Absorption of energy from ionizing radiation by the genetic material in the cell leads to damage to DNA, which in turn leads to cell death, chromosome aberrations and gene mutations. While early or deterministic effects result from organ and tissue damage caused by cell killing, latter two are considered to be involved in the initial events that lead to the development of cancer. Epidemiologica...

h The procedures and dose limitations used for radiation protection in the nuclear industry are founded on the assumption that risk is directly proportional to dose, without a threshold. Based on this idea that any dose, no matter how small, will increase risk, radiation protection regulations generally attempt to reduce any exposure to “as low as reasonably achievable” (ALARA). We know however...

These efforts include the development of customized protocols that take into account the patient’s age, body mass and clinical indication. This allows for lower dose scan parameters and targeted scanning to cover only the region of interest and thereby limit oversampling. In addition, new iterative image reconstruction techniques can improve image quality on low dose, higher noise CT scans. As ...

the biological effects of low-dose radiation exposure are increasingly better understood, continued research is needed to develop better individual risk-based models. Human population exposures to low doses of ionizing radiation (defined by the US Department of Energy as less than 10 rem or 0.1 Sv) are increasing due to occupational exposures of nuclear plant workers, waste managers and medical...

Background Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is ...

Recent years there have been a number of discussions about the magnitude of the health risks resulting from the exposure to low levels of ionising radiation mainly within the American Health Physics Society, the French Academy of Sciences and the Canadian Radiation Protection Association. Essentially, the debate has centred on the question of linearity, i.e., whether to assume that the probabil...

introduction the exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. for most individuals, this exposure exceeds that from all man-made sources combined. materials and methods in this study, the annual effective dose in high level environmental background radiation areas (hlebras) of northern city of ramsar in iran was de...