On the particle size distributions of pesticide aerosols in a greenhouse

Abstract

To evaluate or prevent the pesticide exposure of farmers, the information on particle size distributions of pesticide aerosols are essential, The particle size distributions in a smoking agent, dusts and a spraying agent were investigated in this report.
The results may be summarized as follows.
1) Most of the particles of TPN smoking agent distributed in the respirable range less than 7μm.
2) The particle size distribution functions of a fine dust and a general dust could be expressed by lognormal distributions, and the particles of these dusts also distributed in the respirable range.
3) In order to consider the particle size distribution of sprayed pesticide, the evaporation rate constant by Kobayasi was introduced. Lognormal distribution could be applied to the aerosol particles of sprayed TPN wettable powder, and its geometric mean diameter clearly decreased with the increase of evaporation rate constant. The geometric standard deviation of that distribution did not greatly change.
As a result of estimating particle size distributions of sprayed pesticide in a greenhouse, the case of 50% respirable particles was possible.