Likewise, in the analyzed countries presented below, decreases, increases or a constant level of PM2.5 emissions are observed during confinement. This can be attributed to the confinement level in each country, at the beginning of the quarantine, or to the electricity generation increase depending on the generation technology used. It is important to clarify that not all countries indicate reductions in their PM2.5 particles emitted during the analyzed week (Qut); each capital reflects special conditions that must be analyzed individually and this is not the aim of this paper.