We present a general-purpose mathematical model for pollution concentration studies. The model is an approximate solution for the time dependence of size distribution that takes into account processes like aerosol coagulation and condensation among others. Our model is validated by representative experiments using standard aerosol monitoring devices that measure light scattering, particle cross section, particle bound polycyclic aromatic hydrocarbons and number concentration, showing an excellent agreement with the experimental data. The results demonstrate that aerosol coagulation has to be taken into account when monitoring aerosol particles. We also show that the simultaneous application of different sensors reveals new information about the physical and chemical properties of the aerosol.