Objective To analyze the assessment results of external quality control and network operation of urinary iodine in local laboratories of Shandong Province,to evaluate the ability of consistent analysis; and to provide a reliable laboratory quality assurance for epidemiological surveillance and control of iodine deficiency disorders (IDD) and reliable decision-making.Methods Z-scores of the assessment results of external quality control of urinary iodine in local laboratories of Shandong Province were analyzed from 2000-2013.Results The feedback rate of urinary iodine in local laboratories of ShandongProvince was 100.0％ from 2000-2013; the qualified rate was 100.0％(14/14),100.0％(14/14),92.9％(13/14),100.0％(14/14),92.9％(13/14),100.0％ (14/14),100.0％ (14/14),100.0％ (14/14),92.9％ (13/14),100.0％ (17/17),100.0％ (17/17),94.1％ (16/17),100.0％ (17/17),and 100.0％ (17/17),respectively.The total qualified rate of Z-scores between Zs in local laboratories was 100.0％ (214/214)and within Zs was 98.6％ (211/214).Conclusion The test abilities of urinary iodine in local laboratories of Shandong Province are steady; the overall results are satisfactory,but some laboratories need to improve.

Objective To investigate the epidemic status of endemic fluorosis in Shandong Province,Jining City,and to provide a basis for prevention and control of the disease.Methods Based on Shandong Provincial Project Technical Solutions for Endemic Fluorosis,Rencheng,Jinxiang,Yutai,Jiaxiang and Liangshan Counties in Jining were selected as monitoring sites.According to the illness situation of mild,moderate or serious districts,one village was selected as a major survey site from each county(district).There were a total of 15 such villages selected.Survey content included drinking water fluorine level; dental fluorosis of children,adults' clinical skeletal fluorosis and urinary fluorine levels; water and urinary fluoride content were determined by the method of fluoride ion selective electrode; dental fluorosis of children was diagnosed by Deans method and clinical diagnosis was based on the Diagnostic Criteria of Endemic Skeletal Fluorosis (WS 192-2008).Results Sixty-one water samples from 15 villages of five counties (districts) were tested.Fluoride levels of 9 out of the 61 samples were exceeded the national standard (＞ 1.0 mg/L),and the rate was 14.75％; 1 sample ＞ 2.0 mg/L,and the maximum water fluoride was 2.25 mg/L.Seven hundred and seventeen people's real time urinary fluoride was detected in the 15 villages,including 420 children and 297 adults,and the geometric mean were 1.53 and 1.69 mg/L,respectively.Clinical examination of 755 children aged 8 to 12 showed that the detection rate of dental fluorosis was 26.89％ (203/755); defect rate was 9.12％(29/755) and dental fluorosis index weres 0.65.The detection rate of clinical skeletal fluorosis of 11 565 adults was 4.76％(550/11 565),including 303 moderate or serious cases.Conclusions The situation of excessive water fluorine in outside environment in Jining City has been controlled at a certain degree; groups urinary fluoride level is closed to the normal upper limit; the prevalence of dental fluorosis or skeletal fluorosis has been suppressed at a certain degree,therefore,the results of control should be further consolidated and expanded,in order to completely eliminate the fluoride hazard.

Objective To establish a rapid, simple and accurate method for detection of selenium in grain that is suitable in Chinese situation. Methods Nitric acid and perchloric acid(7: 3, v/v) were used to digest the grain samples by heating on a hot plate. Selenium was determined with hydride generation atomic fluorescence spectrometry. Sample detection limit, precision, accuracy(recovery, method characteristics and method control) were studied. And the grain samples of Shandong Province were determined by this method. Results The lowest detection limit was 4 μg/kg. The coefficient of correlation of working curve was 0.999 9. Intra-day precision was 1.32%, day precision was 4.17%. The total average rate of recovery was 100.5% with a range of 96.7% - 105.5%, and the average rates of recovery were 104.0%, 99.0% and 98.4% (n = 6). The determination results of corn reference material [(0.022 ± 0.006) mg/kg] were in the standard value range [(0.021 ± 0.008) mg/kg]. The determination results of the samples [(0.424 ± 0.096) mg/kg] were consistent with the results of national standard fluorescence method [(0.406 ± 0.108) mg/kg]. The contents of selenium in wheat, maize and sweet potato samples from five regions of Shandong Province were:Shanting:(0.030 3 ± 0.025 2),(0.016 8 ± 0.013 5),(0.015 4 ± 0.002 9) mg/kg; Anqiu:(0.020 3 ± 0.000 1), (0.020 4 ± 0.009 9), (0.017 1 ± 0.007 5) mg/kg; Ju'nan:(0.021 3 ± 0.013 9), (0.018 5 ± 0.007 8),(0.019 9 ± 0.003 6)mg/kg;Yishui:(0.025 7 ± 0.006 2),(0.020 6 ± 0.003 2), (0.018 2 ± 0.003 2) mg/kg; Wulian:(0.020 3 ± 0.004 7), (0.020 1 ± 0.008 9), (0.018 4 ± 0.007 3) mg/kg. Conclusions The method has the advantages of higher precision and accuracy, less time, less pollution, less aciduse, easier operation and repeatability.It is very suitable for measuring selenium content in large amount of food samples.

