Radon is a naturally occurring radioactive gas that can be found in soil, water and air. It is the leading cause of lung cancer in non-smokers. While most homes have some level of radon, elevated levels can be found in homes with poor ventilation or that are located in areas with high concentrations of radon.
Dehumidifiers do not affect radon levels. Radon is a gas that is not affected by changes in humidity. The only way to reduce radon levels in your home is to install a radon mitigation system.