Systematically quantifying the dynamic characteristics of PM2.5 in multiple indoor environments in a plateau city: Implication for internal contribution

• Published in: Environment international 2024-04, Vol.186, p.108641, Article 108641
• Main Authors: Hou, Weiying, Wang, Jinze, Hu, Ruijing, Chen, Yuanchen, Shi, Jianwu, Lin, Xianbiao, Qin, Yiming, Zhang, Peng, Du, Wei, Tao, Shu
• Format: Article
• Language: English
• Subjects: Dynamic characteristics; Indoor air; Microenvironments; PM2.5; Source contributions
• ISSN: 0160-4120; 1873-6750; 1873-6750
• DOI: 10.1016/j.envint.2024.108641

[Display omitted] •Indoor PM2.5 varied largely in different urban microenvironments.•Restaurants suffered from severe indoor PM2.5 pollution due to the strong internal emissions.•Cooking activities could significantly increase indoor PM2.5 levels in short time.•Outdoor penetration contributed mostly to indoor PM2.5 of public and household places. People generally spend most of their time indoors, making a comprehensive evaluation of air pollution characteristics in various indoor microenvironments of great significance for accurate exposure estimation. In this study, field measurements were conducted in Kunming City, Southwest China, using real-time PM2.5 sensors to characterize indoor PM2.5 in ten different microenvironments including three restaurants, four public places, and three household settings. Results showed that the daily average PM2.5 concentrations in restaurants, public spaces, and households were 78.4 ± 24.3, 20.1 ± 6.6, and 18.0 ± 4.3 µg/m3, respectively. The highest levels of indoor PM2.5 in restaurants were owing to strong internal emissions from cooking activities. Dynamic changes showed that indoor PM2.5 levels increased during business time in restaurants and public places, and cooking time in residential kitchens. Compared with public places, restaurants generally exhibit more rapid increases in indoor PM2.5 due to cooking activities, which can elevate indoor PM2.5 to high levels (5.1 times higher than the baseline) in a short time. Furthermore, indoor PM2.5 in restaurants were dominated by internal emissions, while outdoor penetration contributed mostly to indoor PM2.5 in public places and household settings. Results from this study revealed large variations in indoor PM2.5 in different microenvironments, and suggested site-specific measures for indoor PM2.5 pollution alleviation.