2005年全国碘盐监测结果分析

Analysis of national iodized salt surveillance data in 2005

目的了解全国生产和居民层次碘盐的合格及食用情况,为我国碘缺乏病防治提供依据。方法生产层次采样要求对所有碘盐生产、分装和批发企业每月进行一次抽样,每次抽样采用GB/T 8618-2001制盐工业主要产品取样方法。生活层次采样要求每个县按东南西北不同方位随机抽取9个乡,每个乡抽取4个村,其中2个村在乡政府所在地及其附近抽取。另外2个村为"问题地区"或距乡政府5公里以外的村。每个村(居委会)随机抽取8份居民户盐样。碘盐检测采用GB/T 13025.7-1999直接滴定法;川盐或特殊盐种采用仲裁法定量测定。合格碘盐判定标准:盐含碘量为(35±15)mg/kg,非碘盐判定标准:盐含碘量<5 mg/kg。结果除西藏外,全国生产层次碘盐的批质量合格率为97.92%;居民层次的碘盐合格率为97.07%,合格碘盐食用率为95.35%,非碘盐率为1.89%,这几项指标的检测结果,均略好于2004年的情况。全国各省生产层次的批质量合格率均大于90.00%,河北、湖南、广西和贵州4省(区)生产层次的变异系数大于20.00%。海南省居民层次的碘盐合格率低于90.00%。海南、广东、新疆和青海4个省(区)的居民合格碘盐食用率均低于90.00%。西藏、海南、广东、新疆和青海5个省(区)居民非碘盐率均高于10.00%。结论多数省份生产层次的碘盐质量稳定;在居民层次,新疆、青海和西藏3个西部省(区)的各项监测指标依然与全国水平有较大差距,而海南和广东2个东部沿海省份的合格碘盐食用率和非碘盐率与2004年相比情况反而更差,提示今后在关注西部地区的同时,还要关注沿海的问题地区。

Objective To study on the quality and consumption of iodized salt at production and household level based on the 2005 salt surveillance. Methods All iodized salt was sampled every month in all manufactoring and wholesaling industries, using the same sampling method as in the salt industry （GB/T 8618-2001 ）. At household level, 9 townships were chosen in each county at different locations. In each township, two villages in center and another two villages in remote setting were selected. In each village, 8 households were selected for salt collection. The iodine concentrations in salt （except some special kinds of salt） were detected by the method of direct titration with criteria of GB/T 13025.7-1999, in which the iodine content in qualified iodized salt was set as 20 to 50 mg/kg and that in non-iodized salt was set as below 5 mg/kg. Results At production level, the national lot qualified rate of iodized salt, not including Tibet, was 97.92%. At household level, except Tibet. The national qualified rate of iodized salt, the qualified iodized salt coverage rate and the non-iodized salt coverage rate, the three national surveillance indicators was 97.07%, 95.35% and 1.89% respectively, slightly better than 2004. The lot qualified rate of iodized salt in all 30 provinces was above 90.00%. Nevertheless, the coefficient of variation of production level in Hebei, Hunan, Guangxi and Guizhou was higher than 20.00%. The qualified rate of iodized salt at household level in Hainan was below 90.00%. The household qualified iodized salt coverage rate in Hainan, Guangdong, Xinjiang and Qinhai was below 90.00%. Non-iodized salt coverage rate in 5 provinces （Tibet, Hainan, Guangdong, Xinjiang and Qinghai） was above 10.00%. Conclusions The quality of iodized salt at production level in most provinces was satisfying. With regard to the indicators of iodized salt surveillance, there was a big gap between Xinjiang, Qinghai, Tibet and national average level. The surveillance results, e.g. qualified iodized salt coverage rate and non iodized salt coverage rate, in Guangdong and Hainan were worse than those last year. This indicated that we should pay more attention to the western and the coastal areas.