Leaf accumulation of atmospheric dust: Biomagnetic, morphological and elemental evaluation using SEM, ED-XRF and HR-ICP-MS. (15th January 2020)

• Record Type: Journal Article
• Authors: Castanheiro, Ana; Hofman, Jelle; Nuyts, Gert; Joosen, Steven; Spassov, Simo; Blust, Ronny; Lenaerts, Silvia; De Wael, Karolien; Samson, Roeland
• Is Part Of: Atmospheric environment. Volume 221(2020)
• Publication Date: 2020-01-15
• Subjects: Atmospheric dust deposition -- PM leaf accumulation -- Biomonitoring -- Environmental magnetism -- ED-XRF -- HR-ICP-MS; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2019.117082
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Atmospheric dust deposition on plants enables the collection of site-specific particulate matter (PM). Knowing the morphology and composition of PM aids in disclosing their emitting sources as well as the associated human health risk. Therefore, this study aimed for a leaf-level holistic analysis of dust accumulation on plant leaves. Plant species (ivy and strawberry) with distinct leaf macro- and micro-morphology were exposed during 3 months at a moderate road traffic site in Antwerp, Belgium. Leaves collected every three weeks were analyzed for their magnetic signature, morphology and elemental content, by a combination of techniques (biomagnetic analyses, ED-XRF, HR-ICP-MS, SEM). Dust accumulation on the leaves was observed both visually (SEM) and magnetically, while the metal enrichment was limited (only evident for Cr) and more variable over time. Temporal dynamics during the second half of the exposure period, due to precipitation events and reduction of atmospheric pollution input, were evidenced in our results (elements/magnetically/SEM). Ivy accumulated more dust than strawberry leaves and seemed less susceptible to wash-off, even though strawberry leaves contain trichomes and a rugged micromorphology, leaf traits considered to be important for capturing PM. The magnetic enrichment (in small-grained, SD/PSD magnetite particles), on the other hand, was not species-specific, indicating a common contributing source. Variations in pollution contributions, meteorological phenomena, leaf traits, particle deposition (and encapsulation) versus micronutrients depletion, are discussed in light of the conducted monitoring campaign. Although not completely elucidative, the complex, multifactorial process of leaf dust accumulation can better be understood through a combination of techniques. Highlights: Ivy and strawberry leaves followed up every three weeks for a three months period. Dust accumulation observed visually and magnetically, yet limited in metal built-up. Ivy accumulated more than strawberry, with the latter more susceptible to wash-off. Site-source and precipitation dynamics over time were detected by leaf biomonitoring. Combination of techniques assists in understanding the complex leaf-dust interaction.