Abstract
The γ radiation of the ground from natural and artificial radioactivity, and the β radiation from radioactive debris in the atmosphere, have been recorded in Sweden since 1950. On several occasions increased radioactivity has been observed, sometimes producing effects by far exceeding the variations of the normal level. Observations are reported on the influence of rain and snowfall, with and without the effects caused by transportation of radioactive debris from nuclear explosions. DOI: 10.1111/j.2153-3490.1956.tb01204.x