From Fig. 3, Fig. 4 it can be seen the seventeen (17) European capitals analyzed. In general, European capital cities in typical weeks record PM2.5 concentrations below 80 μg/m3, with an AQI between Good and Moderate. 50% of the studied European capitals, during the Qut had a tendency to decrease the PM2.5 concentration at an average of 23%. However, the other 50% show an increase in the confinement season. Budapest, with an annual average concentration of 48 μg/m3, is a city that presents an increase of 35%. This capital does not present total confinement, they are allowed to exercise, go to work, with measures that allow them to circulate more widely, going from having a good to moderate AQI during BQut. Bratislava, does not apply quarantine, leaving citizens to walk freely and exercise. However, the date presented in Table 1, there are distance restrictions, suspension of classes and closure of sectors such as hostelry. This European capital presents an increase in the Qut week, which went from a good to moderate AQI level. Paris, London, Vienna, Brussels and Prague, are capitals that generally have a good AQI level, with an average record of 31 μg/m3. However, in the confinement season, an increase in the concentrations of the PM2.5 particulate matter is observed.
Fig. 3 Capital cities Belgrade, Bern, Bratislavia, Brussels, Budapest, Cyprus, Kyiv, Lisbon and London PM2.5 levels before and during quarantine (WAQ Index, 2020).
Fig. 4 Capital cities Paris, Prague, Pristina, Sarajevo, Skopje, Vienna, Vilnius and Warsaw PM2.5 levels before and during quarantine (WAQ Index, 2020).