ABSTRACT
Objective To investigate the coverage rate of iodized salt and the nutritional status of schoolaged children before and after adjustment of salt iodine concentration in Haishu District,Ningbo City.Methods The observation period (2010-2016) was divided into three sub-periods:before the adjustment (2010,2011),adjustment period (2012-2014) and after the adjustment (2015,2016).Household salt samples and urine samples of school-aged children aged 8-10 were collected during the 3 periods in Haishu District,Ningbo City,and the iodized salt coverage rate,qualified iodized salt consumption rate,urinary iodine concentration were determined.Results Totally 600,900 and 615 household salt samples were collected in the 3 periods,respectively.The medians of salt iodine in the 3 periods were 27.30,23.50 and 23.10 mg/kg;while the iodized salt coverage rates were 97.83％ (587/600),94.67％ (852/900) and 84.72％ (521/615),and the qualified iodized salt consumption rates were 96.50％ (579/600),92.11％ (829/900) and 74.63％ (459/615),respectively.There were significant differences in the iodized salt coverage rates and qualified iodized salt consumption rates among the 3 periods (x2 =86.13,162.57,P ＜ 0.01);and significant decreases of the iodized salt coverage rates and qualified iodized salt consumption rates were observed in the 3 periods (x2trend =77.34,141.11,P ＜ 0.01).The median urinary iodine concentration of the school-aged children in the 3 periods were 171.18,161.95 and 186.07 μg/L;the differences of urinary iodine were statistically significant among the 3 periods (H =11.81,P ＜ 0.01).Conclusions In Haishu District,significant decreases of the iodized salt coverage rates and qualified iodized salt consumption rates are observed after the adjustment of salt iodine concentration.However,the iodine nutrition is adequate in school-aged children.