Background: The first confirmed case of COVID-19 in Mongolia was reported on November 11, 2020. In response, the government imposed a nationwide lockdown, which significantly impacted the population’s mental health. Heightened levels of stress, anxiety, loneliness, and depression during the pandemic altered individuals’ psychological stability and behavior. Personality traits—defined as relatively stable patterns of emotion, cognition, and behavior—play a key role in stress responses and emotional regulation under pressure. Emerging evidence suggests that these psychological factors may influence the immune system’s responsiveness, including vaccine-induced antibody production. Aim: To evaluate the association between post-vaccination antibody responses and personality types following two doses of COVID-19 vaccines. Materials and Methods: A total of 738 participants who received two doses of COVID-19 vaccines (AstraZeneca ChAdOx1, n=29; Pfizer-BioNTech, n=119; Sinopharm BBIBP, n=590) and had no prior SARS-CoV-2 infection were enrolled. Serum samples were collected 21–28 days after the second dose, and SARS-CoV-2 RBD (S) IgG antibodies were measured using ELISA (Proteintech Inc., USA). Personality types were assessed using a 56-item temperament questionnaire developed by A. Belov, categorizing individuals into classical temperament types (choleric, phlegmatic, sanguine, melancholic). Logistic regression and ROC analysis were used to examine associations between personality types and antibody response. Results: The presence of an antibody response was significantly higher among individuals with a melancholic temperament, and significantly lower among those with a phlegmatic temperament. Furthermore, antibody titers were higher in participants with melancholic and sanguine temperaments and lower in those with a phlegmatic type. Conclusions 1. During the early period following the second dose of COVID-19 vaccination, the antibody response was higher in individuals with a pure melancholic temperament, while it was lower in those with a phlegmatic temperament. 2. After the second dose of the Sinopharm BBIBP COVID-19 vaccine, antibody titers were higher in individuals with pure melancholic and sanguine temperaments, and lower in those with a phlegmatic temperament.

Background: An estimated 99% of the global population lives in environments where PM2.5 levels exceed the WHO air quality guideline of 15 μg/m³. In 2018, air pollution contributed to approximately 4.2 million deaths worldwide. In Mongolia, air pollution—particularly in urban centers like Ulaanbaatar, worsens significantly during the winter season, posing a serious public health and local concern. Therefore, it is compulsory to compare the outdoor air quality in Ulaanbaatar, the capital and Darkhan city. Aim: To assess and compare the outdoor PM2.5 concentrations in Ulaanbaatar and Darkhan during the winter season. Materials and Methods: This study was conducted in Ulaanbaatar and Darkhan from December 10, 2024, to February 19, 2025. A total of 60 PurpleAir Classic+ sensors (30 per city) were installed to assess PM2.5 concentrations at 2-minute intervals. We analyzed collected data using R software. The 24-hour average PM2.5 concentrations were compared with both the Mongolian National Air Quality Standard (MNS4585:2016) and the WHO air quality guidelines (2021). Results: The 24-hour average PM2.5 concentration in Ulaanbaatar was 112.3±62.2 μg/m³, which was significantly higher than that in Darkhan (79.2±25.6 μg/m³; p<0.05). In Ulaanbaatar, the monthly averages were 119.9±67.7 μg/m³ (Decem ber), 113.5±60.8 μg/m³ (January), and 95.0±51.9 μg/m³ (February) respectively (p<0.05). In contrast, Darkhan city’s monthly average PM2.5 remained relatively close across the months: 79.1±22.2 μg/m³ (December), 78.7±28.6 μg/m³ (January), and 84.6±30.0 μg/m³ (February), with no statistical significance (p>0.05). During the study period, the 24-hour average PM2.5 concentrations exceeded the MNS4585:2016 (50 μg/m³) in 69.8% of days in Ulaanbaatar and 64.6% in Darkhan. WHO’s guideline of 15 μg/m³ was exceeded 93.4% of the time in both cities. Conclusion Darkhan city has lower PM2.5 concentrations compared to Ulaanbaatar, both cities significantly exceeded MNS4585:2016 standard and the WHO air quality guidelines (2021) during the winter months.

