When an Icelandic volcano erupted in early 2010 it sent ash high into the atmosphere and some of it found its way to the UK. The HPA was involved in advising on the public health implications of this event.
The Icelandic volcano Eyjafjallajökull started to erupt in March 2010.
This volcano stands at about 5,000ft high and lies south east of the Icelandic capital of Reykjavík. It has a long history of eruptions. In 1821 it started erupting and continued doing so until 1823.
Eyjafjallajökull's latest activity is reported to have begun in late 2009 with a series of earthquakes. But in March 2010 it started to erupt, which became more powerful as the days went by.(For more background information on the volcano, visit the British Geological Survey's website at www.bgs.ac.uk.)
By 14 April the eruptions had become so powerful they were sending enough dust into the atmosphere to be considered to be a danger to aviation.
Over the following days more dust was produced by the volcano and was dispersed into the atmosphere.
Many of the weather fronts that cross Britain come from the west. However in mid to late April the prevailing weather system over the UK came from the north west, which led to dust from the eruption crossing this country.
On 15 April the HPA, in consultation with public health experts in Scotland, Wales and Northern Ireland, put out precautionary health advice.
It was recommended that if people were outdoors and noticed symptoms including itchy or irritated eyes, a runny nose, a sore throat or a dry cough, or if they noticed a dusty haze in the air or could smell sulphur, rotten eggs, or a strong acidic smell, they could limit their outdoor activities or go inside.
It was also said that those with existing respiratory conditions such as chronic bronchitis, emphysema and asthma may have noticed any effects more strongly than other people and that they should have ensured that they had any inhalers, or other medications, with them.
Over the following few days small amounts of the volcanic ash, which was mostly suspended in a plume pumped high into the atmosphere by the volcano, fell across different parts of the UK.
Health agencies, including the HPA, closely monitored health surveillance systems to see if the deposited ash had any impact and noted no significant impact on public health.
Because there was some rainfall in different parts of the country over the following few days, the HPA issued guidance on the ash stating that the volcanic ash posed no health threat to public health in wet weather as particles could not be inhaled under such conditions.
Over the following days the plume dispersed and the HPA issued a statement saying there was no longer any threat to public health.