Background: Numerous studies have shown that air pollution is a serious public health threat and risk worldwide. Mongolia is the world leader in outdoor and indoor air pollution, and the morbidity and mortality caused by it are increasing every year. People spend most of their lives indoors, and it is necessary to regularly assess and study indoor air pollution. Aim: To study the concentration of PM2.5 particles in the indoor air of households in Ulaanbaatar and Darkhan cities in relation to some symptoms of respiratory diseases. Materials and Methods: The study was conducted using an analytical cohort design from October 2023 to July 2025, and the 4 districts of the central Ulaanbaatar city and Darkhan cities were included in the study. A total of 240 households were included in the study, including 48 households living in ger and house, 24 households living in apartments, and 48 households living in ger and house, and 24 households living in apartments from Ulaanbaatar city. A direct measurement device (PurpleAir) was installed in the households for 3-4 weeks to measure PM2.5 particles in the indoor air for 24 hours. After measuring PM2.5 particles in the indoor air of the household, data were collected through questionnaires from the participants aged 18-60 who participated in the study and underwent health examinations. The results were processed using STATA-19.0 and R programs. Result: 213-239 households were selected for the study, including households living in 17-26 apartments, 42-58 houses, and 38-50 houses. The 24-hour average concentration of PM2.5 particles in the ambient air of households in Ulaanbaatar city was measured relatively higher in winter and summer than in households in Darkhan city. Among the districts of Ulaanbaatar city, the highest concentration of PM2.5 particles was measured in Songinokhairkhan district, and the lowest concentration was measured in Bayanzurkh district. Considering the cities by heating type, households with stoves are more polluted than households with centralized heating. In Darkhan city, the lowest concentration was measured in apartments (22.78-31.53 μg/m³), houses (44.53-68.17 μg/m³), and the highest concentration was measured in traditional felt houses (houses) (63.20-68.25 μg/m³). In Ulaanbaatar, PM2.5 concentrations were relatively high in all types of housing, including apartments (41.61-58.37 μg/m³), houses (79.22-92.50 μg/m³), and traditional felt dwellings (76.69-86.31 μg/m³). In the summer, PM2.5 concentrations in Darkhan were 3.10-10.03 μg/m³ in apartments, 7.67-14.37 μg/m³ in houses, and 7.98-17.90 μg/m³ in traditional felt dwellings (houses). The concentration of PM2.5 particles in the ambient air of the settlement is statistically significantly associated with shortness of breath, fatigue, weakness, muscle pain, nausea, palpitations, sneezing, runny nose, conjunctivitis, pain in the eye socket, tearing of the eyes, headache, fever, nasal congestion, cough, loss of appetite, sore throat, phlegm, wheezing, and chest pain. Conclusion The 24-hour average concentration of PM2.5 particles in indoor air in households in Ulaanbaatar and Darkhan cities is higher than the Mongolian standard during winter and is statistically significantly associated with some symptoms of respiratory diseases.

Background: Polymyositis (PM) is a rare idiopathic inflammatory myopathy characterized by symmetric proximal muscle weakness, elevated muscle enzyme levels, dysphagia, and respiratory muscle weakness. Rhabdomyolysis is a potentially life-threatening condition caused by extensive skeletal muscle breakdown, resulting in myoglobinuria and an increased risk of acute kidney injury and multiorgan complications. The coexistence of rhabdomyolysis in patients with polymyositis is uncommon and may complicate both diagnosis and management. Case Presentation: A 65-year-old man was admitted with fever up to 39°C, generalized skin rash, dysphagia, progressive muscle weakness, dyspnea, decreased urine output, and dark tea-colored urine. Physical examination revealed symmetric proximal muscle weakness, with muscle strength graded 3/5 in both upper extremities and 4/5 in both lower extremities. Neck muscle strength was 4/5. Dysphagia and a generalized skin rash were also present. Laboratory investigations showed markedly elevated creatine kinase (CK) at 9,943.1 U/L, alanine aminotransferase (ALT) at 449.1 U/L, aspartate aminotransferase (AST) at 222.1 U/L, lactate dehydrogenase (LDH) at 1,342.9 U/L, and C-reactive protein (CRP) at 70.6 mg/L. Urinalysis showed blood 3+ and protein 2+, while no erythrocytes were detected on urine sediment microscopy. Electromyography demonstrated myopathic changes, and muscle biopsy revealed inflammatory infiltrates and necrotic muscle fibers. Conclusion Comprehensive assessment of clinical manifestations, laboratory findings, autoantibody testing, electrophysiological studies, and muscle biopsy is essential for the diagnosis of polymyositis complicated by rhabdomyolysis. An integrated diagnostic approach facilitates confirmation of the diagnosis, differentiation from clinically similar disorders, and appropriate treatment selection. Early recognition of rhabdomyolysis and other potentially life-threatening complications is crucial for preventing organ damage and improving patient outcomes.

