Objective: To explore the relationship between socio ecological risk factors (SERF), physical activity (PA) developmental trajectories, and depressive symptoms among junior and senior high school students in Tianjin, in order to provide theoretical support for comprehensive interventions for adolescent depression. Methods: A longitudinal follow up design was adopted. In September 2022, a baseline survey was conducted using a stratified cluster random sampling method in two junior high schools and two senior high schools in Tianjin, collecting data on students basic information, SERF, PA, and depressive symptoms. Two follow up surveys were conducted in September 2023 and 2024, yielding 588 valid participants. Latent class growth analysis (LCGA) was used to identify PA developmental trajectory categories among junior and senior high school students. Logistic regression was applied to examine the associations between depressive symptoms and SERF as well as PA trajectories. Results: The detection rates of depressive symptoms among Tianjin junior and senior high school students over the three years were 26.53%, 20.24%, and 21.26 %, respectively. Depressive symptoms were positively correlated with SERF ( OR=1.04, 95%CI=1.03-1.05, P <0.05). The highest risks were observed in the individual dimension and family dimension ( OR =1.28, 1.21, both P <0.05). LCGA identified three PA trajectory groups:persistently low level (80.65%), persistently high level (4.58%), and slowly increasing group ( 14.77 %). Multivariate regression analysis showed that compared with the persistently low level PA, the slowly increasing PA significantly reduced the risk of depressive symptoms ( OR=0.44, 95%CI =0.20-0.88), while SERF still increased the risk of depressive symptoms ( OR=1.04, 95%CI =1.03-1.05) (both P <0.05). Conclusion SERF are risk factors for depression symptoms among junior and senior high school students, whereas slowly increasing PA development trajectory demonstrates a protective effect.

Objective To investigate the prevalence and influencing factors of thyroid enlargement in school-age children in Tianjin. Methods School-age children were randomly selected in Tianjin to undergo thyroid ultrasound examination, and salt iodine, urine iodine, height, and weight tests. A questionnaire survey was conducted. Univariate and multivariate regression models were used to analyze the risk factors for thyroid enlargement. Results A total of 917 children aged 7-13 years in Tianjin were surveyed, with a thyroid enlargement rate of 4.03% and a median thyroid volume of 2.60 ml. There was a non-linear relationship between children's body mass index (BMI) and the incidence of thyroid enlargement in children (P=0.008), and a linear relationship between children's body surface area (BSA) and the incidence of thyroid enlargement in children (P<0.001). Being 9 years old (OR=3.728, 95%CI: 1.343-10.343, P=0.012), obesity (OR=3.886, 95%CI: 1.801-8.384, P=0.001), having lunch at school (OR=3.157, 95%CI: 1.497-6.658, P=0.003) and frequent consumption of preserved foods (OR=4.611, 95%CI: 1.643-12.945, P=0.004) were risk factors for goiter in children. Regular consumption of seaweed (OR=0.305, 95%CI: 0.100-0.927, P=0.036) was a protective factor for goiter in children. Conclusion The incidence of thyroid enlargement in children in Tianjin meets national standards. Obesity, eating lunch at school, frequently consuming pickled foods, and being 9 years old may be risk factors for thyroid enlargement in children. Eating seaweed or kelp regularly is a protective factor. At the same time, attention should be paid to the relationship between BMI, BSA, and thyroid enlargement rate in children..

Objective To explore the association between different levels of fluoride exposure and dyslipidemia in elderly people, and to analyze the influencing factors and their interactions. Methods A total of 1 143 elderly people over 60 years old were randomly selected from historical high water fluorosis areas and control areas in Tianjin. Logistic regression model and classification tree model were used to analyze the influencing factors of dyslipidemia, and to analyze the interaction between high fluoride exposure and relevant influencing factors on dyslipidemia. Results The prevalence of elevated low density lipoprotein cholesterol (LDL-C) was 5.69% (65/1 143). There was a significant difference in the prevalence of high LDL-C in different fluoride-exposed areas (2 = 0.092，P = 0.762). Multivariate logistic analysis showed that high fluoride exposure (OR=2.306，95%CI：1.185-4.491) and abdominal obesity (OR=2.274，95%CI：1.299-3.978) were risk factors for high LDL-C, while type B personality (OR=0.529，95%CI：0.308-0.908) was a protective factor for high LDL-C. The results of classification tree model showed that abdominal obesity contributed the most to the prevalence of high LDL-C in the elderly, followed by high fluoride exposure and hyperglycemia. There was a significant multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia (OR=5.191,95%CI：1.609-16.745，P=0.006). Conclusion High fluoride exposure may increase the risk of high LDL-C, and there is a multiplicative interaction between high fluoride exposure and abdominal obesity on dyslipidemia.

