Profile of iodine content of salt and urinary iodine excretion levels in selected districts of Tamil Nadu.

Abstract

Iodine deficiency disorders (IDD) is the most common cause of preventable mental retardation in world today. Out of 29 districts in Tamil Nadu, 24 have been surveyed and all have been found to be endemic to IDD. There is a complete ban on the sale of non iodised salt in the state since 1995. The present study was conducted to assess the iodine content of salt and urinary iodine excretion levels amongst the beneficiaries in the state to help the government to strengthen the existing Universal salt iodisation (USI) programme activities. The study was undertaken in 24 districts of Tamil Nadu during the year 2001. The guidelines recommended by WHO/UNICEF/ICCIDD for a rapid assessment of salt iodisation in a district was adopted. A minimum of 150 salt samples were collected from each district by utilising the uniform sampling methodology. The iodine content of salt samples was analysed using the standard iodometric titration method. At least 60 children from each school were randomly selected and were requested to provide "on the spot" casual urine samples. The urinary iodine excretion (UIE) levels were analysed using the wet digestion method. It was observed that 62.3% of the families were consuming iodised salt with more than 5 ppm of iodine. It was found that district Perambalour had deficient iodine nutriture as revealed by the median UIE levels less than 100 micro g/l. The findings of the present study reveals the success of USI programme and highlights need for continued monitoring of the quality of salt provided to the population in order to achieve the goal of IDD elimination.