Objective To understand the prevalence of thyroid nodules of children lived in different water iodine areas in Cangzhou City. Methods From Oct. 2015 to Jan. 2017, 15 villages were selected as monitoring sites in Cangzhou,two drinking water samples were collected from each survey site(all had centralized water supply), and the water iodine content was determined. A total of 100 children aged 8 to 10 (half male and female) were examined for thyroid nodules, and at least 50 children (half male and half female) were selected to detect urinary iodine content. In the high iodine water counties, the monitoring sites of iodine salt was according to "National Iodine Deficiency Monitoring Program"; in the monitoring sites of iodine salt supplied counties, students in the monitored village were asked to detect urinary iodine and household salt samples were collected to monitor salt iodine. In the high iodine area, the salt iodine test was carried out by semi-quantitative method. In the non-high iodine area, the salt iodine content of the iodized salt monitoring sites was determined by direct titration, the salt iodine content of Chuan salt and other intensified edible salt was tested by arbitration(GB/T 13025.7-2012). Water iodine and urinary iodine were tested by arsenic and cerium catalytic spectrophotometry. Results Water iodine content was 28.2 - 1 128.0 μg/L in 15 villages; a total of 1 066 urine samples were examined, the median of uriary iodine in each village was 102.6-1 162.0 μg/L;a total of 1 575 children aged 8 to 10 years were examined,among them,125 cases of thyroid nodules were detected; thyroid nodules detection rate was 7.9%. The prevalence of male was 7.0% (61/871), and the prevalence of female was 9.1% (64/704), there was no significant difference in the detection rate of thyroid nodules between different sex (χ2=2.07,P>0.05); The detection rate of thyroid nodules were 4.5%(23/508),7.8%(4/51), 11.6%(59/507)in children with urinary iodine at the appropriate level (100 - <200 μg/L), the appropriate level (200 - < 300 μg/L) and iodine excess level (≥300 μg/L), the difference of thyroid nodules in children with different levels of urinary iodine detection rate was statistically significant (χ2=17.30, P < 0.01). The difference of prevalence of thyroid nodules in children aged 8 to 10 years with water iodine concentrations of 10 - < 100, 100 - < 300 and ≥300 μg/L was statistically significant[2.9%(13/448),7.9%(25/317), 10.7%(87/810),χ2=23.86,P<0.05].The patients with unilateral thyroid nodule accounted for 64.8% (81/125); the patients with multiple thyroid nodules counted for 58.4% (73/125), and 34.2%(13/38),69.0%(60/87)in areas with iodine content less than 300 μg/L and no less than 300 μg/L,the difference between the two was statistically significant (χ2= 13.14, P < 0.01). A total of 1 800 salt samples were collected from the high water iodine counties,of which 1 779 were iodine-free salt, the rate of iodine-free salt was 98.8%; a total of 190 salt samples were collected in student family, in the 4 iodized salt monitoring sites, the salt iodine median of resident's edible salt was 0.0 mg/kg. Conclusion The prevalence of thyroid nodules in children aged 8 - 10 years may be related to high water iodine in Cangzhou City; children with multiple thyroid nodules is also significantly higher in water iodine content greater than 300 μg/L areas.

Objective To understand the prevalence of goiter and nodule as well as the iodine nutritional status of 8 to 10 years old children after changing water source with lower iodine so as to evaluate its intervention effectiveness.Methods From 2014 to 2017,Machang Village and Liangzhang Village of Haixing County in Haixing County were selected as monitoring sites in the water-sourced high iodine area in Hebei Province.Using the cross-sectional survey method,100 children aged 8 to 10 years old were randomly selected in each village,half male and half female.Dynamic monitoring of drinking water iodine content,children's prevalence of goiter and nodule as well as urinary iodine content were conducted before and 1-3 years after changing water resource.Iodine detection was performed using an arsenic cerium-catalyzed spectrophotometric method suitable for iodine-deficient and high-iodine areas (recommended method for national iodine deficiency disease reference experiment);urinary iodine was detected by arsenic cerium catalytic spectrophotometry (WS/T 107-2006).The thyroid test was performed using the B-ultrasound method and the criterion was based on the "Diagnostic Criteria for Endemic Goiter" (WS 276-2007).Results The median iodine content of water in the two villages before the reformation was 861.0 μg/L,and it was 71.6,29.1 and 30.4 μg/L in 1-3 years after water was changed.The overall difference before and after water change was statistically significant (x2 =8.48,P ＜ 0.05).The median urine iodine of children in the two villages before the change of water was 705.0 μg/L,and the median urine iodine of children was 306.0,143.0 and 140.0 μg/L after 1-3 years.The differences were statistically significant (Z =6.56,10.82,11.19,P ＜ 0.05).The goiter rate was 10.3％ (21/203) before changing water,and the goiter rate was 6.3％ (13/205),6.4％ (13/203) and 3.8％ (8/208) in 1-3 years after water exchange,and the difference between before and 3 years after water exchange was statistically significant (x2 =6.61,P ＜ 0.05).Children's nodule prevalence before and 3 years after changing water was 11.3％ (23/203) and 1.4％ (3/208),the difference was statistically significant (x2 =13.42,P ＜ 0.05).Conclusion Three years after changing water resource,children's goiter prevalence is back to normal in general,and nodule prevalence is decreased significantly,which indicates sound intervention effectiveness.

Objective To explore the relationship between iodine and fluoride content in drinking water and the incidence of adult thyroid nodules in Cangzhou,Hebei.Methods According to the previous reports on iodine and fluoride levels in drinking water in Cangzhou,from November 2016 to January 2017,Cangzhou was divided into high iodine,low iodine,normal iodine and fluorine,low iodine and high fluorine,high iodine and high fluorine areas,and according to the different contents of iodine and fluorine in drinking water,high iodine and high fluorine area was further divided into high iodine and high fluorine 1 (iodine:743.30 μg/L,fluorine:4.27 mg/L),2 (iodine:119.31μg/L,fluorine:4.67 mg/L) and 3 (iodine:105.30 μg/L,fluorine:1.64 mg/L) subareas.Subjects who lived for 20 or more years and aged 30 or older,without serious disease and not taken iodized salt were selected.Palpation was used to examine the size,texture,mass,tenderness and mobility of the thyroid gland.The boundary,internal echo,blood flow and quantity of nodules were observed and recorded by color Doppler.Results The prevalence difference of thyroid nodules [36.8％ (629/1 710),32.8％ (636/1 938),25.1％ (427/1 700)] in high iodine,low iodine and normal iodine and fluorine areas was statistically significant (x2 =55.597,P ＜ 0.05).The prevalences of thyroid nodules in both high iodine and low iodine areas were higher than that of normal iodine and fluorine area (P＜ 0.016 7).The prevalence difference of thyroid nodules [43.3％ (749/1 730),39.8％ (712/1 790),34.9％ (623/1 785)] in high iodine and high fluorine 1,2 and 3 subareas was statistically significant(x2 =26.220,P ＜ 0.05).Compared with low iodine area,the prevalence of thyroid nodules [41.2％ (735/1 785)] in low iodine and high fluorine area was increased (x2 =6.288,P ＜ 0.05).Conclusions Both high iodine and low iodine can induce thyroid nodules.In water source areas with high iodine content,both high iodine and high fluorine are the factors inducing thyroid nodules.The prevalence of thyroid nodules in low iodine and high fluorine area is significantly higher than that of low iodine area.