Iodine levels in drinking water in iodine deficiency and high iodine areas in Zibo city

Objective To look into the current distribution of iodine deficiency areas in Zibo city and to guide the re-defined iodine deficiency areas in order to supplement iodine scientifically.Methods 8 iodine deficiency counties(cities,districts),and 1 high iodine counties(cities,districts) were investigated in Zibo city according toSupplement iodized salt to eliminate the hazard of iodine deficiency management regulations.One to three samples were collected from water source which was used by the majority of local residents in 8 iodine deficiency areas and iodine concentration was tested by As3+-Ce4+ catalyzing spectrophotometry.Results A total of 3 676 water samples were collected.The median water iodine was 2.0 μg/L,64.71%(88/136) of the township(town) met criteria for the classification of iodine deficiency areas(water iodine10 μg/L),26.47%(36/136)of the township(town) water iodine moderate(water iodine 10~150 μg/L),and 8.82%(12/136)of the township(town) should be defined as high iodine areas(water iodine150~300 μg/L).However,in high iodine areas,9.26%(5/54) township(town) met criteria for the classification of iodine deficiency areas,35.19%(19/54) of the township(town) water iodine moderate,55.56%(30/54) should be defined as high iodine areas.Conclusions The deficiency and high iodine areas should be taken appropriate measures.The township(town) should be set as the smallest place to supply salt with different range of iodine content.