The weather in my part of Spain has changed quite dramatically as summer draws to a close, and I've noticed that my Radon detector which has hovered around the 3 Bq/M3 level for many weeks has gone up to 19Bq/M3 over the last week.
Similarly, my Radbox-20 has shown a 2.26% increase in the background beta/gamma/x-ray level. My question is:- How much of a decrease or increase in the average background level could be considered statistically significant and indicate a real change in the actual radiation level?
