Objective:To study the implementation progress of the prevention and control measures for drinking water-borne endemic fluorosis and the changing trend of fluorosis conditions in Inner Mongolia Autonomous Region, comprehensively evaluate the effectiveness of prevention and control measures, and provide a basis for the next step of prevention and control of the disease.Methods:In 2015 and 2023, a cross-sectional survey method was used to investigate the water improvement situation, the operation of water improvement projects, the detection of fluoride level in water, and the prevalence of dental fluorosis in children aged 8 to 12 in all affected villages of 11 leagues (cities) in the entire autonomous region. The prevention and control effect of drinking water-borne endemic fluorosis in the entire autonomous region was evaluated.Results:The water improvement rates of all affected villages in the entire autonomous region in 2015 and 2023 were 84.12% (8 218/9 769) and 95.38% (8 944/9 377), respectively. The qualified rates of water fluoride in the villages with water improvement in the entire autonomous region were 66.21% (5 441/8 218) and 91.00% (8 139/8 944), respectively. The water improvement rate and water fluoride qualification rate of water improvement villages in 2023 were both higher than those in 2015, and the differences were statistically significant (χ 2 = 652.96, 1 593.81, P < 0.001). The detection rates of dental fluorosis in children aged 8 to 12 years in the entire autonomous region in 2015 and 2023 were 9.26% (7 548/81 484) and 4.46% (3 441/77 155), respectively. The detection rate of dental fluorosis in children in 2023 was lower than that in 2015, and the difference was statistically significant (χ 2 = 1 418.20, P < 0.001). In 2015 and 2023, the total compliance rate of all affected villages in the entire autonomous region reaching the control standards were 57.94% (5 660/ 9 769) and 92.37% (8 662/9 377), respectively. The total compliance rate of all affected villages in 2023 was higher than that in 2015, and the difference was statistically significant (χ 2 = 3 010.38, P < 0.001). Conclusions:Compared with 2015, the prevention and control measures of drinking water-borne endemic fluorosis in Inner Mongolia Autonomous Region have been effectively implemented in 2023, with a significant decrease in the detection rate of dental fluorosis in children. However, there are still a few affected villages that have not achieved the control standards, and prevention and control work still need to be further strengthened.

Objective:To investigate the characteristics of the population of skeletal fluorosis patients in drinking-tea-borne endemic fluorosis (referred to as drinking-tea-borne fluorosis) areas in Inner Mongolia Autonomous Region (referred to as Inner Mongolia) and the influencing factors of treatment willingness, and to provide a basis for improving the prevention and control measures of drinking-tea-borne fluorosis and the treatment plan of skeletal fluorosis.Methods:From August to October 2022, a face-to-face questionnaire survey was conducted in key areas of drinking-tea-borne fluorosis in Inner Mongolia (administrative villages with an average daily intake of tea fluoride > 3.5 mg and skeletal fluorosis patients identified by the general survey of drinking-tea-borne fluorosis in Inner Mongolia in 2019), and to investigate the demographic, severity, and treatment status of patients with skeletal fluorosis, analyze the demographic characteristics of patients with skeletal fluorosis and the influencing factors of treatment willingness.Results:A total of 734 patients with skeletal fluorosis were investigated, including 543 mild cases, 125 moderate cases and 66 severe cases. The gender ratio of patients with skeletal fluorosis was 0.71 ∶ 1.00 (305/429), the age was concentrated in > 50 - 70 years old (70.57%, 518/734), the proportion of Mongolians was 94.28% (692/734), the proportion of herders was 97.68% (717/734), the educational level was mainly primary school (54.63%, 401/734), and the proportion of poor households and immigrants who had moved to their current residence was 7.08% (52/734) and 8.04% (59/734), respectively. The distribution of the severity of skeletal fluorosis in patients of different ages, genders, and educational levels was compared, and the differences were statistically significant ( P < 0.05). Fifty-three point two seven percent (391/734) of the patients had a willingness to undergo non-pharmacological treatment, of which 69.82% (273/391) had already started non-pharmacological treatment, with a treatment effectiveness rate of 73.99% (202/273). Sixty-five point two six percent (479/734) of the patients had a willingness to receive medication treatment, of which 7.31% (35/479) had already started medication treatment, with a treatment effectiveness rate of 54.29% (19/35). Zero point two seven percent (2/734) of the patients expressed a willingness to undergo surgical treatment, while no patients underwent surgical treatment. Multivariate logistic regression analysis showed that the age, ethnicity, occupation, educational level, poverty status, immigrants status, and the severity of skeletal fluorosis were all influencing factors of non-pharmacological treatment willingness ( P < 0.05). Occupation, educational level, poverty status, immigrants status, and the severity of skeletal fluorosis were all influencing factors of medication treatment willingness ( P < 0.05). Conclusions:Patients with skeletal fluorosis caused by tea drinking in Inner Mongolia are mainly from Mongolian ethnic groups, herders, middle-aged and elderly people, and those with a lower educational levels. The willingness of patients to receive treatment is influenced by various factors, and corresponding intervention measures can be formulated and taken based on these influencing factors to effectively improve the disease prevention awareness and treatment willingness of patients and the public.

