“…In the present study (2018/2019), the concentrations of the following elements: Cl (630 ± 590 ng/m 3 ), K (230 ± 140 ng/m 3 ), Ca (50 ± 30 ng/m 3 ), Fe (150 ± 120 ng/m 3 ), Cu (5.9 ± 5.0 ng/m 3 ), Zn (75 ± 56 ng/m 3 ), Br (7.5 ± 4.1 ng/m 3 ) and Pb (12.5 ± 9.8 ng/m 3 ) were significantly lower than in our previous work conducted in 2016/2017 in Krakow. The concentration of V (4.3 ± 2.6 ng/m 3 ), Cr (5.1 ± 3.7 ng/m 3 ), Mn (9.0 ± 6.0 ng/m 3 ) and Ni (5.9 ± 8.0 ng/m 3 [29]. In our previous study, concentrations of SO 4 2− were 6.35 µg/m 3 and 2.44 µg/m 3 in winter and summer, respectively [18].…”