Analysis of investigation results of iodine content of drinking water of residents in Ningxia Hui Autonomous Region in 2017

Objective To understand the iodine content of drinking water in Ningxia, and provide a basis for promoting scientific iodine supplementation. Methods In 2017, 22 counties (cities, districts) of Ningxia Hui Autonomous Region were surveyed by township (town, street office) as the unit. Water samples were collected and iodine content was detected according to the unified centralized water supply, mixed water supply and all the scattered water supply methods. Among them, the investigation at township (town and street office) level found that the median of iodine in water was > 10 μg/L, and then the water samples were collected in administrative villages (neighborhood committees) and the content of iodine in water was detected. Results A total of 242 townships (town, street office) were surveyed at the township level water iodine, and a total of 1 048 water samples were collected, the median water iodine was 6.6 μg/L, the range was 0.0-97.8 μg/L. There were 75 townships with a median water iodine > 10 μg/L, and an administrative village level water iodine survey was conducted. A total of 1 169 water samples were collected, the median water iodine was 14.5 μg/L, and the range was 0.0-97.4 μg/L. The median water iodine at the township level, unified centralized water supply, mixed water supply, and all the scattered water supply was 6.9, 6.8, and 4.5 μg/L, respectively. The difference was statistically significant (χ2 = 7.08, P < 0.05). The median water iodine at the administrative village level, unified centralized water supply, mixed water supply, and all the scattered water supply was 15.8, 8.4, and 11.6 μg/L, respectively. The difference was statistically significant (χ2 = 35.23, P < 0.05). Conclusion The iodine content of drinking water in Ningxia residents is low, which is consistent with the fact that Ningxia is in the iodine deficient area. Key words: Drinking water; Iodine; Investigation