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Objective:To analyze the external quality control assessment results of urinary iodine, salt iodine and water iodine in iodine deficiency disorders laboratories in Qinghai Province, to evaluate the testing capacity of provincial, municipal and county-level laboratories and the operation of external quality control network, so as to provide quality assurance for consolidating and eliminating iodine deficiency disorders.Methods:In 2021, 1 provincial, 8 municipal, and 43 county-level laboratories in Qinghai Province had participated in the assessment of urinary iodine and salt iodine, while 1 provincial and 8 municipal-level laboratories had participated in the assessment of water iodine. The assessment results were evaluated using the method of reference value ± uncertainty of external quality control samples.Results:All laboratories that participated in the assessment had provided feedback. One provincial-level laboratory passed the assessment of urinary iodine, salt iodine, and water iodine. Among 8 municipal-level laboratories, 2 laboratories failed the urinary iodine assessment, with a pass rate of 6/8; the assessment of salt iodine and water iodine in 8 laboratories were all qualified. Among 43 county-level laboratories, 7 laboratories failed the urinary iodine assessment, with a pass rate of 83.7% (36/43); the assessment of salt iodine in 43 laboratories were all qualified.Conclusions:The external quality control network of iodine deficiency disorders laboratories in Qinghai Province has fully covered all municipal and county-level laboratories. The testing capability of provincial-level laboratory is stable and maintains a high level; the testing quality of some municipal and county-level laboratories is still unstable and needs to be further strengthened.
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Objective:To follow up the iodine nutrition and intellectual development of school children aged 8-10 years old in Nangqian County of Qinghai Province after 9 years of the implementation of iodine deficiency disorders intervention measures with iodine supplement as the main measure.Methods:In order to improve the iodine nutritional status of the population in Nangqian County, free iodized salt distribution, health education and other intervention measures for iodine deficiency disorders were implemented for 9 consecutive years since 2013. In May 2012 (before iodine supplementation) and September 2021 (after iodine supplementation), the same 5 townships (towns) were selected, and children aged 8-10 years old (half male and half female, age balanced) born locally in the central primary school of each township (town) were selected as the survey subjects. Household edible salt samples and random urine samples were collected for salt iodine and urinary iodine detection; the second revised version of the Chinese Combined Raven's Test (rural version) was used to assess the intelligence quotient (IQ) of children. The Flynn effect (FE) gain was used to adjust IQ, the corrected IQ = (IQ starting point value - current year's IQ value) - FE gain (calculated by 0.74/year). The differences of salt iodine and urinary iodine related indexes, IQ value and corrected IQ were compared before and after iodine supplementation.Results:After iodine supplementation, the coverage rate of iodized salt reached 100.00% (300/300), and the consumption rate of qualified iodized salt reached95.00% (285/300), the median urinary iodine increased to 157.20 μg/L, and all indexes met the elimination standard of iodine deficiency disorders. The IQ value of children aged 8-10 years old after iodine supplementation was 99.00 ± 14.90, significantly higher than that before iodine supplementation (82.00 ± 13.20, F = 156.82, P < 0.001). The FE gain in 9 years was 6.66, and the actual IQ gain of children aged 8-10 years old after iodine supplementation was 10.34. There were statistically significant differences in IQ value before and after iodine supplementation in male and female children ( F = 78.84, 78.88, P < 0.001). After iodine supplementation, there was a statistically significant difference in IQ value between children in the 8-year-old group and the 10-year-old group ( P = 0.010). There were statistically significant differences in IQ value before and after iodine supplementation in 8, 9 and 10 years old groups ( F = 55.23, 65.79, 36.85, P < 0.001). Conclusion:Intervention measures for iodine deficiency disorders, mainly iodine supplement, can significantly improve the iodine nutrition status of children aged 8-10 years old, and significantly promote the intellectual development of children.
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Objective:To observe the changes of serum C-terminal peptide of type Ⅰ collagen (CTX-1) and N-terminal lengthening peptide of type Ⅰ collagen (P1NP) in adult patients with skeletal fluorosis in the tea-drinking-borne endemic fluorosis area in Qinghai Province, and to find sensitive indicators for diagnosis of skeletal fluorosis.Methods:From April to August 2019, a case-control study was carried out in tea-drinking-borne endemic fluorosis area in Zhiduo County, Yushu Tibetan Autonomous Prefecture, and Gangcha County, Haibei Tibetan Autonomous Prefecture of Qinghai Province. According to the Diagnostic Standard for Endemic Skeletal Fluorosis (WS/T 192-2008), the clinical diagnosis and X-ray examination of skeletal fluorosis were carried out for permanent residents ≥25 years old and living for more than 10 years in the area, combined with face-to-face inquiry and investigation of past disease history, lifestyle and clinical manifestations. The patients with skeletal fluorosis and healthy people were selected as skeletal fluorosis group and control group, respectively. Randomized urine samples and fasting venous blood from the two groups were collected. The content of fluoride in urine was determined by ion selective electrode method, and the contents of CTX-1 and P1NP in serum were determined by enzyme-linked immunosorbent assay (ELISA).Results:A total of 127 people in the disease area were investigated, including 63 cases in skeletal fluorosis group and 64 cases in control group. There was no statistically significant difference in age and sex ratio between the two groups ( t = 0.42, χ 2 = 0.07, P > 0.05). The X-ray examination results showed that the patients with skeletal fluorosis were mainly mild, accounting for 71.43% (45/63); X-ray changes were mainly ossification of interosseous membrane and tendon. The urinary fluoride in control group and skeletal fluorosis group was 1.62 (1.12, 1.95) and 3.22 (2.38, 4.89) mg/L, respectively, with statistically significant difference between the two groups ( Z = 7.07, P < 0.001). The difference of serum CTX-1 and P1NP contents between the two groups was statistically significant ( Z = 2.00, 4.89, P < 0.05). Conclusions:The levels of serum CTX-1 and P1NP in patients with skeletal fluorosis are higher than those in healthy people. Serum CTX-1 and P1NP may be used as sensitive indicators for diagnosis of skeletal fluorosis.
