Urinary Iodine Concentration In Children Research Articles

Analysis of iodine nutritional status of children aged 8-10 years in Zhejiang Province from 2016 to 2021

Objective: To analyze the iodine nutrition status of children aged 8 to 10 years in Zhejiang Province from 2016 to 2021. Methods: A multi-stage stratified sampling method was used to select non-residential children aged 8 to 10 years from 90 counties in Zhejiang Province. A total of 114 103 children were included in the study from 2016 to 2021. Direct titration method and arsenic-cerium catalytic spectrophotometry were used to detect salt iodine content and urinary iodine level, respectively, to evaluate the iodine nutritional status of children. Ultrasound was used to detect thyroid volume and analyze the current prevalence of goiter in school-age children. Results: The age of 114 103 children was (9.04 ± 0.81) years old, with 50.0% of (57 083) boys. The median of iodine content M (Q1, Q3) in children's household salt was 23.00 (19.80, 25.20) mg/kg, including 17 242 non-iodized salt, 6 173 unqualified iodized salt, and 90 688 qualified iodized salt. The coverage rate of iodized salt was 84.89%, and the coverage rate of qualified iodized salt was 79.48%. The proportion of non-iodized salt increased from 11.85% in 2016 to 16.04% in 2021 (χ2trend=111.427, P<0.001). The median of urinary iodine concentration M (Q1, Q3) in children was 182.50 (121.00, 261.00) μg/L, among which the proportions of iodine deficiency, iodine suitability, iodine over suitability, and iodine excess were 17.25% (19 686 cases), 39.21% (44 745 cases), 26.85% (30 638 cases), and 16.68% (19 034 cases), respectively. The median of urinary iodine concentration in children in inland areas [M (Q1, Q3): 190.90 (128.80, 269.00) μg/L] was significantly higher than that in children in coastal areas [M (Q1, Q3): 173.00 (113.00, 250.30) μg/L] (P<0.001). From 2016 to 2021, a total of 39 134 ultrasound examinations were conducted, and 1 229 cases of thyroid enlargement were detected. The goiter rate was 3.14% (95%CI: 2.97%-3.32%). The incidence of goiter in children in coastal areas [3.45% (95%CI: 3.19%-3.72%), 641/18 604] was higher than that in children in inland areas [2.86% (95%CI: 2.64%-3.10%), 588/20 530] (P=0.001). Conclusion: From 2016 to 2021, the iodine nutrition level of children aged 8-10 years in Zhejiang Province is generally suitable, and the rate of goiter in children meets the limit of iodine deficiency disease elimination standards.

Correlations of water iodine concentration to earlier goitre frequency in Sweden\u2014an iodine sufficient country with long-term iodination of table salt

BackgroundBefore iodination of Swedish table salt in 1936, iodine deficiency resulting in goitre and hypothyroidism was common. Sweden has become iodine sufficient, as shown in a national survey in 2007, proving its iodination fortification programme effective for the general population. The objective of this study was to collect drinking water from water treatment plants nationally and test if water iodine concentration (WIC) correlated to urinary iodine concentration (UIC) of school-aged children in a national survey 2007 to former goitre frequency in 1929 and to thyroid volume data in 2007.MethodsIn 2012, 166 treatment plants, located in 57% (166 of 290) of all Swedish municipalities, were asked to collect drinking water samples of approximately 10 ml. In 2007, tap water samples of the same volume were collected from 30 randomly selected schools for the national survey. Analysis of WIC was done in both treatment plants in 2012 (n = 166) and tap water in 2007 (n = 30). The correlation of WIC to the children’s UIC and thyroid volume after iodination was tested based on data from the national survey in 2007. The association of WIC to former goitre frequency was tested based on pre-iodination data, derived from a map of goitre frequency drawn in 1929.ResultsThe median WIC from water treatment plants was 4.0 μg/L (range 0–27 μg/L). WIC was similar in coastal and inland areas, for both ground and surface water.WIC correlated with historical goitre areas and was lower in the goitre areas than in non-goitre areas (p < 0.001). WIC in the same municipalities as the schools correlated with the UIC of children (p < 0.01), but not with their thyroid volume.ConclusionsWIC still contributes to iodine nutrition in Sweden, but iodination overrides the goitre effect.

