Malaria kills nearly one million children in Africa each year and costs the continent between $10 and $12 billion dollars in productivity. This past September, the World Health Organization (WHO) recommended the use of the chemical known as DDT (dichloro-diphenyl-trichloroethane) to control malaria in Africa. DDT is an effective pesticide, but it was banned by the U.S. in the 1970s for its alleged toxicity and damage to the environment. DDT's reintroduction as a means to control malaria is causing great controversy. Should DDT, a toxic chemical, be used to curb malaria in Africa? DDT could potentially save millions of lives, but at what expense?

In Africa, malaria is the number one killer of children and a chronic illness suffered by millions of adults. When the WHO reversed a 30-year long policy that had prohibited the use of DDT, a cheap and effective pesticide, African countries ravaged by the disease rejoiced that they could now possibly access an affordable solution to Africa's malaria epidemic.

DDT was used in the 1940s to effectively eliminate the mosquitoes that carry malaria in the United States and Europe, but the chemical was banned in the U.S. in 1972 because of evidence that it had adversely affected wildlife and was a hazard to human health. Now there is a heated debate between those who support DDT's return to reduce the spread of malaria in Africa and those afraid of its long-term effects on the environment and human health.

Malaria's Effects in Africa

Malaria is a devastating illness for most African countries. It kills over one million people each year, 80 per cent of which are young children. Part of the challenge of controlling malaria is that it is difficult to contain. The disease is caused by a tiny micro-organism or parasite carried by female mosquitoes. When female mosquitoes with this parasite bite humans they infect the red blood cells. Malaria can cause high fevers, vomiting, anaemia and death especially in children under the age of five. Malaria can also interfere with fetus development during pregnancy. If a pregnant woman is infected, the parasites that cause malaria are absorbed into the placenta and steal away essential nutrients from the unborn baby. This often leads to abnormally low birth weights and anaemia. In some cases, malaria infects the human brain. This is most devastating in young children where it may result in seizures, disabilities, blindness, learning difficulties, coma or death.

DDT was used in the 1940s to eliminate mosquitoes that carry malaria in the United States and Europe, but the chemical was banned in the U.S. in 1972 because of evidence that it had adversely affected wildlife and was a hazard to human health.

According to a program about malaria broadcasted by National Public Radio, economists gauge Africa loses between $10 and $12 billion dollars in annual productivity because of malaria. In Uganda, for example, malaria has cost the country more than $347 million dollars per year, more than 80,000 people have died from the disease (half of these are children under five) and 40 percent of the country's medical expenses go to caring for those with malaria.


Rediscovering DDT: An Effective Pesticide

Effective elimination of the tiny organism that causes malaria has proven very difficult. Instead, killing the mosquitoes that carry malaria is accepted as a much more feasible option according to May Berenbaum, head of the department of entomology, the study of insects, at the University of Illinois. This is why mosquito-killing DDT is being reconsidered. The chemical was rediscovered in 1939 by a Swiss chemist named Paul Mueller. Mueller decided to experiment with DDT, which had been first produced in 1874 in a German laboratory. He tested it alongside other manufactured substances for its ability to kill insects and discovered DDT was extremely effective, more so than the other chemicals he tried. DDT was also less expensive and less cumbersome to produce than other chemicals and could be quickly and easily made in chemical factories from cheap ingredients. Mueller won the Nobel Prize in Medicine in 1948 for his discoveries relating to the uses of DDT.

Between 1947 and 1951, DDT was used as part of an effective malaria eradication strategy in the United States. The Center for Disease Control (CDC) states that in July of 1947 applications of DDT were made inside houses where malaria was reported. Most of these were rural homes. In some cases large parts of entire counties were sprayed with DDT. By 1949, over 4.6 million applications of DDT were made to homes throughout the United States. As a result, malaria was no longer considered a major public health concern. It is also worth noting that DDT spraying was accompanied by several other mosquito eradication strategies including drainage, removal of mosquito breeding sites, and spraying of other insecticides, sometimes via aircraft.

