My wife and I are looking for a starter home that we can raise our baby here in central Illinois. We made an offer on a house we liked, but radon tests came back high (around 10 pCi/l) not only in the basement, but also on the main floor. We talked with a mitigator, and all he could say is that he'd get it to below 3.8 pCi/l, since 4.0 is the EPA's 'recommend action' level.

However, we have since been reading the research about radon, and that there is no 'safe' level, so essentially any threshold is arbitrary. (For what it's worth, the World Health Organization recommends 2.7 pCi/l as a limit, and the EPA actually has 2.0 as the 'consider action' level. 0.4 is the typical level outdoors.)

In light of this, we asked the seller to do radon mitigation, and then for us to be able to re-test (at our expense), and then have a contingency that the level be below 1.0 in the living areas where we'd be spending the most time. The seller rejected this, saying only that they'd get the level to below 4.0.

Now we're not sure how to proceed. We're inclined to walk away instead of taking the risk that mitigation won't be fully effective, but we don't have many good alternatives. Most houses here don't have radon mitigation installed, and the sellers of the ones that do, are generally unaware of what the levels have been mitigated to. So if we proceeded with another house, we'd have to get far enough along the buying process (putting in an offer) for us to do testing at our expense. Overall, a very time consuming and expensive way to shop.

Is there a better way?