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Objective:To learn about the detection quality and external quality control assessment of fluoride and arsenic in laboratories at all levels in Qinghai Province.Methods:The Z-score method was used to analyze and evaluate the evaluation results of 1 provincial, 8 municipal and 43 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water fluoride and brick tea fluoride in Qinghai Province in 2021, as well as 1 provincial, 1 municipal and 2 county level laboratories of disease prevention and control institutions participating in the external quality control assessment of water arsenic and urine arsenic. The feedback rate and qualification rate of external quality control of each assessment laboratory were calculated.Results:In 2021, the feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in provincial and municipal level laboratories of Qinghai Province were 100.00%; except that the qualified rate of water fluoride was 7/9, the qualified rate of external quality control of other projects was 100.00%. The feedback rate of external quality control of water fluoride, brick tea fluoride, water arsenic and urine arsenic in county level laboratories was 100.00%; except that the qualified rate of water fluoride was 86.05% (37/43), the qualified rate of external quality control of other projects was 100.00%. In the specific assessment results of the laboratory, the assessment results of water fluoride sample FS20210101 from 1 provincial, 1 municipal and 2 county level laboratories, and FS20210102 from 1 county level laboratory were suspicious; the assessment results of water fluoride sample FS20210101 from 3 county level laboratories were not satisfactory; the assessment results of fluoride and arsenic sample in other laboratories were satisfactory.Conclusions:The qualified rate of external quality control of fluoride and arsenic in laboratories at all levels in Qinghai Province is relatively high, but some county level laboratories are still dissatisfied with the assessment results of water fluoride. Therefore, it is necessary to strengthen the detection level of water fluoride in laboratories.
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Objective:To investigate the molecular mechanism of excessive iodine induced experimental autoimmune thyroiditis (EAT) in mice.Methods:Sixty female non-obese diabetic (NOD) mice were selected and divided into 5 groups according to body weight [(25 ± 3) g] via the random number table method, with 12 mice in each group: control group (group A), 10-fold high iodine group (group B), 100-fold high iodine group (group C), 1 000-fold high iodine group (group D) and 1 000-fold high iodine combined with polyinosinic acid-polycytidylic acid [Poly (I:C)] group (group E). The experiment period was 16 weeks. Mice in each group drank purified water with sodium iodine (NaI) content of 0.000, 0.005, 0.050, 0.500 and 0.500 mg/L, respectively; mice in group E were intraperitoneally injected with Poly (I:C) at week 7 and week 15, respectively. At the end of the 16th week, mice were dissected and blood samples and thyroid tissue were taken. The levels of serum thyroid function indexes [thyroid stimulating hormone (TSH), free triiodothyronine (FT 3), free thyroxine (FT 4), and thyroid peroxidase antibody (TPOAb)] were detected by enzyme-linked immunosorbent assay (ELISA); the pathological changes of thyroid tissue were observed after hematoxylin-eosin (HE) staining; differentially expressed genes in thyroid tissue were detected by RNA-sequencing (RNA-seq), and analyzed by KEGG pathway; mRNA and protein levels of p38, intercellular adhesion molecule-1 (ICAM-1) and chemokine 10 (CXCL10) in thyroid tissue were detected by real-time fluorescence quantitative PCR (qPCR) and Western blotting, respectively. Results:There were statistically significant differences in serum levels of TSH (ng/ml: 6.53 ± 0.86, 6.61 ± 0.82, 7.68 ± 0.55, 7.93 ± 0.60, 8.73 ± 1.60), FT 3 (pg/ml: 59.35 ± 10.16, 53.73 ± 10.96, 46.19 ± 8.03, 41.01 ± 8.67, 34.21 ± 11.75), FT 4 (pg/ml: 136.74 ± 10.06, 124.33 ± 14.34, 101.80 ± 6.78, 91.37 ± 6.75, 73.29 ± 17.31), and TPOAb (U/ml: 130.81 ± 24.53, 145.47 ± 28.89, 166.52 ± 41.59, 199.78 ± 42.19, 201.99 ± 44.03) among the 5 groups of mice ( F = 4.77, 4.96, 23.12, 3.68, P < 0.05). Compared with group A, the serum TSH levels of mice in groups C, D and E were higher, the levels of FT 3 and FT 4 in groups B, C, D and E were lower, and the levels of TPOAb in groups D and E were higher, and the differences were statistically significant ( P < 0.05). HE staining showed that the thyroid follicle lesion in groups D and E was serious, and the EAT phenotype appeared in both groups. The differentially expressed genes were analyzed by KEGG pathway. Compared with group A, 8 metabolic pathways related to thyroid autoimmunity and inflammation were found in groups B, C, D and E. Further analysis found that 3 genes appeared in multiple pathways, namely p38, ICAM-1 and CXCL10. There were significant differences in the mRNA levels of p38, ICAM-1 and CXCL10 in thyroid tissue of the 5 groups of mice ( F = 14.77, 12.76, 16.39, P < 0.05); compared with group A, the mRNA levels of p38 in groups B, C, D and E were higher, and the mRNA levels of ICAM-1 and CXCL10 in groups C, D and E were higher ( P < 0.05). There were significant differences in the protein levels of p38, ICAM-1 and CXCL10 in thyroid tissue of the 5 groups of mice ( F = 7.97, 73.86, 18.02, P < 0.05); compared with group A, the protein levels of ICAM-1 and CXCL10 in groups B, C, D and E were higher ( P < 0.05). Conclusion:Excessive iodine promotes the occurrence and development of EAT in mice by up-regulating the expressions of p38 and ICAM-1 genes that are closely related to thyroid autoimmune and inflammatory responses.
