Legal Imputation of Radiation Harm to Radiation Exposure Situations

The doctrine for legal imputation (including the derivative concepts of legal charging, suing, indicting, prosecuting and judging) of detrimental health effects to those responsible for radiation exposure situations has been a matter of debate for many years and its resolution is still unclear. While the attribution of harm in the situations involving high radiation dose is basically straightforward, the challenge arises at medium doses and becomes a real conundrum for the very common situations of exposure to low radiation doses. The ambiguous situation could be construed to be a Damocles sword for the renaissance of endeavours involving occupational and public radiation exposure. This chapter describes the epistemological situation on the attribution of radiation health effects and the inference of radiation risks, relying on estimates from the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported to the UN General Assembly. It discusses the implications of UNSCEAR’s refined paradigm for assigning legal liability. The chapter concludes with a recommendation to develop an international legal doctrine on the ability to impute detrimental radiation health effects.

Considering Existing Factors That May Cause Radiation Hormesis at <100 mSv and Obey the Linear No-Threshold Theory at ≥100 mSv

The linear no-threshold (LNT) theory describes the linear relationship between a radiation dose and its effects. However, whether the linear relationship is maintained at low radiation doses has yet to be determined. Many previous studies support the radiation hormesis theory, which states that radiation has beneficial effects on health. In this viewpoint, we propose a mathematical function fitted to a model consistent with both the LNT at ≥100 mSv and radiation hormesis theories at <100 mSv, and the model requires a factor whose amount or activity takes a mountain-like shape versus the radiation dose and have one maximum value at 40.9 mSv. We searched a wide range of factors with these features based on searches on PubMed, and then evaluated whether these factors were suitable candidates consistent with both the LNT and radiation hormesis theories. Our consideration indicated that these factors did not completely follow the equation suggested at this time. Of course, other theories do not deny that these factors are involved in hormesis. However, based on our theory, still unknown factors may be involved in radiation hormesis, and then such unknown factors which are activated at <100 mSv should be searched.

Eye protection in interventional procedures

Data suggest that radiation-induced cataracts may form without a threshold and at low-radiation doses. Staff involved in interventional radiology and cardiology fluoroscopy-guided procedures have the potential to be exposed to radiation levels that may lead to eye lens injury and the occurrence of opacifications have been reported. Estimates of lens dose for various fluoroscopy procedures and predicted annual dosages have been provided in numerous publications. Available tools for eye lens radiation protection include accessory shields, drapes and glasses. While some tools are valuable, others provide limited protection to the eye. Reducing patient radiation dose will also reduce occupational exposure. Significant variability in reported dose measurements indicate dose levels are highly dependent on individual actions and exposure reduction is possible. Further follow-up studies of staff lens opacification are recommended along with eye lens dose measurements under current clinical practice conditions.

Radioactive decay of $$\mathrm {{}^{90}Sr}$$ in cement: a non-equilibrium first-principles investigation

Cement is an inexpensive and relatively easily manageable material that is used as a last barrier for nuclear waste disposal. Under these conditions, the cement is in contact with low radiation doses, but there is a distinct possibility of being contaminated with radioactive products. Of particular concern is the medium lived half-life product $$\mathrm {{}^{90}Sr}$$ 90 Sr (28.8 years) due to its ability to replace Ca. $$\mathrm {{}^{90}Sr}$$ 90 Sr undergoes $$\beta $$ β -decay to $$\mathrm {{}^{90}Y}$$ 90 Y which, in turn, $$\beta $$ β -decays to stable $$\mathrm {{}^{90}Zr}$$ 90 Zr . In this work, we discuss systematically the chain of non-equilibrium processes that result as a consequence of $$\beta $$ β -decay events in cement. We first use density functional-based methods to study the consequences of the sudden increase of the nuclear charge from $$Z$$ Z to $$Z+1$$ Z + 1 , a possible induced ionization and the perturbation of the surrounding electronic charge. Secondly, we use molecular dynamics simulations to study the recoil of the daughter nucleus. Finally, we discuss the damage caused by the ionization cascade produced during the propagation of the $$\beta $$ β -electron and the resulting chemical and structural perturbation. Graphic Abstract

Raman and Fluorescence Profiles Modifications of Muscular and Adipose Tissues Exposed to Low Energy X-ray Beams

This work aims to investigate changes induced by low-energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-ray beams expositions with 25 and 35 kV at 0.11, 1.1, and 2.1 Gy radiation dose levels were applied. Changes in Raman line intensities at specific bands assigned to collagen, proteins, and lipids were observed. Autofluorescent analysis exhibit variations in the collagen and nicotinamide adenine dinucleotide emission, resulting from the structural modifications, variations on the reduced/oxidized fluorophores equilibrium followed by radiation exposure. Results show that Raman and fluorescence spectroscopy are suitable techniques to evaluate radiation effects on biomolecules even at low radiation doses and energies.

LONG-TERM OPERATION OF DOSIMETRY FACILITY «PILLE» ONBOARD THE ISS

Malfunctioning of the reader is likely to be the reason for low radiation doses measured by the Pille dosimeters over the more than 20 years of ISS. Rectified measurements of the average daily absorbed dose rate agreed satisfactorily with readings of the other onboard tools of radiation monitoring.