Although using DDT was already banned in many countries in the 1970s and the insecticide has been shown to be harmful to human and animal health, it continues to be used in agriculture and to combat malaria. In 2009, Biovision campaigned for alternatives to DDT at an international conference.
Hans Rudolf Herren is outraged: „It is a scandal that DDT is being used again in developing countries, because it is reputedly cheap“, says the president of Biovision. „It just would not even enter the question for us. And what is bad for us cannot be good for others!“ As food for thought, the president of the Swiss Biovision Foundation reminds us that the insecticide is banned for good reason. DDT undermines efforts towards sustainable agriculture, damages human and animal health, and contributes nothing to the long-term fight against malaria. Random sampling has already shown resistance to DDT in malaria mosquitoes.
From battling the cockchafer to dying birds
Dichlordiphenyltrichlorethan (DDT), before its prohibition, was viewed as a miracle substance for agriculture and control of disease-transmitting insects. At the beginning of the 1950s, aeroplanes dusted huge swathes of land with the insecticide. In Switzerland, these flights went down in history as the ‚cockchafer war’. It was the Swiss citizen Paul Hermann Müller who discovered the insecticidal effect of the substance and who subsequently received the Nobel Prize for his discovery. It was not long before there began to be evidence of the risks and side effects. DDT accumulates in body tissues, and the products of its degradation have similar effects to those produced by hormones. The substance was suspected of being carcinogenic. And it was not just dangerous to human health: birds laid eggs with shells that were too thin and in areas with a high level of DDT they literally fell from the skies.
Poison or lifesaver?
At the beginning of the 1970s, DDT was banned in most industrialised countries. In 2001 the Stockholm Convention came into effect; an international agreement on the prohibition of organic poisons which accumulate in the environment, including DDT. The treaty made the use of DDT possible only in justified, exceptional cases to control the mosquitoes that transmit malaria, provided there were no effective, affordable alternatives available. The Convention is currently recognised by 162 countries but not, however, by the USA. „The tragedy of malaria in Africa must provide the political pressure to bring about change in the international rules on global protection for health and the environment,“ declares Paul Saoke, director of Doctors for Social Responsibility in Kenya.
The lobby of the DDT supporters received reinforcement from the World Health Organisation (WHO), which suddenly expressly approved the use of DDT in households in 2006. Thus walls of huts and houses were sprayed with a suspension of DDT, intended to repel or exterminate mosquitoes, although later WHO explained its support for the goal of replacing DDT use with other measures in the fight against malaria. However, others, especially the USA, have used the position of WHO to preach the use of DDT. The Bush administration allocated millions of dollars for this within the framework of the ‚Presidential Malaria Initiative’. Supporters of DDT maintain that use of the insecticide in the fight against malaria can save lives. They emphasise that a low dosage in household sprays would cause no ill effects. Paul Saoke cautions against this and refers to the latest health studies in countries such as South Africa. These studies make it ever clearer that DDT even in small doses in an interior setting can pose a threat to inhabitants, which manifests itself especially in newborns.
Use of DDT is even more questionable since malaria can be combatted successfully using methods harmless to health and the environment. Hans Rudolf Herren continually points this out: „Producing and importing DDT to developing countries for use in malaria prevention is not the answer. Improper use in agriculture is sure to follow“, says the recognised scientist, and and warns „ We have enough proof that the problem of malaria cannot be solved with this insecticide. Quite the opposite – the whole situation actually becomes even worse!“
Misuse is inevitable
In reality, limitation of DDT use in many countries to controlled application in household rooms is an illusion. In Mozambique, DDT is already seen as a replacement for mosquito nets. The more DDT is in circulation, the greater the danger that it will be utilised in agriculture, and that could be catastrophic for the economies of affected states: under certain conditions they could no longer export their products. The World Trade Organisation allows for import protection against products with DDT residue, therefore many experts suspect that the USA and other industrialised countries are also following an economic and political agenda in advocating the use of DDT. DDT residue is a useful reason for keeping products from developing countries off the market.
There already exist details of its agricultural application at present, such as written by the secretariat of the Stockholm Convention in Genf in its report of autumn 2008. And yet an increasing number of states are introducing DDT without being able to guarantee effective controls and correct usage. According to the report, 4000 to 5000 tonnes of DDT are used annually worldwide; a trend that is growing. India is the main manufacturer, and there production increased 50% between 2005 and 2007. Stockpiles of DDT are growing too, and often there are no current statistics available, which makes it difficult for the appropriate international bodies to exercise control. The most recent reports from Mozambique, for example, date back to 2005. At that time 308 tonnes of DDT were stockpiled in the country.
The search for alternatives is ‚urgent and crucial’ states the current Stockholm Report. In past years these alternatives were pushed aside by DDT. The member states of the Stockholm Convention are meeting at a conference in Genf in May 2009, and for the first time the list of persistent organic pollutants (POPs) will be completed. How the ban can be enforced will also be discussed. Experts have already examined the case of DDT at a preparatory conference last November. Those taking part – among them representatives of Biovision from Switzerland and Kenya- have developed a business plan to promote environmentally friendly alternatives to DDT.
Organic, not chemical methods
Projects supported by Biovision in Kenya prove that there are environmentally friendly ways to combat malaria. Together with the international insect research institute icipe, Biovision carries out numerous projects in areas of Africa afflicted by malaria, covering more than 100,000 affected people. The people are informed of the danger presented by mosquitoes and are included in the elimination of breeding sites.
Through a combination of various methods – treatment of stagnant bodies of water (breeding sites) with environmentally friendly Bti (Bacillus thuringiensis israelensis), distribution of bed nets and treatment of the malaria disease itself – the deadly cycle between human and mosquito can be broken. The approach used by Biovision and icipe is effective: malaria infection rates in the project areas fell dramatically within two years. In Nyabondo (Kenya), for example, cases of malaria among children under five fell from 60 to 20%. And in Mwea (Kenya) the infection rate among schoolchildren fell from 38% to almost zero.
The recipe for success lies in co-operation with those affected, says project leader Charles Mbogo. There is no such thing as a ‚once and for all solution’ for malaria. The Kenyan scientist advocates that malaria control should be integrated into the health concept in the same way as control of disease-transmitting insects is a fixed component of healthcare in industrialised nations. Mbogo will present alternatives to DDT together with Biovision at the Stockholm Conference.