Methods for assessing a condition of property for insurance purposes include determining a concentration of a molecular constituent at the insured property. The molecular constituent may be a byproduct or residual product of anthropogenic fire accelerants or anthropogenic sources of ignition or explosion. In some embodiments, the concentration of the molecular constituent at the insured property is determined using spectral imaging technology. Radiative transfer computer models may be used to determine the concentration of the molecular constituent based on spectral images.