Analysis study of the forms o f water iodine in areas with excessive iodine in water in Henan Province / 中华地方病学杂志

ABSTRACT

Objective To investigate the forms of water iodine in areas with excessive iodine in water of Henan Province.Methods From December 2013 to January 2014,50 water plants in 4 cities (Puyang,Xinxiang,Kaifeng and Shangqiu cities) of Henan Province were selected from the areas with excessive iodine in water where iodized salt and centralized water supply were stopped for more than 5 years.In each selected water plant,3 water samples were collected.I2-Starch Spectrophotometer was used to measure the iodine content and identify the forms of iodine in water samples.Results A total of 403 water samples were collected and ultimately 286 samples met the requirement (water iodine ≥ 80 μg/L).Among the 286 samples,iodine existed in the forms of iodide in 6 water samples,of both iodate and iodide in 139 water samples,and of iodate in 141 water samples.In water samples with iodine content lower than 150 μg/L,the proportions of forms of iodide and both iodate and iodide,were 26.67％ (12/45) and 73.33％ (33/45),respectively.In water samples with iodine content between 150-299 μg/L,the proportions of the forms of iodide,both iodate and iodide,and iodate,were 4.88％ (6/123),79.67％ (98/123) and 24.39％ (30/123),respectively.In water samples with iodine content higher than 300 μg/L,the proportions of the forms of iodide and both iodate and iodide,were 18.18％ (2/11) and 81.81％ (9/11),respectively.Conclusions In areas with excessive water iodine in Henan Province,iodine mainly exists in the forms of iodate,or both iodate and iodide.No sample is found to contain periodate.