Introduction - Ionizing Radiation and Polymers - 1
In this study, we estimated cumulative effective doses of radiation from medical imaging procedures in nearly 1 million nonelderly adults across the United States. Approximately 70% of the study population underwent at least one such procedure during the 3-year study period, resulting in mean effective doses that almost doubled what would be expected from natural sources alone. Although most subjects received less than 3 mSv per year, effective doses of moderate, high, and very high intensity were observed in a sizable minority. Generalization of our findings to the nonelderly adult population of the United States suggests that these procedures lead to cumulative effective doses that exceed 20 mSv per year in approximately 4 million Americans.
Ionizing Radiation: Introduction to Ionizing Radiation ..
They concludedthat any food irradiated to an average dose of 10 kGy (1 Mrad) [see for definitions] or less is wholesome for humans andtherefore should be approved without future testing.
We identified 952,420 subjects in our study population. The mean (±SD) age was 35.6±23.0 years, and 499,342 of the subjects (52.4%) were women. The largest proportion of subjects was located in the Dallas-area market (298,747, or 31.4%) and the smallest proportion in the Orlando-area market (133,561, or 14.0%). We identified a total of 3,442,111 imaging procedures associated with radiation exposure that were performed in 655,613 subjects (68.8%) during the 3-year study period, with a mean of 1.2±1.8 procedures per person per year and a median of 0.7 procedures per person per year (interquartile range, 0.0 to 1.7; 95th percentile, 4.3).
Nonionizing Radiation | Radiation Information and Answers
A GM tube only detects a small fraction of the radiation around because most of it doesn't actually hit the tube. If you want to monitor the total amount of radiation given off by a source then you need to .
Introduction to Ionizing Radiation (MIT)
From each claim, we obtained information on the subject's age, sex, and ZIP Code (based on home address) and on the location where the service was provided. We then categorized procedures into mutually exclusive categories according to the technique used — plain radiography, computed tomography (CT), fluoroscopy (including angiography), and nuclear imaging — and the anatomical area of focus — chest (including cardiac imaging), abdomen, pelvis, arm or leg, head and neck (including brain imaging), multiple areas (including whole-body scanning), and unspecified. We considered the potential for overestimating the radiation dose from procedures that could overlap when performed on the same occasion. For example, a subject who underwent coronary-stent placement in addition to catheterization of the left heart would have two claims — one for each procedure — even if both were performed on the same occasion. To address this issue, we limited subjects to one procedure per day that involved the same type of technique (e.g., fluoroscopy) and the same anatomical area (e.g., chest), selecting the highest dose.
PPT - Non-Ionizing Radiation PowerPoint Presentation - …
Our finding that in some patients worrisome radiation doses from imaging procedures can accumulate over time underscores the need to improve their use. Unlike the exposure of workers in health care and the nuclear industry, which can be regulated, the exposure of patients cannot be restricted, largely because of the inherent difficulty in balancing the immediate clinical need for these procedures, which is frequently substantial, against the stochastic risks of cancer that would not be evident for years, if at all. Previous recommendations related to medical exposures to radiation have therefore focused on justifying the clinical need for a procedure and optimizing its use to ensure that exposure is “as low as reasonably achievable” without sacrificing quality of care.
Non-ionising Radiation Safety -Introduction
GM tubes are good at detecting alpha and beta radiation because they cause lots of ionization in the gas. But gamma rays normally pass straight through the gas without causing any ionization. This makes them difficult to detect.