From clothing to atmospheric fallout: characterising direct microplastic fibre emissions in air

Synthetic textiles are estimated to be a major source of airborne microplastic pollution and microplastic fibres can be found in dry and wet atmospheric deposition in various sample media (air, water and sediment). While this is well known, there is little understanding of the contribution given by the direct emission from synthetic garments. Current literature often focusses more on microfibre emission during washing processes although the majority of microfibres in the environment are considered to originate from land-based sources. This project aims to determine the parameters that will help constrain the role of direct emission from synthetic clothing. This is achieved by performing shedding experiments on clothes under dry friction. Released fibres are collected and characterised in terms of number, length, width and morphology using digital microscopy. Since the majority of synthetic clothing consists of polyester mixed with other synthetic or natural materials, garments made of different polyester blends were tested and the relative amount of shed fibres was determined. The influence of garment age is also tested by performing shedding experiments on similar types of clothing with varying ages. Preliminary results show that the peak of the size distribution for the length of all emitted fibres lies at 310 ± 150 μm and the aspect ratio distribution peak is 16 ± 3. The findings of this project will provide important parameters directly relevant to assess whether the emitted particles are compatible with atmospheric transport processes and inhalation and will direct the designing for further targeted experiments.