of Tajikistan's environmental problems are associated with the agricultural policies imposed on the country during the Soviet period. By 1991 heavy use of mineral fertilizers and agricultural chemicals was a major cause of pollution in the republic. Among those chemicals were DDT, banned by international convention, and several defoliants and herbicides. In addition to the damage they have done to the air, land, and water, the chemicals have contaminated the cottonseeds whose oil is used widely for cooking. Cotton farmers and their families are at particular risk from the overuse of agricultural chemicals, both from direct physical contact in the field and from the use of the branches of cotton plants at home for fuel. All of these toxic sources are believed to contribute to a high incidence of maternal and child mortality and birth defects. In 1994 the infant mortality rate was 43.2 per 1,000 births, the second highest rate among former Soviet republics. The rate in 1990 had been 40.0 infant deaths per 1,000 births. Cotton requires particularly intense irrigation. In Tajikistan's cotton-growing regions, farms were established in large, semiarid tracts and in tracts reclaimed from the desert, but cotton's growing season is summer, when the region receives virtually no rainfall. The 50 percent increase in cotton cultivation mandated by Soviet and post-Soviet agricultural planners between 1964 and 1994 consequently overtaxed the regional water supply. Poorly designed irrigation networks led to massive runoff, which increased soil salinity and carried toxic agricultural chemicals downstream to other fields, the Aral Sea, and populated areas of the region. By the 1980s, nearly 90 percent of water use in Central Asia was for agriculture. Of that quantity, nearly 75 percent came from the Amu Darya and the Syr Darya, the chief tributaries of the Aral Sea on the Kazakhstan-Uzbekistan border to the northwest of Tajikistan. As the desiccation of the Aral Sea came to international attention in the 1980s, water-use policy became a contentious issue between Soviet republics such as Tajikistan, where the main rivers rise, and those farther downstream, including Uzbekistan. By the end of the Soviet era, the central government had relinquished central control of water-use policy for Central Asia, but the republics had not agreed on an allocation policy. Industry also causes pollution problems. A major offender is the production of nonferrous metals. One of Tajikistan's leading industrial sites, the aluminum plant at Tursunzoda (formerly known as Regar), west