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Objective:To understand the detection quality and external quality control assessment of fluorine and arsenic laboratories at all levels in Qinghai Province.Methods:Z-ratio scoring method was used to analyze and evaluate the results of provincial, municipal and county-level laboratories participating in the national fluorine and arsenic external quality control assessment from 2014 to 2020 in Qinghai Province, │Z│≤ 2 was qualified, 2 <│Z│ < 3 was basically qualified and│Z│≥ 3 was unqualified. At the same time, the feedback rate and pass rate of the participating laboratories were calculated.Results:From 2014 to 2020, the external quality control assessment results of water arsenic, urinary arsenic and brick tea fluorine in Qinghai Provincial laboratory were all qualified; except for the external quality control assessment of water fluorine in 2018 that was basically qualified, the results of other years were all qualified. Municipal and county-level laboratories did not give feedback the external quality control assessment results of water arsenic and urinary arsenic in 2017, and the feedback rate and pass rate in other years were 100.0%; except for the external quality control feedback rate and pass rate of water fluorine and brick tea fluorine in 2014 that were all 100.0%, there were laboratories that did not give feedback or failed the assessment in other years.Conclusion:The testing ability of provincial laboratory in Qinghai Province meets the standard, and the testing ability of municipal and county-level laboratories still need to be improved continuously.
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Objective:To evaluate the water fluoride detection ability of county (city, district) level (referred to as the county-level) laboratories in Qinghai Province.Methods:During the "13th Five-Year Plan" period (2016 - 2020), 4, 4, 4, 43, 43 county-level laboratories in Qinghai Province were organized to participate in the national water fluoride external quality control assessment, and the assessment results were evaluated by Z-ratio scoring method.Results:The response rate of county-level laboratories was 86.05% (37/43) in 2019, and 100.00% in other years. The qualified rate of county-level laboratories was 100.00% from 2016 to 2018; in 2019 and 2020, the assessment was fully covered, and the qualified rate was 81.40% (35/43) and 95.35% (41/43), respectively. Compared with 2019, the response rate and qualified rate in 2020 increased significantly, and the differences were statistically significant (χ 2 = 6.450, 4.074, P < 0.05). In the past 5 years, two assessment samples│Z│ < 1 in each laboratory were the most common, but with two assessment samples 2≤│Z│ < 3 in some qualified laboratories. Conclusion:The consistency of water fluoride determination in Qinghai Province is not very ideal, and the detection ability of county-level laboratories still needs to be strengthened.
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Objective:To find out the variety, producing area, fluorine content of brick tea in Qinghai Province, and the drinking situation of brick tea among people, so as to provide basis for preventing and curing endemic fluorosis of drinking tea type.Methods:From April to November 2019, according to historical data, in 3 066 administrative villages in 39 counties (cities, districts, hereinafter referred to as counties) in Qinghai Province that had the habit of drinking brick tea, 10 families were randomly selected from each village to investigate the demographic data of each family and the drinking situation of brick tea, to collect brick tea samples to determine the fluorine content, and to calculate the daily average brick tea fluorine intake of the population > 16 years old.Results:A total of 31 067 brick tea samples were collected. The main brick tea consumed by the residents in the whole province was Fu brick tea, accounting for 89.97% (27 952/31 067), followed by Kang brick tea [5.12% (1 592/31 067)], Green brick tea [2.29% (710/31 067)], Black brick tea [1.85% (574/31 067)], and golden tip, mosaic, black wool and other brick tea [0.77% (239/31 067)]. There were 523 brands of brick tea in circulation in the province, among which there were 410 brands produced in Hunan Province, 26 brands in Sichuan Province, 11 brands in Hubei Province, and 76 brands in Henan Province and other provinces. The average content of fluorine in brick tea was 646.1 mg/kg, which ranged from 40.0 to 2 295.0 mg/kg. Brick tea with fluorine content ≤300 mg/kg accounted for 7.80% (2 422/31 067) of all samples. The annual average consumption of brick tea by population > 16 years old was 1.09 (0.35 - 7.40) kg, and the daily average brick tea fluorine intake was 1.93 (0.39 - 18.64) mg. There were 15 counties and 486 administrative villages in which the daily average brick tea fluorine intake exceeded the national standard (3.5 mg).Conclusion:The main brick tea in circulation in Qinghai Province is Fu brick tea, which has high fluorine content and is harmful to people, and prevention and control measures should be taken as soon as possible.
