title: On the temporal variation of leaf magnetic parameters: seasonal accumulation of leaf-deposited and leaf-encapsulated particles of a roadside tree crown.
abstract: Understanding the accumulation behaviour of atmospheric particles inside tree leaves is of great importance for the interpretation of biomagnetic monitoring results. In this study, we evaluated the temporal variation of the saturation isothermal remanent magnetisation (SIRM) of leaves of a roadside urban Platanus × acerifolia Willd. tree in Antwerp, Belgium. We hereby examined the seasonal development of the total leaf SIRM signal as well as the leaf-encapsulated fraction of the deposited dust, by washing the leaves before biomagnetic analysis. On average 38% of the leaf SIRM signal was exhibited by the leaf-encapsulated particles. Significant correlations were found between the SIRM and the cumulative daily average atmospheric PM10 and PM2.5 measurements. Moreover, a steady increase of the SIRM throughout the in-leaf season was observed endorsing the applicability of biomagnetic monitoring as a proxy for the time-integrated PM exposure of urban tree leaves. Strongest correlations were obtained for the SIRM of the leaf-encapsulated particles which confirms the dynamic nature of the leaf surface-accumulated particles.
authors.affiliation: Research Group on Environmental Ecology & Microbiology, Department of Bioscience Engineering, University of Antwerp, Belgium. Electronic address: Jelle.Hofman@uantwerpen.be.
authors.forename: Jelle
authors.initials: J
authors.lastname: Hofman
authors.affiliation: Research Group on Environmental Ecology & Microbiology, Department of Bioscience Engineering, University of Antwerp, Belgium.
authors.forename: Karen
authors.initials: K
authors.lastname: Wuyts
authors.affiliation: Research Group on Environmental Ecology & Microbiology, Department of Bioscience Engineering, University of Antwerp, Belgium.
authors.forename: Shari
authors.initials: S
authors.lastname: Van Wittenberghe
authors.affiliation: Research Group on Environmental Ecology & Microbiology, Department of Bioscience Engineering, University of Antwerp, Belgium.
authors.forename: Roeland
authors.initials: R
authors.lastname: Samson
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001530:Belgium; D004784:Environmental Monitoring / Q000379:methods*; D060328:Magnetic Phenomena; D008280:Magnetics; D018515:Plant Leaves / Q000737:chemistry*; D014197:Trees
chemical_list: D000393:Air Pollutants
keywords: Air pollution; Biomonitoring; Leaf magnetism; Particulate matter; Saturation isothermal remanent magnetisation; Urban