Objective:To study the implementation progress of the prevention and control measures for drinking water-borne endemic fluorosis and the changing trend of fluorosis conditions in Inner Mongolia Autonomous Region, comprehensively evaluate the effectiveness of prevention and control measures, and provide a basis for the next step of prevention and control of the disease.Methods:In 2015 and 2023, a cross-sectional survey method was used to investigate the water improvement situation, the operation of water improvement projects, the detection of fluoride level in water, and the prevalence of dental fluorosis in children aged 8 to 12 in all affected villages of 11 leagues (cities) in the entire autonomous region. The prevention and control effect of drinking water-borne endemic fluorosis in the entire autonomous region was evaluated.Results:The water improvement rates of all affected villages in the entire autonomous region in 2015 and 2023 were 84.12% (8 218/9 769) and 95.38% (8 944/9 377), respectively. The qualified rates of water fluoride in the villages with water improvement in the entire autonomous region were 66.21% (5 441/8 218) and 91.00% (8 139/8 944), respectively. The water improvement rate and water fluoride qualification rate of water improvement villages in 2023 were both higher than those in 2015, and the differences were statistically significant (χ 2 = 652.96, 1 593.81, P < 0.001). The detection rates of dental fluorosis in children aged 8 to 12 years in the entire autonomous region in 2015 and 2023 were 9.26% (7 548/81 484) and 4.46% (3 441/77 155), respectively. The detection rate of dental fluorosis in children in 2023 was lower than that in 2015, and the difference was statistically significant (χ 2 = 1 418.20, P < 0.001). In 2015 and 2023, the total compliance rate of all affected villages in the entire autonomous region reaching the control standards were 57.94% (5 660/ 9 769) and 92.37% (8 662/9 377), respectively. The total compliance rate of all affected villages in 2023 was higher than that in 2015, and the difference was statistically significant (χ 2 = 3 010.38, P < 0.001). Conclusions:Compared with 2015, the prevention and control measures of drinking water-borne endemic fluorosis in Inner Mongolia Autonomous Region have been effectively implemented in 2023, with a significant decrease in the detection rate of dental fluorosis in children. However, there are still a few affected villages that have not achieved the control standards, and prevention and control work still need to be further strengthened.

