Volcanic eruptions have the potential to cause air pollution on two fronts.

They can release huge quantities of sulphur dioxide, which can lead to acid rain as well as ash and volcanic aerosol, a suspension of fine particulate matter or liquid in the air that can carry pollution for thousands of miles.

The European Environment Agency (EEA) said it has been closely following the impacts the Iceland eruptions, in particular assessing changes in ground-level air pollution.

Apart from a few brief isolated episodes across the continent, particularly in high altitude mountain regions, the EEA says that air quality has not deteriorated significantly in the aftermath of eruptions.

In Iceland itself, however, the situation is different: concentrations of particulate matter are markedly higher than usual.

That potentially represents a significant threat to humans and farm animals, according to the Icelandic Directorate of Health, which closely monitors pollution levels.

In Europe, rain and snowfall are expected to remove volcanic debris from the atmosphere. Detecting this process requires the chemical content of precipitation to be analysed, which takes time.

Should these data indicate high pollutant levels, the current assessment of risk for human health and ecosystems may need to be reassessed.

Because ambient air concentrations and fallout can vary across short ranges within Europe, the EEA is also advising the public to refer to national or local air quality authorities, which may have additional or new information on local conditions.

Sam Bond

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