Nairobi — For some months now, there has been a low-key debate in the opinion pages of various newspapers over the proposal to return to using the pesticide DDT to fight malaria in Kenya.

It is odd that this very significant debate has not attracted more attention. Kenyans affected by malaria occupy more hospital beds than those suffering from any other disease, including HIV/Aids. Malaria, then, is the biggest drain on the limited funding available for public health. It is Kenya's greatest health crisis.

In the circumstances, you might wonder why there should be a debate at all. It was through extensive DDT use that the disease was wiped of Europe and North America in the 1950s .

In fact, even more DDT was used to control the pests on various crops, especially cotton in the US.

But DDT has one major problem: it is not "biodegradable." This means that normal biological processes, such as digestion in animals or the chemical reaction in plants, cannot break it up into simpler chemicals.

Moves up the food chain

It remains as DDT at every level. This causes it to steadily get more and more concentrated as it moves up the food chain.

So if you spray DDT on grass, for example, the insects that feed on the grass will retain a certain level of DDT in their bodies. When birds eat these insects, they will end up with an even higher DDT level within them.

And when some predator eats these birds, then, over a period, the predator will have such a high level of DDT within it as to amount to an effective poison.

Specifically, DDT has been said to be carcinogenic (cancer-causing) if it gets concentrated within a single animal.

In this way, then, DDT ends up poisoning an environment over a period. The tendency to concentrate in food chains is what led to this pesticide being banned in most Western countries due to concerns by environmentalists.

But, as proponents of DDT use point out, signs of excess DDT concentrations in wildlife appeared in zones where, in the US and other countries, DDT had been used as an agricultural pesticide, not to eradicate malaria.

Some scientists claim that the effect of the DDT levels sprayed inside the house in mosquito eradication projects is minimal. It cannot be compared to the many tons of DDT used for aerial spraying of cotton in the US in the 1950s and 60s.

But, as there is no scientific consensus on any of these claims against DDT, the ban remains.

When extended to Africa the ban denies the people most affected by malaria a powerful means of eradicating it.

And the ban is enforced, not by just dictating to the African countries concerned, but by a linkage to one of Africa's most valued exports, horticulture.

The EU has warned of possible sanctions on the agricultural exports from Uganda, Kenya and other countries that use DDT.

Specifically, there have been warnings that Western environmental and consumer organisations are certain to exert pressure on supermarkets to stop selling the agricultural produce from countries that use DDT to fight malaria.

The favoured option by various UN agencies, the EU and various aid agencies is treated mosquito nets, which are available at greatly subsidised prices all over East Africa. These secrete mosquito-repellent chemicals and it is claimed that they are key to preventing malaria in small children.

However, this is one of those solutions which seem feasible at a great distance but which, in practice, are of limited value. What African children need is not treated mosquito nets but DDT sprayed on their walls. Especially as most poor African children do not sleep in beds at all, but on mats scattered on the floor of their mud huts - a situation that makes the use of any mosquito net very complicated.

This ban also has economic implications for the poor African countries.

Lucrative EU market

Countries like Kenya and Uganda, which consider growing fruit, flowers and vegetables for export to the EU to be their most profitable crops, have a stark choice to make. They can either use DDT to wipe out malaria, as the EU countries and the US did some 50 years ago, and risk having their agricultural exports boycotted in the lucrative EU market.

Or they can accept advice by the EU representative and continue to profit from the exports of flowers, vegetables and fruits, while allowing malaria to continue killing their young children.

Both Uganda and Tanzania have moved toward a decisive choice in favour of their children's lives and are set to resume using DDT.

But Kenya, a major flower and vegetable exporter to the EU - and which has an active lobby group for the horticultural sub-sector - has thus far avoided taking any firm decision. And DDT use remains banned in Kenya.

This is not at all a simple choice. Really, the Government cannot be blamed for the hesitation as it seeks viable alternatives to DDT.

Many children are dying of malaria while the Government tries to come up with those solutions. Yet DDT is readily available, the cheapest and most effective solution to the malaria crisis.