Environmentalists criticise use of DDT against Malaria

Environmentalists in Tanzania have criticised the recent decision by a number of East African governments to endorse the use of DDT in the fight against Malaria.

DDT (or Dichlorodiphenyltrichloroethane) is a commonly-used insecticide in developing countries, and the spraying of houses with the chemical has proved to be effective in killing mosquitos and thus reducing the incidence of malaria. But according to the Stockholm Convention, DDT is one of the most persistent organic pollutants, and its use has been banned or severely restricted in all industrialised countries.

A study undertaken by Anyambilile Mwakatole, a chemist with the environmental NGO Envirocare, has found that uncontrolled use of DDT for decades, has had adverse effects on human and environmental health. This has been substantiated by epidemiological and experimental studies in several countires. Some of the studies have shown the persistence of DDT residues in human fats, and in mothers’ milk.

The use of DDT increases cancer risks., as result of residues accumulating in nerve cells, the brain, the liver, heart and glands. Brain growth, mental health and intelligence can be affected and exposure to DDT increases the risk of deformed children being born.

A child who is contaminated with halogenated hydrocarbons in the mother’s womb and from the mother’s milk will have difficult in learning due to possible brain damage or become sick easily due to a reduction of body immunities.

Exposure to DDT occurs mostly from eating foods containing small amounts of DDT compounds, particularly meat, roots, vegetables and fish. High levels of DDT can affect the nervous system causing excitability, tremors and seizures. Breathing contaminated air or drinking contaminated water near waste sites and landfills is extremely dangerous to health. In women, DDT can cause a reduction in the duration of lactation and an increased chance of having premature babies. It has been found to lower sperm count and fertility in men.

Weighed against this, is the fact that DDT is effective in fighting one of East Africa’s biggest killers – malaria. In Tanzania alone, malaria is responsible for more than one-third of the child mortality under age 5 and for up to one-fifth of the deaths among pregnant women. Malaria kills about 100,000 children annually. It also accounts for 55 per cent of hospital admissions.

The 2006 World Malaria Report points out that at present, malaria remains the number one child-killer in Africa. It kills 3 times more people than Aids. Global warming has prompted mosquitoes to spread to areas where they were previously unable to survive.

It is against this background that the Tanzanian government has stated its intention to re-introduce DDT.

But environmentalists, along with many agriculturalists, scientists, and members of the general public, have reacted strongly against the decision. They say the harmful effects of DDT far outweigh its supposed benefits. Environmental activists say the government’s stance on safe application, supervision and monitoring to prevent contamination of the food chain leaves a lot to be desired. The ask whether the authorities are prepared for the long-term adverse effects of the insecticide on humans, ecosystems and biodiversity.

Critics of DDT use point out that any clean-up of homesteads which have used DDT will affect water flows that end up in rivers and lakes, and ultimately, the sea.

Environmentalists and other critics of the chemical charge that the only beneficiaries from DDT use are chemical companies based in developed countries, who must find export markets for the product, as it is banned in their home countries. They have urged the Tanzanian government to fight against malaria without necessarily subjecting its citizens to the pesticide’s toxicity. They have pointed to some possible alternatives – such as destroying the breeding sites of the female anopheles mosquito using environmentally friendly pesticides such as pyrethrims from pyrethrum.

(DDT is sold under many trade names, such as Agrotox, Anofax, Antelope, Arkotine, Azofeno CE, Canfeno DDT, Celbane, Cesarex, Chlorophenothane, Cock, Cotton Dust, Cotton Spray, Diamekta, Dicophane, Didigam, Didmac, Difanil, Digmar, Dinosid, DND, Double sirallow, Estonate, Fedwtox DDT, Genitox, Gesapan, Gesarex, Gesarol,GNB, Guesapon, Guesarol, Gyron, Hildit, Ixodex, Kapsol, Neocid, Palsatox No 79, Panda, Pentachloria, Pentech, R50, Ruksean, Santobane,Tangatox, Toxafeno DDT, Zeidane, Viscafeno DDT, Toxametil and Zertane.)