To analyze the iodine nutritional status of children aged 8-10 in Baoshan City, so as to comprehensively evaluate the effectiveness of eliminating and consolidating iodine deficiency disorders in Baoshan City.

From 2018 to 2024, a stratified random sampling method was used to sample 7 363 non-boarding children aged 8-10 from 35 survey sites in 5 counties of Baoshan City (Longyang County, Shidian County, Changning County, Tengchong City, Longling County).The salt iodine content and urinary iodine concentration were detected, and the thyroid volume of children was measured by ultrasound.Group comparison was conducted by using Mann-Whitney U test, Kruskal-Wallis H test, and Chi-square test.Spearman rank correlation analysis was used to investigate the correlation of salt iodine, urinary iodine and thyroid volume.

A total of 7 361 samples of household edible salt for children were detected.The iodized salt coverage rate was 99.70%, the qualified iodized salt consumption rate was 97.02%.The proportion of unqualified iodized salt fluctuated and decreased from 3.14% in 2018 to 2.14% in 2024.The median iodine content of household edible salt for children was 23.70(21.60, 25.80) mg/kg.The median urinary iodine of children was 217.41(152.40, 294.59)μg/L, and the proportions of iodine deficiency, adequate iodine, and iodine excess were 9.75%, 66.66%, and 23.58%, respectively.There were statistically significant differences in the median urinary iodine of children among different years, ages, genders and before and after the supply of non-iodized salt (Z/H=134.88, 11.04, -4.28, -2.66, all P < 0.01).An average thyroid volume of children was 3.32(2.77, 3.93) mL, with a goiter rate of 1.91%.Before and after the implementation of non-iodized salt supply in Baoshan City in 2023, there were no statistically significant differences in the median iodine content of household edible salt and the goiter rate of children (Z/χ²=-1.54, 3.25, both P>0.05), but there were statistically significant differences in the qualified status of iodized salt, the median urinary iodine, and the frequency distribution of urinary iodine (χ²/Z=15.53, -2.66, 10.14, all P < 0.05).Salt iodine was positively correlated with urinary iodine (r=0.04) and negatively correlated with thyroid volume (r=-0.07), and urinary iodine was negatively correlated with thyroid volume (r=-0.03)(all P < 0.05).The thyroid volume of children consuming iodized salt was larger than that of children consuming non-iodized salt (H=9.99), and there were statistically significant differences in thyroid volume among children with different urinary iodine levels (H=15.13)(both P < 0.01).

From 2018 to 2024, the overall iodine nutritional level of children aged 8-10 in Baoshan City is at an adequate level.The elimination status of iodine deficiency disorders has been continuously consolidated.