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: 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.

Backgroun: Air pollution is a major global public health concern that poses serious risks to human health regardless of a country’s level of economic or technological development. According to the World Health Organization (WHO, 2021), nine out of ten people worldwide breathe polluted air, and air pollution is responsible for the deaths of approximately 800 people every hour and 13 people every minute. Prolonged exposure to polluted air has been linked to a wide range of chronic illnesses, including chronic obstructive pulmonary disease (COPD), lung and bronchial cancers, asthma, and stroke. In Mongolia, air pollution reaches its highest levels during the winter months, particularly in Ulaanbaatar, where the majority of the country’s population resides. A study conducted by Enkhjargal G. (2012) reported that the concentrations of PM10 and PM2.5 in Ulaanbaatar were 7–8 times higher than the WHO recommended guidelines. In response to such challenges, many countries have increasingly adopted low-cost, direct measurement devices such as PurpleAir to monitor air quality. These devices are valued for their accessibility, network connectivity, and potential role in smart city pollution management systems. Despite their global application, there remains a lack of research in Mongolia on the use of PurpleAir sensors to measure PM2.5 concentrations and compare the results with official monitoring station data. Addressing this gap is essential for improving local air quality monitoring capacity and informing effective public health and environmental policies. Aim: Determination of PM2.5 particulate matter pollution in the outdoor environment of Ulaanbaatar city using a direct measurement device (Purple Air). Materials and Methods: A cross-sectional study design was employed. Direct measurement devices (Purple Air) were installed in selected districts of central Ulaanbaatar between December 2024 and February 2025, measuring PM2.5 concentrations at two-minute intervals over 24-hour periods. All data were statistically processed and analyzed using the SPSS-26 software package. Results: The average concentration of PM2.5 particles in the air of Ulaanbaatar city in winter is 66.68 μg/m3. Compared to the districts, the highest concentration was determined in SKHD (118.58±90.22 μg/m3), while the lowest concentration was determined in KHUD (42.37±43.51 μg/m3). Compared to the days of the week, the highest concentrations were measured on Monday (76.68±71.98 μg/m³), Saturday (77.50±71.63 μg/m³), and Sunday (80.34±74.45 μg/m³). The highest concentration of PM2.5 particles occurred from 6 pm to 1 am, and the lowest concentration was measured during the day (between 2 pm and 4 pm). The highest concentration of PM2.5 was measured in December (74.22±73.45 μg/m3), while the lowest concentration was measured in February (50.25±57.44 μg/m3). Conclusion The concentration of PM2.5 in the air of Ulaanbaatar city is 1.7 times higher than the general standard and technical requirements of Mongolia in winter, and the highest concentration is in the SKHD. The highest concentration of PM2.5 occurs more often in December and at night than in the winter months.

Background: Particulate matter with an aerodynamic diameter of 2.5 micrometers or smaller (PM2.5) penetrates deep into the alveoli through the respiratory tract and is characterized by its ability to induce oxidative stress, systemic inflammation, and vascular inflammation. Mongolia ranks among the countries with the highest levels of air pollution. In Ulaanbaatar, where more than half of the country’s population resides, wintertime PM2.5 concentrations often exceed 200 μg/m³, which is about eight times higher than the World Health Organization (WHO) guideline value. A study involving 1,200 adults in Ulaanbaatar showed that quality of life deteriorated sharply during periods of high air pollution, with effects more pronounced among individuals who already had impaired respiratory function. Aim: To examine the relationship between indoor household PM2.5 concentrations and lung function indicators among adults in Ulaanbaatar and Darkhan. Materials and Methods: This analytical cross-sectional study recruited adult participants from Ulaanbaatar and Darkhan through targeted sampling. Household air quality was measured using PurpleAir sensors, which were installed in participants’ homes for one month. After exposure measurement, lung function was assessed via spirometry. Statistical analyses were conducted using SPSS version 25.0. Results: A total of 236 participants were included: 114 (48.3%) from Ulaanbaatar and 122 (51.7%) from Darkhan. The sample consisted of 111 men (47.0%) and 125 women (53.0%). The mean indoor PM2.5 concentration was 66.24 μg/m³ (SD 44.87 μg/m³), ranging from a minimum of 7.79 μg/m³ to a maximum of 264.55 μg/m³. Stratification by housing type showed the highest PM2.5 levels in gers (82.34 μg/m³), followed by detached houses (67.34 μg/m³), while apartments had the lowest concentrations (32.24 μg/m³). Correlation analysis revealed statistically significant negative associations between PM2.5 levels and measures of expiratory function, including the FEV1/FVC ratio, peak expiratory flow (PEF), and mid-expiratory flow (FEF25–75). Reduced forced vital capacity (FVC) was observed in 9.4% of participants, reduced forced expiratory volume in one second (FEV1) in 15.3%, and a decreased FEV1/FVC ratio in 3.8%. Conclusion Indoor household PM2.5 concentrations were highest in gers, and expiratory flow-related lung function parameters showed significant negative associations with particulate exposure. This suggests that indoor PM2.5 primarily affects airflow limitation rather than overall lung volumes in this population.