Objective:To learn about the current status of fluoride in drinking water from historical drinking water-borne endemic fluorosis areas in Tianjin, and to evaluate the non-carcinogenic health risk of fluoride in drinking water for children.Methods:A cross-sectional survey was conducted from January to November 2023 to investigate the fluoride level in drinking water in 2 028 villages with children aged 6 - < 18 years residing in 10 historical drinking water-borne endemic fluorosis areas in Tianjin. Based on the risk assessment model of the Technical Guide for Environmental Health Risk Assessment of Chemical Exposure (WS/T 777-2021) and the child specific exposure parameters in the highlights of the Chinese exposure factors handbook (Children volume), the hazard index (HI) was used to quantify and assess the non-carcinogenic health risk of fluoride in drinking water for children of different age groups (6 - < 9, 9 - < 12, 12 - < 15, 15 - < 18 years old).Results:The water fluoride level [ M ( Q1, Q3)] in the historical drinking water-borne endemic fluorosis areas in Tianjin was 0.28 (0.12, 0.85) mg/L, ranging from 0.05 to 1.08 mg/L. The HI values of children in each age group were 0.218, 0.185, 0.136, and 0.124, respectively, all < 1, indicating low non-carcinogenic health risk. Among them, the age group of 6 - < 9 years old had the highest HI value, with HI values ranging from 0.148 to 0.412 in 10 regions, and the difference was statistically significant ( H = 594.62, P < 0.001). Comparing drinking water of different source types, regions, and treatment methods, there were statistically significant differences in HI values among children of different age groups ( Z = - 9.25, - 9.25, - 9.25, - 9.25, - 6.96, - 6.96, - 6.96, - 6.96, H = 146.75, 146.75, 146.75, 146.75, P < 0.001). Conclusion:The non-carcinogenic health risks of fluoride in drinking water for children in historical drinking water-borne endemic fluorosis areas of Tianjin are relatively low, but there is still a need to strengthen monitoring and early warning for young children.

Objective:To learn about the iodine nutrition status of pregnant women in Tianjin and analyze the influencing factors of moderate to severe iodine deficiency in pregnant women.Methods:From January 2022 to December 2024, a stratified random sampling method was adopted. Each year, five sampling areas were divided into the east, west, south, north and central directions in 16 districts of Tianjin. Ten pregnant women from one township/street in each area were selected for questionnaire surveys. Household salt samples and random urine samples were collected to measure salt iodine and urinary iodine levels. Multivariate logistic regression was used to analyze the influencing factors of moderate to severe iodine deficiency in pregnant women, and a restricted cubic spline model was used to analyze the dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women and salt iodine level.Results:A total of 2 532 pregnant women in Tianjin were surveyed, with an age of (30.70 ± 4.44) years. Among them, 53.20% (1 347/2 532) had received health education, and 52.45% (1 328/2 532) actively supplemented iodine. A total of 2 532 household salt samples of pregnant women were tested, with a median salt iodine level of 23.66 mg/kg. The coverage rate of iodized salt was 74.45% (1 885/2 532), the qualified rate of iodized salt was 87.59% (1 651/1 885), and the consumption rate of qualified iodized salt was 65.21% (1 651/2 532). A total of 2 532 urine samples of pregnant women were tested, with a median urinary iodine level of 151.68 μg/L. Among them, 652, 1 348 and 532 urine samples were collected from pregnant women in the early, middle, and late stages of pregnancy, respectively, with median urinary iodine levels of 150.80, 153.00 and 143.68 μg/L, respectively. Multivariate logistic regression analysis showed that consuming iodized salt was a protective factor for the moderate to severe iodine deficiency in pregnant women ( OR = 0.70, 95% CI: 0.58 - 0.86, P < 0.001). Restricted cubic spline analysis showed that there was a linear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women and salt iodine level ( Poverall < 0.001, Pnonlinear = 0.065). Further stratified analysis revealed that there was a linear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women who had received iodine supplementation and salt iodine level ( Poverall = 0.018, Pnonlinear = 0.554), while there was a nonlinear dose-response relationship between the risk of moderate to severe iodine deficiency in pregnant women who had not received iodine supplementation and salt iodine level ( Poverall < 0.001, Pnonlinear = 0.029). Conclusions:From 2022 to 2024, the overall iodine level of pregnant women in Tianjin is appropriate, but some pregnant women are at risk of iodine deficiency. Consuming iodized salt is a protective factor against the moderate to severe iodine deficiency in pregnant women. It is still necessary to further implement comprehensive prevention and control measures mainly based on iodized salt.

