[Experience with iodine prophylaxis in the province of Bolzano].

Since 1981 in the province of Bolzano a "free-choice" iodine prophylaxis with iodinated dietary salt has been implemented. An epidemiological survey carried out in 1982 in 3109 schoolchildren living in this region showed an incidence of endemic goiter grade 1B-3 (WHO classification) of 23.6 +/- 14.0% and an urinary iodine excretion of 10.2 +/- 8.0 micrograms/l (colorimetric analysis) compared to the values of 39.6 +/- 17.7 micrograms/l found in a similar population of schoolchildren living in a non goitrous urban area in Northern Italy (Padua). This program of iodine prophylaxis was advertised through the local mass media. A further epidemiological survey, performed in the whole province in the year 1990, involving 1046 schoolchildren, randomly selected, showed an average goiter incidence of 1.6 +/- 1.3% and a urinary iodine excretion of 137.1 +/- 104.4 micrograms/l (ICP-MS analysis) in comparison to the values of 182.6 +/- 131.7 micrograms/l seen in the schoolchildren of the town of Padua. During the period of iodine prophylaxis the content of iodine in the commercially available iodinated dietary salt was also estimated. In 1990 the average content was 31.0 mg/kg and in 1997 was 27.1 mg/kg. These data therefore confirm the usefulness of iodinated salt in the prophylaxis of endemic goiter.