In Uganda malaria has cost the country more than $347 million dollars per year, more than 80,000 people have died from the disease (half of these are children under five) and 40 percent of the country's medical expenses go to caring for those with malaria.

In the 1940s, the use of DDT also successfully eliminated malaria in some South African provinces and significantly reduced the number of malaria cases in others. For example, in 1946 in the province Transvaal, cases were reported to have declined to about a tenth of what they had been reported to be in 1942 and 1943. KwaZulu Natal is another area in South Africa that has struggled with malaria since the early 20th century. In 1932, about 22,000 deaths were caused from malaria out of a population of about 1.8 million people. When DDT was introduced, malaria was virtually eliminated. In 1996, however, South Africa caved under the pressure of the environmental lobby and stopped using DDT. Subsequent to the DDT ban, KwaZulu's cases of malaria shot up from a reported 8,000 cases in 1996 to 42,000 cases in 2000. In 2001, DDT spraying resumed and there was a 77% reduction in reported cases that year.

DDT's Opponents

While DDT helped to reduce malaria infection in the U.S. after World War II, it also purportedly had adverse effects on wildlife. Rachel Carson's 1962 book Silent Spring, which is credited with formally launching the environment movement in the U.S., documented DDT's harmful effects on wildlife. Carson's work noted how DDT seeped into the ground and was absorbed by water sources, ultimately becoming stored in the fatty tissue of fish and worms. Birds including bald eagles and robins became ill and many died from eating the contaminated prey. Banning DDT became the cause célèbre for many environmental activists and organizations, and a complete ban on DDT was put into effect in the U.S. in 1972. Since then, major donor countries in Europe and the United States have generally avoided sponsoring projects in developing countries that involve DDT.

The WHO's announcement to reintroduce DDT has enraged the environmental lobby mainly in the U.S. and in Europe. Many environmentalists who belong to these groups fear the implications for human health and the environment that a change in policy on DDT would bring. Richard Posner from the University of Chicago wrote, "DDT is causing 10,000 extinctions of animal species annually. A decrease in biodiversity may have unforeseeable potentially catastrophic implications for the human species." According to Jay Feldman, executive director of the group Beyond Pesticides, DDT has been studied and found to increase the risk of cancer, endocrine disruption and weaken the immune system. Because DDT collects in fatty tissue in humans it can contaminate a mother's breast milk, adversely affecting babies who are breastfeeding. In a study published by Environmental Pollution, "The return of DDT for malaria control in South Africa has lead to women with 77 times the international limit for DDT residue and 12 times more than WHO's acceptable intake limit in infants, even in families not living in treated dwellings."

Vehement protest from the environmental lobby against DDT is also politically motivated. Many of these groups established themselves alongside the campaign to ban DDT in the 60s and 70s. Environmental lobbies in the U.S. and in Europe saw the ban placed on DDT in the 70s as a great political achievement. Prohibiting the use of DDT has been a part of their political campaigns since many of these groups were founded.

As a result many of these environmental groups are raising concern in the U.S. and Europe that reintroducing DDT in African countries will contaminate Africa's agricultural exports. Even though WHO's statement endorses DDT only for public health purposes, some activists in the U.S. and Europe express fear that DDT use will go beyond its intended purpose and contaminate Africa's agricultural and fish exports. Impoverished African countries, therefore, worry that even controlled DDT use will negatively impact demand for their exports. The perception that countries especially in Europe would begin to block imports of African products is so serious that Uganda's ministries of trade and health are in a deadlocked debate over the issue. Dr. Arata Kochi, Director of WHO's Global Malaria Program, has encouraged European countries to step in and dispel the myth that demand for African products will decline if DDT is used for malaria control.

Many environmental groups are raising concern in the U.S. and Europe that reintroducing DDT in African countries will contaminate Africa's agricultural exports. Uganda's ministries of trade and health are in a deadlocked debate over the issue.

