The first step should be to read your report from the lab. These will usually give you a recommended amount of time that you should mitigate within. It will vary from 1-2 years depending on the levels in your home.
If you have done a short term test, you may want to re-test with a long term test 90 Days+, during the fall and winter months to get a more accurate reading or you may decide to address the issue now!
Regardless of when you decide to take action you should visit the C-NRPP website at https://c-nrpp.ca/ to find someone with Certification and training to deal with your problem. There is also lots of useful information on their site regarding Radon.
At Radon East we take pride in the many systems we have installed. In all cases to date we have been able to lower levels to well below guidelines and as close to outdoor air levels as possible. We have addressed high levels of Radon Gas all across our province. Radon is present and we can reduce your levels.
So, don't panic, read your report, go to the CANADIAN – NATIONAL RADON PROFICIENCY PROGRAM Website, find a professional to do your mitigation and breathe easy.