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Objective:To analyze the external quality control assessment results of fluoride in brick tea in the provincial, city (prefecture) and county (city, district)-level endemic fluorosis laboratories in Qinghai Province, and to evaluate the testing capabilities of laboratories at all levels.Methods:The Z-score method was used to analyze and evaluate the results of provincial, city (prefecture) and county (city, district)-level laboratories that participated in the external quality control assessment of fluoride in brick tea in Qinghai Province from 2014 to 2020, and│Z│≤2 was qualified; 2 <│Z│ < 3 was basic qualified; │Z│≥3 was unqualified.Results:From the feedback, the feedback rate of external quality control of fluoride in brick tea in provincial and city (prefecture)-level laboratories in Qinghai Province from 2014 to 2020 was 100.00%; the feedback rate of county (city, district)-level laboratories from 2014 to 2018 was 100.00%, and there were no feedback units in 2019 and 2020. From the assessment of qualification, the qualification rate of provincial, city (prefecture)-level laboratories was 100.00% in all other years except one unit failed in 2017; the qualification rate of county (city, district)-level laboratories was 100.00% in 2014, 2015, 2016 and 2019, and there were 6 unqualified units in other years.Conclusions:From 2014 to 2020, some endemic fluorosis laboratories in Qinghai Province still fail to pass the external quality control assessment of fluoride in brick tea. In the future, it will be the focus of work to strengthen personnel training and improve the detection ability.
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Objective:To study the epidemic status of drinking tea type endemic fluorosis in Qinghai Province.Methods:In 2019, in counties (cities, districts, referred to as counties) that had the habit of drinking brick tea in 8 cities (prefectures) of Qinghai Province, epidemiological investigation of drinking tea type endemic fluorosis was carried out in villages. Ten households were randomly selected from each village, to investigate the demographic data of each household and the drinking situation of brick tea, residents' drinking water and brick tea samples were collected to determine the fluorine content, and calculate the daily per capita tea fluorine intake. At the same time, skeletal fluorosis was examined in all adults over 25 years old, and dental fluorosis was examined in all children aged 8 to 12 years old in survey sites. The content of fluorine in tea and water was detected by ion selective electrode method; the diagnosis of skeletal fluorosis was based on "Diagnostic Criteria for Endemic Skeletal Fluorosis" (WS 192-2008), the diagnosis of dental fluorosis was based on "Diagnosis of Dental Fluorosis" (WS/T 208-2011).Results:The mean (range) of fluorine of the 3 602 water samples was 0.31 (0.20 - 1.00) mg/L. The geometric mean (range) of fluorine of the 31 067 brick tea samples was 646 (40 - 2 295) mg/kg, the fluorine content of the brick tea ≤300 mg/kg accounted for 7.80% (2 422/31 067) of the total samples. The proportion of drinking Fu brick-tea was 89.97% (27 952/31 067); and the daily per capita tea fluorine intake was 1.93 mg, the daily per capita tea fluorine intake in Guoluo, Yushu and Hainan prefectures were higher than the health standard (3.50 mg). The detection rate of skeletal fluorosis in adults was 0.16% (2 357/1 484 907), Yushu Prefecture was the highest [29.23% (592/2 025)], followed by Guoluo Prefecture, which was 8.21% (771/9 393). The detection rate of dental fluorosis in children was 4.79% (8 076/168 623), Yushu Prefecture was the highest [32.61% (1 562/4 790)].Conclusion:Drinking tea type endemic fluorosis is prevalent in Qinghai Province, with obvious regional characteristics, covering a large population. The disease is relatively popular in Yushu Prefecture and Guoluo Prefecture.
