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: 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.

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