Objective:To investigate the coverage of qualified iodized salt in catering service units where residents ate out in Shanxi Province, so as to provide a basis for taking targeted preventive measures timely and adjusting of intervention strategies scientifically, and to consolidate the achievements of eliminating iodine deficiency disorders (IDD) continuously.Methods:One prefecture level city from each of the five directions of east, west, south, north and middle in Shanxi Province in 2021 was selected. One mountainous county and one plain county were selected in each city. Each of the counties was divided into five sampled regions along five different geographic directions: east, west, south, north and middle. From each region, one town/street was selected randomly and then two canteens of enterprises and institutions (canteens), five medium-sized restaurants and five small restaurants were selected from each town/street. We investigated the basic information of catering service units, collected salt samples and then detected the iodine content of these salt samples. In addition, salt iodine testing data of county residents corresponding to catering service units in the 2021 iodine deficiency disorders monitoring were collected from the Shanxi Institute of Endemic Disease Prevention and Treatment, and compared with the survey results of catering service units.Results:A total of 660 salt samples were detected, the median value of salt iodine was 27.65 mg/kg, the coverage rate of iodized salt was 99.39%(656/660), and the coverage rate of qualified iodized salt was 90.76% (599/660). The median value of salt iodine was 26.70, 28.00 and 27.60 mg/kg in canteens, medium-sized restaurants and small restaurants, respectively, and the coverage rate of qualified iodized salt was 95.54% (107/112), 90.42% (236/261), and 89.20% (256/287), respectively. There was no significant difference in the coverage rate of qualified iodized salt among different types of catering service units (χ 2 = 3.92, P = 0.141). The median value of salt iodine was 28.00 and 27.20 mg/kg in mountainous counties and plain counties, respectively, and the coverage rate of qualified iodized salt was 88.67% (266/300) and 92.50% (333/360), respectively. There was no significant difference in the coverage rate of qualified iodized salt among the counties of different geographical types (χ 2 = 2.87, P = 0.090). The median value of salt iodine in catering service units and households was 27.65 and 23.50 mg/kg, respectively, and the coverage rate of qualified iodized salt was 90.76% and 95.91%, respectively. There was a statistically significant difference in the coverage rate of qualified iodized salt between catering service units and households (χ 2 = 31.19, P < 0.001). Conclusions:The coverage rate of qualified iodized salt in catering service units in Shanxi Province generally meets the national elimination standard (> 90%), but there are still some counties that do not meet the standard. The coverage rate of qualified iodized salt in small and medium-sized restaurants is also not optimistic. It is recommended to strengthen monitoring and supervision of edible salt in catering service units in the future.

Objective:To investigate the current situation of water-borne high iodine hazards in Shanxi Province and the implementation of prevention and control measures, providing a scientific basis for prevention and control of the high iodine hazards in the future.Methods:In 2020, a survey was conducted on iodine content of drinking water and water improvement situation in all high iodine administrative villages in 12 water-borne high iodine counties of 4 cities in Shanxi Province. In each monitoring county, five administrative villages were selected as monitoring villages using a systematic sampling method, sorted by the iodine content of the water in the administrative villages. Forty non-boarding students aged 8 - 10 from one primary school and 20 pregnant women were selected from each monitoring village. Household edible salt samples and one random urine sample were collected for salt iodine and urinary iodine content test. B-ultrasound method was used for thyroid examination in children.Results:A total of 297 high iodine administrative villages were surveyed on the drinking water situation of residents, including 268 villages with improved water and 29 villages without improved water, with a water improvement rate of 90.24%. The range of water iodine was 0.33 - 803.75 μg/L, and there were 159 villages with water iodine content > 100 μg/L. A total of 1 926 samples of household edible salt were tested, and the rate of non iodized salt was 62.20% (1 198/1 926); 1 704 urine samples from children and 222 urine samples from pregnant women were tested, with median urinary iodine contents of 426.2 and 318.9 μg/L, respectively. The 1 690 cases of thyroid gland in children were examined, with a goiter rate of 3.91% (66/1 690) and a nodule detection rate of 13.67% (231/1 690).Conclusions:Children's iodine nutrition in water-borne high iodine areas of Shanxi Province is at an iodine excess level, while pregnant women's iodine nutrition is at an iodine excess level. Efforts should be made to increase the popularization of non iodized salt and improve water quality to reduce iodine in areas with high iodine levels, in order to control the harm of high iodine in water sources as soon as possible.

