Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

DDT vs. The Mosquito

Sarah Gale's picture

The continent of Africa is one of the largest land masses of the world and known for its struggles with poverty, AIDS, and civil war. Yet an issue that hasn been discussed or portrayed in the media as openly is the issue of malaria; specifically, prevention of the disease. The World Health Organization (the WHO), has been grappling with this issue since the 1950's. Now, a resurgence of support for the employ of the pesticide DDT to combat the malaria- carrying mosquitoes has sparked controversy. Scientists and politicians seems to be going backwards on such an issue- it as if the environmental revolution never happened! That such polluting practices can continue to be allowed is unjust and exploitative to lesser-developed countries. What is even worse is the pro-DDT propaganda, which denounces the findings of scientists like Rachel Carson that DDT, in any dose, is lethal.

Environmentalism was a big part of the 1960's, along with other scientific achievements like landing on the moon. Specifically, in 1962 the novel Silent Spring brought to the public the dangers behind pollution via pesticides. Its author, Rachel Carson, exposed the risks of using chemicals on the farm or in the home. The book received critical acclaim, but apparently it did not reach the ears of everyone. Around the same time, Africa experienced suffering under a bad case of malaria, suffering that continues into the modern day. 90% of deaths due to malaria occur on the continent (Nabarro and Tayler 1). The World Health Organization then made it a high priority to stop malaria, and scientists believed that the best way to eradicate the disease would be with local spraying of high-risk zones where the mosquitoes thrived.

This practice of spraying, however, cannot have been the best solution because of precedent established by Italy twenty years before- in 1945, DDT was applied intensely. After a year, scientists noticed new strains of housefly and mosquito- new strains impervious to DDT. To combat the new insects, stronger pesticides were applied. By 1951, DT, methoxychlor, chlordane, heptachlor, and benzene hexachloride were rendered useless against the new resistant pests (Carson 267). This chain of events has been repeated in Sardinia, Denmark, Egypt, the United States, and Greece. Each culminated in bigger, badder bugs.

Despite these events of the last century and the book Silent Spring, the WHO still believes that DDT should be used in Africa to combat malaria. According to an article from The New York Times, the WHO publicly supports more liberal application of DDT. The head of the program, Dr. Arata Kochi, is portrayed as a hardliner for DDT use in Africa, saying, e can put to rest the junk science and myths that have provided aid and comfort to the real enemy- mosquitoes (Dugger 1). With his intense style of leadership and blunt manner, he works to encourage and provide for more African countries to use DDT in the fight against malaria. He said that many countries have stopped using it because of their asty environmental reputation when farmers dusted crop fields, a reputation that is irrelevant when DDT is applied in small doses indoors (Dugger 3). However, as Silent Spring points out, a woman once died of leukemia after spraying her basement with DDT, having suffered such symptoms as anxiousness, nausea, fever, aches, and phlebitis before her death.

While green groups like Beyond Pesticides call for an end to use of poisons, other organizations like Africa Fighting Malaria (AFM) advocate DDT usage, sighting that it not harmful in such small doses. What they neglect to discuss is the after-effect of DDT, leaching into groundwater and soil, seeping into the human body and storing itself in human fat tissues, eventually making it to the reproductive organs and human milk. The WHO anticipates halving malaria deaths by 2010, but in using DDT, we may not be killing mosquitoes as much as we are killing ourselves and the ecosystems. The main argument of the WHO maintains that DDT is only toxic when sprayed over fields and forests, but poses no threat if applied locally. While in the short-term, DDT can kill malaria-causing insects, in the long-term, the mosquitoes will either flee the sprayed homes and then return to spread malaria or grow resistant and begin the cycle of harsher pesticides and stronger pests. According to a group of scientists who did research on rats and mice, If DDT use isn stopped, it will continue to affect animals with such health issues as pancreatic, mammary, and liver cancers, tumors of the liver and lungs, and mutations of bone-marrow cells (Rakitsky, Tomatis, and Turusov 2). They concluded that even if DDT was no longer used, it would take from 10 to 20 years for it to leave an individual body. They also concluded that a boycott of DDT was a luxury that poorer countries (say, those in Africa or Latin America or Asia) could not afford ithout substantial and long-term financial help ( Rakitsky, Tomatis, and Turusov 3).

Therein lies the truth of the matter in my mind- it all boils down to money. It is cheaper to continue using harmful pesticides than to switch to environmentally-safe alternatives, like biocontrol, using the mosquitoes enemies in nature, either bacterial, viral, or predatory. While options like these are available, they are not as lucrative and therefore not supported as loudly. This is not to say that the WHO is driven by incentives alone; it is to say that something is rotten if forty years after finding DDT to be toxic, it is still pervasive, especially in countries that lack the finances to make more ecologically sound choices.

1. Balter, Michael. "Can WHO Roll Back Malaria?". Science Magazine. http://www.sciencemag.org/cgi/content/summary/290/5491/430

2. Nabarro, David N. and Tayler, Elizabeth M. "The ‘Roll Back Malaria’ Campaign". Science Magazine. http://www.sciencemag.org/cgi/content/full/280/5372/2067?ck=nck

3. Roberts, Donald R.; Liroff, Richard A.; and McGuiness, Woody R. "Correspondence". Environmental Health Perspectives.http://links.jstor.org/sici?sici=0091-6765%28200107%29109%3A7%3CA302%3ADRA%3E2.0.CO%3B2-N

4. Rakitshy, Valery; Tomatis, Lorenzo; and Turusov, Vladimir. "DDT: Ubiquity, Persistence, and Risks". Environmental Health Perspectives.http://links.jstor.org/sici?sici=0091-6765%28200202%29110%3A2%3C125%3AD%28UPAR%3E2.0.CO%3B2-H

5. Dugger, Celia W. "WHO Supports Wider Use of DDT vs. Malaria". The New York Times. http://www.nytimes.com/2006/09/16/world/africa/16malaria.html?ex=1158724800&en=0f99e187693e3701&ei=5087%0A