Objective:To investigate the characteristics of the population of skeletal fluorosis patients in drinking-tea-borne endemic fluorosis (referred to as drinking-tea-borne fluorosis) areas in Inner Mongolia Autonomous Region (referred to as Inner Mongolia) and the influencing factors of treatment willingness, and to provide a basis for improving the prevention and control measures of drinking-tea-borne fluorosis and the treatment plan of skeletal fluorosis.Methods:From August to October 2022, a face-to-face questionnaire survey was conducted in key areas of drinking-tea-borne fluorosis in Inner Mongolia (administrative villages with an average daily intake of tea fluoride > 3.5 mg and skeletal fluorosis patients identified by the general survey of drinking-tea-borne fluorosis in Inner Mongolia in 2019), and to investigate the demographic, severity, and treatment status of patients with skeletal fluorosis, analyze the demographic characteristics of patients with skeletal fluorosis and the influencing factors of treatment willingness.Results:A total of 734 patients with skeletal fluorosis were investigated, including 543 mild cases, 125 moderate cases and 66 severe cases. The gender ratio of patients with skeletal fluorosis was 0.71 ∶ 1.00 (305/429), the age was concentrated in > 50 - 70 years old (70.57%, 518/734), the proportion of Mongolians was 94.28% (692/734), the proportion of herders was 97.68% (717/734), the educational level was mainly primary school (54.63%, 401/734), and the proportion of poor households and immigrants who had moved to their current residence was 7.08% (52/734) and 8.04% (59/734), respectively. The distribution of the severity of skeletal fluorosis in patients of different ages, genders, and educational levels was compared, and the differences were statistically significant ( P < 0.05). Fifty-three point two seven percent (391/734) of the patients had a willingness to undergo non-pharmacological treatment, of which 69.82% (273/391) had already started non-pharmacological treatment, with a treatment effectiveness rate of 73.99% (202/273). Sixty-five point two six percent (479/734) of the patients had a willingness to receive medication treatment, of which 7.31% (35/479) had already started medication treatment, with a treatment effectiveness rate of 54.29% (19/35). Zero point two seven percent (2/734) of the patients expressed a willingness to undergo surgical treatment, while no patients underwent surgical treatment. Multivariate logistic regression analysis showed that the age, ethnicity, occupation, educational level, poverty status, immigrants status, and the severity of skeletal fluorosis were all influencing factors of non-pharmacological treatment willingness ( P < 0.05). Occupation, educational level, poverty status, immigrants status, and the severity of skeletal fluorosis were all influencing factors of medication treatment willingness ( P < 0.05). Conclusions:Patients with skeletal fluorosis caused by tea drinking in Inner Mongolia are mainly from Mongolian ethnic groups, herders, middle-aged and elderly people, and those with a lower educational levels. The willingness of patients to receive treatment is influenced by various factors, and corresponding intervention measures can be formulated and taken based on these influencing factors to effectively improve the disease prevention awareness and treatment willingness of patients and the public.

Objective:To investigate the distribution of physical and chemical water improvement areas of drinking water-borne endemic fluorosis in Inner Mongolia Autonomous Region, as well as the use of household water purifiers.Methods:From April to October 2021, a survey was conducted in a drinking water-borne endemic fluorosis areas in Inner Mongolia Autonomous Region where physical and chemical water improvement was carried out. The survey included the basic situation of the affected villages (number of permanent households, number of permanent residents, historical water fluoride content) and the use of residential water purifiers. Household peripheral water samples were collected to test the water fluoride content. Water purifier installation rate, normal usage rate, qualified water fluoride rate in normal usage, and the proportion of households covered by filter replacement departments were calculated.Results:In Inner Mongolia Autonomous Region, the physical and chemical water improvement areas of drinking water-borne endemic fluorosis were distributed in 2 735 villages in 11 leagues (cities) throughout the region, with 192 950 permanent households and 540 216 permanent residents. The average historical water fluoride content in all leagues (cities) was 2.18 mg/L, and the current average water fluoride content was 0.40 mg/L. A total of 134 763 water purifiers were installed, with an installation rate of 69.84% (134 763/192 950). A total of 10 773 households were surveyed, with 10 396 households using water purifiers normally and a normal usage rate of 96.50% (10 396/10 773). Among them, 10 158 households had qualified water fluoride of normal usage, with a qualified water fluoride rate of 97.71% (10 158/10 396). Of the 10 396 households using water purifiers normally, 3 974 households (38.23%) had filter cartridges used within one year, and 3 961 households had qualified water fluoride, with a qualified rate of water fluoride of 99.67% (3 961/3 974). Six thousand four hundred and twenty-two households (61.77%) had filter cartridges used for more than one year, with 6 197 households had qualified water fluoride and a qualified rate of water fluoride of 96.50% (6 197/6 422). There was a statistically significant difference in the qualified rate of water fluoride between purifiers with different filter cartridge usage times (χ 2 = 110.73, P < 0.001). Among the 10 773 surveyed households, the filter cartridges replacement department covered 10 470 households, accounting for 97.19% (10 470/10 773). Conclusions:In Inner Mongolia Autonomous Region, the physical and chemical water improvement areas of drinking water-borne endemic fluorosis are widely distributed, and the normal usage rate of household water purifiers is relatively high. The qualified rate of water fluoride in household water purifiers with filter cartridges used for more than one year is low.