Association of iodized salt with goiter prevalence in Chinese populations: a continuity analysis over time

BackgroundIodine deficiency disorders (IDD) refer to diseases that are caused by insufficient iodine intake, and the best strategy to prevent IDD is the addition of iodine to dietary salt. Because iodine deficiency is a common cause of goiter, the prevalence as effectively controlled after the implementation of universal salt iodization (USI) in China. However, there is substantial controversy as to whether the incidence of thyroid disorders is related to iodized salt intake. Therefore, we aimed to clarify whether the risk of goiter can be promoted by USI.MethodsA longitudinal continuous study based on the national monitoring results of IDD in China was performed for 3 consecutive years. We recorded the following indicators of IDD from 31 provinces: goiter number, two degrees of goiter (the degree of goiter severity) and cretinism (three endemic diseases), iodized salt intake, median urinary iodine concentration (UIC), soil iodine content and coverage rates of iodized salt. One-way Analysis of Variance (ANOVA) and linear regression analyses examined the differences between the three groups and correlations, respectively. Data were collected from the Chinese national IDD surveillance data in 2011-2013, and the background values of Chinese soil elements were published in 1990.ResultsA reference male’s daily intake of maximum iodine was 378.9 μg, 379.2 μg and 366.9 μg in 2011, 2012, and 2013, respectively. No statistical association between daily iodized salt intake and the three endemic diseases was observed in 2011-2013 (P > 0.05). No association was observed between daily iodized salt intake and the UIC of children in 2011 (P > 0.05). Linear regression revealed no significant correlation between the soil iodine content and three endemic diseases. The present study indicated no difference in the daily iodized salt intake in each province during three years (F = 0.886, P = 0.647). The coverage rate of iodized salt remained above 98.7%, and goiter rates were stable in 2011-2013.ConclusionThere was no significant association between iodized salt intake and the three endemic diseases, suggesting that the current nutrition level of iodized salt did not cause the high goiter prevalence.

Iodine and autoimmune diseases. Urinary iodine concentration in children affected by coeliac disease or thyroiditis

Iodine and autoimmune diseases. Urinary iodine concentration in children affected by coeliac disease or thyroiditis

Relationship between Iodine Content in Household Iodized Salt and Thyroid Volume Distribution in Children

ObjectiveTo assess the effect of different levels of salt iodine content on thyroid volume (ThV) distribution using data from the 1999, 2011, and 2014 Chinese national iodine deficiency disorder (IDD) surveys. MethodsProbability proportion to size (PPS) sampling method was used to obtain a representative national sample of 34,547, 38,932, and 47,188 Chinese children aged 8-10 years in 1999, 2011, and 2014 Chinese national IDD surveys, respectively. The iodine content in household iodized salt and urinary iodine concentration were measured and thyroid ultrasound examination was performed. The data were analyzed by SAS software using histograms and box plots. The skewness and kurtosis were calculated for testing the normality of ThV. ResultsThe median iodine content in household iodized salt dropped from 42.30 mg/kg in 1999 to 25.00 mg/kg in 2014. The median urinary iodine concentration of children aged 8-10 years decreased from 306.0 μg/L in 1999 to 197.9 μg/L in 2014. The median and interquartile range (IQR) of ThV in 1999, 2011, and 2014 surveys were 3.44 mL and 1.50 mL, 2.60 mL and 1.37 mL, 2.63 mL and 1.25 mL, respectively. The skewness and kurtosis of ThV distribution in 1999, 2011, and 2014 surveys were 1.34 and 5.84, 0.98 and 3.54, 1.27 and 5.49, respectively. ConclusionWith reduced salt iodization levels, the median urinary iodine concentration and median ThV of children decreased significantly, and the symmetry of the ThV distribution improved.

A meta-analysis combining parallel and cross-over randomized controlled trials to assess impact of iodine fortified foods on urinary iodine concentration among children.

