I couldn’t find much detail about the sources of home/office radon in the linked site. Is it suspected to naturally occurring ie coming out of the ground or from some product or chemical used?
It rises up out of the ground, and the (expensive) solution is to install a vacuum system beneath the slab that vents the the outside. I know because my parents' house has such a system. More info: https://sosradon.org/reducing-radon-in-your-home
It comes out of the ground naturally in many places and accumulates to dangerous levels in buildings with poor ventilation. There is very little industrial use of radon.
You can tell it's working because there's a U-shaped pressure gauge attached to the system showing the differential between under the slab and outside: https://www.clutchprep.com/physics/gauge-u-shaped-tube