NX-illite consists of illite (main component with 74 wt% ), kaolinite, quartz, calcite, and feldspars and has been used as a proxy for mineral dust INPs. K-feldspar is one of the most effective types of mineral dust INPs and has been incorporated into models of atmospheric INPs. Fungal spores have been found in atmospheric aerosol and cloud water samples and are moderately effective INPs. In addition, fungal spores and microplastics can have similar sizes, and the impact of ice nucleation by fungal spores on their long-range transport and atmospheric concentrations and distributions has been investigated. Figure shows that 𝑛 𝑠 (𝑇)-values for PP-needles c , PPfibers b , and PET-fibers b are comparable to those for volcanic ash, NX-illite and fungal spores. On the other hand, 𝑛 𝑠 (𝑇) values for the same microplastics are approximately 2-3 orders of magnitude lower than those for K-feldspar and a parameterization for natural mineral dust. K-feldspar and natural mineral dust are considered highly effective INPs.