Revision 1
March 19, 1998
by Radiation, Science, and Health, Inc.,
Edited by J. Muckerheide

1.2.4
Radium Body-Burden

1.2.4.1
Bone and Nasal Cancers

References

Dr. Constantine Maletskos of MIT confirms (1994) Evan’s argument, stating that: "Over ...five or six decades, about 2000 subjects were investigated… The curve was a step function with incidence at zero in the first three decades of 0 to 10 Gy and essentially constant at 28% beyond the 10 Gy up to 500 Gy. R.E. Rowland (1978) showed the relationship of incidence to cumulative dose was quad-multiplied by an exponential term to explain the peak in the response at high dose due to cell killing. The quadratic response started at zero with no implication of a threshold. In all three studies, only Evans faced the fact that a large fraction of the subjects was symptom free below ~10 Gy. Recently, some new analyses have been conducted using new approaches that minimize or avoid the biases of grouping by dose intervals, that include the more recent data that have become available, and that, in effect, allow the data to speak for themselves. Three different approaches, without significant restraints, show that the dose responses for exposure to internal radium do not pass through zero and, in fact, predict a threshold of cumulative dose below which cancers are not to be expected."

Professor Emeritus Otto Raabe of the Radiobiology Laboratory at the University of Califormia at Davis, also in support of Evans’ thesis, states (1994) that: "Beagles... administered ²²⁶Ra from 1963 through 1967, and were maintained concurrently from 1963 to 1985, when the last of these beagles died… At lower dose rates it takes longer to reach any specified level of risk, and may exceed the natural life span. This results in a life-span effective threshold for cancer induction at low dose rates similar to the ‘practical’ threshold described by Evans."

Dr. R.E. Rowland et al. report (1983) on radium health effects in dial painters, that: "The best group for a dose-response analysis is the female dial worker population. In this case the measured population contains 1,468 cases who experienced 42 bone sarcomas; age- and time-specific rates for white females indicate that 0.5 bone sarcoma was expected in this cohort. Since no bone sarcomas have been observed among the 1680 measured cases with systemic intakes less than 50uCi, it is evident that the life-span probability of bone sarcoma induction is very small for small doses of radium."

Dr. Robert Thomas of LANL, US DOE, and ANL reports (1995), on dial painter health effects, that: "Some of the most extensive epidemiological studies of the effects of ionizing radiation in humans have failed to conclude that there are health effects below whole-body equivalent radiation doses of 0.2 Gy (20 rads). This has been demonstrated in the study of survivors of the bombings in Japan; in the cases of radium dial painters (luminizers) studied in the United States, this value is 10 Gy (1000 rads)… (T)here are 1391 female luminizers with average estimated skeletal doses below 10 Gy who have not shown skeletal tumors. This totals to a mean collective dose of about 850 person-Gy, this cohort would have been expected to reveal at least five cancer deaths."

Dr. Robert Rowland former director of the Center for Human Radiobiology at Argonne National Laboratory, states (1997) that: "Today we have a population of 2383 cases for whom we have reliable body content measurements; they experienced 64 bone sarcomas, none below 10 Gy. From this population we can draw a cohort with similar age, sex, method of exposure and period of exposure, the female dial workers. This cohort of 1530 women experienced 46 bone sarcomas… No sarcomas appeared in the 1370 dial workers who accumulated less than 10 Gy to the skeleton. No one who entered the dial painting industry after 1925 has developed either of the radium induced tumors. It was in 1925 that the request was made that dial painters were not to tip their brushes with their mouths. The dial painting studios had no rules for cleanliness, no attempts were made to clean up the spilled radium, and of course there were no health physicists monitoring their activities in those days. However, just the simple instruction, ‘Don’t put the brush in your mouth’ was sufficient to stop completely the induction of malignancies."

Dr. R.G. Thomas of the Argonne National Laboratory reports (1994) on the female dial painters:

"Lognormal analyses were done for radium-induced bone sarcomas and head carcinomas after the respective dose populations were determined to be lognormally distributed. Luminisers with average measured skeletal doses below 10 Gy (1391 subjects) showed no incidence of cancer… It is time to evaluate the data objectively instead of formatting the extrapolation scheme beforehand and forcing the data to fit a preconceived pattern such as linearity through the dose-effect origin. It is also time to re-evaluate (again) variations in background radiation levels throughout the world and to cease being concerned with, and regulating against, miniscule doses for which no biomedical effects on humans have ever been satisfactorily quantified."

"To say that all radiation is harmful and to use the collective dose concept is easy. One problem facing regulatory agencies and radiation protection bodies is the restrictions sometimes placed on them, by themselves or by others, through application of preconceived interpretation and application of scientific data. A classical example of this is excerpted below from the Federal Register containing the US Environmental Protection Agency’s (EPA’s) proposed drinking water standards for radionuclides including radium (EPA 1991). 'EPA policy, supported by recommendations of SAB/RAC, is to assess cancer risks from ionising radiation as a linear response. Therefore, use of the dial painter data requires either deriving a linear risk coefficient from significantly non-linear exposure-response data, or abandoning EPA policy and SAB/RAC advice in this case.’ This excerpt exemplifies how the need to satisfy certain ground rules (the use of linear modelling with what the EPA referred to as dose-squared radium dial painter data) forces the rulemakers to use only data that tend to give the desired result, or to use dicta for the interpretation of scientific data. One can only marvel that such results are generally acceptable by the standard-setting community."