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.

Objective:To study the prevalence of skeletal fluorosis in drinking-water-borne endemic fluorosis areas in Inner Mongolia Autonomous Region (Inner Mongolia), and to provide reference for further prevention and treatment of skeletal fluorosis at this stage.Methods:From March to October 2019, a survey of skeletal fluorosis was carried out in all diseased villages of the eight diseased leagues (cities) in Inner Mongolia, including Alxa, Bayannur, Baotou, Ordos, Hohhot, Hulunbeier, Ulanqab and Xilingol. Permanent residents aged 18 years and above in the diseased villeges were investigated. Face to face questionnaires were used to collect the basic data of age, sex, epidemiological history, etc. of all subjects, and clinical examination of skeletal fluorosis was carried out. Drinking water samples were collected from residents for fluoride content testing.Results:A total of 123 166 residents aged 18 years and above were investigated, 1 781 cases of skeletal fluorosis were detected, and the detection rate was 1.45%. The degree of skeletal fluorosis was mild, accounting for 72.26% (1 287/1 781); the others were moderate and severe, accounting for 20.38% (363/1 781) and 7.36% (131/1 781), respectively. There were statistically significant differences in the detection rates of skeletal fluorosis among people of different water fluoride content, age, gender and regions (χ 2 = 565.96, 671.32, 4.38, 17 283.80, P < 0.05). Among them, the detection rates of skeletal fluorosis in water fluoride content > 4.0 mg/L, ≥56 years old and female population were relatively high, which were 5.21% (49/941), 2.26% (1 428/63 188) and 1.52% (905/59 555), respectively. The detection rates of skeletal fluorosis in Xilingol League and Baotou City were significantly higher, 25.48% (745/2 924) and 24.32% (225/925), respectively. Conclusion:The situation of skeletal fluorosis in drinking-water-borne endemic fluorosis areas in Inner Mongolia has been effectively controlled, but there are still relatively many patients with skeletal fluorosis in some areas, and further targeted prevention and control work is needed.

Objective:To understand the demographic characteristics and treatment intention, treatment status and therapeutic effect of patients with skeletal fluorosis in Inner Mongolia Autonomous Region (reffered to as Inner Mongolia) in order to provide a basis for next step treatment program.Methods:From March to June 2020, a face-to-face questionnaire survey was conducted among 3 570 patients with skeletal fluorosis in 11 leagues (cities) of Inner Mongolia to understand their basic information, treatment intention, treatment status and therapeutic effect. Patients with skeletal fluorosis of different demographic characteristics were compared with each other in their treatment intention and treatment status, and the therapeutic effects of different drugs were compared by χ 2 test. Results:A total of 3570 patients with skeletal fluorosis were investigated. There were slightly more women than men with skeletal fluorosis (1.29 ∶ 1.00, 2 014/1 556). The ages were mainly from 40 to 79 years old (95.4%, 3 406/3 570). Mongols patients accounted for 36.0% (1 285/3 570). Patients with low education (primary school and below) accounted for 82.2% (2 935/3 570). Eighty-five per cent (3 035/3 570) of the patients had drug treatment intention and 37.1% (1 325/3 570) of the patients had drug treatment. Thirty-seven point five per cent (1 338/3 570) of the patients had surgery intention and surgery was performed in 0.2% (8/3 570) of the patients. Combination therapy (98.5%, 194/197) and chondroprotective agents alone (98.3%, 173/176) were more effective than anti-inflammatory and analgesic agents alone (84.2%, 48/57) in the treatment of skeletal fluorosis ( P < 0.05). Surgery was effective (8/8). Conclusions:Most of the patients with skeletal fluorosis are middle-aged and elderly, and the patients with skeletal fluorosis in Mongols account for a certain proportion. At present, all the patients with skeletal fluorosis who have the will to be treated have not been effectively treated, and the means of treatment is relatively single. It should be advocated to carry out various forms of treatment of skeletal fluorosis, so that patients could relieve symptoms, reduce pain and improve their quality of life.

