ABSTRACT
Objective To master the status of iodine content in drinking water and iodine nutritional status of population before and after the salt iodine concentration reduction in 2012 in Meizhou City, and to provide a scientific basis for safety assessment of salt iodine content after adjustment of the policy.Methods Using stratified random sampling method, drinking water samples were collected, and iodide content was measured by cerous sulfate catalytic spectrophotometry.Urine samples of children aged 8-10 were collected, in which the iodide content was quantitatively tested by arsenic cerium catalytic spectrophotometry.Samples of household edible salt were collected to determine iodine content by direct titration in 2012 before (September 2011), and after the salt iodine concentration reduction (September 2012 and September 2013).Results A total of 422 water samples were measured, the median iodine content of water was 2.4 μg/L.The water iodine median was 2.1 μg/L in centralized water supply (n =163),and 2.9 μg/L in decentralized water supply (n =259), the difference was statistically significant (U =-2.526, P ＜ 0.05).Totally 800 and 803 urine samples of children aged 8-10 were collected in 2011 and 2012, median urinary iodine was 216.5 and 207.5 μg/L, respectively, which were higher than that in 2013 (n =807, 190.0 μg/L, x2 =17.040,24.868, all P ＜ 0.05).Urinary iodine ≥300 μg/L ratio was significantly decreased (2013 than 2011 and 2012,19.3％ (156/807) vs.26.5％ (212/800) and 24.5％ (197/803), x2 =6.363, 11.695, all P ＜ 0.05), and urinary iodine ＜ 100 μg/L rose in the proportion (2013 than 2011, 18.0％ vs.13.5％, x2 =6.045, P ＜ 0.05).A total of 2 410 household salt samples were tested, and the coverage rate of iodized salt, iodized salt qualified rate, the consumption rate of qualified iodized salt were all higher than 98.8％.Totally 800, 803 and 807 salt samples were collected in 2011, 2012 and 2013, the salt iodine medians were 31.0, 27.7 and 25.4 mg/kg, respectively, the difference between the salt iodine medians was statistically significant (H =91.422, P ＜ 0.05).Conclusions Iodine excess risk is significantly decreased, and the level of iodine nutritional status of the city's population is appropriate after the salt iodine concentration reduction in 2012.The salt iodine concentration adjusted is suitable and safe.