Objective:To analyze the main causes of death of residents in arsenic poisoning areas of Inner Mongolia Autonomous Region, providing a scientific basis for preventing and controlling the long-term effects of arsenic poisoning and ensuring the health of residents.Methods:The data on the causes of death among residents in arsenic poisoning areas of Inner Mongolia Autonomous Region from 2016 to 2021 were collected from the population death information registration management system and the population information system of various league and city statistical bureaus in Inner Mongolia Autonomous Region. Residents were divided into exposed and non exposed groups based on whether they drank high arsenic water. SPSS 25.0 software was used to statistically analyze the crude mortality rate (CDR), standardized mortality rate (SMR), disease-specific mortality rate, proportion of causes of death, and order of causes of death.Results:Over the past 6 years, there was a total of 9 583 deaths, with an average annual CDR of 633.12/100 000 and an average annual SMR of 446.65/100 000. The CDR of each year showed a decreasing trend over time (χ 2 = 1 058.86, P < 0.001). Male CDR was higher than female CDR (χ 2 = 325.04, P < 0.001). Heart diseases and malignant tumors were the main causes of death for residents in arsenic poisoning areas, with proportions of 25.00% (2 396/9 583) and 18.86% (1 807/9 583), respectively. The top three leading causes of malignant tumor death were lung cancer, liver cancer and gastric cancer. Among residents who died from various diseases and malignant tumors, the SMR of the exposed group was higher than that of the non exposed group (χ 2 = 147.08, 26.26, P < 0.001). Conclusions:The main causes of death of residents in arsenic poisoning areas in Inner Mongolia Autonomous Region are heart diseases and malignant tumors, with lung cancer, liver cancer, and gastric cancer being the top three leading causes of death for malignant tumors. Although the arsenic poisoning areas in the entire region have basically achieved water improvement, the long-term effects of chronic arsenic exposure still exist.

Objective:To investigate the epidemic status of drinking-tea type endemic fluorosis (fluorosis for short) in Inner Mongolia Autonomous Region (Inner Mongolia for short), and to provide theoretical basis and basic data for formulation and evaluation of prevention and control measures.Methods:From May to October 2022, a cross-sectional survey was conducted in key areas (168 administrative villages in 6 leagues or cities) identified in the 2019 regional census with tea drinking habits, daily per capita intake of tea fluoride > 3.5 mg, and patients with skeletal fluorosis. The drinking condition of brick tea in 10 households of each administrative village was investigated, and the brick tea samples were collected to detect fluoride level. The prevalence of dental fluorosis in children aged 8 - 12 and skeletal fluorosis in adults aged 16 and older was investigated, and urine samples of patients with skeletal fluorosis were collected to detect urinary fluoride levels.Results:Totally 98.40% (1 657/1 684) of the households in the surveyed areas had a habit of drinking brick tea, with an annual per capita consumption of brick tea and a daily per capita intake of tea fluoride of 5.07 kg and 5.38 mg, respectively. The qualified rate of fluoride level in brick tea samples was 55.64% (922/1 657), the average fluoride level of all other brick tea varieties exceeded the national standard limit (300 mg/kg) except for black brick tea (291.08 mg/kg). Totally 2 747 children aged 8 to 12 were examined, with a detection rate of 13.91% (382/2 747) for dental fluorosis. The disease was mainly mild. There was no statistically significant difference in the detection rate of dental fluorosis among different age groups (χ 2 = 5.53, P = 0.238). Totally 71 708 adults aged 16 and older were examined, and the detection rate of skeletal fluorosis was 1.02% (734/71 708). Patients were mainly aged between 50 and 70 years old, and the condition in each age group was mainly mild. Totally 715 urine samples of skeletal fluorosis patients were collected and tested, and 55.24% (395/715) of the urine samples had fluoride levels higher than 1.6 mg/L. Conclusions:In Inner Mongolia, the proportion of high fluoride brick tea in endemic areas of drinking-tea type fluorosis is high. The detection rates of dental fluorosis in children and skeletal fluorosis in adults are relatively high. The prevention and control situation of drinking-tea type fluorosis is still serious.