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Objective:To investigate the contents of soil metal elements in the plague high incidence area and resting area in the plague natural foci of Qingnan region in Qinghai Province, and to compare and analyze the differences of the contents of soil metal elements between the two areas.Methods:A total of 69 soil samples were collected from 11 sites in the plague high incidence area (Yushu Prefecture) and resting area (Guoluo Prefecture) in Qingnan region, including 39 samples from high incidence area and 30 samples from resting area. The contents of 12 soil metal elements, such as iron (Fe), magnesium (Mg), calcium (Ca), barium (Ba), cobalt (Co), copper (Cu), manganese (Mn), lead (Pb), rubidium (Rb), titanium (Ti), vanadium (V) and zinc (Zn), were measured by X-ray fluorescence spectrometry and SPSS 20.0 software was used for Spearman correlation and other statistical analysis.Results:The contents of Fe and Ca in the soil of the plague natural foci of Qingnan region were relatively high. The contents of 12 soil metal elements in the high incidence area were significantly higher than those in the resting area ( P < 0.01 or < 0.05). There were statistical significant differences in the contents of Mg, Ca, Ba, Mn, Pb and Zn in the soil among the sample plots of the plague high incidence area ( P < 0.01 or < 0.05). There were statistical significant differences in the contents of Fe, Mg, Ca, Rb and Ti in the soil among the sample plots of the plague resting area ( P < 0.05 or < 0.01). Except for Mg and Ca, Fe was positively correlated with other metal elements in the high incidence area and resting area ( P < 0.01 or < 0.05), and Fe was strongly positively correlated with Rb, Ti and V ( r = 0.780 - 0.838). Mg was only positively correlated with Ca in the high incidence area and resting area ( P < 0.01). Ca was negatively correlated with Mn, Pb, Rb, Ti, V and Zn in the high incidence area, and with Rb and Zn in the resting area ( P < 0.01 or < 0.05). The rest of the metal elements were mostly positively correlated in the high incidence area and resting area. Conclusions:The contents of Fe and Ca are rich in the plague natural foci of Qingnan region in Qinghai Province. There are correlations among most soil metal elements in the high incidence area and resting area. The correlation between the contents of soil metal elements in the plague natural foci and the epidemic of plague is worth further exploring.
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Objective:To verify the revised method of cerium sulfate catalytic spectrophotometry for iodide index of "Standard Examination Methods for Drinking Water-Nonmetal Parameters" (GB/T 5750.5-2006).Methods:From July to September 2019, the Laboratory of Department for Endemic Disease Prevention and Control of Qinghai Institute for Disease Prevention and Control verified the revised method (determination of iodide in drinking water by cerium sulfate catalytic spectrophotometry) of cerium sulfate catalytic spectrophotometry (hereinafter referred to as original method) in "Standard Examination Methods for Drinking Water-Nonmetal Parameters" (GB/T 5750.5-2006). The revised method was verified according to the requirements of "Standard Examination Methods for Drinking Water-Water Analysis Quality Control" (GB/T 5750.3-2006), including standard curve, detection limit, precision, accuracy and actual sample determination.Results:The linear range of the revised method was 0 - 20.0 μg/L, the correlation coefficient was - 0.999 4 - 0.999 8, and the detection limit was 0.231 μg/L. The relative standard deviation ( RSD) of low, medium and high iodine water samples of 6 times detection ranged from 1.4% to 9.6%, and the recoveries of low and medium water samples ranged from 89.0% to 108.0%. The detection results of national first-class reference materials for iodine composition analysis in water were within the range of standard value ± uncertainty. There was no significant difference in the test of results of 12 tap water samples between the revised method and the original standard method ( t = - 0.075, P > 0.05). Conclusion:The revised method has a good linear relationship of standard curve, high precision and accuracy, and good reproducibility, is simple and easy to operate, and is suitable for promotion and application.
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Objective:To investigate the dietary iodine intake of people in different areas of Qinghai Province, and to provide the basis for scientific iodine supplementation and continuous elimination of iodine deficiency hazards.Methods:From 2018 to 2019, according to administrative division, natural geographical regions, population distribution and economic development level of Qinghai Province, a total of 14 survey sites were selected. One village was selected from each survey site, and 20 households were selected from each village, the salt samples and 24 h urine samples of all family members were collected to detect salt iodine and urinary iodine. One drinking water sample was collected at the five directions of east, west, south, north and middle of each village to detect water iodine. Salt iodine was detected by direct titration, urinary iodine and water iodine were detected by arsenic-cerium catalytic spectrophotometry. At the same time, the 3-day weighing method was used to investigate the diet, the daily dietary iodine intake per capita (the result was expressed as average) and the proportion of dietary iodine in urinary iodine were calculated, the daily dietary iodine intake per capita of different production modes (agricultural region and pastoral region), different geographical environment (Hehuang Valley, Qaidam Basin, Qilian Mountain and Qingnan Plateau), different nationalities (Han, Tibetan, Hui, Mongolian, Tu, Salar) and different economic levels (< 8 000, 8 000 -, 10 000 -, ≥12 000 Yuan) were compared.Results:A total of 999 people from 280 families were surveyed, including 511 males and 488 females. The median water iodine of each survey site was less than 10 μg/L, all of which were environmentally iodine-deficient areas. A total of 280 salt samples were collected, the median salt iodine was 26.0 mg/kg, and the consumption rate of qualified iodized salt was 100% (280/280). A total of 999 urine samples were tested, and the median urinary iodine of people was 192.5 μg/L, which was at an appropriate level of iodine. There was