Linking Combustion-Derived Magnetite and Black Carbon: Insights from Magnetic Characterization of PM2.5 in Downwind East Asia

• DOI: 10.1021/acs.est.4c14187
• Publication Date: 2025-05-22T13:30:58Z
• Authors: Nozomu Tsuchiya; Fumikazu Ikemori; Kazuo Kawasaki; Reina Yamada; Mitsuhiko Hata; Masami Furuuchi; Yoko Iwamoto; Naoki Kaneyasu; Yasuhiro Sadanaga; Takahiro Watanabe; Takayuki Kameda; Masayo Minami; Toshio Nakamura; Atsushi Matsuki
• Keywords: Characterization; Carbon fibers; Environmental Magnetism

Combustion-derived magnetite has recently attracted attention for its health risks and potential impact on atmospheric heating/cooling. This study provides new observational insights into the relationship between black carbon (BC) at a remote site in East Asia, Japan, focusing combustion sources, seasonal trends, overestimation of BC by light-absorbing magnetite. Magnetic measurements PM2.5 samples, complemented detailed chemical analyses, reveal similar temporal variations while demonstrating that relative abundance to varies source, driving trends. Magnetite during episodes was found follow order: coal > oil biomass, with mass concentrations roughly estimated via magnetization be 9-10%, 5-6%, <2% BC, respectively. Furthermore, contribute up 5% absorption coefficient, suggesting considerable depending source. Although regionality source mixing should further verified, these findings show magnetic archived samples can offer valuable contributions reconstructing long-term trends or overestimates conventional observations BC.