"A situation of poor air quality is expected to occur on the Continent, with an increase in concentrations of inhalable particles of natural origin in the air, affecting, in particular, the Alentejo and Algarve regions and the interior of the Central Region", indicated the DGS in a note on its website.

According to the authority, the pollutant "has effects on human health, affecting the most sensitive population, children and the elderly", and health care should be "doubled".

Therefore, "the general population should avoid prolonged exertion, limit physical activity outdoors and avoid exposure to risk factors, such as tobacco smoke and contact with irritating products".

The elderly, children, patients with respiratory problems and cardiovascular patients, due to their "greater vulnerability to the effects of this phenomenon", should also, "whenever feasible, remain inside buildings and, preferably, with the windows closed".