Respiratory Symptoms Associated with Household Indoor PM2.5 Exposure

Abstract

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. Results: 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.