What is the general contribution of radon in water to airborne radon levels?

The contribution of radon in water to airborne radon levels is typically understood to be around 1 picocurie for every 10,000 picocuries per liter (pCi/L) in water. This ratio indicates that while radon can emanate from water into the air, the amount that actually contributes to airborne concentrations is relatively small compared to the levels present in the water itself.

When water containing radon is aerated—such as in activities like showering, cooking, or washing—radon gas can escape from the water and enter the indoor air. The 1:10,000 ratio encapsulates the average estimations seen in studies regarding how much radon from drinking water influences the air quality, helping to provide a contextual understanding of how different sources of radon can affect indoor environments.

The other ratios provided in the options suggest a significantly lower contribution of radon from water to the air, which does not align with established findings regarding radon behavior and its transfer from water to air.