Page 68 - GTM-4-1

Global Translational Medicine Low-dose radiation

and more reliable than that in men. This notion does not Sv for acute exposure. However, observation bias appears
62
contradict the higher relative risk in some low-dose male to be probable in the study. The workers and some
51
groups, as indicated in Tables 1. CeVD is more frequent medical personnel knew the individual work histories,
47
in men, among other reasons, due to alcohol abuse from which accumulated doses could be approximately
and cigarette smoking. Some mild conditions may be inferred, potentially influencing diagnostic thoroughness.
overdiagnosed because these conditions are expected. For The skin doses were unknown. The participants were
example, the author encountered descriptions of age- and exposed mainly to gamma rays, which have a relatively
hypertension-related changes of retinal vessels in a medical high penetration distance in tissues so that the absorbed
record of a middle-aged man after a dispensarization doses within the skin must have been relatively low.
(yearly workplace examination), where his eye grounds Accordingly, the premalignant skin lesions and actinic
had not been inspected. As for post-mortem supposedly keratoses were “very rare” in the study cohort. Radiation
51
age-related changes (aortal, coronary, cerebral, or basilar exposure is associated with premalignant epidermal
atherosclerosis), they have habitually been written changes; in particular, actinic keratosis may be caused
without sufficient evidence in autopsy reports and death by X-ray and radiotherapy. 63,64 Therefore, a cause–effect
certificates. In higher-dose groups, the diagnostics would relationship between radiation and skin tumors in the
46
be more reliable, resulting in a more pronounced screening study is improbable.
51
effect in women but less frequent unsubstantiated
recordings in men. 6. Confounding factors and bias: About
In the MPA cohort, the incidence of circulatory motives
diseases was found to be higher in members who received Considering the above, the following claims by the same
gamma-ray doses of >0.1 Gy than those exposed to lower scientists, being unfounded and/or excessively generalized,
doses. 49,50 The ERR/Gy of CeVD in MPA employees was create a biased impression of the risks associated with
claimed to be even higher than that among atomic bomb low-dose low-rate radiation exposures. The statements
survivors in Japan, 49,51 where dose-dependent selection cited below, not specifying dose levels, does not apply to
could have taken place, as in other epidemiological studies. the cohorts under discussion (EURT, MPA, and Techa
Some data assessments of life span studies of atomic River) and to low doses in general. The claims exemplified
bomb survivors are compatible with hormesis. 52-55 For below, reiterated in numerous papers, demonstrate that the
cancers, a dose–response association was detected among risks have been intentionally exaggerated. An unofficial
survivors who received doses ≤0.5 Sv but not <0.2 Sv. 55-57 directive was behind this ideological bias. Trimming of
For example, the data about renal cancer in men indicated statistics has been not unusual in the former SU. Here,
22
hormesis: U-shaped dose–response curves with negative follow the examples:
ERR estimates at low-to-moderate doses, whereas those in “It was shown that ionizing radiation is one of the
women did not. These findings could have been observed promoters of the development of atherosclerosis.” 65
by chance. A preceding article by the same researchers “It is concluded that this study provides evidence
54
also showed different shapes of the dose–response curves for an association of lower extremity arterial disease
for men and women. When studies based on the same incidence with dose from external gamma-rays.” 32
58
cohort revealed different dose–response curves, reliability “This study provides strong evidence [emphasis
should be doubted. Other studies found no significant risks added] of ischemic heart disease (IHD) incidence
for kidney cancer from low doses. 59-61 To reliably evaluate and mortality association with external gamma-ray
dose–effect relationships at low doses, epidemiological exposure and some evidence of IHD incidence and
data have too many uncertainties. Thus, large-scale animal mortality association with internal alpha-radiation
experiments would be more informative. exposure.” 66
“A significant increasing trend in circulatory diseases
5. Cancer-related research: An example mortality with increasing dose from internal alpha-
This perspective article is about cardiovascular diseases; radiation to the liver was observed.” 67
however, one insightful example from the oncology field “Significant associations were observed between
should be provided at the end. A significantly increased doses from external gamma-rays and IHD and CVD
risk of non-melanoma skin cancer was reported in MPA incidence and also between internal doses from alpha-
workers exposed to radiation at doses ≥2.0 Sv accumulated radiation and IHD mortality and CVD incidence.” 68
over prolonged periods. In comparison, the non- “Findings are that aortal atherosclerosis prevalence
51
melanoma skin cancer dataset among Japanese atomic was higher in males and females underwent external
bomb survivors indicated a threshold of approximately 1.0 gamma-irradiation of total dose over 0.5 Gy, in males

Volume 4 Issue 1 (2025) 60 doi: 10.36922/gtm.7229