In the past, the World Bank, USAID and other global development agencies refused to fund anti-malaria initiatives that involved the use of DDT. In 2003, USAID informed The Washington Monthly that its activities are focused to reduce reliance on the pesticide DDT. Instead, they emphasized prevention, medical intervention, and mosquito nets dipped in pyrethroid, another kind of insecticide. It was also reported that UNICEF, The United Nations Children's Fund, and the international aid agencies of Sweden, the United Kingdom, Norway, Japan, and Germany would not fund DDT projects.

Reconsidering DDT for Malaria Control

Since the WHO's announcement, however, the Bush administration appears to fully back the use of DDT as a tool for malaria control. The head of President Bush's $1.2 billion dollar anti-malaria effort, Mr. R. Timothy Ziemer said in a news conference that spraying with insecticides is a tool "that must be deployed as robustly and strategically as possible."

The argument against DDT is both moral and practical. If DDT is known to be a toxic chemical then why should impoverished countries have to settle for poisonous short-term solutions that may have more serious longer-term implications? Then there is the practical concern that the mosquitoes transmitting malaria are increasingly resistant to DDT. Entomologist May Berenbaum points out that DDT was discontinued not primarily because of its effects on wildlife or the environment, but because mosquitoes became resistant to it. By 1949, a number of cases where DDT failed to kill off the malaria-carrying mosquitoes had been documented. Even in cases where mosquitoes are not resistant to DDT, in order for the pesticide to have a significant impact, 80 percent of households must be sprayed every 6-12 months. The infrastructure, coordination, equipment and labour required to support such initiatives do not exist in most African countries.

No Panacea

The WHO's announcement has come at a time when malaria infection is at an all time high and is severely hindering Africa's development. The fact that DDT is understood to be a toxic chemical illustrates the WHO's desperation to find a way to get Africa's losing battle against malaria under control. Having worked in African countries, I have witnessed malaria's debilitating impact on individuals, families and communities. People are unable to work and children cannot go to school or learn properly as a result of this incapacitating disease. The malaria issue must be addressed before economic development, democratisation or other attempts to improve Africans' quality of life can be achieved.

It's important to note that the WHO is not advocating exclusive reliance on DDT and has clearly stated that DDT should be used in conjunction with bed-nets and medicines. Moreover, it is not advocating for DDT to be used beyond controlling the spread of malaria. Critics are right, however, to point out that DDT may not be a good solution in cases where mosquitoes are resistant. And environmentalists are right to raise awareness regarding DDT's potential effects on plant and animal life. Neither overselling DDT and ignoring its risks nor prohibiting its use entirely when millions of lives are at stake is the solution. Instead, a diversified approach drawing on precise, adaptable and effective tools is required. At this point in time, there is no panacea for malaria. All methods to eliminate the disease-carrying mosquitoes have benefits and drawbacks. For now, Africa will have to do its best with the tools available to save as many lives as it can while mitigating environmental and health costs. The best the rest of the world can do is let them.

Links:

2004. "Eradication of Malaria in the United States (1947-1951)." Source: National Center for Infectious Diseases, Division of Parasitic Diseases. 23 April. Available from Center for Disease Control and Prevention .

2006. "DDT, Malaria, and the Environment--Posner's Comment." 24, September. Source: The Becker - Posner Blog by Gary Becker and Richard Posner. Available from Becker-Posner Blog.

Beyond Pesticides. "Groups Say DDT Use for Malaria Control Threatens Public Health." Available from Beyond Pesticides [online].

Dugger, Celia W., 2006. "W.H.O. Supports Wider Use of DDT vs. Malaria." The NY Times. 16 September.

Gourevitch, Alexander, 2003. "Better Living Through Chemistry." The Washington Monthly. March.

Tren, Richard, Bate, Roger, 2005. "South Africa's War against Malaria. Lessons for the Developing World." Policy Brief No. 513. 25 March. Source: Cato Institute. Available from CATO Institute [online].

Wilson, Brendon, 2005. "New Malarial Therapy Reaches Remote Africa." National Public Radio. All Things Considered. 2 November.




Contributed by Cory McCruden, a Rotary World Peace Fellow and writer for Global Envision.

To read another Global Envision article about health effects of DDT, see DDT, Malaria, and Africa.



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