The purpose of this analysis was to combine evidence from parallel and cross-over randomized controlled trials to assess the impact of iodine fortified foods on urinary iodine concentration (UIC) in children. A structured search for studies on iodine intervention studies on MEDLINE, Pro Quest, and the Cochrane Library from Jan, 1990 to Dec, 2012 was carried out. Carry-over effect was estimated by general linear model. We explored two methods to pool continuous outcomes in a meta-analysis by combining parallel and cross-over trial designs. The standard mean difference was calculated for net change in UIC. Fixed or random-effects models were used to summaries fortified food response data. Meta-regression and covariate meta-analysis were performed to explore the influ-ence of confounders on the net pooled effect on UIC. The overall pooled estimate, which combined parallel with cross-over trials in the absence of carry-over effect of UIC from 9 studies, showed a significant increase in the fortified group compared with the control group (n=3448; standard mean difference=2.02 μg/L; 95% CI: 1.30, 2.73; I2=99%, τ2=1.81, p<0.01). Meta-regression analysis indicated that dose of the feeding was positively related to the effect size (regression coefficient=0.014; 95% CI: 0.003, 0.026; p<0.019). The net pooled effect size after removing the confounders was 1.59 (95% CI: 0.953, 2.23) μg/L. There was an association between intakes of io-dine fortified foods and UIC in children. These results suggest that we can combine parallel with cross-over trials for meta-analysis for nutrients such as iodine when absorption is high.

Multiple pesticides exposure of greenhouse workers and thyroid parameters

Objective: The persistence of high prevalence of thyroid pathology (goiter, nodules) in Romanian population, despite the correction of iodine defi ciency, determined us to evaluate the impact of factors different than iodine intake on the thyroid gland as environmental endocrine disruptors. We studied the potential correlation between pesticide exposure and parameters of the function, autoimmunity and morphology of the thyroid in a group of greenhouse workers (GHWs) exposed to multiple uncontrolled pesticides across agricultural seasons. Materials and methods: A group of 108 GHWs, 18‐78 year olds, with normal iodine intake, from a plain village, exposed to multiple pesticides was enrolled voluntary in this study. Thyroid echography, thyroid parameters [thyroid stimulating hormone (TSH), free T4 (FT4), and antibody to thyroid peroxidase (ATPO)], some of the used pesticides (chlorpyrifos, trichloropyridinol (TCP), carbofurane, cypermethrin, dimethoate) and cholinesterase activity were determined in biological samples (urine, blood) collected across two agricultural seasons. Results: The median urinary iodine concentration in children from this village was 135.20 µg/L, while median TSH and median FT4 was 1.72 μUI/mL and 16.68 pmol/L, respectively. Hypothyroidism (TSH > 4.2 μUI/mL) was present in 12.4% of patients, median TSH value was 7.26 μUI/mL. In four of them post-thyroidectomy hypothyroidism was present. Elevated titres of anti-TPO antibodies were found in 22 (20.37%). Echographic pattern of thyroiditis was present in 16.49% of the patients, and thyroid nodules were detected by ultrasonography in 38.13%. There were two subjects with Graves’ disease. The detectable level of TCP was bigger in the fi rst season (range 120‐190 μg/L) than in the second (range 0.7‐1.7 μg/L). The range of seasonal concentration of urinary carbofurane was 0.004‐0.25 μg/mL. Cypermethrin was detected in a small number of subjects (range: 12.5‐13.3 μg/g creatinine). Dimethoate was undetectable. Conclusions: The distribution of thyroid disorders in study group living in an area with normal iodine intake did not differ from known epidemiological studies. The most frequently encountered pesticide was chlorpyrifos. Some samples presented several pesticides simultaneously.

Long-Term Exposure to Excessive Iodine from Water Is Associated with Thyroid Dysfunction in Children

Previous studies have indicated an association between iodine excess and increased incidence of thyroid dysfunction in adults. However, there have been few studies on how the intake of excessive iodine affects thyroid function in children. The objective of this study was to assess the effects of a long-term exposure to excessive iodine on thyroid dysfunction in children. Urinary iodine concentration (UIC) and thyroid function in 371 children from a high iodine (HI) area (water iodine: 150–963 μg/L) and 150 children from an adequate iodine (AI) area (water iodine: 12.8–50.9 μg/L) were measured. The water iodine concentration in the HI area was higher than that in the AI area (P < 0.001) and the median urinary iodine concentration of children in the HI area was 1030 μg/L, which was 8.6 times that of children in the AI area (123 μg/L) (P < 0.001). Children in the HI area had a higher concentration of sensitive thyroid stimulating hormone and higher positivity of both thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TGAb). The prevalence of thyroid diseases was higher in HI area children than that in AI area children (P = 0.000), especially subclinical hypothyroidism (SCH; P = 0.004). A body mass index (BMI) of ≥22.3 kg/m2 was associated with the incidence of SCH (OR: 5.51; 95% CI: 1.52, 19.9; P = 0.009). UIC ≥600 μg/L (OR: 3.62; 95% CI: 1.22, 10.8; P = 0.024) and TPOAb or TGAb-positivity (Ab+ OR: 6.48; 95% CI: 1.78, 23.6; P = 0.005) in children were significantly and independently associated with SCH. Interactions between UIC ≥800 μg/L and Ab+ (P-interaction = 0.004) were found. Furthermore, increased thyroid volume was correlated with higher UIC (β = 0.22; P = 0.002). Excessive iodine intake in children in HI areas is associated with impaired thyroid function; UIC ≥600 μg/L and Ab+ are the risk factors for SCH. Effective measures need to be taken for reducing excessive iodine intake.

