The entry of this substance depends on how much uranium is present in soil and rocks beneath the residence and available routes through which it can enter the home. Moreover, the rate of exchange for outdoor and indoor air will determine the amount that will enter the house. Specifically, its ability to enter the home will be a function of window sealing, the owners’ patterns of ventilation, and the construction of the home .
Radon may enter the residence via sumps and drains, floor gaps, pores in hollow-block walls, and cracks which are present at the junctions of floors and walls. In light of these observations, improvement in home ventilation will reduce its concentration. Sealing of floors and walls will help as well .
Sump system installation in the basement and avoidance of radon passage from the basement to living rooms will alleviate exposure risk. In general, levels of this gas are higher in basements than on upper floors of the building. An increase in under-floor ventilation or installation of positive-pressure ventilation systems will ameliorate the situation .
In Europe and the United States, safety measures to reduce radon exposure in homes are routine in their construction. This toxic substance is present in all homes to some extent, and age or type of construction does not exempt any residence. This is true for homes which are crawl space, slab on grade, basement, non-basement, brick, or frame .
Community members must also understand that radon is present in drinking water and that higher concentrations of the gas occur in groundwater sources such as springs, wells, and boreholes than in surface water from rivers, streams, and lakes .