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A level of 2.4 is actually very low. I would suggest you do research on radon from objective sources and draw your own conclusions on whether a reduction system is necessary. As an additional sample point, the limit in Canada is (or was until recently) 14. From my research I found the majority of people pushing radon reduction systems for moderate levels were those that would somehow profit from it (it should be noted radon is more dangerous for households with smokers than non). Again, your level is low.

Good luck.