This article is a study on iodine nutritional status among 1627 school children aged 6-12 years, along with biochemical analysis of iodine of 200 urine samples, 50 drinking water samples and 175 salt samples carried out in certain randomly selected areas of the district Howrah in Gangetic West Bengal. Results indicate that the entire region is clinically goitre endemic having goitre prevalence 38%; however the median urinary iodine level was 25 microg/dl indicating no biochemical iodine deficiency, 70% salt samples had a recommended level of iodine and the region was found to be environmentally iodine sufficient. Consumption of dietary goitrogen and hard drinking water may have the possible role for the persistence of endemic goitre in the region.

Iodine content in drinking water samples ranged from 1.8-2.6 microg/l showing that the studied region is environmentally iodine deficient. Inspite of the consumption of adequate iodine, the existing goiter prevalence among school children during post salt iodization phase ensures that environmental factors other than iodine deficiency may have the possible role in the persistence of endemic goiter in the population. The role of thiocyanate in this regard may not be ruled out.

No abstract

Marine deposits in the Neogene Siwalik succession have been documented from the Tista valley, Bhutan and Kameng river sections of the Eastern Himalaya. This study was designed to investigate possible marine influence further east. During this investigation, it was revealed that the current classification and description of the stratigraphic units were inadequate to describe the variations present in this succession fully. In place of the existing three-fold classification, a four-fold lithostratigraphic classification of the Siwalik Group in the Arunachal Himalaya has been proposed by adding a new Siji Formation. This newly proposed formation is completely different from the underlying sand-dominated Subansiri or overlying conglomerate-dominated Kimin formations. Nearly 1000 m thick succession of the Siji Formation is characterised by of alternating tabular sheet like beds of grey mudstone, siltstone and sandstone with uncommon thin conglomerate beds. On the basis of the four-fold classification, the Siwalik rocks of the Arunachal Himalaya have been mapped over a strike length of ~230 km, demonstrating the lateral continuity of the individual formations and the large-scale deformational features affecting the rocks. Three lithologs prepared show the distinctive lithological characters and overall paleocurrent pattern of these formations. The lithological, sedimentological and ichnological features of the Dafla and Siji formations provide evidence for marine influence in the study area. The proposed new lithostratigraphic subdivisions are expected to facilitate regional correlation and evidence of marine sedimentation which will throw new light on the basin analysis of the Siwalik Group in the Eastern Himalayan.

No abstract