Objective:To learn about the status of iodine deficiency disorders (IDD) and iodine nutrition of residents in Shanxi Province since the implementation of the standard of "Iodine Content in Edible Salt" (GB 26878-2011), to evaluate the level of prevention and control of IDD, and to provide scientific basis for adjusting prevention and control strategies.Methods:The data of core indicators monitored by Shanxi Province in accordance with the requirements of the national iodized salt and IDD monitoring program for each year from 2012 to 2021 were comprehensively reviewed, and the change trends of the indicators such as coverage rate of iodized salt, consumption rate of qualified iodized salt, children's median urinary iodine and goiter rate, and pregnant women's median urinary iodine were analyzed; the evaluation of IDD elimination in counties (cities and districts, hereinafter referred to as counties) was analyzed.Results:From 2012 to 2021, the coverage rate of iodized salt in Shanxi Province was remained > 95%; from 2012 to 2014 (transition period between new and old standard iodized salt), the consumption rate of qualified iodized salt had an upward trend (χ 2trend = 2 703.32, P < 0.001), with a downward trend from 2015 to 2017 (before and after the reform of the salt industry system, χ 2trend = 122.18, P < 0.001), and with an upward trend from 2018 to 2021 (after the reform of the salt industry system, χ 2trend = 455.11, P < 0.001), from 2018, the consumption rate of qualified iodized salt remained > 90%; from 2015 to 2021, the average content of salt iodine was between 23 - 25 mg/kg, and the coefficient of variation of salt iodine was 15% - 18%. From 2014 to 2021, the median urinary iodine of children in Shanxi Province remained at 200 - 250 μg/L, the median urinary iodine of pregnant women remained at 150 - 200 μg/L, and the goiter rate of children remained below 5%. Every year, iodine nutrition of pregnant women in some counties was insufficient. In 2016, the proportion of counties with insufficient iodine nutrition of pregnant women was high, reached 30.0% (12/40); from 2018 to 2021, the proportion of counties with insufficient iodine nutrition of pregnant women had a downward trend (χ 2trend = 9.37, P = 0.002), which was 11.1% (13/117) in 2021. In 2020, 117 counties in the province reached the IDD elimination standard, with a compliance rate of 100.0%. Conclusions:Since the implementation of the current salt iodine content standard for 10 years, the consumption rate of qualified iodized salt has gradually stabilized and remained at a high level, which can ensure that IDD is in a sustainable state of elimination in Shanxi Province, and the iodine nutrition of school-age children and pregnant women is generally at a suitable level. However, there are a certain number of counties with insufficient iodine nutrition of pregnant women. It is recommended to guide pregnant women to supplement iodine or set the average standard of salt iodine for pregnant women separately.

