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Real‐time characterization of aerosol particle composition, sources and influences of increased ventilation and humidity in an office
Author(s) -
Li Junyao,
Xu Weiqi,
Li Zhijie,
Duan Minzheng,
Ouyang Bin,
Zhou Shan,
Lei Lu,
He Yao,
Sun Jiaxing,
Wang Zifa,
Du Lin,
Sun Yele
Publication year - 2021
Publication title -
indoor air
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.387
H-Index - 99
eISSN - 1600-0668
pISSN - 0905-6947
DOI - 10.1111/ina.12838
Subject(s) - aerosol , environmental chemistry , particulates , environmental science , relative humidity , indoor air quality , mass concentration (chemistry) , humidity , ventilation (architecture) , pollutant , chemical composition , chemistry , environmental engineering , atmospheric sciences , meteorology , physics , organic chemistry , geology
Most of human exposure to atmospheric pollutants occurs indoors, and the components of outdoor aerosols may have been changed in the way before reaching indoor spaces. Here we conducted real‐time online measurements of mass concentrations and chemical composition of black carbon and the non‐refractory species in PM 2.5 in an occupied office for approximately one month. The open‐close windows and controlled dampness experiments were also performed. Our results show that indoor aerosol species primarily originate from outdoors with indoor/outdoor ratio of these species typically less than unity except for certain organic aerosol (OA) factors. All aerosol species went through filtration upon transport indoors. Ammonium nitrate and fossil fuel OA underwent evaporation or particle‐to‐gas partitioning, while less oxidized secondary OA (SOA) underwent secondary formation and cooking OA might have indoor sources. With higher particulate matter (PM) mass concentration outdoors than in the office, elevated natural ventilation increased PM exposure indoors and this increased exposure was prolonged when outdoor PM was scavenged. We found that increasing humidity in the office led to higher indoor PM mass concentration particularly more oxidized SOA. Overall, our results highlight that indoor exposure of occupants is substantially different from outdoor in terms of mass concentrations and chemical species.