Which of the following statements is true about radon measurement?

Higher levels of radon require immediate action because prolonged exposure to high radon concentrations is associated with an increased risk of lung cancer. The Environmental Protection Agency (EPA) recommends taking remedial measures when radon levels exceed 4 picocuries per liter (pCi/L) to ensure the safety of occupants. This emphasis on prompt mitigation highlights the importance of regularly testing radon levels, as they can fluctuate based on various factors, including weather conditions, home ventilation, and property characteristics.

In contrast to other statements, radon levels can vary with the season, indicating that testing should occur at different times to get a comprehensive understanding of a home's radon levels. Passing an initial test does not guarantee that future levels will remain low, as changes in circumstances could lead to varying results. Finally, radon testing can be conducted year-round, not just in the summer, to capture accurate assessments of indoor air quality at any time.