Mandatory fortification of bread with iodised salt modestly improves iodine status in schoolchildren

Iodine deficiency has re-emerged in many parts of the world including the UK, Australia and New Zealand (NZ). In 2009, the NZ government introduced the mandatory fortification of bread with iodised salt as a strategy to improve iodine intakes. The aim of the present study was to assess the impact of fortification on the iodine status of NZ schoolchildren. A school-based cluster survey was used to randomly select schools from two NZ cities. Children aged 8-10 years were administered a general questionnaire, and asked to provide a casual urine and finger-prick blood sample. The median urinary iodine concentration (UIC) of the children (n 147) was 113 μg/l, which falls between 100 and 199 μg/l indicating adequate iodine status; 12 % of children had a UIC < 50 μg/l and 39 % had a UIC < 100 μg/l. The median serum thyroxine concentration was 115 nmol/l. The median serum thyroglobulin (Tg) concentration was 10.8 μg/l and falls in the 10.0-19.9 μg/l range indicative of mild iodine deficiency, suggesting that these children still had enlarged thyroid glands. When compared with the median UIC of 68 μg/l reported in the 2002 NZ Children's Nutrition Survey, the UIC of children in the present study had increased, which is probably caused by the addition of iodised salt to bread. However, the elevated concentration of Tg in these children suggests that the increase in UIC is not sufficient to ensure that thyroid volume has normalised. The fortification of other staple foods, in addition to bread, should be considered to ensure good iodine status in NZ children.

Fortification of Bread with Iodized Salt Corrected Iodine Deficiency in School-Aged Children, But Not in Their Mothers: A National Cross-Sectional Survey in Belgium

In the years 1985-1998, it was noted that mild iodine deficiency (MID) was a public health problem in Belgium. Therefore, an agreement was signed in 2009 between the bakery sector and the Ministry of Health, to fortify bread with iodized salt. We tested the hypothesis that the iodine status of Belgian children improved after the introduction of bread fortified with iodized salt. Since the dietary habits of children and adults may differ, we also investigated whether the median urinary iodine concentration (UIC) among the children in this study reflected the iodine status of their mothers. The study was cross-sectional. In a van, equipped with an ultrasound device, the thyroid volumes (Tvol) of children were measured and household salt samples and urine samples were collected from the children and their mothers. From across Belgium, 60 schools were selected and 1541 children participated in the study. The median UIC in children was 113.1 and 84.4 μg/L among their mothers. The median UIC among children was substantially greater compared to more than 10 years ago (80 μg/L; p<0.001). The median UIC in school-aged children was lower in Wallonia than in Flanders (p<0.001) and was higher in boys than in girls (p<0.001). The percentage of children with goiter was 7.2%. Of the 904 salt samples received, 63.2% did not contain iodine. Fortification of bread with iodized salt corrected iodine deficiency in Belgian children, but not in their mothers. To provide these women with an adequate iodine intake, the use of both iodized salt in bread and iodized instead of noniodized household salt needs to increase. Our findings suggest that the median UIC in children may not be an adequate surrogate of adults' iodine status. Therefore, monitoring iodine status should not be limited to children, but should be extended to women of child-bearing age.

Iodine status and fish intake of Sudanese schoolchildren living in the Red Sea and White Nile regions.

