The Hosoi-Sakamoto study demonstrated another tenet of the hormesis theory, however, which most other experimenters have neglected to investigate - namely that hormesis is a property of the organism and not its individual cells. When tumor cells that had been irradiated with 10 to 50 cGy gamma rays in vitro were injected in the mice, there was no difference from the controls - indicating that the suppression affects the mouse, not tumor cells. Unfortunately, the study involved only 200 - 250 mice (perhaps they are scarce in Japan?) and lacks the statistical significance I would like to see for compelling evidence.
Both of the lung cancer experiments were performed by Ullich et al., whom we have seen laboring earlier with mouse pituitaries; and both experiments involved several thousand mice. His 1977 investigation [Ullrich, R.L., et al. Neutron carcinogenesis. Dose and dose-rate effects in BALB.C mice. Radiation Research, 72, 487, 1977], which showed a minimum lung cancer mortality in the area of 100 cSv, was repeated in 1979 [Ullrich, R.L., et al. Influence of irradiation on the development of neoplastic disease in mice. Radiation Research, 80, 135, 1979]. This time, instead of only two data points, six were examined from 10 to 300 cSv. As shown in Figure 9, the minimum appeared around 25 cSv in the 1979 data but was still significantly lower than controls even at the 100 cSv level.
At the risk of sounding repetitive, it is evident that the LNT is completely inadequate to explain this phenomenon, while the hormesis theory predicts just such an occurrence.