Assessing Atmospheric PM2.5 as a Proxy for Subjects’ Exposure Through Seasonal, Floor, Source-Specific Analysis

• Published in: International Journal of Environmental Research Vol. 19; no. 3
• Main Authors: Jung, Chien-Cheng, Chou, Charles C.-K., Huang, Yi-Tang
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.06.2025; Springer Nature B.V
• Subjects: Correlation coefficient; Correlation coefficients; Earth and Environmental Science; Environment; Environmental Engineering/Biotechnology; Environmental Management; Environmental research; Exposure; Factor analysis; Geoecology/Natural Processes; Impact analysis; Indoor environments; Isotope ratios; Landscape/Regional and Urban Planning; Lead isotopes; Natural Hazards; Particulate matter; Pollution sources; Research Paper; Samples; Seasons; Vehicle emissions; Pb; Isotope; PM; Atmosphere; Indoor air quality
• ISSN: 1735-6865; 2008-2304
• DOI: 10.1007/s41742-025-00770-2

Most studies use atmospheric PM 2.5 data to investigate its health effects and the impact of outdoor air on indoor PM 2.5 . However, people spend most of their time indoors, studies have not investigated whether atmospheric PM 2.5 can represent the indoor and outdoor PM 2.5 of buildings. This study collected indoor, outdoor (balconies), and atmospheric (rooftop) PM 2.5 samples across different floors and seasons to assess representative of atmospheric PM 2.5 in exposure assessment and impact analysis. Factor analysis and lead isotope ratios were applied to identify pollution sources. Average PM 2.5 concentrations were 18.2 ± 10.2 μg/m 3 , 31.8 ± 19.2 μg/m 3 , and 33.3 ± 23.5 μg/m 3 in indoor, outdoor, and atmospheric samples, respectively. Atmospheric and outdoor PM 2.5 concentrations have significant correlations and showed no differences across floors and seasons. Although atmospheric PM 2.5 concentration was associated with indoor PM 2.5 , atmospheric PM 2.5 concentration was higher than indoor PM 2.5 , especially in the high PM 2.5 season. Traffic-related emissions were major sources of indoor, outdoor, and atmospheric PM 2.5 , with long-range transportation from China also contributing to PM 2.5 in the high PM 2.5 season. Significant differences were observed in elemental concentrations between indoor, outdoor, and atmospheric PM 2.5 , with varying correlation coefficients among them. These findings highlight that: (1) atmospheric PM 2.5 data can represent outdoor PM 2.5 but indoor PM 2.5 sampling is essential for accurate exposure assessment, (2) atmospheric PM 2.5 sources were similar with indoor and outdoor PM 2.5 , and (3) collecting both indoor and outdoor PM 2.5 is necessary to estimate exposure to specific elements and assess the impact of outdoor air on indoor environments.