PROGRESS IN INDOOR PARTICULATE POLLUTION (IPP) RESEARCH AND HOTSPOT ANALYSIS BASED ON CITESPACE ANALYSIS

Indoor particulate matter directly influences indoor air quality. Short-term and long-term exposure to particulate matter (PM) in microenvironments can both seriously threaten human health. People are being exposed to increasingly severe indoor environmental pollution, and research on indoor particulate pollution (IPP) has developed rapidly. However, the existing relevant reviews are based on unique research perspectives and do not provide systematic quantitative and visual investigation of of the structure and evolution of this field. The purpose of this paper is to help clarify the research status of indoor particulate pollution and reveal the main research hotspots and trends between 1998 and 2019. In total, 7161 articles from the Web of Science core database were analyzed by CiteSpace software, and the results were visualized by mapping knowledge domains. The results show the following. (1) Increasingly more attention has been given to IPP research in academia. During 1998-2009, research on IPP showed a steady growth trend. Since 2010, the amount of literature has increased rapidly. The United States and China are the backbones of IPP research, accounting for a significant proportion of all research, with the US EPA being the key institution performing such research. (2) In the carrier analysis of existing research results, the literatures were published primarily in the journals "Atmospheric Environment", "Science Of The Total Environment", "Building And Environment" and others, mainly in categories such as environmental science ecology and engineering. (3) Reference co-citations clustering analysis showed that the main research topics in the domain of indoor particulate pollution could be summarized as: (a) Children; (b) Infiltration factor; (c) Deposition; (d) Residential monitoring; (e) Household air pollution; (f) Rcsuspension. Meanwhile, keyword bursts analysis showed that the new research hotspots or research frontiers, including the establishment of a low-cost monitoring system, health risk assessment, household air pollution and black carbon. Through in-depth analysis of indoor particulate pollution research, this paper provides a better understanding of development trends over the past 22 years, which can also offer reference for future research.