Objective:To investigate the prevalence of dental fluorosis in children in Tianjin and study its influencing factors.Methods:From January to December 2023, 5 affected villages were selected from each of the drinking water-borne endemic fluorosis (drinking water-borne fluorosis for short) areas of 10 agricultural areas in Tianjin, and 50 children aged 8 - 12 years (gender and age balanced) were selected from each affected village for questionnaire survey and dental fluorosis examination. At the same time, water samples from affected villages and children's one random urine sample were collected to test for fluoride levels in water and urine. Multivariate logistic regression was used to analyze the influencing factors of dental fluorosis prevalence in children, and a restricted cubic spline model was used to analyze the dose-response relationship between the years of water improvement and dental fluorosis prevalence.Results:A total of 50 water samples were collected, with water fluoride levels ranging from 0.05 to 0.85 mg/L. All affected villages had completed the water improvement and the water fluoride levels were qualified. A total of 2 439 urine samples were collected from children, with urinary fluoride levels ranging from 0.05 to 12.56 mg/L and a geometric mean of 0.82 mg/L. A total of 2 439 children were examined for dental fluorosis, with a detection rate of 22.67% (553/2 439). The results of multivariate logistic regression analysis showed that age ( OR = 1.26, 95% CI: 1.15 - 1.37, P < 0.001), father's education level of junior high school or below ( OR = 1.57, 95% CI: 1.04 - 2.38, P = 0.033), and high urinary fluoride (0.74 - 1.58 mg/L: OR = 1.59, 95% CI: 1.19 - 2.13, P = 0.002; 1.59 - 12.56 mg/L: OR = 2.00, 95% CI: 1.48 - 2.70, P < 0.001) were risk factors for dental fluorosis prevalence in children. The total annual household income with 40 000 to 80 000 yuan ( OR = 0.76, 95% CI: 0.58 - 0.99, P = 0.041), father's occupation was self-employed and other occupation ( OR = 0.69, 95% CI: 0.51 - 0.92, P = 0.013), the years of water improvement in affected villages ≥10 years ( OR = 0.39, 95% CI: 0.30 - 0.50, P < 0.001), and the material of the drinking water container at home was stainless steel products ( OR = 0.58, 95% CI: 0.40 - 0.85, P = 0.005), ceramic or glass products ( OR = 0.66, 95% CI: 0.48 - 0.90, P = 0.010) were protective factors for dental fluorosis prevalence in children. By constructing a restricted cubic spline model, it was found that there was a linear dose-response relationship between the prevalence of dental fluorosis in children and the years of water improvement in affected villages ( Poverall < 0.001, Pnonlinear = 0.059). The longer the years of water improvement, the lower the risk of dental fluorosis prevalence. Conclusions:The detection rate of dental fluorosis in children in Tianjin is relatively high. The fluoride reduction and water improvement measures implemented in drinking water-borne fluorosis areas can effectively reduce the risk of dental fluorosis prevalence. Factors such as age, urinary fluoride, economic conditions, and lifestyle also have important impacts on the prevalence of dental fluorosis.

