The prediction was made by Francisco Ferreira, professor at the Faculty of Science and Technology at Universidade Nova de Lisboa, who monitors the evolution of recorded air quality values daily, in a project with the Portuguese Environment Agency.

“Almost all air quality monitoring stations in Portugal have very high particle concentration values”, explained Francisco Ferreira, noting that particularly high levels were recorded in areas such as Portimão, Santiago do Cacém, Estarreja and Vila Real.

Air pollution by inhalable particles (PM10) arises from a mass of air coming from the deserts of North Africa, which carries suspended dust, and has been crossing mainland Portugal since Friday.

The daily limit value, to guarantee the protection of individuals from exposure to this pollutant, is set at 50 micrograms per cubic meter, but in the most affected areas levels close to double were recorded.

From Monday onwards, a “complete change in the weather pattern is expected and, from the outset, concentrations will return to normal levels”, he said.

The Directorate-General for Health (DGS), on Thursday, warned the population to take precautions against a situation of poor air quality due to a mass coming from North Africa with suspended dust.

The DGS recommended that the population not make prolonged efforts, limit physical activity outdoors and avoid exposure to risk factors, such as tobacco smoke and contact with irritating products.

Chronic patients should continue ongoing medical treatments and, if symptoms worsen, call the Saúde 24 line (808242424).