Objective To understand the iodine nutritional status and thyroid function of different populations after 20 years of universal salt iodization in iodine deficiency area of Shanxi Province, and to provide data support for scientific iodine supplementation according to local conditions. Methods In 2014, six townships (Chengguan, Dadeng, Dengzhuang, Gucheng, Xiangling and Fencheng townships) in Xiangfen County, Linfen City, Shanxi Province, were selected as the place of investigation. Four hundred school-age children aged 6 - 12 years (school-age children), 400 child-bearing women aged 18 - 44 (child-bearing women), 400 pregnant women, 400 lactating women and their 0 - 6 months breast-feeding infants (breast-feeding infants), and 400 children aged 7 -24 months were selected by two-stage sampling method. Water samples of school-age children's domestic drinking water and salt samples for domestic consumption were collected, and the water iodine and salt iodine were detected by arsenic and cerium catalytic spectrophotometry ( recommended by the National Iodine Deficiency Disorders Reference Laboratory) and "General Test Method in Salt Industry-Determination of Iodine" (GB/T 13025.7-2012). Random urine samples of all subjects were collected, urine iodine was detected by "Method for Determination of Iodine in Urine by As3+-Ce4+ Catalytic Spectrophotometry" ( WS/T 107-2006 ) . Samples of filter paper dried blood spots (DBS) of school-age children, child-bearing women, pregnant women, lactating women and breast-feeding infants were collected, and serum total thyroxine (TT4) and thyroid stimulating hormone (TSH) levels were detected by time-resolved fluorescence immunoassay. Results A total of 290 water samples were collected, and the median of water iodine was 9.37μg/L. A total of 406 salt samples were collected, the median of salt iodine was 25.0 mg/kg, the coverage rate of iodized salt was 98.52％ (400/406), and the consumption rate of qualified iodized salt was 92.61％ (376/406). Urine samples of 389 school-age children, 379 child-bearing women, 363 pregnant women, 365 lactating women, 366 breast-feeding infants, and 366 children aged 7 - 24 months were collected, and the medians of urine iodine were 200.7, 175.0, 186.0, 113.2, 285.8 and 204.8 μg/L, respectively. Among them, school-age children, breast-feeding infants, and children aged 7-24 months were over the appropriate level, while the rest populations were at the iodine appropriate levels. Blood samples of 402 school-age children, 397 child-bearing women, 398 pregnant women, 390 lactating women, and 386 breast-feeding infants were collected, and the medians of TT4 were 127.2, 110.2, 141.7, 95.8 and 139.0 nmol/L, respectively; the medians of TSH were 1.2, 0.9, 0.8, 0.9 and 0.9 mU/L, respectively, and they were all within the reference ranges. The abnormal rates of TT4 (8.46％, 33/390) and TSH (7.95％, 31/390) in lactating women were higher than those in school-age children, child-bearing women, pregnant women and breast-feeding infants [TT4 abnormal rates were 0.25％(1/402), 1.26％ (5/397), 0.50％ (2/398), 1.04％ (4/386), respectively; TSH abnormal rates were 1.24％ (5/402), 1.51％ (6/397), 1.51％ (6/398) and 0.78％ (3/386), respectively, P < 0.05]. The rate of thyroid dysfunction in lactating women (7.95％, 31/390) was higher than those in the rest populations [1.24％ (5/402), 1.51％ (6/397), 1.51％ (6/398), 0.78％ (3/386), P < 0.05]. Conclusions The iodine intake of different populations in the survey area is generally sufficient, and the current salt iodine content standard can meet the iodine nutrition needs of different populations. Lactating women have a high rate of thyroid dysfunction. It is suggested to stick to the strategy of universal salt iodization to prevent iodine deficiency hazards in iodine deficiency areas, and further strengthen the monitoring of iodine nutrition and thyroid function of pregnant women and lactating women.

