The relationship between atmospheric settling velocity and physical properties of pollen

摘要

Pollen can cause unwanted side effects such as allergies to human. Over 10% of the Japanese population is reported to be pollinosis sufferers and the disease is becoming serious social problem (Kawashima et al., 1995), thus the estimation of pollen dispersion from its emission source can be a great concern in Japanese society. Although the estimation of pollen dispersion by using the regional transportation model has been developed in recent years, its accuracy is still poor due to lack of input parameters, especially the settling velocity. This is attributed to pollen’s irregular shapes and morphological surface features such as spikes (Sabban et al., 2011) which in turn affect its aerodynamic behavior in the atmosphere. Therefore, it is not suitable to use the settling velocity based on Stokes’ law due to these physical properties of pollen.