Objective To investigate the status of iodine content in the inner and outer environment of residents in excessive iodine intaking areas in Liaocheng of Shandong Province after stop taking iodized salt.Methods Totally 300 residents from each county (city) were selected for semi-quantitatively examination of their household salt in seven excessive iodine intaking counties (cities) in 2015 and 2016.Five counties were surveyed in 2015,and two other counties were surveyed in 2016.Then one town was selected from every county (city) as test site,one hundred children aged 8-10 (50 males and 50 females) from every test site were selected to measure their household salt iodine level.If the household salt was confirmed a non-iodized salt,water samples and urine samples were collected.Water iodine and urinary iodine contents were measured by arsenic cerium catalytic spectrophotometry (WS/T 107-2006).Results In 2015 and 2016,non iodized salt rates were 97.4％ (1 753/1 800) and 96.6％ (1 738/1 800),respectively in Liaocheng.Totally 686 household drinking water samples were measured.The water iodine levels were 2.7-748.4 μg/L,and the median was 203.4 μg/L.Totally 699 urine samples were measured.The urine iodine levels were 33.6-1 692.0 μg/L,and the median was 486.8 μg/L.The median of children's household water iodine level and median of children's urinary iodine level were significantly positively correlated (r =0.857,P ＜ 0.05).Conclusions The measurement of stop taking iodized salt in excessive iodine intake areas in Liaocheng is well implemented.Some monitoring sites show significant improvement.However,the urine iodine level of most residents is still high.The harmful effects of excessive iodine intaking are still constantly existed in some areas.In the future,in addition to continue to change the water to reduce iodine,it is also necessary to strengthen the health education of residents to improve the residents' awareness of the dangers of excessive iodine.

Objective:To analyze the assessment results of the external quality control and network operation of urinary iodine in local laboratories of Shandong Province, to evaluate the ability of consistent analysis.Methods:In 2016, there were 65 county-level urinary iodine laboratories participated in the provincial external quality control assessment, and there were 124 county-level urinary iodine laboratories participated in the national external quality control assessment in 2017. In 2018, all 137 county-level urinary iodine laboratories in the province participated in the national external quality control assessment. The testing results were analyzed with Z score method (qualified:│Z│≤2; basically qualified: 2 <│Z│ < 3; unqualified:│Z│≥3).Results:The 65 county-level laboratories in Shandong Province were evaluated in the provincial quality control test of urinary iodine in 2016, the feedback rate was 92.3% (60/65), the overall qualified rate was 81.7% (49/60); 124 county-level laboratories in Shandong Province were evaluated in the national quality control test of urinary iodine in 2017, the feedback and qualified rate were both 100.0% (124/124). All the 137 county-level laboratories were evaluated in the national quality control test of urinary iodine in 2018, the feedback and qualified rate were both 100.0% (137/137).Conclusions:The test abilities of urinary iodine in local laboratories of Shandong Province has been increasing continuously, and it has initially reached the detection level required for the full coverage of urinary iodine monitoring in all counties of the province.

Objective:To evaluate the detection ability of water fluoride of county-level laboratories in Shandong Province.Methods:From 2017 to 2019, Shandong Province organized 30, 30 and 37 county-level laboratories to participate in the national water fluoride external quality control assessment and the assessment results were evaluated by Z-ratio score method.Results:From 2017 to 2019, the feedback rate and qualified rate of water fluoride external quality control assessment of county-level laboratories were 100% (30/30, 30/30, 37/37) for three consecutive years.Conclusion:Over the past three years, the water fluoride detection ability of county-level laboratories in Shandong Province has been maintained at a satisfactory level.