Background: According to the World Health Organization (WHO), 99 percent of the world’s population is exposed to air that exceeds WHO recommendations, with low- and middle-income countries being the most affected. The main causes of indoor air pollution include human activities such as fuel burning, cooking, cleaning, and smoking; housing characteristics such as walls, floors, ceilings, and furniture; ventilation; and outdoor air pollution. Aim : To assess PM1 and PM10 concentrations in 120 selected households in Ulaanbaatar. Materials and Methods : Indoor PM1 and PM10 concentrations were measured using Purple Air real-time sensors in randomly selected Ulaanbaatar households between October 2023 and January 2024. Supplementary data on factors affecting the PM2.5 concentration were collected via questionnaires. Each measurement was taken in 10-minute intervals, yielding 51,309 data for analysis. Results : PM1 concentrations were measured at 55.5±53.2 μg/m³ in gers, 54.9 ± 46.7 μg/m³ in houses, and 31.6±40.1 μg//m³ in apartments (p<0.001) and measuring PM10 concentrations were 110.6±108.6 μg/m³ in gers, 110.6±96.7 μg/m³ in houses, and 62.2±83.0 μg/m³ in apartments (p<0.001) When considering the concentration of PM1, PM10 by heating type, PM1 was 55.3±50.1 μg/m³ and PM10 was 110.6±103.0 μg/m³ in households with stoves and furnaces, and PM1 was 31.6±40.1 μg/m³ and PM10 was 62.2±83.0 μg/m³ in households connected to the central heating system (p<0.001). Regarding the months of measurement, the highest concentration was observed in December 2023, at 77.1±94.1 μg/m³. The highest concentrations for both PM₁ and PM₁₀ were recorded in January 2024, at PM₁: 64.8±55.1 μg/m³, PM₁₀: 131.4±116.0 μg/m³. Conclusion 1. Indoor PM10 concentrations in residential environments in Ulaanbaatar city were within the MNS4585:2016 Air Quality Standard, however, it was exceeded the WHO air quality guidelines, indicating an excessive risk of increasing morbidity and mortality among the population. 2. Indoor PM1 and PM10 concentrations in residential environments in Ulaanbaatar varies depending on location, type of housing, type of heating, and month of measurement.

Background: The development of a country is often measured by the state of human development, especially maternal and child health indicators. In Mongolia, public health policies targeting the prevention of non-communicable diseases related to lifestyle and physical development among adolescents are critically needed. However, there is a lack of regional studies on adolescent health, particularly in rural areas. Aim: To study certain physical development indicators among adolescents in Bulgan province. Materials and Methods: This analytical study was conducted in 2022 involving 781 twelve-year-old children. Data were collected from parents and processed using Stata 17.0. Percentages were calculated for qualitative data, and Chi-square and Fisher’s exact tests were used for statistical analysis. Where statistically significant, multinomial logistic regression analysis was applied to identify risk factors affecting physical development. Results: 52.88% of the participants were boys,92.45% lived in traditional or private hous12.04% of the children showed growth retardation. 49.68% were overweight.70.94% were classified as overweight or obese based on their Body Mass Index (BMI).Weak muscle strength (1.66%), flexibility (2.05%), endurance (1.66%), and agility (1.92%) were observed. Boys were more likely to experience height retardation but had stronger muscle strength.Girls showed a higher prevalence of being overweight.Children living in the provincial center had higher height and BMI, while those in soum centers demonstrated statistically significant strength in muscle power, flexibility, and endurance. Conclusion 1. Among the study participants, 70.94% of children were overweight or obese. 2. 1.66% of the study participants had weak muscle strength, 2.05% had weak flexibility, 1.66% had weak endurance, and 1.92% had weak speed and agility. 3. The use of mobile phones, parental involvement, inactivity, lack of sports, and lack of horse riding have negative effects on physical development.

