A toxic cloud of sulfur dioxide (SO2), resulting from a volcanic eruption on Iceland's Reykjanes Peninsula, has been spreading across the UK, prompting health warnings. The cloud initially hit parts of the Scottish Highlands and is expected to move south, affecting the Midlands and then southern England by Tuesday morning. SO2 inhalation can cause respiratory issues, particularly in vulnerable groups like the elderly and young children, who are advised to stay indoors. Despite the health risks, the Met Office has stated that the concentration at ground level remains low, minimizing the impact on air quality. The eruption, accompanied by strong seismic activity, has led to evacuations and travel warnings in the affected areas in Iceland. Monitoring of the situation continues, but current forecasts suggest the gas cloud will clear by Wednesday evening.