Objective To understand the distribution of water iodine in the external environment of Shanxi Province, and to provide a basis for redefining and implementation of scientific iodine supplementation in iodine deficiency, iodine adequate or iodine high areas. Methods In 2012 - 2016, administrative villages (neighborhood committees)in 119 counties(cities,districts)in 11 cities of Shanxi Province were selected as the investigation units, and 1 to 5 drinking water samples were collected. Water iodine content was detected using arsenic-cerium catalytic spectrophotometry. Areas standard was designated: water iodine content < 10 μg/L as iodine deficiency areas, > 100 μg/L as iodine high areas. Results A total of 26 213 administrative villages (neighborhood committees) of 1 362 townships (towns) of 119 counties (cities, districts) were surveyed, covering 2 850.94 ten thousand people. A total of 32 766 water samples were collected and the median iodine was 5.2 μg/L. There were 18 199 villages with water iodine < 10 μg/L, accounting for 69.4% (covering 1 812.17 ten thousand people, accounting for 63.6%), 6 471 villages with water iodine 10-<50 μg/L,accounting for 24.7%(covering 787.44 ten thousand people,accounting for 27.6 %),1 166 villages with water iodine 50 - < 100 μg/L,accounting for 4.4% (covering 181.46 ten thousand people, accounting for 6.4%), 377 villages with water iodine ≥100 μg/L, accounting for 1.4%(covering 69.87 ten thousand people, accounting for 2.5%).In 1 362 townships (towns), 71.1% (969)water iodine median was<10 μg/L,24.2%(330)water iodine median was in 10-<50 μg/L,3.4%(46)water iodine median was in 50-<100 μg/L,and 1.2%(17) water iodine median was ≥100 μg/L. In 119 counties(cities,districts),there were 90 counties(accounting for 75.6%) with the water median < 10 μg/L, there were 26 counties (accounting for 21.8%) with the water median 10 - < 50 μg/L. Conclusions Most parts of Shanxi Province(or the resident population) are iodine deficiency areas, the external environment water iodine contents in the rest of the regions are different, we should adopt different iodine supplement or iodine reduction measures in regions with different water iodine levels.

Objective To study the nutritional status of pregnant women in Shanxi Province before and after the implementation of the new standards of iodized salt content,provide the basis for scientific supplementation of iodine for pregnant women.Methods According to the method of population proportion sampling,30 county-level monitoring sites were selected,a primary school was selected from each county (city,district) by the method of simple random sampling and 40 students in 2011 or 50 students in 2014 aged 8-10 years were selected in each school,direct titration was used to detect salt iodine;at the same time,20 pregnant women were selected from each town where the primary school was located and urinary iodine was determined using arsenic cerium catalytic spectrophotometry (WS/T 107-2006).Results A total of 1 182 and 1 437 salt samples was detected in Shanxi Province in 2011 and 2014,the median of salt iodine was 30.5 and 24.1 mg/kg,respectively,and the difference was statistically significant (H =567.45,P ＜ 0.01);it was 95.41％,80.31％,76.62％ of the coverage rate of iodized salt,qualified rate of iodized salt,qualified iodized salt consumption rate in 2014,respectively;which were compared with those in 2011 (97.63％,97.49％,95.18％),the differences were statistically significant (x2 =9.27,232.40,166.25,P ＜ 0.01).A total of 440 and 630 urinary samples of pregnant women were tested in 2011 and 2014,the median of urinary iodine was 279.6 and 177.1 μg/L,respectively,iodine nutrition of pregnant women was more than adequate in 2011,and iodine nutrition was suitable in 2014.The difference was statistically significant (H =153.89,P ＜ 0.01).The proportion of pregnant women's median of urinary iodine less than 150 μg/L in 2014 [41.11％ (259/ 630)] was significantly higher than that in 2011 [8.18％ (36/440),x2 =140.68,P ＜ 0.01].The constituent ratio of 250 to 500 μg/L was significantly decreased [23.65％ (149/630) vs 54.77％ (241/440),x2 =108.33,P ＜ 0.01).Conclusion It is at a reasonable level of iodine nutrition level of pregnant women in Shanxi after the adjustment of iodized salt content,but the ratio of ＜ 150 μg/L is increasing,which needs to be paid attention to.

