Study of deposited energy in lung tissue from radon's progeny calculated by Monte Carlo

 

A. Ángeles^a and G. Espinosa^b

 

^a Instituto Nacional de Investigaciones Nucleares, Km 36.5 Carretera México–Toluca, La Marquesa, Ocoyoacac, 52750, Estado de México.

^b Instituto de Física, Universidad Nacional Autónoma de México, Apartado Postal 20364, México D.F., 01000, México.

 

Recibido el 10 de marzo de 2010
Aceptado el 31 de agosto de 2010

 

Abstract

Because the deposited ²²²Rn progeny distribution in lung airways, these sources can contribute hardly to critical cells absorbed dose in neighbourhood of alpha track by the alpha particles from ²¹⁸Po and ²¹⁴Po. According to epidemiological data [1], lung cancers are primarily bronchogenic and mainly originate in the first five airway generations of the bronchial tree. Generally for deposited energy calculations, uniform deposit in source layers and the whole layers as sources has been considerated too. Discretional point deposits in the diferent and most important bronqui (BB) and bronchial (bb) layers for main generations is a more realistic case. Because that facts we have calculated the average deposited energy by Monte Carlo in the most important different target cell layers for the main BB and bb branch generations considering the radioactive ²²²Rn progeny puntual deposit in the source epithelium walls, from this location, It irradiate the neighbor cells in all directions.

Keywords: Radon; absorbed dose; bronchial; bronchiolar; secretory cell; basal cell.

 

Resumen

Debido a la distribución de la progenie del ²²²Rn en las vías aéreas del pulmón, estas fuentes contribuyen importantemente a la dosis absorbida en la vecindad de la trayectoria de las partículas alfa emitidas por el ²¹⁸Po y el ²¹⁴Po. Conforme a datos epidemiológicos, el cáncer de pulmón es principalmente broncogénico y se genera principalmente en las primeras cinco generaciones del árbol bronquial. Para realizar los cálculos de energía depositada generalmente es considerado el depósito uniforme de las fuentes en las capas celulares y las capas mismas completas como la fuente también. Un caso más real es el depósito puntual y discreto en los diferentes y más importantes capas bronquiales (BB) y bronquiolares (bb). Tomando en cuenta lo anterior hemos calculado la energía promedio depositada en las mas importantes capas celulares blanco en las principales generaciones bronquiales y bronquiolares considerando el deposito puntual de la progenie del ²²²Rn en la pared epitelial de las capas celulares fuente, desde su ubicación el material fuente irradia las células vecinas en todas direcciones.

Descriptores: Radon; absorbed dose; bronchial; bronchiolar; secretory cell; basal cell.

 

PACS: 87.10.Rt

 

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Acknowledges

The authors wish to thank to J.I. Golzarri from IFUNAM for his technical help. This paper was partially supported by UNAM–DGAPA–PAPIITIN101910.

 

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