Background: Vitamins are nutrients essential for human health. They act as coenzymes that help trigger important chemical reactions necessary for energy production. Reference values for vitamins help physicians evaluate the health status of patients and make clinical decisions. The aim of this study was to determine the mean values and reference intervals for some water-soluble vitamins of Mongolian adults. Materials and Methods: Three hundred and forty healthy adults (170 males and 170 females) of 17 to 69 years of age were selected for the study based on CLSI C28-P3 criteria Defining, establishing & Verifying reference interval in the clinical laboratory; Proposed Guidelines. The study was approved by the Resolution No.76 of 2018 of the Medical Ethics Review Committee of the Ministry of Health. Informed consents were taken from the selected individuals. Morning blood samples of the participants were collected under aseptic conditions. Levels of vitamins B₆, B₉, B₁₂ and vitamin C were measured using a high performance liquid chromatography method. The lower- and upper reference limits were defined as the 2.5th and 97.5th percentiles, respectively. The data were analyzed using SPSS and Excel programs. Results: The mean blood level of vitamin C was 11.88 mg/L (95% CI 10.47-13.29) for men and 9.62 mg/L (95% CI 8.11-11.13) for women. The calculated reference interval for males was 1.40-19.40 mg/L and 1.17-18.04 mg/L for females. The mean concentration of vitamin B₁₂ in the blood of males was 938.45 ng/L (95% CI 747.22-1129.68) and that of females was 864.03 ng/L (95% CI 603.81-1124.25). The reference interval for vitamin B₁₂ was 233.03-1597.00 ng/L in men and 132.45-1623.86 ng/L in women. The mean level of vitamin B₉ was 8.47 ng/mL (95% CI 5.64-11.30) for men and 6.91 ng/mL (95% CI 4.89-8.93) for women. The calculated reference interval for this vitamin in males was 1.04-24.74 ng/mL and that in females was 1.04-21.46 ng/mL. As for vitamin B₆, the mean concentration for men was 44.42 ng/mL (95% CI 37.01-51.83) and for women was 34.67 ng/mL (95% CI 29.97-39.39) with the reference intervals of 5.90-79.02 ng/mL for men and 5.27-61.72 ng/mL for women. Conclusion The reference values for vitamins B₆, B₉, B₁₂ and vitamin C of Mongolian adults do not differ significantly from those observed in other populations. The calculated reference intervals can be used in the practice of health laboratories.

Introduction: Coronavirus infection 2019 (Ковид-19) is an infection caused by a novel virus and induces severe ARDS. КОВИД-19 pandemic has rapidly spreaded in 221 countries, 245,373,039 cases and 4,979,421 mortalities have been reported. Pulmonary and renal thrombotic angiopathy occur in patients with complications of ARDS, sepsis, and multi-organ failure. Elevated D-dimer in КОВИД-19 patients has been reported firstly by doctors in Wuhan, China. In addition, many studies have revealed that elevated D-dimer has been associated with the severity of the diseases, an increased rate of poor prognosis. Objective: We aim to determine D-dimer in КОВИД-19 patients, and patient condition a decrease of D-dimer level after administration of anticoagulant therapy. Case report: We introduce a rare case of КОВИД-19. Laboratory test results and the effect of anticoagulant therapy have been evaluated during the infection. 85 aged women were admitted with a diagnosis other than КОВИД-19. PCR for SARS-Cov-2 was negative on the previous day of admission, and Sars-Cov-2 Ag rapid test was also negative on the admission day. However, the D-dimer test result was much higher with 7120 ng/мл and X-ray and CT revealed a similar pattern to the КОВИД-19 patient. Then anti-Sars-Cov-2 test was positive with 4,08 COI. Based on laboratory test results of D-dimer, LDH, CRP, and CT pattern the patient was diagnosed with post-КОВИД-19 pneumonia, and anticoagulant therapy was initiated additionally to prevent hypercoagulation induced by КОВИД-19. D-dimer test taken before administration of anticoagulant therapy increased more to 10910 ng/мл. 3 days later D-dimer level decreased to 8180ng/мл and the patient’s condition was improved. Conclusion The evaluation of D-dimer of the patients with КОВИД-19 is highly significant. Anticoagulant therapy might be necessary for КОВИД-19 patients with high D-dimer level in serum. Further studies are needed to assess the long-term outcome of the illness and mortality.