Objective:To investigate the awareness of prevention and treatment knowledge of drinking water-borne endemic fluorosis among children in Tianjin, explore its influencing factors, analyze the needs of children's health education methods, and provide a basis for carrying out health education in school.Methods:From January to December in 2024, a stratified sampling method was employed to select two endemic villages from each of the 10 areas with drinking water-borne endemic fluorosis in Tianjin as survey sites. In each village, no fewer than 50 children aged 8 - 12 (gender and age balanced) were recruited to conduct a questionnaire survey. Multivariate logistic regression analysis was used to analyze the influencing factors of children's awareness of prevention and treatment knowledge.Results:A total of 1 678 valid questionnaires were collected. The overall awareness rate of prevention and control knowledge of drinking water-borne endemic fluorosis among children in Tianjin was 67.62% (11 346/16 780). Children had the highest awareness of the hazards of drinking water-borne endemic fluorosis (83.61%, 1 403/1 678), while their awareness of the clinical manifestations of dental fluorosis was the lowest (44.87%, 753/1 678). Multivariate logistic regression analysis showed that children in higher grades [grades 5 to 6, OR (95% CI) = 1.66 (1.36, 2.03), P < 0.001], with a larger number of permanent residents in the family [≥6 people, OR (95% CI) = 1.58 (1.13, 2.23), P = 0.008], whose mothers had a college education or above [ OR (95% CI) = 1.45 (1.08, 1.95), P = 0.014], and who had received health education [ OR (95% CI) = 1.46 (1.19, 1.78), P < 0.001] had a higher awareness rate of the prevention and control knowledge of drinking water-borne endemic fluorosis. There were statistically significant differences in the demand rates for access to prevention and control knowledge via school teachers, promotional videos, and online/WeChat official accounts among children of different grades ( P < 0.05). Conclusions:The awareness rate of prevention and treatment knowledge of drinking water-borne endemic fluorosis among children in Tianjin is relatively low. Special attention should be paid to children with a small number of permanent residents in the family, mothers with low educational levels, and who have not received health education. At the same time, detailed health publicity services should be carried out for children of different grades.

Objective:To understand the occurrence of different patterns of multimorbidity among children and adolescents aged 9-18 in Tianjin City and analyze the cumulative effects of lifestyle on these patterns of multimorbidity.Methods:From September to November 2022, a stratified cluster random sampling method was used to select students from primary schools, junior high schools, general high schools, and vocational schools in 16 districts of Tianjin to screen for height, weight, blood pressure, distant vision, and diopter. One year later, a follow-up measurement and questionnaire survey were conducted. The log-binomial model was used to analyze the strength of the association between lifestyle factors and different patterns of multimorbidity.Results:The age of 9 488 students was (12.37±2.49) years old, including 4 999 boys and 4 489 girls. The detection rates of three patterns of multimorbidity of overweight obesity and high blood pressure, overweight obesity and myopia, and overweight obesity with high blood pressure and myopia were 6.63%, 9.32%, and 4.21%, respectively. The detection rates of the three types of multimorbidity in boys were higher than those in girls (all P<0.001). The detection rate of overweight obesity and high blood pressure in suburban areas was higher than that in urban areas ( P=0.002). The detection rate of overweight obesity and myopia in suburban areas was lower than that in urban areas ( P=0.034). The detection rate of overweight obesity and myopia among those aged 9-12 years old was higher than other age groups (all P<0.001). The ARR (95% CI) for the association between favorable physical activity and the occurrence of overweight obesity and high blood pressure was 0.79 (0.68-0.92). The ARR (95% CI) for the association between favorable physical activity and the occurrence of overweight obesity with high blood pressure and myopia was 0.82 (0.67-0.99). Compared with children and adolescents with 0-2 favorable lifestyle factors, those with 4-5 favorable lifestyle factors had a lower risk of overweight obesity and high blood pressure ( ARR=0.84, 95% CI: 0.59-0.92). Conclusion:Boys aged 9-18 in Tianjin City are more prone to multimorbidity of overweight obesity and high blood pressure, overweight obesity and myopia, and overweight obesity with high blood pressure and myopia. Children and adolescents with 4-5 favorable lifestyle factors have a reduced risk of occurrence of overweight obesity and high blood pressure. Lifestyle has cumulative effects on multimorbidity of overweight obesity and high blood pressure.