Objective To investigate the prevalence of hypertension in adults in different water iodine areas and to explore the epidemiological association between high iodine intake in drinking water and hypertension.Methods In 2016,Xiwenzhuang Village of Taiyuan City as an appropriate-indine area,Gaoche Village and Maxi Village of Wenshui County were selected in Shanxi Province as a high-iodine area and a low-iodine area,respectively,and conducted questionnaire surveys,clinical hypertension examinations,and determination of urinary iodine levels of residents aged 18 to 65 years.Results A total of 853 people were investigated,including 283 in high-iodine area,258 in appropriate-indine area and 312 in low-iodine area.The medians urinary iodine in high,appropriate and low iodine areas were 423.0,218.5 and 126.6 μg/L,respectively,and the difference was statistically significant (H =289.7,P ＜ 0.05).The detection rates of hypertension in adults with high,appropriate and low iodine levels were 38.9％ (110/283),41.9％ (108/258) and 34.0％ (106/312),respectively,the difference was not significant statistically between the three groups (x2 =3.87,P ＞ 0.05).There was no significant difference in the detection rate of hypertension among males [45.9％(62/135),50.0％ (53/106),40.8％ (53/130)] in different areas (x2 =2.04,P ＞0.05),and no significant difference in the detection rate of hypertension among females [32.4％ (48/148),36.2％ (55/152),29.1％ (53/182),x2 =1.89,P ＞ 0.05];The difference between the three groups was not significant statistically in the detection rate of hypertension both among the 18-＜ 45 years group and 45-65 years group (x2 =1.22,5.66,P ＞ 0.05).Conclusion Drinking water with excess iodine might not increase the risk of hypertension in adults in Shanxi Province.

Objective To investigate the prevalence of thyroid nodules in the adults in high water iodine area and to reveal the risk factors of thyroid nodules.Methods Questionnaire investigation,determination of urinary iodine and thyroid ultrasound were carried out for residents aged 18 to 65 years old in Gaoche Village of Wenshui County in Shanxi Province,with the exception of pregnant and lactating women.Possible risk factors for thyroid nodules were analyzed.Results Of the 286 residents,89 cases of thyroid nodule were detected and the prevalence rate was 31.1％.The prevalence rate was 25.7％ (35/136) in male and 36.0％ (54/150) in female,there was no significant difference between sex (x2 =2.49,P ＞ 0.05).The average age of the cases with thyroid nodules was (49.6 ± 11.3) years old and was (43.5 ± 11.6) years old in cases without thyroid nodules,there was significant difference between age groups (t =4.11,P ＜ 0.05).The median of urinary iodine of the cases with thyroid nodules was 453.0 μg/L and was 408.4 μg/L in cases without thyroid nodules,there was no significant difference in the median of urinary iodine (Z =-0.616,P ＞ 0.05).The prevalence rate of solitary nodule was 57.3％ (51/89) and multiple nodules 42.7％ (38/89).As to the property nodule,the cyst nodule,the cyst-solid nodule and the solid nodule was 49.4％ (44/89),29.2％ (26/89) and 21.3％ (19/89),respectively.The results of Logistic regression showed that the prevalence of thyroid nodule increased with age (OR =1.048,95％CI:1.024-1.073,P ＜ 0.05) and the multiple nodule increased with age (OR =1.086,95％CI:1.044-1.129,P ＜ 0.05).The cyst nodule was a more common form in women (OR =2.559,95％CI:1.245-5.262,P ＜ 0.05).The prevalence of cyst-solid nodule increased with age (OR =1.125,95％CI:1.065-1.189,P ＜ 0.05).Conclusions The prevalence of the thyroid nodule in adults is high and the thyroid nodules are mainly the cyst nodules.The prevalence of the thyroid nodule is increased with age,especially the multiple nodules and the cyst-solid nodule in high water iodine area.The cyst nodule is a more common form in women.

