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 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.

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 investigate the situation of mild cognitive impairment (MCI) in elderly people in fluorosis areas, and analyze its potential influencing factors.Methods:From April to October 2020, a cluster random sampling method was used to select local elderly people aged 60 and older in areas of drinking-water-borne endemic fluorosis in Tianjin, and their general information was collected through face-to-face surveys. Terminal drinking water samples were collected from survey subjects. Water fluoride concentration was measured using ion-selective electrode method. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE), and survey subjects were categorized into MCI group and control group based on MMSE scores. Logistic regression and Chi-squared automatic interaction detection classification tree models were constructed to analyze the influencing factors of MCI.Results:A total of 677 subjects were included, including 160 cases in the MCI group and 517 cases in the control group, with a MCI detection rate of 23.63%. The detection rates of MCI in the high fluoride exposure group and non high fluoride exposure group were 30.82% (94/305) and 17.74% (66/372), respectively, with a statistically significant difference between the groups (χ 2 = 15.88, P < 0.001). The results of univariate analysis showed that MCI was associated with high fluoride exposure, age, per capita annual household income, sleep duration, personality, and interpersonal relationships (χ 2 = 15.88, 16.17, 12.32, 8.91, 14.03, 9.81, P < 0.05). The results of multiple logistic regression analysis showed that moderate interpersonal relationships ( OR = 2.13, 95% CI: 1.08, 4.20) and high fluoride exposure ( OR = 1.91, 95% CI: 1.03, 3.54) were both risk factors for MCI ( P < 0.05). The classification tree model analysis result showed that high fluoride exposure was the primary factor affecting MCI in elderly people in fluorosis areas, followed by per capita annual household income, personality, and age. Conclusions:The detection rate of MCI in the high fluoride exposure group of elderly people in fluorosis areas is higher than that in the non high fluoride exposure group. High fluoride exposure, interpersonal relationships, per capita annual household income, personality, and age are all influencing factors of MCI in elderly people in fluorosis areas.

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 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 investigate the situation of mild cognitive impairment (MCI) in elderly people in fluorosis areas, and analyze its potential influencing factors.Methods:From April to October 2020, a cluster random sampling method was used to select local elderly people aged 60 and older in areas of drinking-water-borne endemic fluorosis in Tianjin, and their general information was collected through face-to-face surveys. Terminal drinking water samples were collected from survey subjects. Water fluoride concentration was measured using ion-selective electrode method. Cognitive function was evaluated using the Mini-Mental State Examination (MMSE), and survey subjects were categorized into MCI group and control group based on MMSE scores. Logistic regression and Chi-squared automatic interaction detection classification tree models were constructed to analyze the influencing factors of MCI.Results:A total of 677 subjects were included, including 160 cases in the MCI group and 517 cases in the control group, with a MCI detection rate of 23.63%. The detection rates of MCI in the high fluoride exposure group and non high fluoride exposure group were 30.82% (94/305) and 17.74% (66/372), respectively, with a statistically significant difference between the groups (χ 2 = 15.88, P < 0.001). The results of univariate analysis showed that MCI was associated with high fluoride exposure, age, per capita annual household income, sleep duration, personality, and interpersonal relationships (χ 2 = 15.88, 16.17, 12.32, 8.91, 14.03, 9.81, P < 0.05). The results of multiple logistic regression analysis showed that moderate interpersonal relationships ( OR = 2.13, 95% CI: 1.08, 4.20) and high fluoride exposure ( OR = 1.91, 95% CI: 1.03, 3.54) were both risk factors for MCI ( P < 0.05). The classification tree model analysis result showed that high fluoride exposure was the primary factor affecting MCI in elderly people in fluorosis areas, followed by per capita annual household income, personality, and age. Conclusions:The detection rate of MCI in the high fluoride exposure group of elderly people in fluorosis areas is higher than that in the non high fluoride exposure group. High fluoride exposure, interpersonal relationships, per capita annual household income, personality, and age are all influencing factors of MCI in elderly people in fluorosis areas.

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.