On: Fear may be more dangerous than radiation

[neutronicus]

    If a particle happens to decay at your detector when it is detecting, you'll get a massive spike.

This is not true. The energy deposited by a single quantum of radiation is negligible, and at this point most of the activity is from long-lived isotopes and so shouldn't change from day to day.

I would guess that wind patterns are responsible for the variability in measurements, not nuclear physics.