【作者】 杭景仙；

【导师】 刘殿武；

【作者基本信息】 河北医科大学 ， 流行病与卫生统计学， 2008， 硕士

【摘要】 目的:碘是人体必需的微量元素之一,是合成甲状腺激素的主要原料。碘元素与人体健康息息相关,研究表明碘对机体的作用是双向的,碘缺乏与碘过多都会对人的健康造成危害,碘缺乏(缺碘)可造成碘缺乏病(IDD),碘过多(高碘)可造成碘过多病(症)(IED)。碘缺乏引起甲状腺功能低下,造成人体智能和体能发育障碍,从而影响人们的生活质量。全民食盐加碘(USI)是消除碘缺乏的最佳干预措施。但随着碘缺乏病防制科研工作的深入开展,居民碘营养水平的不断提高,高碘问题日益凸现出来。本次研究通过对河北省沧州市中东部地区63个乡镇的居民生活饮用水中碘含量的调查,了解高碘水源的地理分布及地貌和地层沉积环境对水碘的影响;并对14个乡镇的8~10岁儿童进行了甲状腺肿患病率的调查,了解我省目前高碘对人群的危害程度。方法:依据历史资料,选取了河北省沧州市中东部地区63个乡镇,每个乡镇按东、南、西、北、中不同方位随机抽取5个自然村,在每个被抽取的自然村采集1~5份有代表性的居民生活饮用水样本,共饮自来水的自然村采集水样1份,了解水源类型及水井深度等信息资料。水碘测定,采用硫酸铈催化分光光度法;利用Autodesk Map 3D绘制了水碘分布图。对14个乡镇的8~10岁儿童进行甲状腺触诊检查,诊断标准按GBl6004—1995(地方性甲状腺肿的诊断及分度标准);并采集尿样,应用砷铈催化分光光度法进行尿碘测定。全部数据信息通过Excel2003建立数据库,用SPSS13.0统计软件包对数据库进行处理分析。结果:本次调查共采集居民生活饮用水样315份,饮用水样涉及居民人数1 732 226万,水碘中位数为359.72μg/L,最小值为6.76μg/L,最大值为1457.50μg/L。其中,水碘含量超过150μg/L的水样有272份,占86.35%;超过300μg/L的水样有193份,占61.27%。63个乡镇的水碘中位数均大于150μg/L,其中39个乡镇的水碘中位数大于300μg/L。在调查的315份水样中,手压井水15份,占4.76%,水碘中位数为202.11μg/L;机井水295份,占93.65%,水碘中位数为375.53μg/L;水库水5份,占1.59%,水碘中位数为371.89μg/L。315份水样中共有310份井水(包括手压井水和机井水),井深中位数为360m,最小值为7m,最大值为920m。井深小于40m的浅井40眼,占12.90%,水碘中位数为176.55μg/L;40m及以上的深井270眼,占87.10%,水碘中位数为395.32μg/L。经统计学检验,深井的水碘含量高于浅井(u=2099,P<0.001)。对水碘含量与井深作相关性分析,40眼浅井水碘含量与井深之间无相关关系(rs=0.115,P>0.05);270眼深井水碘含量与井深之间存在正相关关系,(rs=0.414,P<0.001)。沧州市中东部的高碘地区自东北向西南方向延伸,水碘含量自西向东,自北向南呈现递增趋势;多数高碘地区呈片状分布。调查范围内涉及两种地貌单元,即黄河-漳卫河冲积平原区和滨海平原冲积海积区。在调查的315份水样中,属于黄河-漳卫河冲积平原区的水样有109份,占34.60%,水碘中位数为274.33μg/L,属于滨海平原冲积海积区的水样206份,占65.40%,水碘中位数为447.40μg/L。滨海平原冲积海积区的水碘含量高于黄河-漳卫河冲积平原区(u=6355,P<0.001)。依据沧州市第四纪更新世的不明显海侵影响范围,按深度在100-400m的地层沉积环境的不同将调查范围分为两部分,即陆相沉积区和海陆交互相沉积区。井深在100-400m范围内属于陆相沉积区的水样111份,水碘中位数为290.96μg/L,属于海陆交互相沉积区的水样61份,水碘中位数为650.50μg/L。经统计学检验,海陆交互相沉积区的水碘含量高于陆相沉积区(u=1173.5,P<0.001)。在选择的14个乡镇中,对2952名8~10岁儿童进行了甲状腺触诊检查,发现207名儿童I度肿大,15名儿童II度肿大,平均肿大率为7.52%,范围在3.45~14.63%之间。依据国家标准,有12个乡镇属于高碘病区,占所调查乡镇的85.71%。通过儿童甲肿率与水碘之间的相关性分析表明,二者之间存在正相关关系(P<0.05)。共采集尿样1494份,以乡镇为单位尿碘中位数为258.01μg/L,范围在104.24 ~489.06μg/L之间。通过水碘、儿童甲肿率与尿碘的相关性分析表明,尿碘与水碘、儿童甲肿率之间均存在正相关关系(P<0.05)。结论:1沧州中东部高碘地区居民生活饮用水以深井水居多,深井水碘含量与井深之间存在正相关关系;浅井水碘含量与井深之间则无相关性。2沧州中东部高碘地区涉及两种地貌单元,即黄河-漳卫河冲积平原区和滨海平原冲积海积区,滨海平原冲积海积区的水碘含量高于黄河-漳卫河冲积平原区。3从地层沉积环境上分析,认为第四纪以来的海侵与高碘水的形成存在一定的关系。4沧州中东部高碘地区儿童甲状腺肿大率和尿碘值随水碘值的增加而升高。研究结果提示针对高碘地区和高碘病区水碘分布状况及地方性甲状腺肿流行情况,应采取积极有效的干预措施来降碘,减少居民碘的摄入量,以降低甲状腺肿的患病率。更多还原