Background: Ambient and household air pollution remain leading risk factors for global morbidity and mortality. Exposure to fine particulate matter (PM₂.₅) is associated with increased risks of cardiovascular and respiratory diseases, as well as lung cancer, metabolic and neurological disorders, and immune dysfunction. In urban areas of Mongolia, air pollution reaches critical levels during the winter season. Although improved solid fuels have been introduced in recent years, their impact on both outdoor and indoor air quality remains insufficiently characterized. Aim: To compare outdoor and household air pollution levels in Ulaanbaatar and Darkhan cities. Materials and Methods: Outdoor air pollution data for Ulaanbaatar were obtained from fixed monitoring stations of the National Agency for Meteorology and Environmental Monitoring for the period 2014–2026, with seasonal comparisons performed. For indoor air quality assessment, a longitudinal study was conducted among 240 households (apartments, houses, and traditional gers) in Ulaanbaatar and Darkhan from 2023 to 2026. PM₂.₅ concentrations were measured using real-time sensors (PurpleAir sensor), deployed for 14–21 days per season (winter and summer) in each household, recording data at 10-minute intervals over 24-hour periods. Result: Between 2014 and 2026, the 24-hour mean concentrations in Ulaanbaatar were 60.5 µg/m for PM₂.₅, 117.3 µg/m for PM₁₀, 37.3 µg/m for NO₂, 41.8 µg/m for SO₂, and 27.5 µg/m for O₃. While particulate matter levels showed a decreasing trend following the introduction of improved fuels, SO₂ concentrations increased, and overall pollution levels remained higher than those observed in Darkhan. Indoor PM₂.₅ concentrations were higher in Ulaanbaatar compared to Darkhan (60.7±86.1 vs 48.4±96.7 µg/m). Significant differences were observed by housing type (p<0.0001), with higher concentrations in households using solid fuels (houses and gers) and lower levels in apartments. These findings indicate substantial variability in indoor air pollution by city, housing type, and season, with persistently elevated exposure levels. Conclusion Outdoor air pollutant concentrations in Ulaanbaatar, including particulate matter, NO₂, and SO₂, exceed national standards and WHO guideline values by 1–4 times. Indoor PM₂.₅ pollution is higher in Ulaanbaatar than in Darkhan and varies significantly by housing type and season, indicating a high and heterogeneous exposure burden among urban populations.

Background: Occupational stress among dentists has both direct and indirect effects on individual mental health and work productivity. Furthermore, it is a critical factor influencing patient satisfaction, quality of care, human resource stability, and the sustainable development of healthcare organizations. Aim: To assess job satisfaction among dentists and to identify selected factors associated with it. Materials and Methods: This analytical cross-sectional study included a total of 98 dentists providing oral healthcare services in both public and private dental clinics in Mongolia. Data were collected using a structured questionnaire administered via Google Forms. The questionnaire consisted of 30 items across three sections, covering general information, working conditions, and job satisfaction. Data were analyzed using Microsoft Excel and SPSS version 31.0. Results: The overall job satisfaction score among participating dentists was above average (3.68±0.77). The findings revealed that workplace comfort (r=0.570), colleague relationships (r=0.560), salary (r=0.501), managerial professional competence (r=0.484), and opportunities for professional advancement (r=0.482) were significantly and positively correlated with job satisfaction (p<0.001). Workload did not show a statistically significant association with job satisfaction (p>0.05). Notably, the level of satisfaction regarding institutional support for professional skill development was relatively low (1.87±0.86). Conclusions 1. Factors such as workplace comfort, colleague relationships, salary, managerial competence and opportunities for professional advancement showed a statistically significant positive correlation with job satisfaction among dentists (p < 0.001). 2. The level of job satisfaction among dentists was assessed as above average (3.68±0.77).

