PMID: 11783849Jan 11, 2002

Microdosimetric calculation of absorption fraction and the resulting dose conversion factor for radon progeny

Radiation and Environmental Biophysics
D Nikezic, K N Yu

Abstract

It is an established fact that radon progeny can induce lung cancers. However, there is a well-known discrepancy between the epidemiologically derived dose conversion factor for radon progeny (4 mSv/WLM) and the dosimetrically derived value (15 mSv/WLM) (mSv is a unit of the dose while WLM is a unit of exposure to radon progeny). Up to now there is no satisfactory explanation to this. In the present study we propose that microdosimetry will help reduce the discrepancy significantly. The ICRP Human Respiratory Tract Model (HRTM) has been applied to calculate the effective dose conversion factor. All parameters have been kept at their best estimates. Modifications were made in the calculation of the absorbed fractions of alpha particles. In contrast to the ICRP approach where the energy has been considered to be deposited in the layer containing the sensitive cells, we used a microdosimetric approach in which the alpha particles deposit their energy only in the nuclei of sensitive cells. This modification alone has lowered the dose conversion factor by about one-third (from 15 mSv/WLM down to approximately 10 mSv/WLM).

Citations

Jun 19, 2009·Radiation Protection Dosimetry·V M MarkovicD Nikezic
May 9, 2006·Journal of Environmental Radioactivity·D NikezicK N Yu
May 16, 2003·Health Physics·D Nikezic, K N Yu
Jan 11, 2007·Radiation Protection Dosimetry·B M F LauK N Yu

Related Concepts

Cell Nucleus
Dose-Response Relationship, Radiation
Monte Carlo Method
Nuclear Track Detection
Computer Programs and Programming
Thoron Daughters

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

The Tendon Seed Network

Tendons are rich in the extracellular matrix and are abundant throughout the body providing essential roles including structure and mobility. The transcriptome of tendons is being compiled to understand the micro-anatomical functioning of tendons. Discover the latest research pertaining to the Tendon Seed Network here.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Incretins

Incretins are metabolic hormones that stimulate a decrease in glucose levels in the blood and they have been implicated in glycemic regulation in the remission phase of type 1 diabetes. Here is the latest research.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Long COVID-19

“Long Covid-19” describes illness in patients who are reporting long-lasting effects of the SARS-CoV-19 infection, often long after they have recovered from acute Covid-19. Ongoing health issues often reported include low exercise tolerance and breathing difficulties, chronic tiredness, and mental health problems such as post-traumatic stress disorder and depression. This feed follows the latest research into Long Covid.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.