To investigate iodine status and fish consumption of schoolchildren living in the Red Sea and White Nile regions of Sudan. Cross-sectional study to determine urinary iodine concentration, visible goitre rate, iodine content of salt and fish consumption. Port Sudan (Red Sea) and Jabal Awliya (White Nile), Sudan. Two hundred eighty (n 280) children aged 6-12 years (142 boys, 138 girls). The median urinary iodine concentration in children from Port Sudan and Jabal Awliya was 553 and 160 μg/l, respectively. Goitre was detected in 17.1 % of children from Port Sudan but only in 1.4 % from Jabal Awliya, The salt samples from Port Sudan contained 150-360 mg iodine (KOI3)/kg salt, whereas those from Jabal Awliya had levels below the detection limit. Despite consuming salt devoid of iodine, children from Jabal Awliya had optimal iodine status. It is plausible that consumption of Nile fish from Jabal Awliya Reservoir, which is a good source of iodine and favoured by the locals, might have provided sufficient iodine. In contrast, children from Port Sudan were at higher risk of iodine-induced hyperthyroidism resulting from consumption of excessively iodised salt. The findings of the study clearly demonstrated that (i) Sudan still has a problem with iodine nutrition and quality control and monitoring of salt iodisation and (ii) including fish in the diet could provide a sufficient amount of iodine for schoolchildren.

Eighteen Years of Continuously Sustained Elimination of Iodine Deficiency in the Islamic Republic of Iran: The Vitality of Periodic Monitoring

Two decades ago the Islamic Republic of Iran was among countries most severely affected by iodine deficiency. Iran has since achieved great success in the control and elimination of iodine deficiency disorders (IDDs) following the national salt iodization program, initiated in 1989. The aim of the study was to evaluate the effectiveness of sustained consumption of iodized salt by Iranian households and the current status of iodine nutrition in all 30 provinces of Iran. Goiters-measured by palpation-and urinary iodine concentration of children were assessed. In this descriptive cross-sectional study, 36,000 schoolchildren (18,000 girls and 18,000 boys), aged 8-10 years, were randomly selected, from October 2007 to February 2008, from 30 provinces of the country. Goiter prevalence and urinary iodine excretion in schoolchildren and the iodine content of salt at household, factory, and distribution site levels were measured. The goiter rate in the country was 6.5% (6% grade 1 and 0.5% grade 2), and the weighted goiter rate was 5.7%. The total goiter rate in Hamedan, Zanjan, Kermanshah, Mazandaran, and Gilan provinces was over 10%. The median urinary iodine was 140 μg/L. Urinary iodine levels of 20-50, 50-99, and ≥100 μg/L were noted in 15.3%, 19.8%, and 64.9% of the samples, respectively. In four provinces, the median urinary iodine was lower than 100 μg/L. The mean (±SD) and median salt iodine values were 23.2 (±13.8) and 34.7 ppm, respectively, at the production level, and 32.4 (±14.7) and 32.3 ppm, respectively, at the distribution level. Ninety-eight percent of households consumed iodized salt, 58% of households had appropriate salt storage, and 27% of the household salts contained <20 ppm. Iran has achieved much in the development of universal salt iodization strategy and elimination of IDDs and currently meets all criteria for sustainable elimination of iodine deficiency. However, the lack of adequate iodine nutrition in some provinces necessitates special attention and proper monitoring.

Iodine deficiency disorders in 6–12 years — Old rural primary school children in Kutch district, Gujarat

To compare prevalence of goitre in primary school children; to determine median urinary iodine concentration in children; and, to assess level of salt iodization at retail trader level. 30 cluster survey study. Primary schools of Kutch district, Gujarat, India. Total 70 students including five boys and five girls from 1st to 7th standard, present in class on the day of visit were selected randomly for Goitre examination (n=2100). Urine sample was collected from one boy and one girl from each standard in each cluster. From the community, 28 children, including two boys and two girls from each standard in the same age group were examined, and salt samples were tested from their households. From each village, one retail shop was visited and various salts available were purchased and tested for iodine on the spot with spot kit. Goitre prevalence of 11.2% was found among primary school children (grade 1- 8.6% and grade 2-2.6%). As the age increased, the Goitre prevalence also increased except in age group of 8 years. Median urinary iodine excretion level was 110 µg/L. Iodine level more than 15 ppm was found in 92.3% salts samples tested at the household level. Present study showed mild goitre prevalence in primary school children in Kutch district of Gujarat.

