停供碘盐后水源性高碘地区人群每日饮食碘摄入量调查

目的了解停供碘盐3年后水源性高碘地区人群每日饮食碘的摄入量及其构成,为制定水源性高碘地区干预策略提供依据。方法采用两阶段抽样方法,分别从水碘含量为50.01～150μg/L、150.01～300μg/L、300.01～500μg/L、500.01μg/L以上的4个层次的行政村中选定335名对象进行调查,采用入户调查的方法进行饮水量和膳食调查,并采集居民户生活饮用水、粮食和蔬菜样本,检测碘含量。结果当地居民户生活饮用水碘含量中位数为431.5μg/L;三组人群每日饮食碘的摄入量均远高于碘的推荐摄入量,水碘含量在300μg/L以上的人群每日饮食碘的摄入量超过了碘的可耐受最高摄入量,三组人群每日饮食碘的摄入量在不同水碘水平下的差异均有统计学意义(P<0.01),且随着水碘含量的升高而升高;三组人群每日饮食碘摄入量的构成有83.2%～98.7%来自饮水,1.3%～16.8%来自食物;饮食碘的摄入量与居民户生活饮用水水碘含量之间存在高度正相关关系(等级相关系数为0.953,P<0.01)。结论水是水源性高碘地区居民碘摄入量的主要来源,占80%以上。对于水碘含量在300μg/L以上的人群仅仅单靠停供碘盐的干预措施来减少碘的摄入是远远不够的,还必需采取改水降碘等综合干预措施,预防控制高碘的危害。

study on the amount of daily iodine intake of inhabitants living in drinking water with excessive iodine content areas after termination of iodized salt supply

OBJECTIVE: To investigate the amount of daily iodine intake in the diet of the target population in drinking water with areas of excessive iodine after stopping supply of iodized salt, to provide evidence for developing strategies on control and prevention of excessive iodine. METHODS: 335 objectives were selected by a two-stage sampling method in 4 administrative villages with different iodine contents in drinking water. The amount of drinking water intake and dietary survey for 335 people were done by a door-to-door survey,while the iodine contents in the drinking water of each selected family, local staple food and vegetable were measured. RESULTS: The median level of iodine in drinking water was 431.5 microg/L while the daily amount of iodine intake among the three groups of waters with different iodine contents were all greater than RNI. The daily iodine intake of local people was all greater than UL in the areas where the water iodine contents were more than 300 microg/L. It was of statistical sense that the iodine mean intake per capita per day of the three groups differed at different water iodine levels (P < 0.01). The iodine mean intake per capita per day of the three groups of different water iodine levels increased along with water iodine and showed a uptrend (P < 0.01). 83.2%-98.7% of the daily iodine intake of the three groups was from drinking water and 1.3%-16.8% came from food. The iodine intake had high-positive correlation relation with the content of water iodine (P < 0.01). CONCLUSION: It was concluded that drinking water was the main source of iodine intake in areas with iodine excessive water by the percentage of over 80%. It was necessary to adopt measures to improve the quality of water to decrease the iodine content other than just stopping supplies of iodized salt in the areas where the water iodine contents were greater than 300 microg/L, in order to prevent and control excessive intake of iodine.