ABSTRACT
Objective To assess the quality of iodized salt and investigate the urinary iodine level of pupils and women after implementation of universal salt iodization in Shijiazhuang city. Methods Between 2004 and 2008, nine salt samples were randomly collected from wholesale enterprises of 5 different directions of east,south, west, north and center in Shijiazhuang city every month. Meanwhile, eight salt samples, four urine samples of women, were randomly collected in each of the 8 households of 210 villages selected from 23 counties. Between 2004 and 2008, twenty urine samples of 8 - 10 year old pupils were collected in each of 160 schools from the 23 counties. Direct titration method was used for salt iodine determination, iodine concentration in urine was detected by the method of ammonium persulfate digestion-As3+-Ce4 + catalytic spectrophotometry. Results At wholesale level, the qualified rate of iodized salt was above 99%. At household level, the consuming rate of iodized salt was above 95%, and the rate of consuming non-iodized salt was less than 5%. The rate of qualified iodized salt was above 90% in every year except 2004(87.10%), and the rate of consuming qualified iodized salt was above 90% in those years except 2004(83.08%). Urinary median iodine level of both the pupils and the women was higher than 100 μg/L, and the rate of urinary iodine level that less than 50 μg/L was below 10%. Conclusions The quality assessment of iodized salt from wholesale companies and related indices of urinary iodine level of pupils, women and household iodized salt have already reached the national standard for eliminating iodine deficiency disorders.