An Estimation of Canadian population exposure to cosmic rays

Chen, J.*; Timmins, R.*; Verdecchia, K.*; Sato, Tatsuhiko   

The worldwide average exposure to cosmic rays contributes to about 16% of the annual effective dose from natural radiation sources. At ground level, doses from cosmic ray exposure depend strongly on the elevation above sea level, and weakly on geographical locations and solar activities. With the analytical model PARMA developed by the Japan Atomic Energy Agency, annual effective doses due to cosmic ray exposure at ground level were calculated for more than 1500 communities across Canada which cover more than 85% of the Canadian population. Averaged over solar activities, the Canadian population weighted average annual effective dose due to cosmic ray exposure at ground level is estimated to be 0.31 mSv.