Figure 10: Time run of: (a) total number concentration of general aerosol particles ( 𝐶 N g e n ( t o t ) ) and geometric mean values of their diameters ( 𝑑 G M ), (b) number fraction of particles smaller than 10 nm ( 𝑥 g e n (<10)) and smaller than 20 nm ( 𝑥 g e n (<20)), (c) activity concentration of radon ( 𝐶 A R n ) and equilibrium factor between Rn and RnDP ( 𝐹 ), and (d) equilibrium equivalent activity concentration of radon decay products ( 𝐶 A R n D P ) and activity fraction of the unattached RnDP ( 𝑓 u n ), in indoor air from October 28 to January 6.