Background: The first case of COVID-19 was reported in our country on November 11, 2020. As of 2023, a total of 869,385 cases and 2,128 deaths have been recorded nationwide. The World Health Organization (WHO) has recommended that countries use 15 vaccines from 11 manufacturers listed for emergency use. The WHO has advised low-income member states to prioritize vaccinating healthcare workers and other high-risk populations vulnerable to severe illness and death from COVID-19. The main goal of the coronavirus vaccination program is to prevent infection, complications, and death among priority target groups, such as healthcare workers and other populations at high risk of severe illness. The effectiveness of the vaccination is measured by its ability to reduce the risk of illness, hospitalization, and death from COVID-19-related complications among vaccinated individuals. While extensive research is being conducted globally to develop, evaluate, and assess the effectiveness and outcomes of COVID-19 vaccines, there has been limited research focused on these outcomes within our country. This gap highlights the need for and serves as the basis of the present study. Аim: To assess the risk of infection, hospitalization, and associated risk factors among healthcare workers vaccinated against COVID-19, and to examine the factors that influence these risks. Materials and Methods: A This follow-up study was conducted over an 80-week period—at weeks 12, 24, and 48—from February 23, 2021, to December 31, 2022. The study involved healthcare workers from Ulaanbaatar city and the aimags of Bayankhongor, Orkhon, Bulgan, Dundgovi, Darkhan-Uul, and Dornod. The study was conducted over a period of 1.5 years (80 weeks) following the administration of the first two doses of the COVID-19 vaccine. Data were collected from participants at three time points: before vaccination, after the second dose, and after each booster dose. A structured questionnaire comprising 7 sections and 49 questions was used for data collection, and the results were analyzed using SPSS version 26.0. Results: Of the total respondents, 574 (60%) worked in direct contact with infected individuals in the 'red zone,' while 370 (40%) worked in the 'yellow zone.' Additionally, 250 participants (27.1%) were healthcare workers from Ulaanbaatar city, and 674 (72.9%) were from rural areas. In our observational study, the risk of new infections among healthcare workers increased over time, rising from 38.4% at week 24 to 59.6% by week 80. Hospitalizations also increased during the follow-up period: 24 cases (2.6%) were recorded at week 12, 160 (17.3%) at week 24, 202 (21.9%) at week 48, and 204 (22.1%) by week 80. Among frontline workers in rural areas, those in Bayankhongor and Orkhon aimags exhibited a lower risk of infection compared to their counterparts in other aimags. Conclusion In our follow up study, an increase in the duration since primary immunization was associated with a higher risk of new infection among workers, rising from 38.4% at 24 weeks to 59.6% at 80 weeks post-vaccination. Administration of additional (booster) immunizations was associated with a reduced risk of subsequent infection. COVID-19 vaccination was associated with a reduced risk of complications necessitating hospitalization. Employment in rural settings and designated red zones was identified as a risk factor for incident infections, hospitalizations, and reinfections.

Background: A 2018 study on the global burden of disease, accidents, and risk factors reported that 1.6 million peo ple died in 2017 due to household air pollution. Poor indoor air quality has been highlighted as a contributing factor to respiratory diseases, cardiovascular conditions, and exacerbation of asthma and allergies. A 2019 study estimated that long-term exposure to fine particulate matter (PM2.5) with a diameter of 2.5 micrometers or less reduces average life expectancy by 1.8 years, with more severe effects in highly polluted regions. Additionally, a study by Miller et al. (2007) found that prolonged exposure to PM2.5 increases the risk of cardiovascular diseases, particularly among women. Direct measurement devices are highly effective in determining indoor PM2.5 concentrations, identifying sources of pollution, tracking pollutant dispersion, and monitoring temporal variations. Studies suggest that direct measurement is an accurate, cost-effective method that provides detailed data suitable for local conditions. Aim: To investigate the indoor air quality of houses and apartments in Darkhan city during the winter season using the Purple Air monitoring device. Materials and Methods: A cross-sectional study was conducted with a targeted sample of 128 households in Darkhan city. The study examined factors such as stove type, type of coal used, annual and daily coal consumption, frequency of heating, and chimney sealing conditions. To collect data, the Purple Air monitoring device was installed in each house hold for a month, after which it was retrieved. During retrieval, participants completed a questionnaire. The questionnaire consisted of 55 questions across 7 pages at the time of device installation and 25 questions across 3 pages at the time of device retrieval. The collected data was analyzed using SPSS 25.0. Results: A total of 128 households in Darkhan city participated in the study. The average duration of residence in the current home was 9.5 years, with no statistically significant variation. The distribution of housing types was as follows: traditional Mongolian gers (40.6%), houses (39.1%), and apartments (20.3%). The 24-hour average PM2.5 concentration was highest in gers (70.9 μg/m³), followed by houses (46.8 μg/m³) and apartments (22.8 μg/m³), with a statistically significant difference (p=0.0001). PM2.5 levels were most variable in gers, followed by houses and then apartments. House holds using central heating (apartments) had an average 24-hour PM2.5 concentration of 22.8 μg/m³, whereas households using stoves (gers and houses) had a significantly higher concentration of 59.4 μg/m³ (p=0.0001). However, there was no statistically significant difference between traditional and improved stoves. Among study participants, 21.4% reported that someone in their household smoked indoors. Additionally, 86.5% regularly burned incense, candles, or herbs, while 99.2% did not use an air purifier. Conclusion The indoor particulate matter concentration in houses and gers in Darkhan was 59.4μг/m3. Variations in stove types, poor chimney sealing limited space, and frequent gaps and cracks contribute to increased spread of indoor air pollutants.