Objective To evaluate feasibility of a method for determining low and medium concentrations water iodine by an automatic iodine analyzer (hereinafter referred to as this method).Methods The low (0-10 μg/L)and medium (0-100 μg/L) concentrations water iodine were determined by an automatic iodine analyzer.Methodological experiments were carried out on this method,including standard curve linearity,detection limit,precision experiment,standard recovery experiment,and standard substance determination.Results The absolute values of the linear correlation coefficients of the low and medium concentrations standard curves were ＞ 0.999 0,and the detection limits were 0.32 and 2.60 μg/L,respectively.Precision:the coefficient of variations were all below 2％ (n =18) of low,medium and high iodine concentrations water samples in the range of low and medium concentrations water iodine,and the average recovery rates were 100.7％ and 101.1％ (n =6),respectively.The determination results of the water iodine standard substance GBW 09113d and GBW 09114d were (8.3 ± 0.3)and (61 ± 2) μg/L (n =6),respectively,which were within the given standard values range.Conclusions This method has higher precision and accuracy,less reagent consumption,less time consumption,and simple operation.It is convenient for large-scale detection,and has strong applicability.

Objective:To analyze the external quality control assessment results of salt iodine, urine iodine, and water iodine in iodine deficiency disorders (IDD) laboratories at all levels in Shandong Province, and provide reliable quality assurance for monitoring and prevention of IDD.Methods:The external quality control assessment of salt iodine, urine iodine and water iodine in provincial, municipal and county levels IDD laboratories in Shandong Province from 2017 to 2021 were conducted, and feedback rate and qualification rate were calculated.Results:From 2017 to 2021, the feedback rates and qualification rates of external quality control assessment of salt iodine, urine iodine and water iodine at provincial and municipal levels IDD laboratories in Shandong Province were all 100.0%. The feedback rates of county level laboratories participating in the salt iodine external quality control assessment were all 100.0%. The qualification rate in 2021 was 99.3% (135/136), and the other four years were all 100.0%. The feedback rates of county level laboratories participating in the urine iodine external quality control assessment were all 100.0%. The qualification rates in 2017 and 2021 were 98.4% (122/124) and 97.1% (132/136), respectively, and the other three years were all 100.0%. In 2021, the county level laboratories in Shandong Province participated in the water iodine external quality control assessment for the first year, and the feedback rate and qualification rate of 69 laboratories were both 100.0%.Conclusion:From 2017 to 2021, the detection capacity of IDD laboratories at the provincial and municipal levels in Shandong Province remains at a high level, and the detection capacity of salt iodine and urine iodine in some county level laboratories still needs to be further improved.

Objective To explore the correlation of waist-to-height ratio (WHtR) and triglycerides (TG) with changes in cerebral hemodynamic index (CVHI) and the risk of stroke. Methods From March 2018 to March 2019, a total of 500 medical examinees were selected from the civil servants who underwent a physical examination in the physical examination department of our hospital. According to the TG level, the subjects were divided into two groups: HTG group (208 cases) and normal group (292 cases). According to WHtR value, the subjects were divided into an abnormal group (216 cases) and a normal group (284 cases). According to the test results, CVHI and other information the stroke risk was analyzed among the 4 groups. Results The right Vmax and bilateral Qmean, Vmean, Vmin, and Dp in the HTG group were significantly lower than those in the normal group (P<0.05), while the bilateral Wv, Zcv, Rv, DR, and Cp were higher than those in the normal group (P<0.05). The parameters of bilateral Vmax, Qmean, Vmean, Vmin, and Dp in the abnormal group were significantly lower than those in the normal group (P<0.05), while the bilateral Wv, Zcv, Rv, DR, and Cp were higher than those in the normal group (P<0.05). The CVHI scores of the HTG group and the abnormal group were lower than those of the normal group (P<0.05), and the FSP scores were higher than those of the normal group (P<0.05). The proportion of high-risk strokes with CVHI<75 and FSP score ≥10 in the HTG group were both higher than that in the normal group (P<0.05). There were 4 predictors including HTG, WHtR, CVHI score, and FSP score. There was a statistically significant difference in the etiology of stroke between CVHI and FSP (P<0.05). The risk of stroke in patients with abnormal WHtR increased by 2.746 times, and the relative risk of stroke in patients with CVHI<75 increased by 3.298 times. Conclusion WHtR abnormality and CVHI<75 were two independent predictors of stroke risk. HTG may increase the risk of stroke by affecting cerebral hemodynamic indicators.