Negative correlation between the number of sunspots and the occurrence of 7Be and 22Na in the surface air and their contribution to radiation doses

Abstract

This article presents yearly mean concentrations of cosmogenic radionuclides ⁷Be and ²²Na occurring in dry and wet depositions (fallout) and aerosols. Time dependencies negatively correlated with the yearly mean number of sunspots. Activity concentrations of ⁷Be and ²²Na in aerosols in the surface air had a correlation of near-unity. ⁷Be in aerosols exhibited a smoother time dependence than ²²Na, implying that the production of ²²Na is more sensitive to the solar activity than the production of ⁷Be. The effect of the measured doses on the general population through internal and external exposure to radiation from cosmogenic radionuclides was small.