Fig. 9

Displacement of radon atoms and their progeny over time without considering air movement, with shaded regions representing the range between the lower (bottom lines) and upper (top lines) displacement values for both horizontal (XY plane) and vertical (height) movement. The left subplot shows the entire time from 0 to 8\(\times 10^{6}\) seconds with steps of 2\(\times 10^{6}\), while the right subplot focuses on a shorter period, from 0 to 5\(\hbox {e}^{6}\) seconds.