Background: Hepatitis virus infections are widespread and highly endemic in Mongolia and ranks first in the world for liver cancer mortality per 100,000 population, eight times the world average. The World Health Organization estimates that more than 2 billion people are infected with the hepatitis B virus. Each year, 1 million people die from the infection, 4 million are newly infected, and approximately 350-400 million are chronic carriers. In 2018, 475 cases of viral hepatitis were recorded nationwide, accounting for 1.1 percent of all communicable diseases, a decrease of 59 cases or 0.2 per 10,000 population compared to the previous year. In 2016, 194 WHO member countries joined forces to develop a strategy to reduce viral hepatitis, with the goal of reducing mortality by 65% and new infections by 90% by 2030. In order to achieve this goal, the strategic goal states that each country must conduct a comprehensive public health study and intervention on the spread of infection, risk factors, and early detection. Aim: Study to the coverage of hepatitis B immunization among children aged 0-9 years in urban and rural Mongolia and to determine the influencing factors. Materials and Methods: A Nationwide population based cross-sectional study design was used in this study. Mongolia is geographically divided into the western, Khangai, eastern, and central regions. A total of 14 provinces were selected randomly in addition to Ulaanbaatar city. The appropriate sample size was estimated at 4500 children aged 0-9 years, based on 2019 demographic data from the National Statistics Office. The questionnaire contained closed and semi-closed questions on demographics, socio-economic status, vaccination history and etc. Results: A total of 5027 children aged 0-9 years were enrolled in this study out of which 33.7% (n=1692) and 66.3% (n=3335) were enrolled from capital city Ulaanbaatar and provinces, respectively. Almost half (n=2552) of the study participants were boys whereas the remaining were girls 50.0% (n=2554). According to the history of Hepatitis B vaccination by questionnaire of parents’, 91.2% [91.2-92.0] were vaccinated with Hepatitis B. The proportion was 89.7% [89.7-90.8] and 94.1% [94.1-95.2] in rural and urban areas, respectively. Nearly 90% [89.6-90.5] of children were vaccinated in hospitals, 2.3% [2.0-5.0] were vaccinated at home, 8.1% [7.9-10.7] were unaware of the study participants’ location of vaccination. There were no statistically significant differences by urban and rural residences. Vaccination coverage against Hepatitis B was 91.5% (n=2300) and 90.9% (n=2284) among boys and girls, respectively and 89.6% (n=4506) were vaccinated at hospitals. Vaccination coverage were similar by sex. We also used Health Documents /pink book of children/ or vaccination card for each child to determine the coverage. According to the data from the children’s vaccination card and health documents’, 917 (18.2%) children were not vaccinated against hepatitis, 57 (1.1%) children received 1 dose, 235 (4.7%) children received 2 doses, and 3818 (75.9%) children received all 3 doses of hepatitis B vaccine. There was no significant difference by sex, though the coverage varied by age. For instance, proportion of children with no written documentation in the vaccination card was 13.5% among children aged 1 years that increased to 22.5% and 25.3% among children aged 8 and 9 years, respectively. In contrast the coverage rate of 3 doses of hepatitis B vaccination declined from 77.8% to 70.7% among children aged 1 years and 9 years, respectively. Hepatitis B vaccination coverage according to the vaccination card was different by provinces and within the districts of Ulaanbaatar city. Conclusion A total of 5027 children aged 0-9 years were included in the study, of which 917 (18.2%) children were not vaccinated against hepatitis, 57 (1.1%) children were vaccinated against the first dose, 235 (4.7%) children were vaccinated against the second dose, and 3818 (75.9%) children were fully vaccinated against the first-third dose. Although the coverage of the study participants varied depending on age and place of residence, no significant differences were observed in terms of gender. The current rate of children who are not fully vaccinated stands at 18.2%, emphasizing the need to ensure all children receive full vaccinations for hepatitis B and the required five doses as per the schedule. Furthermore, it is essential to mandate booster vaccinations for those with delayed immunizations and improve the accuracy of registration data.

