Volcanic eruptions represent a significant source of volatile gases that are harmful to human health. This chapter reviews and develops current understanding of the human health response to volcanogenic pollution and dry fog events; in particular it explores the health impact of the gases from the Laki fissure eruption, and presents data that point to a significant increase in the national death rate in England coincident with the early phases of the eruption. It is noted that many common symptoms of severe exposure to air pollution can be linked to the dry fog of 1783; these included difficulty in breathing, eye and skin irritation, headaches, loss of appetite and tiredness.