A Study of Airborne Microplastics in a Brazilian Urban Setting: Addressing a Knowledge Gap
ADMIR CRESO TARGINO, Gustavo Akutagawa, Anggraini Widyastuti, Jheng-Jie Jiang, Federal University of Technology - UTFPR
Abstract Number: 60
Working Group: Urban Aerosols
Abstract
Microplastic (MP) pollution, stemming from the widespread use and mismanagement of plastics, represents a critical environmental challenge globally, particularly in high-plastic-producing, low-recycling nations. In Brazil —a major plastic producer— studies on atmospheric MP remain limited. To address this regional scientific gap, we quantified and characterised MPs in indoor and outdoor air samples, examining temporal variations across weekdays and weekends/holidays. Total suspended particulate matter was collected over five weeks using active samplers, and subsequent analyses involved optical microscopy for size, shape and colour classification, followed by µ-FTIR for polymer identification.
Airborne MPs were ubiquitous, with higher indoor concentrations (mean: 2.17 ± 0.94 MP/m³) compared to outdoor concentrations (1.24 ± 0.56 MP/m³), potentially linked to human activity patterns. Overall, fragments and fibres were the most common MP shapes, with fibres being predominant in indoor samples (55%), followed by fragments (38%). In outdoor samples, fragments were the most prevalent (53%), followed by fibres (37%). Indoor MP concentrations also seem to be correlated with human activity, peaking on weekdays. Size distribution revealed that 100–300 µm MPs were most frequent indoors, and 25–50 µm outdoors. Polymer analysis revealed cellulose as the most prevalent material (overall mean 74%), particularly indoors. Whilst polyvinyl chloride (PVC) was the most prevalent petrochemical polymer overall (30%), the indoor and outdoor distributions differed. Polyamide (PA) dominated indoors, whereas PVC prevailed outdoors, with polystyrene (PS) and polyethylene (PE) also detected. The prevalence of different polymers in indoor versus outdoor air suggests that their origins and contributing sources vary. We will also explore how atmospheric conditions influence MP abundance. This research provides crucial baseline data on airborne MPs in a Brazilian urban setting, highlighting the significance of indoor sources and transport and contributing relevant insights to the global understanding of atmospheric MP pollution risks and implications.