Objective To master the iodine nutritional status of residents and to evaluate the effect of iodine nutrition improvement on residents health after the adjustment of salt iodine concentration. Methods According to the method of population proportion sampling, 30 county-level monitoring sites were selected in 2014, a primary school was selected from each county (city, district) by the method of simple random sampling and 50 students aged 8 - 10 (half males and half females) were selected in each school, B ultrasound was used to detect thyroid volume, arsenic cerium catalytic spectrophotometry (WS/T 107-2006) was used to detect urinary iodine, direct titration was used to detect salt iodine; At the same time, 20 pregnant women were selected from each town and urinary iodine was determined. All results were compared with the results of 2011 to evaluate the effect of iodine nutrition improvement on resident's health after the adjustment of salt iodine concentration. Results A total of 1 437 edible salt samples were tested, the median of salt iodine concentration was 24.1 mg/kg. Based on the new standard (18 - 33 mg/kg), the coverage rate of iodized salt was 95.4%(1 371/1 437), the qualified rate of iodized salt was 80.3%(1 101/1 371), the consumption rate of qualified iodized salt was 76.6% (1 101/1 437). A total of 1 496 urine samples of children and 630 urine samples of pregnant women were tested, the median of urinary iodine of children and pregnant women was 224.6 and 177.1 μg/L, respectively, which were significantly lower than those of 2011 (274.6, 279.6μg/L), the differences were statistically significant (H=70.10, 153.50, all P<0.05). The proportion of counties which iodine nutrition of children and pregnant women in suitable range was 36.7% (11/30) and 56.7% (17/30), which were higher than those of 2011 [6.5%(2/31), 25.8%(8/31)], the differences were statistically significant (χ2 = 7.88, 5.00, all P < 0.05). Totally 1 552 children were examined thyroid in Shanxi Province, the rate of goiter was 4.4% (69/1 552). Conclusion The new standard of iodine concentration makes it possible to maintain a sustainable elimination of iodine deficiency disorders, and it can improve the iodine nutrition of children aged 8-10 years and pregnant women to more reasonable level.

Objective To investigate resident iodine nutrition level in waterborne high iodine areas and prevalence of high iodine goiter in Shanxi Province.Methods In 2014,in Shanxi Province,in all the 10 high iodine counties (cities,districts),the jurisdiction area of each county (city,district) was divided into two blocks,high iodine and not high iodine districts,and in high iodine area of each county (city,area) according to their sub-area positions of east,south,west,north and center,a township was randomly selected (if the number of high iodine area in iodine excessive township ≤5,all townships were selected);four administrative villages in each monitoring township were randomly selected;in each administrative village,the edible salt samples of 15 randomly selected households were collected for detection of iodine content.Five counties (cities,districts) were selected from the province's 10 high iodine counties (cities,districts),water iodine content of 3 counties (cities,districts) was 150-300 μg/L,and 2 were ＞ 300 μg/L,one administrative village was selected from each county (city,area),household drinking water samples were collected to detect iodine content;and 100 elementary school children aged 8-10 were selected from the village where the monitoring stations located in for thyroid volume ultrasound measurement,and 30 of them were randomly selected for urinary iodine content detection.Results ① In the 10 high iodine counties (cities,districts),1 680 households salt samples were detected,and the rate of no iodine salt samples was 89.2％(1 499/1 680).② Fourteen water samples were collected in 5 counties (cities,districts),and the water iodine content was 155.7-467.3 μg/L.③ In the five high iodine counties (cities,districts),197 urine samples were collected from children aged 8 to 10.The median of urinary iodine was 466.5 μg/L;the median urinary iodine was 650.1 μg/L in water iodine≥300 μg/L children group which was significantly higher than that of the group with 150-300 μg/L water iodine content 332.5 μg/L (Z =-6.164,P ＜ 0.05);urinary iodine level of children and the water iodine of the corresponding village was positively correlated (r =0.543,P ＜ 0.05).④ In the five high iodine counties (cities,districts),543 children aged 8-10 were measured with their thyroid volume,the thyroid goiter rate was 6.8％(37/543);the goiter rate of water iodine ≥300 μg/L children group was [9.0％(28/311)] which was significantly higher than that in the iodine content of drinking water 150-300 μg/L group [3.9％(9/232),x2 =5.494,P ＜ 0.05].Conclusion The measurement of stopping iodized salt supply in high iodine areas in Shanxi Province is well implemented,iodine nutrition level and thyroid goiter rate in those areas are still too high,high iodine intervention measures can be focused on changing of the drinking water.