ABSTRACT
OBJECTIVES: Four hundred million people or more may be exposed to iodine deficiency worldwide, in developing countries in particular. Because of the practical problems with existing methods for the large-scale prevention of iodine deficiency, the authors developed a new approach to collective prophylaxis. METHODS: This approach relies on the controlled diffusion of iodine into water from a silicone elastomer. Silicone matrices installed in a bore well released iodine at a rate sufficient to permit the daily per capita intake of at least 100 micrograms of iodine, the amount recommended by the World Health Organization. The matrices were tested over 1 year in a village in Mali, West Africa, an area in which goiter was highly endemic. The effects on the well water and population were compared with those of a placebo system in a control village. RESULTS: An increase in urinary iodine levels was observed in the treated population, and after 12 months the incidence of goiter had fallen from 53.2% to 29.2%. CONCLUSIONS: This new concept, adaptable to all sources of water supply, may contribute to the eradication of iodine deficiency.