Clothing Textiles as Carriers of Biological Ice Nucleation Active Particles

Abstract

Microplastics have littered the globe, with synthetic fibers being the largest source of atmospheric microplastics. Many atmospheric particles can act as ice nucleators, thereby affecting the microphysical and radiative properties of clouds and, hence, the radiative balance of the Earth. The present study focused on the icenucleating ability of fibers from clothing textiles (CTs), which are commonly shed from the normal wear of apparel items. Results from immersion ice nucleation experiments showed that CTs were effective ice nucleators active from −6 to −12 °C, similar to common biological ice nucleators. However, subsequent lysozyme and hydrogen peroxide digestion stripped the ice nucleation properties of CTs, indicating that ice nucleation was biological in origin. Microscopy confirmed the presence of biofilms (i.e., microbial cells attached to a surface and enclosed in an extracellular polysaccharide matrix) on CTs. If present in sufficient quantities in the atmosphere, biological particles (biofilms) attached to fibrous materials could contribute significantly to atmospheric ice nucleation.

Pristine and Aged Microplastics Can Nucleate Ice Through Immersion Freezing

“…Additionally, a study by Teska et al looked at the ice nucleating activity of fibers from worn clothing textiles and found that polyester (PET) fibers had an increase in median freezing temperature, ΔT50, of 5.0°C compared with background freezing. 37 However, this high freezing activity was attributed to non-bacterial biological ice nucleating particles, as freezing dropped to around background freezing temperatures following H2O2 digestion, which deactivates any biological ice nucleating particles. This result stands in comparison to our pristine PET fragments which had a ΔT50 of 8.8 ± 1.1°C and 5.0 ± 1.1°C compared with background freezing at 1 wt % and 0.1 wt % concentrations compared with background freezing, respectively.…”