Objective:To investigate the epidemic scope and intensity of drinking water type endemic arsenic poisoning in Inner Mongolia Autonomous Region, as well as the prevalence and influencing factors, in order to provide scientific basis for precise formulation of prevention and control measures.Methods:A sampling survey was conducted on residents' drinking water in all villages and counties in Inner Mongolia Autonomous Region, water samples were selected according to different water supply methods (engineering water supply, physical and chemical water purification, and decentralized water supply), and the arsenic content was detected by atomic fluorescence method. The "Diagnosis of Endemic Arsenicosis" (WS/T 211-2015) was used for diagnosis of arsenic poisoning among all permanent residents who were exposing to or had been exposed to excessively high arsenic water, in order to search all the arsenic poisoning patients. Analyze the distribution of water arsenic in the historical disease areas and high arsenic villages and newly discovered high arsenic villages, and explore the prevalence and influencing factors of arsenic poisoning.Results:There were a total of 1 186 historical disease areas and high arsenic villages in Inner Mongolia Autonomous Region, mainly distributed in 28 banner counties of 8 league cities such as Bayannur, Hohhot and Baotou, with a regional distribution trend of more in the west and less in the east. At present, the water improvement rate in the historical disease areas and high arsenic villages was 98.23% (1 165/1 186), and the qualified rate of arsenic content in the water was 99.83% (1 184/1 186). The arsenic content in the water of historical disease areas and high arsenic villages ranged from 0.000 to 0.093 mg/L. Four newly discovered villages with arsenic exceeding standards had been found, and their arsenic content ranged from 0.074 to 0.142 mg/L. A total of 2 249 patients with arsenic poisoning were detected in the confirmed disease area/high arsenic villages, and the detection rate was 1.67% (2 249/134 645). The number of patients in Bayannur City was the largest with the most severe disease, accounting for 82.70% (1 860/2 249). Patients aged 60 and above accounted for 61.41% of the total cases (1 381/2 249), which was higher than other age groups (χ 2 = 840.52, P < 0.001). The detection rate of arsenic poisoning was higher in males than in females (χ 2 = 132.38, P < 0.001). There are statistically significant differences in the detection rate and severity distribution of arsenic poisoning patients among different water arsenic content groups(χ 2 = 1 557.85, 1 741.05, P < 0.001). Conclusions:After years of prevention and control work, the arsenic content in most historical disease areas and high arsenic villages in Inner Mongolia Autonomous Region is currently qualified, and some areas have water arsenic exceeding standards or newly discovered villages with arsenic exceeding standards. At the same time, there are still a large number of arsenic poisoning patients in Inner Mongolia Autonomous Region. In the future, the prevention and control of endemic arsenic poisoning in Inner Mongolia Autonomous Region cannot be relaxed, and it is necessary to strengthen water quality monitoring and improve water quality in newly discovered villages with arsenic exceeding standards to prevent the occurrence of new cases.

