The Met Office has said it is monitoring a cloud of sulphur dioxide which passed over the UK after a volcanic eruption in Iceland.
The “plume” of gas is understood to have begun passing over the country early on Sunday morning and has since cleared to the south-east.
It was released high into the atmosphere by a volcano in Iceland and should have “little influence on ground-level air quality”, the forecaster said.
Sulphur dioxide is a colourless gas with a strong smell which is commonly released in coal burning and other refining or manufacturing processes.
The gas can cause irritation to the throat, nausea, stomach pain and vomiting if breathed in at high levels.
The Met Office said “small concentrations” of the compound mean UK air pollution should remain low.
A Met Office spokesperson said: “A sulphur dioxide plume which originated from the volcano in Iceland has been crossing the UK high up in the atmosphere and will soon clear to the south-east.
“Impacts have been low from this sulphur dioxide, as it is high in the atmosphere and is having little influence on ground-level air quality.
“Small concentrations at surface level mean that the air pollution levels remain low.
“Air pollution is currently low and expected to remain that way for the whole of the UK today.
“We’re continuing to monitor any sulphur dioxide release originating from Iceland, with current forecasts suggesting little influence on UK surface air pollution in the coming days.”
A volcano in south-western Iceland erupted for the sixth time since December on Thursday, spewing red lava and accompanied by strong earthquakes.
