  In order to study the dispersion and deposition of coarse anthropogenic
particulate matter (PMc, aerodynamic diameters> 10 mm), a FORTRAN simulator
based on the numerical integrator of Bulirsch and Stoer has been developed. It
calculates trajectories of particles of several shapes released into the
atmosphere under very general conditions. This first version, fully
three-dimensional, models the meteorology under neutral stability conditions.
The simulations of such pollutants are also important because the standard
software (usually originating in the United States Environmental Protection
Agency-EPA-) describe only the behavior of PM10 (diameter less than 10 mm).
Bulirsch and Stoer integrator of widespread use in astrophysics, is also very
fast and accurate for this type of simulations. We present 2D and 3D
trajectories in physical space and discuss the final deposition in function of
various parameters. PMc simulations results in the range of 50-100 mm and
densities of 5.5 g cm-3 emitted from chimneys, indicate that for the purpose of
deposition, the emission velocities are not as important as wind speed and the
shape of the particles. For densities less than 2 g cm-3, the lack of
consideration of buoyancy introduces important changes in the distribution of
deposited PMc.
