main reasons why most countries have banned the substance. An example of such damage occurred in the late 1950’s when a spraying of DDT to control beetle populations caused a mass die off of robins in the area (Ehrlich et al. 1988). Kamwi (2010) also states that “DDT is essential for managing insecticide resistance”; this is, however, not backed up by any argument or research in this article (Kamwi, 2010, p. 12). Moreover, it is not clear how DDT could kill pesticide resistant pests, nor whether there is a connection between this and malaria. Also, this statement seems to ignore the fact that insects and other pests have become pesticide resistant in the past and will continue to do so in the future. In fact, a possible side effect of increased spraying of DDT is the possibility that mosquitoes will develop a resistance to it, causing it to become ineffective. The possibility that pesticide resistant mosquitoes could arise poses the threat that they may become more difficult to control and kill. Kamwi (2010) does not even explore this possibility in his article and assumes that DDT is, and will continue to be, effective against mosquitoes. Adding to this, If DDT is reintroduced it would discourage research into new forms of mosquito control that are safer for the environment.

The other issue that Kamwi (2010) dismisses in his argument is that the widespread death of mosquitoes and other animals targeted by DDT might also hurt the environment. As these animals are a critical part of many ecosystems, their removal might have a very negative impact, similar to the slippery slope argument in which the removal of one animal may cause the deaths of many more in any given ecosystem. This argument for the slippery slope arises as mosquitoes are a food source to many species of insects, fish, and birds. As well, Kamwi (2010) says that the intrinsic value of humans is considerably more important than that of other animals. This opinion may not be shared by others, especially those who require a healthy ecosystem to continue to live.

Kamwi also states that “DDT is safe for humans” which may be a premature statement (Kamwi, 2010). The evidence that he cites to support this claim is that the many studies claiming that DDT is harmful are “weak, inconclusive or contradictory” (Kamwi, 2010, p. 12). Although it may be true that some of these studies may have been incorrect, Kamwi himself states that “thousands of scientific studies have investigated potential harm to human health from DDT” and it is doubtful that all of these studies were misleading and poorly conducted (Kamwi, 2010, p. 12). Kamwi (2010) assumes that because some studies may be incorrect then they all are; without citing evidence that this assumption is correct, the accuracy of this assumption must be questioned. Kamwi does not cite proof that DDT is safe for humans, and the negative effect that it has on humans must be considered before this product is allowed on large scale. These considerations are not addressed by Kamwi in his article.

Another argument made by Kamwi is that “there are few alternative insecticides suitable for malaria control and approved by the World Health Organization” (Kamwi, 2010, p.12). There are, however, some alternatives. In response to this, Kamwi (2010) states that the alternatives do not work in the same way and are usually less effective. Nonetheless, these alternatives are less likely to cause long term irreversible damage to the environment upon which people depend to live. As well, Kamwi (2010) argues that most developed countries have eradicated malaria and did so in the 1950’s with the aid of DDT. Though it is true that DDT may have played a role in the eradication of malaria in these countries, one question that must be asked is if DDT was the primary cause of the eradication. Another possible reason for the eradication of this disease in developed countries is the improved standard of health, as people infected with malaria stay in areas that are generally mosquito free while recovering, decreasing the spread of the disease. This is just one possible reason why malaria was eradicated in developed nations in addition to the use of DDT, and it is possible that other factors related to higher standards of living and improved health care could have caused this effect as well.

In conclusion, Kamwi’s Free the Fight Against Malaria (2010) makes many claims which may be oversimplified or not well supported by research. He states that the use of DDT will have no effect on the environment, without citing evidence to support this claim. His claim that DDT is completely harmless to humans may also be unfounded as he assumes that the thousands of studies conducted on this topic are all false or poorly executed, which is highly unlikely. As well, Kamwi makes the assumption that DDT is the best solution to malaria which may not be true due. There are other possible insecticides that could be considered, and factors other than DDT may have lead to the eradication of malaria in the past. DDT is a very controversial insecticide; it’s toxicity to both the environment and to humans who come into contact with it must be considered before its use is considered.

References

Kamwi, R. (2010, November 8). Free the Fight Against Malaria. The Wall Street Journal Europe, p. 12

Ehrlich, P., Dobkin, D., & Wheye, D. (1988). DDT and Birds. Stanford University. Retrieved November 9, 2010, from http://www.stanford.edu/group/stanfordbirds/text/essays/DDT_and_Birds.html

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