When should water testing for radon be conducted?

Water testing for radon should be conducted when indoor air levels are high because it indicates a potential source of radon exposure in the home. Radon can enter the household not only through the air but also through groundwater sources, such as wells. High levels of radon in indoor air suggest that the building may have high radon levels originating from the surrounding geological material or possibly from water sources used within the home.

Conducting water testing in this scenario helps to determine if the water supply contributes significantly to the radon exposure, allowing homeowners to take appropriate measures to mitigate risks. If air levels are elevated, it raises the possibility that the source of the radon could also be present in the water supply, making it prudent to test the water for further evaluation.

In contrast, testing when air levels are low may not yield beneficial information, as it is less likely that the water source is contributing significantly to the radon levels. Previous test history may affect the decision-making process, but high indoor air levels are a clear signal to investigate water sources as a potential issue. Lastly, outdoor air levels are generally not a primary concern when assessing the need for water testing since the focus is on indoor environmental health risks.