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close this bookCentral Eurasian Water Crisis: Caspian, Aral, and Dead Seas (UNU, 1998, 203 pages)
close this folderPart II: The Aral Sea
close this folder5. the Aral Sea and socio-economic development
View the document(introduction...)
View the documentIntroduction
View the documentThe technical system of cotton monoculture
View the documentThe cotton swindle
View the documentEnvironmental problems and human health
View the documentThe problem of pesticide pollution
View the documentThe environment of the Aral Sea and international cooperation
View the documentThe future of Central Asia
View the documentRecommendations
View the documentReferences

The problem of pesticide pollution

Pollution of water and soil

The catastrophe of the Aral Sea can be summarized in one word: cotton. For years, huge overdoses of chemical fertilizers, pesticides, and defoliants have been poured onto the cotton fields. Among them were DDT, BHC, methyl mercaptophos, octamethyl, butifos, milbex, hexachlorane (BHO), phosphamide (dimethoate), phosalone, lenacil, ronit (Ro-Neet), yalan (molinate), sodium TCA, chlorazone, and aldrin. The chemicals are not only discharged into the rivers through drainage canals, but have also filtered through to the groundwater layer when the salinated land is flushed by huge amounts of irrigation water, thus creating capillary channels between surface water and groundwater. The capillary action carries groundwater containing minerals and chemicals to the surface, where they are left to accumulate after the evaporation of the water. The groundwater itself also carries chemicals to the lower part of the river basin, where people are forced to use it for drinking and cooking.

In Uzbekistan, an average of 146.8 kg of chemical fertilizer in 1965, 238.3 kg in 1975, and 305.6 kg in 1987 was applied to each hectare of agricultural land, whereas the figure was 122.1 kg in 1987 for the whole USSR. Pesticides and herbicides too were dumped onto the cotton fields of Uzbekistan. In 1980, for example, 121,400 tons of chemicals were used. In the late 1970s, the total amount was between 30 and 35 kg per hectare on Uzbekistan's cultivated land, almost 30 times higher than the average for the whole USSR.

Butifos and its history

Butifos (S, S, S-tributyl-trithiophosphate; (C4H9S)3PO) is similar to the American preparations Folex and DEF. It was recommended for use in 1964 on the initiative of the USSR Ministry of the Chemical Industry and the USSR Ministry of Agriculture's State Commission on Chemical Herbicides and Pesticides, with the consent of the USSR Ministry of Public Health but with incomplete data on its toxicity. Butifos acts on the human body by affecting the central nervous system, the heart, the liver, and the kidneys and disturbing immunological reactivity, especially in children. The nauseating stench from the fields creeps over villages and suburbs, causing a sharp deterioration in the way residents feel, and sometimes leading to dangerous allergic reactions. In 1983, finally responding to the demands of the republic's physicians and scientists, the USSR Ministry of Public Health banned the use of butifos in agriculture altogether. But it reserved the right to authorize its use in certain campaigns and in certain republics at the request of interested departments. In 1984 roughly 70 per cent of Uzbekistan's fields were treated with butifos, and in 1985 the figure was still about 60 per cent.

Substitutes and intoxication

Substitutes appeared as early as 1965. The Institute of Chemistry of the Uzbek Academy of Sciences developed a less toxic, inexpensive, and sufficiently effective defoliant based on calcium cyanamide. Its proposal was rejected by the Ministry of Agriculture, which claimed that the republic was already supplied with an "effective" defoliant. By the late 1970s, another preparation was developed in the republic that was superior to butifos in every way and was still only slightly toxic. This preparation, known as UDM, underwent the prescribed tests and in 1980 received the approval of the highest authority the USSR Ministry of Agriculture's State Commission on Chemical Herbicides and Pesticides. It was only in March 1987, however, that the USSR Ministry of Public Health banned the production and usage of butifos.

With regard to the health status of schoolchildren living in a rural area of Uzbekistan, a high proportion of diseases of the nervous system and mental disorders may be associated with chronic pesticide intoxication and Beketova, 1993). It has been noted that in regions where toxic chemicals are intensively used children exhibit a significant decrease in phagocytic activity of leukocytes (Sadikova et al., 1990). Examinations of the eyes of 5-14-year-old children living near fields and exposed to pesticides revealed significant increases in intra-ocular pressure and in humour production (Khamdamov, 1976). Water samples from different sources to the south of the Aral Sea region indicate the ability to induce chromosomal abnormalities in the somatic and sexual cells of mammals (Zakhidov et al., 1993). A four-fold increase in chromosomal rearrangement and a five-fold increase in polychromatophilic erythrocytes with micronuclei were found in the bone marrow of wild mice caught in cotton fields subjected to intensive application of various pesticides (Khalikov, 1990).