Objective:To understand the prevalence of tea-drinking-borne fluorosis in Inner Mongolia Autonomous Region, and to provide a data basis for formulation of prevention and control measures.Methods:All administrative villages of 53 banners (counties) in 10 leagues (cities) of Inner Mongolia Autonomous Region were investigated for tea-drinking-borne fluorosis. The basic information and demographic information of each administrative village were collected, and 10 households were selected from each administrative village to investigate the basic information of family members and the drinking situation of brick tea, and collect household brick tea samples to determine the fluorine content. The prevalence of dental fluorosis in children aged 8 to 12 and skeletal fluorosis in adults over 16 years in the administrative villages were investigated.Results:There were 39 banners (counties) in Inner Mongolia Autonomous Region that had the habit of drinking brick tea, people who habitually drink brick tea a lot accounted for 70.22% of the total population (4.278 5 million/6.092 8 million). The per capita annual consumption of brick tea was 1.00 kg and the per capita daily intake of brick tea fluoride was 0.68 mg. A total of 24 282 brick tea samples were collected, and the samples with fluorine content exceeding the standard accounted for 74.77% (18 155/24 282). Except that the fluorine content of black brick tea was lower than the national health standard (300 mg/kg), other varieties of brick tea exceeded the standard. A total of 97 295 children aged 8 to 12 years were examined, and 6 558 cases of dental fluorosis were detected. The detection rate of dental fluorosis was 6.74%. Among them, 3 623 cases were very mild, 2 440 cases were mild, 489 cases were moderate and 6 cases were severe. There were significant differences in the detection rates of dental fluorosis in children of different regions and ages (χ 2 = 6 803.76, 30.82, P < 0.05). A total of 115 251 adults over 16 years old were examined, and 1 691 cases of skeletal fluorosis were detected. The detection rate of adult skeletal fluorosis was 1.47%; among them, 1 043 cases were mild, 481 cases were moderate and 167 cases were severe. There were statistically significant differences in the detection rates of skeletal fluorosis among adults of different regions and ages (χ 2 = 3 584.26, 562.67, P < 0.05). Conclusions:The fluoride content of brick tea consumed by residents in Inner Mongolia Autonomous Region seriously exceeds the standard. Moderate and severe patients with dental fluorosis in children aged 8 to 12 years and skeletal fluorosis in adults over 16 years old have been detected. The prevention and treatment of tea-drinking-borne fluorosis in Inner Mongolia Autonomous Region should be continuously strengthened.

Objective:To learn about the distribution of fluoride content in drinking water of residents in Inner Mongolia Autonomous Region, so as to provide scientific basis for formulation of refined prevention and control measures for drinking-water-type endemic fluorosis.Methods:From January 2017 to December 2019, water fluoride surveys were carried out in all natural villages of 103 banners (counties) in 12 leagues (cities) of Inner Mongolia Autonomous Region, and drinking water samples of residents were collected according to different water supply methods (engineering water supply, physical and chemical water improvement, and decentralized water supply). The ion selective electrode method was used for water fluoride detection, and whether the water fluoride exceeded the standard was determined according to the "Standards for Drinking Water Quality" (GB 5749-2006).Results:The survey was carried out in 36 625 natural villages in 103 banners (counties) of 12 leagues (cities) in the region, among which 24 682 were engineering water supply villages, accounting for 67.39%; 2 610 were physical and chemical water improvement villages, accounting for 7.13%; and 9 333 were decentralized water supply villages, accounting for 25.48%. The median values of water fluoride in the engineering water supply villages, the physical and chemical water improvement villages and the decentralized water supply villages were 0.62, 0.23, and 0.52 mg/L, respectively, and the difference between different water supply methods was statistically significant ( H = 2 809.95, P < 0.001); the qualified rates of water fluoride were 96.47% (23 810/24 682), 99.73% (2 603/2 610) and 96.37% (8 994/9 333), respectively, and there was significant difference between different water supply methods (χ 2 = 132.74, P < 0.001). All the 12 leagues (cities) in the region had villages with water fluoride exceeding the standard, among which Chifeng City and Ordos City had more villages with water fluoride exceeding the standard (479, 282). Conclusions:All the 12 leagues (cities) in Inner Mongolia Autonomous Region have villages with water fluoride exceeding the standard. It is necessary to urge relevant departments to carry out planning and management of villages with water fluoride exceeding the standard.