【Abstract】 Objective: Iodine is one of the trace elements essential for thyroid hormone synthesis and has a lot of affects on our health. Low iodine level results in iodine deficiency disorders (IDD), while high level of iodine cause iodine excess disorders (IED). Children affected by hypothyroidism caused by iodine deficiency suffer both mental and physical disabilities and had been the main public health concern in China. This situation was approved dramatically by an intervention method called universal salt iodization. Followed the USI intervention and advance in the treatment of iodine deficiency disease, the IDD is under control gradually. On the other hand, the disease caused by IED is becoming as a main player. In this study, we first survey the iodine level in water source and describe the data by geographic distribution, geomorphic characteristics and sedimental environment of geologic strata. Then investigate the prevalence rate of endemic goiter in school children, so master the effect of high iodine on people.Methods: Based on the historical data, 63 small towns were selected to investigate the iodine concentration of drinking water (ICDW) in the central and east area of Cangzhou. 5 villages were selected according to directions of east, west, south, north and center of each town. Drinking water samples from each village were determined for their water iodine concentration and the data was collected regarding the type of water source and the depth of wells. Water iodine concentration was determined by cerous sulfate catalytic spectrophotometry, and the distribution of water iodine was mapped by using Autodesk Map 3D. Thyroid of children aged 8~10 years in 14 small towns was diagnosed by palpating and diagnostic criterion was GB16004-1995 (Diagnostic and classificatory criteria of endemic goiter); urine samples were collected and urine iodine was determined by arsenic-cerium catalytic spectrophotometry. The database was created by Excel2003, and analyzed by SPSS13.0 software package.Results: A total of three hundred and fifteen water samples were collected and the median of water iodine (MWI) was 359.72μg/L. The lowest ICDW was 6.76μg/L and the highest ICDW was 1457.50μg/L. The ICDW in 272 samples was higher than 150μg/L, accounting for 86.35% of the total; the ICDW in 193 samples was higher than 300μg/L, accounting for 61.27%. The MWI was over 150μg/L in all 63 towns, and the MWI in 39 towns was over 300μg/L.15 out of 315 water samples were from hand-press well, and the MWI was 202.11μg/L; 295 samples were from driven well, and the MWI was 375.53μg/L; 5 samples were from water reservoir, and the MWI was 371.89μg/L. The median of well depth was 360m in 310 wells. The shallowest was 7m, and the deepest was 920m. The depth of 40 wells was below 40m, accounting for 12.90%, and the MWI was 176.55μg/L. The depth of 270 wells was over 40m, accounting for 87.10% , the MWI was 395.32μg/L. The ICDW in deep phreatic well was higher than that in shallow well (u=2099, P<0.001). There was no correlation between well depth and ICDW in shallow wells (P>0.05). But there was a positive correlation between well depth and ICDW in deep phreatic wells (rs=0.414, P<0.001).Iodine excess areas ranged from northeast to southwest, and the tendency of the ICDW was heightening from west to east, from north to south in the central and east area of Cangzhou. Most iodine excess areas were connected with others. The survey scope was involved in two geomorphic units. They were Yellow River–Zhangwei River alluvial plain and alluvial and marine accumulating littoral plain. 109 water samples were collected in Yellow River–Zhangwei River alluvial plain, and the MWI was 274.33μg/L, accounting for 34.60%; 206 water samples were collected in alluvial and marine accumulating littoral plain, and the MWI was 447.40μg/L, accounting for 65.40%. The ICDW in alluvial and marine accumulating littoral plain was higher than that in Yellow River–Zhangwei River alluvial plain (u=6355, P<0.001).The survey scope were divided to two parts by different sedimental environments in geologic strata with the depth between 100m and 400m based on unclear marine transgression in Pleistocene of Quaternary period in Cangzhou. They were sediment area of sea and continental alternation and continental sediment area. 111 water samples with the well depth between 100m and 400m were in continental sediment area; 61 samples were in sediment area of sea and continental alternation. The ICDW in sediment area of sea and continental alternation was higher than that in continental sediment area (u=1173.5, P<0.001).207 cases of I°goiter and 15 cases of II°goiter were diagnosed among 2952 children aged 8~10 years in 14 towns and the goiter rate was 7.19%, between 3.45% and 14.63%. 12 out of 14 towns were identified as iodine excess areas in line with national criterion, accounting for 85.71% of the total. There was a positive correlation between the goiter rate of children and water iodine (P<0.05). The median of urine iodine was 258.01μg/L in 1494 urine samples, between 104.24μg/L and 489.06μg/L. There were positive correlations between urine iodine and the goiter rate of children and between urine iodine and water iodine (P<0.05).Conclusions: 1.Most drinking water using by inhabitants was deep phreatic well water in the central and east area of Cangzhou. There was a positive correlation between well depth and ICDW in deep phreatic wells; there was no correlation in shallow wells.2. The central and east area of Cangzhou included two geomorphic units. They were Yellow River–Zhangwei river alluvial plain and alluvial and marine accumulating littoral plain. The ICDW in the latter was higher than that in the former.3. High iodine water may be related to marine transgression in Quaternary period in geologic layer.4. With the concentration of water iodine increasing, the concentration of urine iodine and the goiter rate of children both increased in iodine excess areas in the central and east area of Cangzhou.The finding suggests that intervention measures should be taken to reduce the intake of iodine on the basis of the distribution of water iodine and the goiter prevalent condition. The purpose is to lower the prevalence rate of goiter.更多还原