Fig. 7: Impact of precipitation intensity on micro- and nanoplastic particle (MNP) atmospheric half-lives.

Half-lives of MNPs of different diameters (0.1 μm, 1.0 μm, 2.5 μm, 10 μm) in a 1 km atmosphere for a low-density polyethylene (LDPE) and b polyvinyl chloride (PVC) under different rain intensities (RI), where the uniform raindrop diameter D_p for each rain intensity is calculated as follows⁸³: D_p = 0.97e⁻³ x (RI x 0.158). Drizzle with RI < 0.5 mm h⁻¹ (D_p = 0.87 mm), moderate rain with 0.5 mm h⁻¹ < RI < 4 mm h⁻¹ (D_p = 1.10 mm), heavy rain with 4 mm h⁻¹ < RI < 8 mm h⁻¹ (D_p = 1.35 mm), very heavy rain with RI > 8 mm h⁻¹ (D_p = 1.40 mm).