Objective:To investigate the main influencing factors of mild cognitive impairment(MCI)in the elderly and explore the interaction between high fluoride exposure and related co-factors on MCI.Methods:A cross-sectional study was conducted from May to December 2024 in four towns in the rural areas of Tianjin(two historically high-fluoride towns and two non-high-fluoride towns). A total of 125 elderly people aged 60 years and above were randomly selected from each township.MCI was diagnosed using the Mini-Mental State Examination(MMSE)and Montreal Cognitive Assessment-Basic(MoCA-B)according to the diagnostic criteria for MCI.Binary logistic regression was used to analyze the influencing factors of MCI, and conditional logistic regression was employed to assess multiplicative and additive interaction effects.Results:A total of 481 participants were included, with 354 in the normal group and 127 in the MCI group, and the incidence of MCI was 26.40%.Univariate analysis showed that MCI was associated with age, annual household income per capita, high fluoride exposure, life stress, depression, and abnormal urinalysis( χ2=4.241, 4.017, 4.552, 7.143, 4.151, 5.113, all P<0.05). Multivariate logistic regression revealed that after adjusting for other confounders, high fluoride exposure( OR=1.816, 95% CI: 1.177-2.802), age ≥70 years( OR=1.584, 95% CI: 1.034-2.428), depression( OR=2.106, 95% CI: 1.042-4.254), and abnormal urinalysis( OR=1.595, 95% CI: 1.041-2.444)increased the risk of MCI.Compared with severe life stress, moderate stress( OR=0.254, 95% CI: 0.082-0.790)reduced the risk of MCI.No multiplicative or additive interaction was found between high fluoride exposure and depression, life stress, or abnormal urinalysis. Conclusions:High fluoride exposure, age ≥70 years, depression, abnormal urinalysis, and severe life stress may increase the risk of MCI in the elderly, but there is no interaction among them.

Objective: To understand the dose response relationship between urinary fluoride and dental fluorosis among children from drinking water borne endemic fluorosis areas in Tianjin, so as to provide a scientific basis for assessing fluoride exposure risk among children from endemic areas and establishing reference values for urinary fluoride. Methods: From January to December 2024, 83 endemic villages were selected in Tianjin. A total of 2 382 children aged 8-12 years from these villages underwent dental fluorosis examination, along with water fluoride and urinary fluoride testing. Additionally, data from areas where the drinking water fluorosis control target was achieved for more than 12 years (10 villages, 50 people per village) were included as controls. A restricted cubic spline model was used to analyze the relationship between urinary fluoride levels and dental fluorosis prevalence, and benchmark dose (BMD) and benchmark dose lower bound (BMDL), as well as reference dose (RfD), were calculated using the benchmark dose method. Results: The prevalence rates of dental fluorosis among children in drinking water borne endemic fluorosis areas and areas of normal fluoride content in water in Tianjin were 10.58%, 7.60%, with a geometric mean urinary fluoride level of 0.72 and 0.60 mg/L,respectively. There were statistically significant differences in both dental fluorosis prevalence and geometric mean urinary fluoride levels between the drinking water borne endemic fluorosis areas group and the areas of normal fluoride content in water ( χ 2/Z = 4.05 , -7.31, both P <0.05). Across different periods of water source improvement, there were statistically significant differences in overall population, male, and female dental fluorosis prevalence rates and geometric mean urinary fluoride levels ( χ 2/H =44.95, 23.96, 21.05; 168.39, 63.93, 107.50, all P <0.01). Significant differences were also observed across age groups among children from drinking water borne endemic fluorosis areas in terms of dental fluorosis prevalence and geometric mean urinary fluoride levels ( χ 2/H =32.14, 79.73, both P <0.01). The results of the restricted cubic spline model showed that the risk of dental fluorosis in different sex, age and overall children in the drinking water borne endemic fluorosis areas increased significantly with rising urinary fluoride concentration(all P-general trend <0.05). The BMD value for the drinking water borne endemic fluorosis areas was 1.72 mg/L, the BMDL was 1.31 mg/L, and the RfD was 1.31 mg/L. Conclusions The prevalence of dental fluorosis among children in the drinking water borne endemic fluorosis areas in Tianjin has been effectively controlled, but it is still higher than that in the areas of normal fluoride content in water. Moreover, urinary fluoride levels and dental fluorosis prevalence among children from drinking water borne endemic fluorosis areas show a clear dose response relationship.