Background: Hand hygiene is a fundamental component of infection prevention and control in healthcare facilities. Healthcare workers’ hands can transmit pathogens between patients, medical equipment, and environmental surfaces, contributing to healthcare-associated infections (HAIs). Objective: To synthesize evidence on hand hygiene conditions, soap and alcohol-based hand rub availability, compliance, public health importance, and economic benefits in healthcare facilities, with particular relevance to Mongolia. Material and Methods: A narrative review was conducted using published studies, international guidelines, WHO/UNICEF reports, and Mongolian regulatory documents addressing hand hygiene infrastructure, essential supplies, compliance, HAI prevention, and economic outcomes. Results: Hand hygiene compliance remains suboptimal in many healthcare settings and is frequently reported below 40%. Compliance is influenced not only by healthcare workers’ knowledge and attitudes but also by the availability of running water, functional sinks, liquid soap, alcohol-based hand rub, hand-drying facilities, training, workload, institutional leadership, monitoring, and feedback. HAIs are more common in low- and middle-income countries, where limitations in water, sanitation, hygiene, and infection prevention infrastructure increase risks for patients and healthcare workers. In Mongolia, basic hand hygiene service coverage has been reported at approximately 72%, indicating continuing gaps in essential facilities and supplies. Multimodal strategies that combine system improvement, education, reminders, monitoring, feedback, and institutional support are more likely to improve compliance and reduce infection risks. Economic evidence also indicates that hand hygiene is a high-value intervention: every US$1 invested in hand hygiene improvement may save up to US$16.50 in healthcare expenditure, while hygiene promotion including handwashing can avert one DALY at an estimated cost of US$3.35. Conclusion Strengthening hand hygiene in Mongolian healthcare facilities requires sustainable financing, reliable supply systems, adequate infrastructure, continuous training, and routine monitoring. Integrating these measures into IPC and WASH programmes can improve patient safety, reduce HAIs, and generate substantial public health and economic benefits.

Background: Hand hygiene is a fundamental component of infection prevention and control in healthcare settings. Effective hand hygiene requires functional infrastructure and the consistent availability of essential supplies, including clean water, soap, hand disinfectants, and hand-drying materials. Assessing these conditions is essential for identifying gaps in service provision and informing targeted improvements in healthcare facilities. Aim: To assess hand hygiene conditions and the availability of essential handwashing supplies in selected healthcare facilities in Mongolia. Materials and Methods: An analytical cross-sectional study was conducted in 20 healthcare facilities located in urban and rural areas of Mongolia. Hand hygiene conditions and the availability of essential supplies were assessed at 186 handwashing stations using a structured observation checklist. Additionally, information on the budgeting and financial planning of handwashing supplies was collected from each participating healthcare facility using a structured questionnaire. Data were analyzed using IBM SPSS Statistics version 27.0. Ethical approval was obtained from the Research Ethics Committee of the Mongolian National University of Medical Sciences on April 17, 2026 (Approval No. 26/04-01). Results: Of the 186 observation points, 55.9% were located in urban areas and 44.1% in rural areas. Overall, 92.5% had functional handwashing sinks, 88.2% had access to clean water, 73.7% had liquid soap, 57.0% had disposable paper towels, and 52.2% had hand sanitizer available at the handwashing station. Accessible handwashing facilities for persons with disabilities were identified at 26.3% of observation points. The availability of liquid soap (82.7% vs 62.2%; p=0.002) and hand sanitizer (72.1% vs 26.8%; p<0.001) was significantly higher in urban than in rural areas. Among the 20 healthcare facilities, 80.0% allocated a budget for handwashing supplies, but only 5.0% based their budget planning on actual soap consumption reports. Conclusion Although basic handwashing infrastructure was generally available in the surveyed healthcare facilities, gaps persisted in the availability of essential hand hygiene supplies, particularly in rural areas. Limited accessibility for persons with disabilities and the infrequent use of consumption data in budget planning indicate areas requiring improvement. Strengthening the continuous provision of hand hygiene supplies, improving accessible infrastructure, and adopting consumption-based budgeting practices are essential priorities for improving hand hygiene conditions in healthcare facilities.

