The direction of the wind determines where particulates in the atmosphere will travel. Another factor that influences particulates is the wind speed – low wind speeds reduce dispersion which can result in increasing concentrations of particulates while high wind speeds, which can increase the rate of dispersion, also results in wind erosion from open areas such the spoil bank.
Unseasonal or unusual wind patterns can impact can result in a variation to average seasonal dust outcomes. The classic example are the iconic dust storms that occur in the Pilbara when air from the base of a storm pushes dust upwards creating a wall of dust.