There are tons of different possible results, depending on what they measure. Maybe the machines are dangerous for the people who work around them every day. W

There are tons of different possible results, depending on what they measure. Maybe the machines are dangerous for the people who work around them every day. Why aren't these people wearing dosimeters? Maybe the machines have an effect that only appears in a very small percentage of individuals. Maybe the danger only comes after the machine drifts out of calibration, while in a humid room, operated by poorly trained persons who misinterpret a control panel, when the person scanned has a given gene, that is being expressed because they have a viral infection. Conclusion 3(that you listed) can only be considered crap. To arrived at it is to claim to have a perfect understanding of several very complex systems. No matter how many studies you perform that fail to find a danger, that is not evidence that no danger exists. "The absence of evidence is not evidence of absence." The most you can ever say is "We found no evidence of dangers."