A stochastic model for transport of particulate matter in air: An asymptotic analysis

A branching particle system with changes of size is considered as a model f or transport of particulate matter in air. This type of model is motivated by problems arising in the context of air pollution. High-density fluctuati on limits for the process recording the positions and sizes of the particle s through time are presented. These results allow to compute approximate pr obabilities for the temporal and spatial concentrations of particles of giv en sizes (in particular the small-sized pollutant particles which pose a he alth hazard).