The Evidence for Excess Risk of Cancer and Non-Cancer Disease at Low Doses and Dose Rates

Abstract

The question of whether there are excess radiation-associated health risks at low dose is controversial. We present evidence of excess cancer risks in a number of (largely pediatrically or in utero exposed) groups exposed to low doses of radiation (<0.1 Gy). Moreover, the available data on biological mechanisms do not provide support for the idea of a low-dose threshold or hormesis for any of these endpoints. There are emerging data suggesting risks of cardiovascular disease and cataract at low doses, but this is less well established. This large body of evidence does not suggest and, indeed, is not statistically compatible with any very large threshold in dose (>10 mGy), or with possible beneficial effects from exposures. The presented data suggest that exposure to low-dose radiation causes excess cancer risks and quite possibly also excess risks of various non-cancer endpoints.

Estimation of radiation doses and lifetime attributable risk of radiation-induced cancer in the uterus and prostate from abdomen pelvis CT examinations

“…Although there is some radiobiological support for LNT based on DNA damage considerations, it is acknowledged to be an estimate made for practicality in the context of radiological protection. In fact, a substantial body of evidence suggests that there is considerable evidence of cancer risk at low doses ( 16 , 17 ).…”

“The History of the Linear No-Threshold Model” video series

“…We offer opinions supporting it as the most conservative strategy to protecting humans at potential cancer risk. Two recent publications support this approach (Simon et al 2022;Little and Hamada 2022).…”

Science-informed Policy Making for Protecting People and the Environment from Radiation

“…As specified in the US EPA Cancer Risk Assessment Guidelines, linear extrapolation should be used when there are data to suggest the dose-response curve has a linear component in the lower end of the observed range or when the mode of action of an agent is DNA-reactive and has direct mutagenic activity; ionizing radiation satisfies this criterion (US EPA 2005). Even though available scientific evidence does not exclude the possibility that risks of some cancers at low doses may be overestimated or underestimated by a linear extrapolation, the LNT model remains justifiable for estimating risks at low doses for radiation protection purposes, and its use continues to be endorsed by experts and multiple scientific advisory bodies given the lack of a practical alternative model (ICRP 2005; National Research Council 2006; NCRP 2018a; UNSCEAR 2021; Rühm et al 2022; Simon et al 2022; Laurier et al 2023; Wakeford et al 2023).…”