BUSCADOR RECOLECTA

Digital.CSIC. Repositorio Institucional del CSIC

oai:digital.csic.es:10261/336994

8 Pág., Plastic production continues to increase every year, yet it is widely acknowledged that a significant portion of this material ends up in ecosystems as microplastics (MPs). Among all the environmental compartments affected by MPs, the atmosphere remains the least well-known. Here, we conducted a one-year simultaneous monitoring of atmospheric MPs deposition in ten urban areas, each with different population sizes, economic activities, and climates. The objective was to assess the role of the atmosphere in the fate of MPs by conducting a nationwide quantification of atmospheric MP deposition. To achieve this, we deployed collectors in ten different urban areas across continental Spain and the Canary Islands. We implemented a systematic sampling methodology with rigorous quality control/quality assurance, along with particle-oriented identification and quantification of anthropogenic particle deposition, which included MPs and industrially processed natural fibres. Among the sampled MPs, polyester fibres were the most abundant, followed by acrylic polymers, polypropylene, and alkyd resins. Their equivalent sizes ranged from 22 μm to 398 μm, with a median value of 71 μm. The particle size distribution of MPs showed fewer large particles than expected from a three-dimensional fractal fragmentation pattern, which was attributed to the higher mobility of small particles, especially fibres. The atmospheric deposition rate of MPs ranged from 5.6 to 78.6 MPs m-2 day-1, with the higher values observed in densely populated areas such as Barcelona and Madrid. Additionally, we detected natural polymers, mostly cellulosic fibres with evidence of industrial processing, with a deposition rate ranging from 6.4 to 58.6 particles m-2 day-1. There was a positive correlation was found between the population of the study area and the median of atmospheric MP deposition, supporting the hypothesis that urban areas act as sources of atmospheric MPs. Our study presents a systematic methodology for monitoring atmospheric MP deposition., The authors acknowledge the support provided by Spanish Network of Plastics in the Environment, EnviroPlaNet (www.enviroplanet.net) and the financial support provided by the Spanish Government, Ministerio de Ciencia e Innovación, grants PID2020-113769RB-C21/C22. The authors would like to thank the Interdepartmental Investigation Research Service of the Universidad Autónoma de Madrid (SIDI-UAM and Segainvex) for the use of their infrastructures and their technical support. J.G.S. thanks ACIISI for the contract from the Viera y Clavijo program at the University of La Laguna (85 % co-financed by the European Social Fund)., With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S)., Peer reviewed