Linked Life Data

2691450

Source:http://linkedlifedata.com/resource/pubmed/id/2691450

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1990-2-16
pubmed:abstractText
Improved lung models provide a more accurate assessment of dose from inhalation exposures and, therefore, more accurate dose-response relationships for risk evaluation and exposure limitation. Epidemiological data for externally irradiated persons indicate that the numbers of excess respiratory tract carcinomas differ in the upper airways, bronchi, and distal lung. Neither their histogenesis and anatomical location nor their progenitor cells are known with sufficient accuracy for accurate assessment of the microdosimetry. The nuclei of sensitive cells generally can be assumed to be distributed at random in the epithelium, beneath the mucus and tips of the beating cilia and cells. In stratified epithelia, basal cells may be considered the only cells at risk. Upper-airway tumors have been observed in both therapeutically irradiated patients and in Hiroshima-Nagasaki survivors. The current International Commission on Radiological Protection Lung-Model Task Group proposes that the upper airways and lung have a similar relative risk coefficient for cancer induction. The partition of the risk weighting factor, therefore, will be proportional to the spontaneous death rate from tumors, and 80% of the weighting factor for the respiratory tract should be attributed to the lung. For Weibel lung-model branching generations 0 to 16 and 17 to 23, the Task Group proposes an 80/20 partition of the risk, i.e., 64% and 16%, respectively, of the total risk. Regarding risk in animals, recent data in rats indicate a significantly lower effectiveness for lung-cancer induction at low doses from insoluble long-lived alpha-emitters than from Rn daughters. These findings are due, in part, to the fact that different regions of the lung are irradiated. Tumors in the lymph nodes are rare in people and animals exposed to radiation. The Task Group, therefore, suggests that the total risk to the nodes cannot exceed 1/100th of the total risk to the respiratory tract, which, in turn, leads to an extremely low cancer incidence per unit dose for lymphatic tissue.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0017-9078
pubmed:author
pubmed:issnType
Print
pubmed:volume
57 Suppl 1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
283-9
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Risk considerations related to lung modeling.
pubmed:affiliation
CEA, Institut de Protection et de Sûreté Nucléaire, DPS/SPE, Centre d'Etudes de Fontenay aux Roses, France.
pubmed:publicationType
Journal Article, Review