MEAN ANNUAL Pu-239 AND Pu~24d CONCENTRATIONS IN BREATHABLE AIR DURING THE . PERIOD 1966 - 1969 CONCENTRATIONS AT STATION . (pci x m> x 197°) YEAR 2-1 1966 1.13 2 1967 | 8.41 1968. 1969 1979 | 2-2 P 3-1 0.4 0.74 11.94 8.11 8.35 | 8.19 8.59 9.07 8.29 4.35 3.84 9.07 9.38 6.16 0.06 | 1971 0.26 1972 8.28 8.05 1973 8.28 0.06 1974 8.22 8.11 1975 6.44 9.95 1976 G.12 1977 | | | 8.89 9.05 8.32 3.15 1978 | 9.45 9.06 1979 8.52 9.15 1980 8.89 8.76