By this morning, the disruption to air traffic stretched from the UK to Scandinavia.

"Airspace was shut down to all but emergency flights from midday to 1800BST (1100-1700 GMT) in the UK.
It was also closed in Ireland.
Oslo airport, which is Norway's largest, was closed, while Finland's airport agency Finavia said air traffic to northern Sweden and northern Finland was also affected
In Denmark, officials said airspace would be closed from 1800 (1600 GMT).
There were also reports of major disruption expected in the Netherlands, Germany and Belgium."

BBC report

The British Lung Foundation's spokesman has recommended anyone living with a lung condition to carry their medication as a precaution although does not feel it poses a major health hazard