Table 2: Concentration ranges and calculated values of 239,240Pu and 137Cs dissolved in Japanese river water.
* The effect of the Chernobyl fallout was removed from this calculation.
Year | 239,240Pu range | Calc. | 137Cs range | Calc. |
| mBq m–3 | Bq m–3 |
1966 | 8.5–154 | 30 | | |
1967 | 2.6–19 | 13 | | |
1978 | 1.9–11 | 5.4 | 0.6–2.2 | 0.78 |
1979 | 0.4–30 | 2.2 | 0.3–1.4 | 0.36 |
1980 | 0.8–58 | 0.8 | 0.07–0.59 | 0.22 |
1981 | 0.04–1.3 | 4.9 | 0.11–0.33 | 0.51 |
1982 | 0.4–2.8 | 1.0 | 0.14–0.27 | 0.18 |
1983 | 1.1–11 | 0.54 | 0.03–0.18 | 0.15 |
1984 | 0.06–0.48 | 0.52 | 0.015–0.21 | 0.14 |
1985 | 0.33–0.67 | 0.34 | 0.03–0.69 | 0.12 |
1986 | 0.04–1.5 | 0.35 | 0.06–1.4 | 0.10* |
1987 | | | 0.05–0.52 | 0.12 |