Background: A particular appealing problem in the medical field of our country is non-communicable diseases, which are derived from child development and lifestyle, prevention and the decision was approved on being used the maternal and child health handbook in order to be promptly needed the publicly covered medical policy toward those. Several researchers have noted that in developed countries longitudinal studies are used for checking and controlling in wide range of epidemic diseases and health issues for maternal and child, pregnancy and postpartum period as well as this method is directed to be found out multiple information and knowledge. Not having studied enough how well current situations for postpartum period and maternal and child health in our countryside is become the foundation for our research work. Moreover, it needs to be found out what kind of factors, which are effected on children who were born to the year of 2010 in Bulgan province, where it started using the first and only maternal and child health handbook (so called a pink handbook) in Mongolia, health issues. Also, the foundation of this study was to be needed to focus on our attention to which level of the medical field in order to improve those generations health issues are improved, Aim: to evaluate of a written usage of the maternal and child health handbook, to define its needs, to advertise its results to the public. Materials and Methods: The study is made with a cohort design of an analytical method based on collected information in 2013, of mothers and children, who are in need, giving birth and being born in 2010 and the results were made on Stata 17 program. The answers were taken with the base study of 2013 from 1015 original case sources within study groups in needs, and collected information covered with current and actual local situation, as well as to be involved in mothers and children, who gave birth and were born in 17 sums’ health institutions of Bulgan province. Results: Participants age range and educational backgrounds; 70.34 % of mothers were between 20-34 ages, 29.36% of mothers were 35 and over ages. 1.51% of uneducated mothers, 39.06 % of high school graduates, 49.1% of permanent residents, 45.38 % of temporary or nomadic or the smallest units residents of administration, 92.08% of married, 39.88% of families are consisted in members over 5, 52.12% of boys with average weights of 3389.8 grams during the period of being born, 9.86% of heavy pregnancy or heavy weight fetuses, 4.14% of light weight fetuses or light weight infants. Plus, the study was defined the mothers educational background to be great and helpful strength to use and record and to define the usages of the maternal and child health handbook, which was given and thoroughly explained to the mothers at the beginning. The leading diseases and their reasons were among three-year aged children, who were covered and recorded with 173 severe burnt, 42 falling injuries from something, 22 being hit and 19 were bitten by animals. In this study there were 17.83% of participants without the maternal and child health handbooks (pink handbooks), 81.77% of participants carried their pink handbooks with them when they went to the health facilities, 68.47% of them, who were gotten explanations from the doctors, when the pink handbooks were opened by, 71.72% of participants answered the pink handbooks to be needed. The results of this study have indicated that 71.72% of mothers, who used it at first time, answered the maternal and child health handbooks were very important and handy for understanding to check and observe for mothers and children’s development and growth. Conclusion It was the leading reason, which was predominantly recorded with cases of burning, falling injuries, hit and bitten by animals among three-year of children, who were participated in this study. There were high amounts of respiratory diseases and diarrheas among toddlers. 71.72% of participants considered that the maternal and child health handbooks were important.

