No, air purifiers are not an effective way to reduce or remove radon. Radon is a radioactive, inert gas that cannot be filtered by standard air purifiers, which are designed to capture particulates like dust and mold. While an air purifier can improve indoor air quality by removing other pollutants, it should not be relied upon for radon. The only effective solution for high radon levels is a dedicated radon mitigation system.

Keeping radon from getting into your home is much better than having to get rid of it once it's already indoors. While there may not be a way to fully prevent radon from getting into your home, there are things you can do to reduce the gas's ability to enter. 

Sealing foundation cracks and openings can help keep the gas from seeping inside. Improving air flow, such as by opening windows, can also be helpful. If you're building your home from scratch, talk to your contractor about using radon-resistant construction to keep the gas out.

You'll need to test your home for radon after installing the mitigation system, then again every two years. If radon remains elevated, contact a licensed radon professional, either the contractor who installed the system or a different one, and have them evaluate the system. They may need to make some changes to improve its effectiveness and performance.

Use a radon test kit or hire professionals to conduct a detailed assessment of radon levels in your home.