What are the acceptable radon levels in a home and how can they be measured and mitigated effectively?

The acceptable radon levels in a home are below 4 picocuries per liter (pCi/L). Radon levels can be measured using radon test kits or electronic radon detectors. To mitigate radon effectively, techniques such as sealing cracks in the foundation, installing a radon mitigation system, and improving ventilation can be used.