Background: According to the World Health Organization (WHO), air pollution was responsible for 8.1 million deaths globally in 2021, making it the second leading cause of death, including among children under 5 years old. Air pollution is also linked to a range of diseases such as stroke, chronic obstructive pulmonary disease, lung cancer, and asthma. In Ulaanbaatar, the capital of Mongolia, the average daily concentration of PM2.5 particles in the air reaches 750 μg/m3 during winter, which is 50 times higher than the WHO’s recommendation, making it one of the most polluted cities in the world. Air pollution continues to pose a significant public health challenge not only in Mongolia but also in many countries globally. However, there is a lack of comprehensive research and studies that summarize and review the existing work in this field. Aim: To summarize and review thematic works on air pollution conducted by researchers from Mongolian universities. Materials and Methods: A systematic review and analysis were performed on thematic works by researchers who completed their master’s and doctoral degrees in the field of air pollution between 2011 and 2024. Results: In terms of the type of master’s and doctoral dissertations, 76.0% (n=19) were master’s theses and 24.0% (n=6) were doctoral dissertations. Among the total number of works included in the study, 36.0% (n=9) focused on the health effects of air pollution, while 64.0% (n=16) addressed other related areas. Some studies indicated that PM2.5 levels in the air between 2011 and 2024 were 1-6 times higher than the Mongolian standard, with the highest levels observed from November to February and the lowest in July. Additionally, some studies suggested a reduction in PM2.5 levels following the introduction of improved fuel in Ulaanbaatar. Air pollution was found to increase the risk of respiratory and cardiovascular diseases, as well as cancer, and to contribute to reduced fetal weight. Conclusion When examining thematic studies on air pollution conducted by state-owned universities in Mongolia, the primary focus has been on the composition, concentration, and health impacts of air pollution. Going forward, research aimed at mitigating air pollution should be driven by collaborative efforts and leadership from universities, with the results being effectively communicated to policymakers.

Background: According to the World Health Organization (WHO), 6.7 million people die annually due to air pollution caused by solid fuel use, with the majority of deaths resulting from respiratory diseases and cardiovascular conditions. In Mongolia, air pollution ranks as the fourth leading risk factor contributing to mortality, following hypertension, diabetes, and other major health risks. Although there have been numerous studies on outdoor air pollution in Mongolia, research linking indoor air pollution at the household level with the health status of residents remains limited. Aim: To compare indoor PM2.5 concentrations in households of Ulaanbaatar and Darkhan and examine their association with hypertension during the winter season. Materials and Methods: The study was conducted during November and December 2023, and January 2024, involving 240 households in Ulaanbaatar and Darkhan. Indoor PM2.5 concentrations were measured using Purple Air real-time sensors continuously for 24 hours over approximately one month. After measuring indoor air pollution, individuals aged 18–60 years living in the selected households were recruited based on specific inclusion criteria. Blood pressure was measured three times and the average value was recorded. Information on respiratory illnesses was collected through structured questionnaires. Statistical analysis was performed using STATA version 19.0. Results: A total of 241 households participated in the study, with 116 from Ulaanbaatar and 125 from Darkhan. Of the participants, 46.5% were male and 53.5% were female. In terms of housing type, 96 households (39.8%) lived in gers, 97 (40.2%) lived in stove-heated houses, and 48 (19.9%) lived in apartments. Among all participants, 66.0% (n=159) had hypertension and 34.0% (n=79) had normal blood pressure. Among participants aged over 40, 69.9–88.5% had hypertension, which is statistically significantly higher compared to younger individuals (p=0.0001). By body mass index, 75.3% (n=72) of overweight individuals and 78.4% (n=58) of obese participants had hypertension, showing a statistically significant difference compared to participants with normal weight (p=0.0001). The 24-hour average concentration of indoor PM2.5 was measured using the Purple Air device, and the levels in gers and stove-heated houses exceeded the limit set by the MNS 4585:2025 standard (37.5 µg/m³) Conclusion This study identified a relationship between environmental factors, such as air pollution and housing type, and the prevalence of hypertension. The indoor PM2.5 concentration in gers and stove-heated houses was above the standard limit, indicating a negative impact on the health of those residents. Furthermore, the high prevalence of hypertension among participants over the age of 40 and those who are overweight suggests a possible link to lifestyle and environmental conditions.