Analysis of a national surveillance results of iodized salt in 2008 / 中国地方病学杂志

ABSTRACT

Objective To study the national surveillance results and learn the current situation of iodized salt consumption at household level in 2008, and to find out the remaining problems and to provide scientific basis for developing control strategies against iedine deficiency disorders. Methods In 2008, in accordance with the requirements of the "National Iodine Deficiency Disorders Surveillance Program (Trial)", the surveillance was conducted at county level in 31 provinces and at division level in Xinjiang Production and Construction Corps. In each county 9 townships were randomly selected according to their sub-area positions of east, west, south, north and center;4 villages were randomly sampled in each chosen township;8 households were randomly selected in each chosen village. In every county with 9 or less townships, 1 township was randomly selected respectively in the east, west, south,north and center sub-areas;4 villages were randomly sampled in each chosen township;15 households were randomly selected in each chosen village. Edible salt from these households was collected. Iodized salt coverage rate, proportion of qualified iodized salt and consumption rate of the qualified iodized salt of the households in each province were counted and analyzed. Iodized salt was determined by direct titration;the salt samples from Sichuan and other enhanced salt were detected by arbitration. Results Totally 2817 counties (districts, cities, banners) and 14 divisions of the Xinjiang Production and Construction Corps reported the monitoring results, monitoring coverage reached 99.96%(2831/2832). Mean of iodine content was 31.51 mg/kg.Sixteen provinces had a variation coefficient of iodine content for more than 20%. A total of 826 968 households were tested of their edible salt, in which iodized salt 798 725 copies, non-iodized salt 28 243 copies, and unqualified iodized salt 20 270 copies. Weighted by population,at national level, the coverage rate of iodized salt was 97.48%, qualified rate of iodized salt 97.16%, and consumption rate of qualified iodized salt was 94.79%.Twenty seven provinces (autonomous regions and municipalities) and Xinjiang Production and Construction Corps had a qualified iodized salt coverage rate of above or equal 90.00%. Tibet, Hainan, Xinjiang and Tianjin provinces (regions) had a qualified iodized salt coverage rate lower than 90.00%. Further, 2487 counties had the rate high or equal 90.00% accounting for 87.82% (2487/2831) of complementing monitoring counties. One hundred and four counties and 1 division of the Xinjiang Production and Construction Corps had the coverage rate of iodized salt below 80.00%. Conclusions Sixteen provinces(autonomous regions and municipalities) have relatively a high degree of variation coefficient in salt iodine content. The quality of iodized salt needs to be improved. The coverage rate of iodized salt and the qualified iodized salt at national level are both above or equal 90.00%. However, the non-iodized salt problem is still serious and have a relatively lower coverage of iodized salt in Tibet, Hainan and Xinjiang.