Purpose: To investigate the outcomes of ROP screening of retinopathy of prematurity (ROP). Methods: This was a prospective of prematurity infants screened ROP from 2020 April 13th to April 28th 2020 and from 2020 June 08 th to June 22th 2020 and prospective cohort study of premature infants with treatment-requiring ROP who received intravitreal injections, laser surgery. Demographic factors, diagnosis and clinical course were recorded. Indirect ophthalmoscopy and Retinal imaging was performed using RetCam (Natus Medical, Pleasanton, CA) and images were taken. Each eye was evaluated by the pediatric ophthalmologist and aimag’s ophthalmologist for the presence or absence of ROP, zone of vascularization, stage, plus disease, and aggressive posterior ROP (AP-ROP). The diagnosis and classification of ROP for this current study were determined by examination using indirect ophthalmoscopy, and treatment plans were determined according to the International Classification for ROP and the Early Treatment for ROP Study (ET-ROP).^2,13 Results: A total of 90 premature infants with BW ≤ 2000g and/or GA ≤ 34 weeks were screened for ROP during the study period. 8 (8.8%) of the 90 infants screened required treatment. The 8 infants who received ROP treatment had a mean GA of 28.5 ± 1.7 weeks, mean BW of 1237.5 ± 125.42g, mean PMA of 36 weeks and mean follow-up time of 2 months. Conclusion After treatment, resolution of ROP was noted in approximately 100 % of the patients who had treatment-requiring ROP.

Outcomes of retinopathy of prematurity screening Background: Retinopathy of prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants weighing about 1250 grams or less that are born before 31 weeks of gestation (a full-term pregnancy has a gestation of 38-42 weeks). The smaller a baby is at birth, the more likely that baby is to develop ROP. This disorder — which usually develops in both eyes — is one of the most common causes of visual loss in childhood and can lead to lifelong vision impairment and blindness. ROP was first diagnosed in 1942. Our goal was to investigate the outcomes of ROP screening of retinopathy of prematurity (ROP). Materials and methods :This was a prospective of prematurity infants screened ROP from 2020 April 13th to April 28th 2020 and from 2020 June 08 th to June 22th 2020 and prospective cohort study of premature infants with treatment-requiring ROP who received intravitreal injections, laser surgery. Diagnosis and clinical course were recorded. Indirect ophthalmoscopy and Retinal imaging was performed using RetCam (Natus Medical, Pleasanton, CA) and images were taken. Each eye was evaluated by the pediatric ophthalmologist and aimag's ophthalmologist for the presence or absence of ROP, zone of vascularization, stage, plus disease, and aggressive posterior ROP (AP-ROP). The diagnosis and classification of ROP for this current study were determined by examination using indirect ophthalmoscopy, and treatment plans were determined according to the International Classification for ROP and the Early Treatment for ROP Study (ET-ROP). Results: A total of 90 premature infants with BW ≤ 2000g and/or GA ≤ 34 weeks were screened for ROP during the study period. 8 (8.8%) of the 90 infants screened required treatment. The 8 infants who received ROP treatment had a mean GA of 28.5 $ 1.7 weeks, mean BW of 1237.5 $ 125.42g, mean PMA of 36 weeks and mean follow-up time of 2 months. Conclusions: After treatment, resolution of ROP was noted in approximately 100 % of the patients who had treatment-requiring ROP

