steady-state

The world has experienced the devastating nature of airborne transmitted diseases through the COVID-19 pandemic. Significant actions were taken in order to reduce the number of new infections, such as quarantines, social distancing, mask wearing, frequent hand washing and surface disinfection. However, all these measures have proven insufficient to eradicate short and long-range infections, confirming the need for engineering tools to control the indoor air quality.

Two methods for determining the 222Rn diffusion coefficient in building materials are presented.Experimentally, the measurement of radon release rates under well-controlled conditions, using aflush and adsorption technique, underlies both methods. However, the theoretical principle of thetwo methods differs. The first method uses samples with a cubical or rectangular geometry andhas, as a prerequisite that a 100% radon tight surface covering method is available.