What is the estimated ratio of radon in air compared to groundwater from a well?

The correct answer identifies the significant disparity that exists between the concentration of radon in air and that in groundwater from a well. In many cases, the level of radon in the air can be estimated to be approximately 10,000 times greater than that found in groundwater.

This substantial difference can be attributed to the fact that radon is a gas that can easily escape from groundwater into the atmosphere. Since radon is produced through the decay of uranium in the soil and rocks, its concentration in groundwater is often low due to the restricted ability of the gas to accumulate in a liquid state. Moreover, when water is exposed to air, radon can readily release into the atmosphere, leading to a significantly higher concentration of radon in the air as compared to groundwater.

Understanding this ratio is crucial for radon mitigation specialists as they assess and manage radon risks in residential and commercial properties. It underscores the importance of considering both air and water sources when evaluating radon exposure.