Background: Minerals are important for the proper body functioning. They also play a role in preventing and fighting diseases. Reference values for minerals help physicians evaluate the mineral status of patients and make clinical decisions. The aim of this study was to determine the mean values and reference intervals for some minerals to be used for evaluation of the nutrition status of Mongolians. Materials and Methods: Two hundred and forty healthy adults (120 males and 120 females) of 17 to 70 years of age were selected for the study based on CLSI C28-P3 criteria Defining, establishing & Verifying reference interval in the clinical laboratory; Proposed Guidelines. The study was approved by the ethical committee of the Ministry of Health of Mongolia. Informed consents were taken from the selected individuals. Morning blood samples of the participants were collected under aseptic conditions. Levels of iron (Fe), zinc (Zn) and copper (Cu) were measured by graphite furnace atomic absorption spectrometry. The lower and upper reference limits were defined as the 2.5th and 97.5th percentiles, respectively. The data were analyzed using SPSS and Excel programs. Results: The mean level of blood iron was 30.50 µmol/L (95% CI 29.71-31.29) for men and 30.91 µmol/L (95% CI 30.03-31.79) for women. The calculated reference interval for males was 21.39-37.72 µmol/L and 19.87-39.67 µmol/L for females. The mean concentration of zinc in the blood of males was 11.00 µmol/L (95% CI 10.69-11.31) and that of females was 11.79 µmol/L (95% CI 11.39-12.19). The reference interval for blood zinc was 8.20-14.92 µmol/L in men and 8.52-16.67 µmol/L in women. The mean level of blood copper was 15.28 µmol/L (95% CI 14.64-15.89) for men and 18.08 µmol/L (95% CI 17.30-18.86) for women. The calculated reference interval for copper in males was 9.72-22.34 µmol/L and that in females was 11.18-27.27 µmol/L. Conclusion The reference values for zinc, copper and iron of Mongolian adults do not differ significantly from those observed in other countries. The calculated reference intervals can be used for evaluation of the nutrition status and making clinical decisions.

Background: We set the average value and reference range of blood plasma proteins (total protein, albumin, transferrin, retinol binding protein, prealbumin) to be used to assess the nutritional status of Mongolian adult. According to step by step research methodology, 170 women, 170 men and a total of 340 people were surveyed using a combination of questionnaires and analytic methods. Methods: The total protein and albumin content of the collected samples was analyzed by colorimetric method using “Humalyzer 2000” semi automatic analyzer and prealbumin, transferring and retinol binding protein was analyzed by ELISA method of “ELX 880”. The lower limit of the reference value of the identified parameters was calculated to be 2.5 per centil and the upper limit was 97.5 per centil. Results: Determining average and reference range of proteins in the plasma of a total 340 participants, the average of total protein was 74.54(CI 95%; 72.67-76.38) g/l for men, and 73.59(CI 95%; 72.39-74.79) g/l for women, while the reference range was 55.26-95.79 g/l for men and 58.38-84.72 g/l for women. According to determined above, there is no statistically significant difference in gender (p>0.40). The average albumin level is 48.20(CI 95%; 47.04-49.36) g/l for men and 46.28(CI 95%; 45.32-47.24) g/l for women, while reference range is 37.14-60.01 g/l for men and 34.97-57.60 g/l for women. It means there is a statistically significant difference for the gender (p=0.012). The average prealbum level is 332.43(CI 95%; 311.28-353.58) mg/l for men, 381.67(CI 95%; 360.98-402.36) mg/l for women, while reference range is 171.3-485.0 mg/l for men and 215.5-535.0 mg/l for women. It means there is a statistically significant difference for the gender (p=0.0012). The average range of transferrin 4.01(CI 95%; 3.76-4.26) g/l for men and 4.43(CI 95%; 4.20-4.66) g/l for women while reference range is 2.20-6.92 g/l for men and 2.58-7.05 g/l for women, is a statistically significant difference for the gender (p=0.017). The average level of retinol binding protein is 1.73(CI 95%; 1.61-1.85) μmol/l for men and 2.01(CI 95%; 1.89-2.13) μmol/l for women, while reference range is 0.73-3.08 μmol/l for men and 0.73-3.08 μmol/l for women, is a statistically significant difference for the gender (p=0.0017). Conclusions For the first time we conducted a study to determine the average amount and reference range of proteins needed to assess the nutritional status of adults (total protein, albumin, prealbumin, transferring, retinol binding protein) according to international standard methods, which is relatively high compared to other researchers. According to the result of the study, it is not possible to directly follow the result of researchers from other countries and the reference range of blood proteins directly to Mongolians. The result of this study has become an important innovation in practice and treatment, as medical professionals have been able to use it in their diagnosis and treatment.