Survey results of iodine content in drinking water in Yunnan Province from 2017 to 2018 / 中华地方病学杂志

ABSTRACT

Objective:To accurately grasp the current status of water iodine distribution in environmental of Yunnan Province, and provide a basis for scientific iodine supplementation.Methods:In 2017, according to the "National Drinking Water Iodine Content Survey Program", a survey of water iodine content was conducted in townships. In 2018, a search survey was carried out for administrative villages with water samples of iodine content > 40 μg/L in drinking water found in previous surveys. In centralized water supply villages, 2 samples of end water were collected. In decentralized or partially decentralized water supply villages, each village was divided into 5 parts east, south, west, north and center. In villages with more than 50 water sources, 10% of the water sources were selected from each part; villages with less than 50 water sources, one water source was selected from each part; villages with less than 5 water sources, all the water sources were selected to determine the water iodine content. At the same time, the mode of water supply and demographic data were investigated.Results:At the township level water iodine survey, a total of 24 589 water samples were collected from 1 389 townships in 129 counties of 16 prefectures (cities). The median water iodine content of township was 1.3 μg/L, ranging 0.0 - 9.3 μg/L. The population covered by the survey accounted for 53.94% (25 013 804/46 371 207) of the total population of the province. According to the survey results of high iodine villages, 93 administrative villages in 68 townships of 37 counties in 12 prefectures (cities) were surveyed, covering 40 940 households and 208 880 people. A total of 761 samples of drinking water were tested, and the median water iodine content of administrative villages was 1.3 μg/L (ranging 0.0 - 196.8 μg/L). There were 2 administrative villages with iodine higher than 100 μg/L, which were Xiaobona Administrative Village (145.8 μg/L) in Liuchang Township, Xiangyun County, and Dasongshu Administrative Village (196.8 μg/L) in Yangchang Township, Xuanwei City.Conclusions:The iodine content of water in Yunnan Province is generally low, which belongs to the area of environmental iodine deficiency. For the high iodine villages, further investigation should be carried out to clarify the prevention and control measures.