Résumé
Objective To understand the situation of iodine of Taishan nuclear power station employees,and assess the relationships between iodine nutrition and thyroid nodule of Taishan nuclear power station in Taishan,Guangdong.Methods Totally 300 people were selected from of Taishan nuclear power station through stratifiedrandom sampling method,random urine samples were collected and urinary iodine level was tested in 2014.According to 20 to 29 years old,30 to 39 years old,40 to 59 years old,3 age groups were sampled,and each age group was 100 people.Drinking water and edible salt samples of the of nuclear power station were collected and iodine level was tested.Daily dietary intake of the staff was investigated,and daily iodine intake was calculated.Result of thyroid B ultrasonic of the employees (1 091) were studied,and detection rate of thyroid nodule was calculated.Results Totally 308 urine samples were tested,and the median urinary iodine was 193 μg/L.The difference of urinary iodine between 20-year-old group (201 μg/L) and 30-year-old group (165 μg/L) was statistically significant (P ＜ 0.05).A total of 9 iodized salt samples were collected,with an average iodine value of (24.4 ± 0.5)mg/kg.A total of 9 water samples were collected,the median of water iodine was 20.5 μg/L in 3 centralized water supply samples.The daily iodine intake per capita of the staff was 274.0 μg/d,the highest contribution among all the varieties of food was iodized salt,the second was seafood,which were 45.26 percent and 41.86 percent,respectively.A total of 99 thyroid nodules and suspicious nodules were detected in 1 091,and the prevalence was 9.07 percent (99/1 091).The prevalence of people aged 40-59 [15.6％ (22/141)] was significantly higher than those of people aged 20 to 29 [8.1％ (51/633)] and aged 30 to 39 [8.2％ (26/317)],and the differences were statistically significant (P ＜ 0.05).Conclusions The iodine nutrition of Taishan nuclear power station employees is appropriate as a whole.The detection rate of thyroid nodules is higher in people aged 40 to 59.
Résumé
Objective Through the investigation of the iodine content in residents drinking water in Jianjiang River Basin of Guangdong,the scope and distribution of waterborne high iodine areas in this region were grasped so as to provide a basis for taking appropriate prevention and control measures.Methods All towns (streets) covering seven counties (cities,districts) of Jianjiang River Basin were selected by cross sectional screening method in 2012 and 2013,which were divided into mainly-investigated town (street) and generally-investigated town (street) according to the direction,geographical position and other situations of all branches of Jianjiang River.In each mainly-investigated town (street),two natural villages were selected according to the river direction and terrain conditions,and one water sample was collected from each village.In each generally-investigated town (street),one administrative village was selected respectively according to the locations (east,west,south,north and middle);two natural villages were selected from each administrative village,and one water sample was collected from each natural village.The water supply types of each natural village were investigated,including centralized water supply,decentralized water supply and river (reservoir) water.If the iodine content of the water samples was higher than 100 μg/L in the natural villages,then 10％ more water samples were collected.The inductive coupling plasma mass spectroscopy (ICP-MS) was adopted for water iodine detection.Results A total of 3 583 residents drinking water samples from Jianjiang River Basin were investigated,and the median of water iodine was 15.1 μg/L;the median of water iodine in reservoirs,river,mountain spring,well water was 12.1,9.8,2.5 and 18.6 μg/L,respectively.Iodine content of 341 water samples was ＞ 100 μg/L,accounting for 9.5％;228 water samples were ＞ 150 μg/L,accounting for 6.4％;58 water samples were more than 300 μg/L,accounting for 1.6％.The water samples with iodine content higher than 100 μg/L were all from decentralized well water.There were 18 natural villages which could be determined as the waterborne high iodine areas (water iodine ＞ 150 μg/L);they were distributed in 16 administrative villages in 14 towns (streets) of 5 counties (cities,districts) and had a registered population of 23 915 in total.The difference of water iodine between the 5 counties (cities,districts) in middle and lower reaches of Jianjiang River Basin (24.7,28.6,20.5,23.2,24.0 μg/L) and the 2 counties (cities,districts) in upper reaches (12.0,10.9 μg/L) was statistically significant (Z =13.5,P ＜ 0.05);the difference of water iodine between coastal and non-coastal areas (12.5 vs.5.9 μg/L) was statistically significant (Z =6.1,P ＜ 0.05).Conclusions The iodine content in surface water of Jianjiang River Basin is generally lower;,the high water iodine phenomenon dispersedly occurs in the underground water (well water),and the iodine content is different in different areas;the iodine content of the middle and lower reaches is higher than that of the upper reach,and the iodine content of the coastal alluvial areas is higher than that of the non-coastal areas.The natural villages with waterborne high iodine are spottily distributed in the coastal areas of all backbones and branches of Jianjiang River,but not connected together basically.