DYNAMICS OF ENVIRONMENTAL SUPPLEMENTATION OF IODINE - 4 YEARS EXPERIENCE OF IODINATION OF IRRIGATION WATER IN HOTIEN, XINJIANG, CHINA

Hotien prefecture, Xinjiang Province, China, in the Taklamakan Desert, is an area of severe iodine deficiency. Because usual methods of iodi ne supplementation failed here, we began supplementation in 1992 with potassium iodate, which was added to irrigation water (Lancet 1994; 33 4:107-110). We report 4 y experience with this method in 3 townships t hat contained a total treated population of 37 000. Potassium iodate w as dripped into irrigation water (to a concentration 10-80 mu g/l) dur ing a 2- to 4-wk period. During the 3 y that followed, no further supp lementation was made, and iodine concentrations increased several fold in crops and plants, sheep and chicken thyroid glands, and meat and i n urine of children 2-6 y of age and of women who were of childbearing age. Infant mortality decreased 50%, and sheep production increased 4 3%. iodine repletion of soil through irrigation water is an effective and cost-efficient way of providing iodine in appropriate situations.