Background: Globally, gastric cancer accounts for 1,089,000 new cases and 769,000 deaths annually, ranking fifth in overall cancer incidence and third in cancer-related mortality. The aim to determine HER2 expression in patients with gastric cancer and to evaluate its correlation with clinical and immunological biomarkers, as well as the need for further laboratory diagnostics. Aim: To determine HER2 expression in patients with gastric cancer and to evaluate its association with clinical and immunological biomarkers, as well as the potential need for further laboratory diagnostics. Materials and Methods: A retrospective study was conducted using archived materials from patients with gastric cancer at the Clinical Pathology, Molecular Genetics, and Pathology Laboratories of the National Cancer Center of Mongolia, covering the period from 2019 to June 2025. HER2 protein expression in tumor tissue was assessed using immunohistochemistry (IHC), and chromogenic in situ hybridization (CISH-HER2) was employed to confirm gene amplification. Statistical analysis was performed using the Prisma-10 software. Results: In our study, among 210 cases of gastric cancer evaluated by IHC for HER2, 46 (21.9%) were HER2-positive and 164 (78.1%) were HER2-negative. When comparing patients with gastric cancer stratified into HER2 1+ (negative) and HER2 3+ (positive) groups, no statistically significant differences (p < 0.05) were observed in age, sex, tumor location (surgically resected tissue), morphology, or disease stage. However, a higher proportion of males was noted in the HER2 3+ group (80.9%), though this did not reach statistical significance (p = 0.0879). Significant associations were found with tumor markers. Elevated serum CA-72-4 (>5 ng/mL) was more frequent in the HER2 3+ group (58.8%; p = 0.0069). In contrast, elevated CA-19-9 (>35 U/mL) was more common in the HER2 1+ group (93.5%; p = 0.0117), and elevated CEA (>6.9 U/mL) was also predominant in the HER2 1+ group (90.6%; p = 0.002). These findings suggest that HER2 3+ status predominates in cases with elevated CA-72-4, which may influence diagnostic strategies and HER2-targeted therapies (e.g., trastuzumab). Conversely, elevated CA-19-9 and CEA were more associated with HER2 1+ status, indicating a need for further detailed investigation of these markers in relation to HER2 expression. In patients evaluated by CISH for HER2 expression, stratification into HER2-positive and HER2-negative groups revealed no statistically significant differences (p < 0.05) in age, sex, tumor location, morphology, stage, or serum tumor markers (CA-72-4, CA-19-9, CEA). This suggests that HER2 status (positive/negative) may be independent of these variables. Although HER2 positivity was higher in poorly differentiated tumors (48% vs. 30.6% negative; p=0.1414) and in stage IV disease (50% vs. 39.3% negative; p=0.2607), these differences were not statistically significant. Elevated serum markers (CA-72-4, CA-19-9, CEA) were observed but showed no significant correlation with HER2 status. Conclusion Determining the molecular profile of gastric cancer patients can significantly contribute to refining clinical diagnosis, developing treatment strategies, enhancing therapeutic outcomes, and improving patients’ quality of life.

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: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by degeneration of upper and lower motor neurons, leading to muscle weakness, spasticity, dysarthria, and dysphagia. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an autoimmune-mediated neuropathy that primarily affects nerve fibers specifically myelin sheets. Clinically, CIDP presents with distal muscle weakness, prominent sensory disturbances, and diminished or absent deep tendon reflexes. The co-occurrence of ALS and CIDP is exceptionally rare and poses significant diagnostic and therapeutic challenges due to overlapping and distinct clinical features. A Case: A 44-year-old male presented to the Department of Neurology at the Mongolia-Japan Hospital, Mongolian National University of Medical Sciences, with progressive muscle weakness in both upper and lower extremities, along with dysphagia, especially for solids with frequent choking episodes. The initial symptoms began in May 2023 with muscle fasciculations, followed by progressive weakness, initially in the right upper limb and gradually progressing to the left. By August 2023, the patient developed bilateral arm weakness, dysarthria, and worsening dysphagia. From August 2024, episodes of head drop were noted. A progressive weight loss of 11 kg was recorded since January 2024. Comprehensive neurological evaluation, including antibody profiling, electromyography (EMG), and nerve conduction studies (NCS), supported a diagnosis of amyotrophic lateral sclerosis with chronic inflammatory demyelinating polyradiculoneuropathy-like neuropathy. Outcome: One month after hospital discharge, the patient demonstrated improvement in self-care abilities and increased muscle strength in both proximal and distal upper limb muscles. Notably, there was marked improvement in overall clinical status. Conclusion To our knowledge, this is the first reported case in Mongolia documenting the simultaneous presentation of ALS and CIDP-like neuropathy. Globally, such cases are exceedingly rare. Timely and accurate diagnosis, along with appropriate treatment, contributed to improved clinical outcomes and a deceleration of disease progression in this patient.

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.