Particle size coefficients for PM₁₀ and PM_2.5 from surface soils in Bole City (March 2021)

In March 2021, 48 surface soil samples (0-10 cm) from different land use types were collected in Bole. Samples were proportionally distributed across four dominant land-use categories, grassland (12 samples, 25%), farmland (15 samples, 31%), bare land (8 samples, 17%), and rocky terrain (13 samples, 27%), based on their areal coverage in the study region. The samples were air-dried naturally in the laboratory, sieved through a Taylor standard sieve of 200 mesh (75 μm), and resuspended to obtain particle size information.