[Investigation of iodine content in drinking-water of Gansu Province in 2017].

OBJECTIVE: To investigate the water iodine content and distribution of drinking-water in Gansu Province, and provide scientific evidence for the implementation of strategies for prevention and treatment of iodine-related diseases. METHODS: The multilevel sampling method was adopted, take the township as sampling unit at the first level, and the administrative village with the median water iodine ≥10 μg/L as the second level sampling unit, different water supply modes(centralized, partial concentration and decentralized water supply) were sampled and the water iodine were detected by recommended iodine deficiency disease test method. RESULTS: A total of 8976 drinking water samples were detected from 1388 towns of 14 cities. the detection range was 0. 0-84. 6 μg/L, the median water iodine was 2. 3 μg/L, and 8301 samples were<10 μg/L, 663 samples were 10～<50 μg/L, 12 samples were ≥50 μg/L, with a ratio of total at 92. 5%, 7. 4% and 0. 1%, respectively. Water iodine content varies between three different water supply method(χ~2=8. 923, P<0. 05), decentralized water iodine was lower than partial concentration water supply(Z=-2. 891, P<0. 01). 71 townships of median water iodine were ≥10 μg/L(5. 1%), the water iodine median range was 10. 1～64. 3 μg/L, 76. 1% of townships were 10-<20 μg/L, 11. 3% were 20-<30 μg/L, 5. 6% were 30-<40 μg/L, 7. 0% were ≥40 μg/L(χ~2=13. 302, P<0. 05). Water samples of 895 administrative villages were detected, the median water iodine was 10. 8 μg/L, 466 administrative villages with a median water iodine ≥10 μg/L, the water iodine range was 10. 0～113. 1 μg/L, the median water iodine was 10. 8 μg/L, Administrative villages of 10-<50 μg/L, 50～<100 μg/L and ≥100 μg/L accounted for 96. 6%, 2. 4% and 1. 0%, respectively. CONCLUSION: Iodine deficiency areas were exist universally in Gansu Province, but there is high iodine point-like distribution areas in the administrative villages. While pay close attention to prevention of Iodine deficiency, the iodine nutrition status monitor in different iodine areas and the iodine supplementation strategy adjusting should be concerned too.