In areas where radon is a problem, what location is considered to have the highest risk?

Radon is a naturally occurring radioactive gas that can accumulate in buildings, particularly in enclosed spaces. The primary source of radon is from the ground beneath a structure; therefore, the places that are closest to the ground level, particularly finished basements, tend to have the highest levels of radon.

Basements are especially at risk because they are typically located in direct contact with or very near to the ground, which allows radon gas to easily enter through cracks, gaps, or other openings in the foundation. This accumulation can be exacerbated in poorly ventilated areas where there is little air exchange, resulting in higher concentrations of radon.

In contrast, higher floors, such as second-floor areas with showers or first-floor washrooms, are generally less susceptible to radon exposure since the gas is less likely to migrate upwards. Consequently, while all areas in a residence should be monitored for radon, basements are recognized as the highest risk location due to their proximity to the ground and the potential for concentration of this gas. This knowledge is essential for implementing effective radon mitigation measures in homes.