ABSTRACT
Many volcanic gases and resultant aerosols are toxic and may have severe impacts upon environments which are exposed to these emissions. Studies of these phenomena have emphasised the toxic impact upon environments in close vicinity to the volcano[1,2] or even in close proximity to an active vent[3]. However, the impact of volcanic gases may be felt over a much larger area, one need only consider the impact of the Laki fissure eruption, 1783-1784 AD, upon the vegetation, livestock and people of Iceland[4-6], to realise the magnitude of the environmental disaster brought about by the gases emitted at that time. Similar phenomena are now known to occur on a continental scale. In 1783 AD much of Europe was covered in a dry fog composed of volcanic gases emitted from eruptions in Iceland and Italy[7,9]. The environmental impact of this event across Europe was dramatic. The hazard posed by this and similar phenomena will be assessed and their potential role in the contemporary European environment will be discussed.