no statistically significant difference ( t =-1.599, P > 0.05) in the daily dietary iodine intake per capita (28.53, 33.44 μg) of people in agricultural region ( n = 643) and pastoral region ( n = 356). The daily dietary iodine intake per capita (25.38, 33.30, 32.98, 34.79 μg) of people in Hehuang Valley ( n = 448), Qaidam Basin ( n = 125), Qilian Mountain ( n = 157), and Qingnan Plateau ( n = 269) were compared, the difference was statistically significant ( F = 2.883, P < 0.05); among them, the daily dietary iodine intake per capita in Hehuang Valley was lower than that in Qingnan Plateau ( P < 0.05). The daily dietary iodine intake per capita of different nationalities were compared, the difference was statistically significant ( F = 3.647, P < 0.05), Salar ( n = 68) and Tibetan ( n = 239) were higher (37.21 and 32.21 μg). The daily dietary iodine intake per capita (38.97, 17.01, 30.86, 33.14 μg) of annual per capita disposable income < 8 000 ( n = 194), 8 000-( n = 221), 10 000-( n = 302), ≥12 000 Yuan ( n = 282) were compared, the difference was statistically significant ( F = 9.407, P < 0.05). The proportions of dietary iodine in urinary iodine of various population ranged from 5.35% to 15.54%. Conclusions:The iodine nutrition of people in Qinghai Province is suitable, the dietary iodine intake of people is closely related to geographical environment, nationality and economic level. But the proportion of dietary iodine in urinary iodine is relatively low, the consumption of iodized salt is still the main way for people to intake iodine, and it is also the main measure to continuously eliminate the harm of iodine deficiency in Qinghai Province.
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Objective:To understand the situation of drinking water-borne endemic fluorosis (short for drinking water fluorosis) in Huangzhong, Ping'an and Ledu districts of Qinghai Province and operation status of water improvement projects, and to evaluate the effect of control measures.Methods:In historical drinking water fluorosis villages of Huangzhong, Ping'an and Ledu districts of Qinghai Province in 2018, the status of water improvement, the operation of water improvement projects and the content of water fluoride were investigated; the dental fluorosis of 8-12 years old children in all investigated villages was checked; 3 villages from 3 districts were selected, X-ray examination for skeletal fluorosis and urinary fluoride detection of adults over 25 years old of age were performed.Results:Eight-two historical drinking water fluorosis villages in 3 districts were investigated and all the villages had water improvement projects, in addition, the water improvement projects were operating normally, and the water fluoride content ranged from 0.10 to 0.37 mg/L, which were in line with the drinking water fluoride content standard (< 1.2 mg/L). Totally 2 503 children aged 8-12 years old were examined, the detection rate of dental fluorosis was 6.03% (151/2 503), the index of dental fluorosis was 0.13, the epidemic intensity was negative; the detection rates of dental fluorosis in 3 districts were 6.24% (129/2 068), 4.05% (7/173), 5.73% (15/262), respectively, reaching the control standard (< 30%), and the detection rate of dental fluorosis in 81 villages was less than 30%; 198 adults over 25 years old were examined, the detection rate of skeletal fluorosis was 5.05% (10/198), the geometric mean of urinary fluoride was 0.81 mg/L, and skeletal fluorosis cases were mainly in the age group over 40 years old, all of them were mild cases.Conclusions:The fluoride content in drinking water and the detection rate of children's dental fluorosis are all up to the control standard, and the condition of skeletal fluorosis is significantly reduced after the implementation of water improvement measures in Huangzhong, Ping'an and Ledu districts. It can be seen that the prevention and control of drinking water fluorosis in Huangzhong, Ping'an and Ledu districts have achieved good results, but later management and condition monitoring of water improvement projects should be strengthened to prevent the disease from rebounding.
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Objective:To observe and evaluate the effect of health education on drinking brick-tea type fluorosis in Zhiduo County, Qinghai Province, so as to provide basis for further formulating health education strategies.Methods:From April 2019 to April 2020, according to the historical prevalence of drinking brick-tea type fluorosis in Zhiduo County, Qinghai Province, 3 townships (towns) were selected to carry out the health education activities on drinking brick-tea type fluorosis for students of grade 4 - 6, village doctors, adults and monks in each township (town). We carried out a one-year publicity on the prevention and treatment of drinking brick-tea type fluorosis, distributed health education materials and organized health education activities. Before and after the intervention, we conducted a questionnaire survey on health education among the target population (grade 4 - 6 students, village doctors, adults and monks), to evaluate the awareness rate and behavior formation rate of fluorosis prevention and control, and to evaluate the intervention effect.Results:A total of 86 students of grade 4 - 6, 40 village doctors, 42 adults and 20 monks were investigated, after the intervention, the awareness rates of prevention and treatment of drinking brick-tea type fluorosis in grade 4 - 6 students, village doctors, adults and monks were 87.98% (227/258), 96.67% (116/120), 81.75% (103/126), 83.33% (50/60), respectively, which were significantly higher than those before the intervention [38.38% (76/198), 83.33% (100/120), 15.45% (19/123), 28.89% (13/45), P < 0.05]. After the intervention, the behavior formation rates of prevention and treatment of the drinking brick-tea type fluorosis in grade 4 - 6 students, village doctors, adults and monks were 74.42% (128/172), 72.50% (58/80), 52.38% (44/84), 60.00% (24/40), respectively, which were significantly higher than those before the intervention [14.39% (19/132), 38.75% (31/80), 3.66% (3/82), 0(0/28), P < 0.05]. Conclusion:The comprehensive intervention measures based on health education can significantly improve the knowledge of local residents, and improve their bad drinking habits of drinking tea, which is of great significance to the prevention and treatment of drinking brick-tea type fluorosis.
