What factor contributes most significantly to the risk of lung cancer from radon?

The most significant factors contributing to the risk of lung cancer from radon are the concentration of radon gas and the length of exposure to it. Radon is a naturally occurring radioactive gas that can accumulate in homes, particularly in basements and lower levels.

High concentrations of radon in indoor environments can significantly increase the risk, as more radioactive particles are present in the air, leading to higher levels of exposure when breathed in. Similarly, the duration of exposure is crucial; the longer individuals are exposed to these elevated radon levels, the greater the potential cumulative radiation dose absorbed by lung tissues, which can lead to cellular damage and an increased likelihood of cancer.

Together, these two factors—how concentrated the radon is within a given space and how long a person is subjected to that concentration—interact to heighten the risks associated with radon exposure. This interplay is why both concentration and length of exposure are emphasized as significant contributors to lung cancer risk from radon.