An assessment of progress toward universal salt iodization in Rajasthan, India, using iodine nutrition indicators in school-aged children and pregnant women from the same households.

In Rajasthan, an Indian State with significant salt production, the sale of non-iodized salt for human consumption was banned in 1992. This study explored the relationships between the use of iodized salt in Rajasthan and the iodine status of children and pregnant women living in the area. In a State-wide survey, 30 clusters were selected proportionate-to-population-size and 40 school children, 6-12 years old, were enrolled by random house-to-house visits in each cluster. Twelve pregnant women from the same households were also sampled. Salt used for cooking and a casual urine sample from each child and pregnant woman were collected. The salt iodine content was measured by titration and the urinary iodine concentration (UIC) by a quality-assured colorimetric method. Salt iodine content was >or=15 mg/kg in 41.9% of the households, and 23.0% used non-iodized salt. Median UIC was 139 microg/L in children and 127 microg/L in pregnant women. In households using non-iodized salt, the median UIC's were 96 microg/L and 100 microg/L in children and women, respectively. Dis-aggregating the UIC distributions by salt iodine levels revealed a consistent, step-wise pattern of UIC in children with increasing salt iodine content. A similar but less steep pattern was observed in pregnant women. The iodine status of both children and pregnant women attained the optimal range only when the salt iodine content was close to 30 mg/kg. For optimum iodine status in the population of Rajasthan, the iodization of household salt should be mandated at a higher level than what is practiced at present.

Progress in Salt Iodization and Improved Iodine Nutrition in China, 1995–99

In 1993, the State Council of China announced the policy to virtually eliminate iodine-deficiency disorders (IDD) by 2000 and adopted universal salt iodization (USI) as the national strategy. Biennial province-based monitoring from 1995 onward aimed at capturing the use and iodine content of household salt, along with urinary iodine concentrations among schoolchildren from the same households. This paper reports on the progress made in China toward the goal of virtually eliminating iodine-deficiency disorders on the basis of 85 population-representative surveys in China's provinces during 1995--99. The percentage of households using adequately iodized salt (iodine > or = 20 mg/kg) increased from 43.1 % in 1995, to 82.2% in 1997, to 89.0% in 1999. In 1999, at least 90% of the households in 15 (48%) of the 31 provinces used adequately iodized salt, and a median urinary iodine concentration of less than 100 microg/L in children was reported in only one province. Across provinces, the median urinary iodine concentrations in children were positively correlated in each survey year with the median household salt iodine contents (combined r(s) = 0.74, p < .001) and with the proportions of households using adequately iodized salt (combined r(s) = 0.81, p <.001). Also in each survey year, the percentage of children with urinary iodine concentrations of at least 300 microg/L was correlated (combined r(s) = 0.69, p < .001) with the proportion of households using salt with iodine content of at least 40 mg/kg. The median urinary iodine concentration in children had reached 300 microg/L or more in 13 provinces (42%) by 1999. In a little more than five years, then, China has achieved outstanding progress toward the goal of virtual elimination of IDD through USI. Policy recommendations include improvement of quality assurance by salt manufacturers, along with a modest reduction in the mandated salt iodization levels.

Iodine deficiency in Papua New Guinea (sub-clinical iodine deficiency and salt iodization in the highlands of Papua New Guinea)

Data on the status about iodine nutrition in children in Papua New Guinea (PNG) are scarce. This study attempts to determine the mean daily per capita consumption of salt, the iodine content of salt in the households and retail shops and the urinary iodine concentration in children (6-12 years) in Hella Region, Southern Highland Province (SHP), PNG. The mean daily consumption of salt was 2.62 +/- 1.29 g. The iodine content of salt was >30 p.p.m. in 95 per cent of households and 100 per cent of retail shops. The median urinary iodine concentration of 48.0 mg/l for all the children indicates moderate iodine deficiency. The median urinary iodine concentrations for the male (67.0 mg/l) and female (44.0 mg/l) children indicate mild and moderate iodine deficiency, respectively. 68.42 per cent of the male and 81.82 per cent of the female children have urinary iodine concentration <100 mg/l, indicating that iodine deficiency is a potential public health problem in the Hella region. These results indicate a need for further assessment of the implementation of the universal salt iodization strategy for the elimination of iodine deficiency in the SHP, PNG.