• What Should You Do If Test Results Show Elevated Radon Levels?
  
  Results indicating indoor levels higher than 4 pCi/L call for immediate radon mitigation. Systems for radon mitigation most commonly involve a combination of sprayed-on sealants, fans and vent pipes that pump radon out from the soil around your house. However, there are different methods of reducing radon, and you will need to hire a professional to assess the best approach to combating your particular problem. Mitigation is not very expensive, but can cost up to a few thousand dollars for an average size home. Mitigation techniques are effective and can sufficiently reduce radon to safe levels.
  
  See the National Environmental Health Association’s National Radon Proficiency Program Web site for guidelines on hiring a professional to perform radon mitigation. You’ll find details on exactly what to do before and after a test, useful checklists for choosing a contractor and obtaining estimates, as well as guidelines for drafting or reviewing a contract for the necessary work.
  
  Bear in mind that California state law mandates that all providers of radon services be certified by either the National Radon Safety Board (NRSB) or the National Environmental Health Association (NEHA).
  
  The California Department of Health Services provides an online list of certified radon service providers which you should consult for names of qualified testers, mitigators, and laboratories.