A plume of Sahara dust that has blanketed parts of southern and central Europe in recent days caused a sharp rise in air pollution across the region, researchers have said.

The European Commission’s Copernicus satellite monitoring programme said measured levels of particles smaller than 10 micrometres – so-called PM10s – spiked in cities such as Barcelona, Lyon and Marseille on Sunday.

The cloud of fine sand blown northward from Algeria tinted skies red and mixed with fresh snowfall in the Alps and Pyrenees, leaving slopes looking orange.

While PM10 particles can enter the lungs, causing breathing difficulties, asthma attacks and other health problems, the concentration of Sahara dust did not reach levels considered harmful.