Environmental assessment of several scenarios of active and passive radon control measures

In buildings, radon gas mainly enters through cracks in the floors and gaps around pipes and cables in contact with the soil, thereby increasing indoor radon levels. Like other building components or systems, the radon control measures have embodied and operational environmental impacts that have been neglected to a certain extent. While many actions have been taken recently to achieve carbon-neutral yet energy-efficient buildings, even radon control measures should be investigated not only for protecting human health since radon gas is the major source of ionising radiation for humans but also for the environment. This paper aims to undertake a comparative analysis of the embodied and operational impacts of variant radon-protective measures installed at the floor foundation level (both active and passive solutions) for new and existing buildings. In particular, this analysis includes four different measures based on radon venting from i) floor air gap created from plastic components, ii) flexible perforated pipes embedded in the gravel layer under the floor, iii) radon sump placed in the sub-floor layer, and iv) perforated tubes drilled horizontally into the subsoil under the house. In all cases, radon will be removed through a vertical exhaust pipe terminated above the roof or by a roof fan. The impacts are calculated for the life cycle assessment (LCA) stages A1-A3 (production phase) and B6 (operational energy) to determine whether future research should be focused on the reduction of environmental impacts on the production stages or the operational ones.