الفهرس Only 14 pages are availabe for public view
 |  | from | 152 |  |  |
| | | from | 152 | | |
Abstract
Radon is a natural radioactive gas that may cause health hazards for human beings if its concentration increases to a certain limit. The aim of the present work is to study the effect of different environmental conditions such as humidity, static air, moving air and ventilation on radon detectors using active technique (surface barrier detector) and passive technique (CR-39 and activated charcoal detectors), and to calculate the equilibrium factor between radon and its progeny and also estimate radon annual dose equivalent.
In order to achieve this, the thesis is composed of four chapters:
Chapter 1:
Is a historical review of radon, its progeny, sources, health hazards and some definitions and terminologies like working level (WL) and working level month (WLM).
Chapter 2:
Includes theoretical background of techniques used in radon measurements.
Chapter 3:
Describes radon calibration chamber which was constructed in our lab. And some modifications that had been introduced to it, where environmental conditions can be varied and controlled. Also connection of surface barrier detector circuit and CR-39 detectors. Experimental procedure was devoted in this chapter.
Chapter 4:
Contains experimental work and discussion of obtained data. Calibration factor for CR-39 detector was determined.
The effect of different environmental conditions of humidity, static air, moving air and ventilation on radon detectors using active technique (surface barrier detector) and passive technique (CR-39 detector and activated charcoal canister detector) was tested. Equilibrium factor between radon and its progeny using different techniques was calculated. For the first time, it had been concluded a new method for the calculation of equilibrium factor using activated charcoal canister detector.
This chapter also contains radon field measurements, where activated charcoal after calibration was used to measure radon concentration and equilibrium factor in some houses in different locations in Cairo at different floors (ground floor and third floor) and in different ventilation cases (static air and ventilation). Radon dose equivalent was calculated. It was lower than the maximum permissible dose according to the recommendable of ICRP-60-1990.
Radon concentration and annual equivalent dose for public and workers in some car garages were measured. It was observed that the average of radon concentration as well as the annual equivalent dose were lower than the alert international limit.
Finally some recommendations (which were concluded from the present study) were suggested to reduce the health hazards of radon to human beings.