Dynamic fluctuations in plant leaf interception of airborne microplastics

• Published in: The Science of the total environment 2024-01, Vol.906, p.167877-167877, Article 167877
• Main Authors: Jiao, Meng, Wang, Yijin, Yang, Fei, Zhao, Zhen, Wei, Yihua, Li, Ruilong, Wang, Yinghui
• Format: Article
• Language: English
• Subjects: Diurnal fluctuation; Intercepting mechanism; Leaf micromorphological structures; Microplastics; Terrestrial plant (trees)
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.167877

Plant leaves have been demonstrated to be a crucial sink of airborne microplastics (MPs). However, because of the particular shape of MPs and their relatively weak forces with leaves, the traditional accumulation model used for the adsorption of particulate matter and persistent organic pollutants may not be appropriate for describing the interception of MPs by leaves. Here, we performed a 7-day exploration of the interception of MPs by leaves in downtown Nanning. The abundances and characteristics of leaf-intercepted MPs showed dramatic diurnal fluctuations and interspecies differences (conifers > arbors > shrubs). The fluctuation (Coefficient of Variation (CV) = 0.459; abundances 0.003 ± 0.002 to 0.047 ± 0.005 n·cm−2) was even more drastic than that measured across species (CV = 0.353; 0.06 ± 0.01 to 0.40 ± 0.04 n·cm−2). Further analysis using partial least-squares path modeling demonstrated that stomatal variation and divergence largely dominated diurnal fluctuations and interspecies differences in microplastic interception by leaves, respectively. Our results highlight that the leaf-intercepted MPs is characterized by dynamic fluctuations rather than static equilibrium and reveal the important regulatory roles played by leaf micromorphological structures in intercepting MPs, thus enhancing our understanding of the interactions between terrestrial plants and airborne pollution. [Display omitted] •Abundance and compositions of leaf-intercepted MPs show dramatic diurnal fluctuation.•Comparisons before and after 7:30 reveal substantial variation in MPs interception.•Stomata is considered as the most effective leaf trait for MPs interception in a day.•Botanical traits and sampling times should be part of planning MPs-intercept study.