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Objective:To understand the water iodine content in Qinghai Province and draw a distribution map of water iodine, so as to provide a basis for scientific supplementation of iodine and continuous elimination of iodine deficiency hazards.Methods:In 2017, in all counties (cities, districts) in Qinghai Province, with townships (towns, streets, referred to as townships) as the unit, the residents' drinking water samples were collected, water iodine content was tested, the median water iodine was calculated, and the water iodine distribution map of Qinghai Province was drew.Results:Totally 1 836 drinking water samples were collected in 392 townships, the median water iodine was 1.7 μg/L. Townships that had the median water iodine < 5 μg/L, in the range of 5 to 10 μg/L and > 10 μg/L accounted for 80.6% (316/392), 17.1% (67/392) and 2.3% (9/392), respectively. Among all townships, the highest of the median water iodine was 24.8 μg/L. Based on the results, water iodine distribution map of Qinghai Province, water iodine distribution map of Xining City and water iodine distribution map of Haidong City were compiled.Conclusions:Iodine deficiency is widespread throughout natural environment in Qinghai Province. Hence, salt iodization measures to prevent iodine deficiency disorders should be implemented continuously. According to the water iodine distribution map, the people should be guided to supplement iodine scientifically.
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Objective:To analyze the assessment results of the external quality control in iodine deficiency disorders laboratories at all levels in Qinghai Province so as to provide quality assurance for monitoring and control effect evaluation of iodine deficiency disorders.Methods:The results of urinary iodine, salt iodine, and water iodine quality control assessments at the provincial, city (state) and county-level iodine deficiency disorders laboratories were analyzed in Qinghai Province from 2013 to 2018 (sourced from the annual evaluation results issued by National Reference Laboratory for Iodine Deficiency Disorders). Among them, there were 1 provincial, 8 city (state) and 43 county-level (2017, 2018) laboratories participated in the urinary iodine assessment; 1 provincial, 8 city (state) and 30 county-level (43 in 2017 and 2018) laboratories participated in the salt iodine assessment; 1 provincial and 8 city (state)-level laboratories participated in the water iodine assessment.Results:From 2013 to 2018, the feedback rates and qualified rates of provincial and city (state)-level laboratories participated in the urinary iodine external quality control assessment were 100.0%; the feedback rates of 43 county-level laboratories (2017 and 2018) were 100.0%, and the qualified rates were 93.0%(40/43) and 88.4%(38/43), respectively. The feedback rates and qualified rates for salt iodine assessment in provincial and city (state)-level laboratories were 100.0%; the county-level laboratories feedback rates were 100.0%, and the qualified rates were > 90.0% except for 2014. And the feedback rates of provincial and city (state)-level laboratories for water iodine assessment were 100.0%; the qualified rate of provincial-level laboratory was 100.0%, and the city (state)-level laboratories were 100.0% except 2016 (7/8).Conclusions:The quality control network of Qinghai Province's iodine deficiency disorders laboratories has fully covered all city (state) and county-level laboratories. Provincial, city (state)-level laboratories have stable and reliable levels of urinary iodine, salt iodine, and water iodine; some individual county-level laboratories testing capabilities still need to be improved.
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Objective:To study the epidemic status of drinking brick-tea type fluorosis in Haibei Prefecture, Qinghai Province, and to provide evidence for future targeted intervention measures.Methods:In 2018, according to the historical prevalence of drinking brick-tea type fluorosis in Haibei Prefecture, in Haiyan, Menyuan, Qilian, Gangcha counties, based on the classification of pastoral area, agricultural area, semi-agricultural and semi-pastoral areas, one township (town) was selected, and one natural village was selected in each township (town) as a survey site. Drinking water samples of local residents were collected, water fluorine content was detected; and 10 households in Haiyan and Menyuan counties were selected, respectively, 100 brick-tea samples of different brands were collected, brick-tea fluorine content was detected. At the same time, dental fluorosis was examined in all children aged 8 to 12 years old in survey sites; and X-ray of skeletal fluorosis was examined in all adults aged 26 - 55 years old in Haiyan and Menyuan counties, urine samples were collected from adults at random for 1 time and urine fluorine content was detected. Water fluorine, brick-tea fluorine, and urine fluorine contents were detected by ion selective electrode method; the diagnosis of dental fluorosis was based on "Diagnosis of Dental Fluorosis" (WS/T 208-2011), and the diagnosis of skeletal fluorosis was based on "Diagnostic Criteria for Endemic Skeletal Fluorosis" (WS 192-2008).Results:The mean of fluorine of the 10 water samples was 0.33 mg/L (0.20 - 0.84 mg/L). The mean of fluorine of the 100 brick-tea samples was 750 mg/kg (230 - 1 660 mg/kg), and the mean of daily fluorine intake from brick-tea of each person was 1.87 mg. The detection rate of dental fluorosis in children was 22.56% (217/962), and the dental fluorosis index was 0.42. The detection rate of skeletal fluorosis in adults was 6.88% (24/349); and the geometric mean of urine fluorine was 1.53 mg/L (0.20 - 20.60 mg/L).Conclusion:In Haibei Prefecture, residents are still affected by drinking brick-tea type fluorosis, which needs to be paid attention to.
