Fission Product Radioactivity in the Air along the 80th Meridian — January–June 1957

Measurements of gross fission product radioactivity in the air at a number of sites along the 80th meridian (west) are reported for the period January–June 1957.

The concentration of long-lived radioactive products (primarly fission products) in the air continues to remain considerably higher in the Northern than in the Southern Hemisphere. Among the more interesting developments, there has been obtained a definite inverse relation between the air concentration of radioactivity and rainfall during the dry and rainy seasons at Panama.

The use of “radioactivity profiles” (plots of latitude vs fission product concentration) to represent a cross section of the average air concentrations of fission products along the 80th meridian for any given period offers a ready means to obtain the total burden of such activity in the atmosphere for such a period and to follow its increase or decrease with time.