This estimate is evidently subject to large uncertainties concerning the underlying physical or chemical mechanisms of the gas-particle interactions, the capacity of volcanic particles to take up GEM, their global mass flux, the role of somewhat larger volcanic particles (e.g. PM2.5, PM10), the influence of particle composition (e.g. sulfate and halogen content, acidity, noble metals or transition metal oxides), and so on. Nevertheless, it illustrates that the source and sink effects of terrestrial volcanism on the atmospheric Hg budget may be of similar magnitude and that both require attention.