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Objective To understand the epidemic situation of tea-drinking-borne fluorosis among children in Haixi Prefecture of Qinghai Province,and to provide basis for taking pertinent prevention and control measures.Methods In 2017,three townships (towns) were selected from five counties (cities) in Golmud,Delingha,Dulan,Ulan and Tianjun,Haixi,and one village (villages excluding excessive water fluoride) was selected from each township (town) as the investigation site.Fluoride content in drinking water,tea fluoride content and dental fluorosis in children aged 8-12 years were investigated.Water fluoride was determined using "Standard Test Method for Drinking Water" (GB/T 5750.5-2006);brick tea fluoride content was detected using "The Fluoride Content in Brick Tea" (GB 19965-2005);children's dental fluorosis was diagnosed using "Diagnosis of Dental Standard for Fluorosis"(WS/T 208-2011).Results Totally 75 drinking water samples were collected from each county (city).The water fluoride content ranged from 0.35 to 0.41 mg/L,with an average value of 0.37 mg/L,which was lower than the national drinking water fluoride standard of 1.00 mg/L.The fluoride content of 150 brick tea samples ranged from 206.0 to 796.0 mg/kg,with an average value of 629.8 mg/kg.A total of 1 325 children aged 8-12 were examined.The detection rate of dental fluorosis was 13.43％ (178/1 325),the index of dental fluorosis was 0.27,and the overall epidemic intensity was negative.The epidemic intensity in Dulan and Tianjun counties was marginal.There were significant differences in the detection rate of dental fluorosis among children of different ages (x2=35.26,P ＜ 0.05),and dental fluorosis was increased with ages in children.The detection rate of dental fluorosis in boys and girls was 13.31％ (90/676) and 13.56％ (88/649),respectively,with no significant difference (x2 =0.02,P ＞ 0.05).Conclusions There is an epidemic of tea-drinking-borne fluorosis among children in 5 counties (cities) of Haixi Prefecture.Although the epidemic is mild,it should not be ignored.Health education and publicity work for tea-drinking-borne fluorosis should be strengthened.
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Objective To understand the current environmental selenium and T-2 toxin levels in the critically ill areas of Kaschin-Beck disease in Qinghai Province.Methods In three historical villages with serious diseases of Kaschin-Beck disease,Xia,Xiemalang and Yaoshidao were selected;at the same time,three villages from non-diseased areas were selected as control villages including Damitan,Gongba and Deang in 2018.Six villages were used as survey sites.Collected hair samples of children aged 6-12 years old,to measure the hair selenium content in Xinghai and Guide survey sites [children's selenium content reference value was (0.60 ± 0.03)mg/kg].Ten samples of self-produced grain were collected from each survey site,selenium content [wheat selenium content reference value was (0.053 ± 0.007) mg/kg] and T-2 toxin content in grain was detected in the six survey sites.Ten soil samples were collected from each survey sites.Soil selenium content was detected in the six survey sites [soil selenium content reference value was (0.24 ± 0.03) mg/kg].Results The selenium contents of children's hair in the diseased and non-diseased areas of Xinghai County,Guide County were (0.252 ± 0.071),(0.296 ± 0.087);(0.225 ± 0.032),(0.238 ± 0.040) mg/kg,respectively.The selenium contents of wheat in the diseased and nondiseased areas of the three counties were 0.000 19,0.003 66;0.000 15,0.004 16;0.016 78,0.016 94 mg/kg.The soil selenium contents in the diseased and non-diseased areas of the three counties were (0.095 ± 0.015),(0.114 ± 0.014);(0.082 ± 0.013),(0.083 ± 0.018);(0.080 ± 0.005),(0.060 ± 0.013) mg/kg.The T-2 toxin contents of wheat in the diseased and non-diseased areas of the three counties were (3.173 ± 0.762),(3.100 ± 0.473);(2.506 ± 0.430),(3.186 ± 0.451);(2.416 ± 0.619),(2.879 ± 0.456) μg/kg.Conclusions The content of hair selenium of children is close to the normal reference value in the area of Kaschin-Beck disease in Qinghai Province.The contents of soil selenium and the main grain selenium of the residents are low in the diseased village.A certain amount of T-2 toxin is detected in the main grain of residential households.