Iodine nutritional status & prevalence of goitre in Sundarban delta of South 24-Parganas, West Bengal.

BACKGROUND & OBJECTIVE In post salt iodization phase endemic goitre and associated iodine deficiency disorders (IDD) were found prevalent in a randomly selected rural area of Sundarban delta and its adjoining areas of West Bengal. The present investigation was thus undertaken to study the total goitre rate, urinary iodine and thiocyanate excretion pattern of the school going children, iodine content in edible salt and drinking water in the Sundarban delta of South 24-Parganas in West Bengal. METHODS A total of 4656 school children (6-12 yr) were clinically examined for goitre from 13 different areas in the delta region. Urinary iodine and thiocyanate levels were measured in 520 (40 from each area) samples collected randomly to evaluate the iodine nutritional status and consumption pattern of dietary goitrogen. Simultaneously iodine content was determined in 104 (8 from each area) drinking water samples and 455 (35 from each area) edible salt samples collected from the areas. RESULTS Children of all the areas were affected by endemic goitre. The prevalence rates were in the ranges from 25-61 per cent; overall goitre prevalence was 38.2 per cent (grade 1--34.0%; grade 2--4.2%). Median urinary iodine level in the studied areas was 225 microg/l (range 115-525 microg/l) indicating no biochemical iodine deficiency in the region. Mean urinary thiocyanate levels were in the range from 0.326-1.004 mg/dl. Iodine content in drinking water samples were in the ranges from 22-119 microg/l, and 55.6 per cent edible salt samples had iodine level above the recommended 15 ppm at the consumption point. INTERPRETATION & CONCLUSION The severity of endemic goitre was high in the studied population though the iodine nutritional status was found satisfactory in the region indicating no biochemical iodine deficiency. The people of the region consumed iodine through iodized salt but about 44 per cent of the salt samples at household level contained inadequate iodine, however their iodine intake was compensated through iodine in water and food. They also consumed dietary goitrogen. Environmental factors other than iodine deficiency may have possible role for the persistence of endemic goitre in the region. More investigations are thus necessary to arrive at certain definite cause of high goitre rates in this population.