Objective:To study the effects of water fluoride and tea fluoride on the occurrence of dental fluorosis in children, and to provide a basis for scientific prevention and control of the disease.Methods:From April to September 2020, Baolongshan Town with qualified water fluoride but no habit of drinking brick tea, Xingyao Town with qualified water fluoride and habit of drinking brick tea, Baokang Town with exceeded water fluoride but no habit of drinking brick tea, and Wuliyasitai Town with exceeded water fluoride and habit of drinking brick tea were selected as survey sites in Inner Mongolia Autonomous Region based on historical monitoring data. In all Gacha (villages) of 4 towns, a survey was carried out on residents' drinking water, brick tea drinking habits and children's dental fluorosis detection, and the water fluoride, tea fluoride exceeding standard rates, daily per capita intake of brick tea fluoride and the detection rate of children's dental fluorosis were calculated. At the same time, multivariate logistic regression was used to analyze the influencing factors affecting the occurrence of dental fluorosis in children.Results:In 2020, a total of 165 water samples were collected in 4 towns of Inner Mongolia Autonomous Region, and the total water fluoride exceeding standard rate was 38.18% (63/165). A total of 320 tea samples were collected, the tea fluoride exceeding standard rates in Xingyao Town and Wuliyasitai Town were 96.38% (213/221) and 89.90% (89/99), respectively; the daily per capita intake of brick tea fluoride was 5.67 and 7.35 mg, respectively. A total of 1 652 children were examined for dental fluorosis, and 639 cases were detected, the detection rate was 38.68%. The detection rates of dental fluorosis in boys and girls were 37.18% (322/866) and 40.33% (317/786), respectively, with no significant difference between sexes (χ 2 = 1.72, P = 0.104); the detection rates of dental fluorosis in children aged 8 - 12 years were 43.93% (105/239), 40.50% (147/363), 46.57% (163/350), 30.56% (88/288) and 33.01% (136/412), respectively, with statistical significant difference among ages (χ 2 = 26.07, P < 0.001); the detection rates of dental fluorosis in children in Baolongshan, Baokang, Xingyao and Wuliyasitai towns were 0.68% (2/293), 14.09% (31/220), 24.79% (89/359) and 66.28% (517/780), respectively, with statistical significant differences among regions (χ 2 = 213.05, P < 0.001). Multivariate logistic regression analysis showed that when the fluoride content in water was 1.2 - < 2.0, 2.0 - < 2.5, and ≥2.5 mg/L, the risk of dental fluorosis in children was 3.93, 6.60, and 9.02 times of water fluoride content < 1.2 mg/L; when the daily per capita intakes of brick tea fluoride was 3.6 - 7.0 and > 7.0 mg, the risk of dental fluorosis in children was 2.94 and 3.90 times of daily per capita intakes of brick tea fluoride ≤3.5 mg; the risk of dental fluorosis in children aged 10 years was 1.81 times of children aged 8 years; the risk of dental fluorosis in children in Xingyao, Baokang, and Wuliyasitai towns was 22.35, 40.93, and 151.58 times of Baolongshan Town, respectively. Conclusions:The prevalence of dental fluorosis in children still exists in Inner Mongolia Autonomous Region, and the detection rate of dental fluorosis is high. High water fluoride and high tea fluoride are the main risk factors for dental fluorosis in children.

Objective:To investigate the distribution of fluoride content in water and dental fluorosis in children and skeletal fluorosis in adults in drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region.Methods:From April to November 2021, all natural villages in the drinking water-borne endemic fluorosis areas of Inner Mongolia Autonomous Region were investigated on the status quo of water improvement and water fluoride monitoring. At the same time, all children aged 8 - 12 and adults aged 18 and older were examined for dental fluorosis and skeletal fluorosis, respectively, and the detection rates were calculated.Results:There were 9 465 villages in drinking water-borne endemic fluorosis areas in Inner Mongolia Autonomous Region, among which 8 920 villages had completed the water improvement, with a water improvement rate of 94.24% (8 920/9 465); 8 664 villages had completed the water improvement with qualified water fluoride, and the qualified rate of water improvement was 97.13% (8 664/8 920). A total of 80 915 children aged 8 - 12 in the villages underwent dental fluorosis examination, and 4 868 children were diagnosed with dental fluorosis, with a detection rate of 6.02%. A total of 3 545 915 adults aged 18 and older in the villages were examined for skeletal fluorosis, and 3 567 adults were diagnosed with skeletal fluorosis, with a detection rate of 0.10%.Conclusion:The water improvement rate and qualified rate of water improvement in drinking water-borne endemic fluorosis areas in Inner Mongolia Autonomous Region are high, while both of the detection rates of dental fluorosis in children and skeletal fluorosis in adults are relatively low.