PROCESS FACTORS INFLUENCING THE SUPPLY OF IODISED SALT TO HOUSEHOLDS IN SOUTH AFRICA

摘要

Several factors playing a role in the supply of adequately iodised salt to households have been investigated in South Africa after the introduction of mandatory iodisation of salt at a higher iodine concentration than before. The iodine concentration studied quantitatively (titration method) at the retail level in 48 magisterial districts over a five year period showed an initial improvement followed by signs of backsliding necessitating an investigation at the production sites. Wide variation was found in the iodine concentration, determined by means of the titration method, of iodised salt at the production sites mainly due to a lack of internal monitoring. An educational campaign and providing training in the titration method to all salt producers improved the accuracy of salt iodisation. In two national studies, in 1998 and 2005, the coverage of adequately iodised salt (>15 ppm, titration) at the household level improved from 62.4% to 76.9% and identified reasons for not achieving the goal of 90%. The iodine concentration in drinking water was low in 7 of the 9 provinces, slightly elevated in one province and greatly elevated in another province. Despite no legal requirement to use iodised salt in processed foods, a significant amount of iodine was found in the processed foods of a third of the food companies included in a study. Nationally, the knowledge of iodine nutrition was low amongst the general population, particularly amongst low socio-economic groups.This model of investigating the process factors involved in the supply of adequately iodised salt to households showed a progressive improvement over recent years and identified weaknesses requiring targeted intervention.