الفهرس 
Introduction and Literature ReviewOnly 14 pages are availabe for public view
 |  | from | 222 |  |  |
| | | from | 222 | | |
Abstract
Components of natural environmental such as soils, rocks, sediments,
vegetation, air and water include some naturally occurring radioactive
materials (NORM). These radionuclides give rise to internal and
external radiation exposures both indoor and outdoor .so, the
measurements of radon exhalation rates of soil and rocks are helpful
to study health hazard. According to the plan of Nuclear Materials
Authority, that is based on radiation survey in various regions of the
Arab Republic of Egypt. It have been developing a national program
for radioactive mineral exploration, especially uranium mineralization
Wadi Sahu as a part of Sinai area is inhabited by Migrant Bedouins
which used natural materials in building. Also, there is a quarry and
manganese mine in this region that cause significant environmental
and occupational radiological impacts. The study area lies between
longitude 33 º 25 `00 and 33 º 22` 19 ”East and latitude 28 º 58` 54 ”5
and 28 º 58` 00 North.
The aim of the present work is to determine the environmental
radioactivity hazards indices and the exposure dose rate for the public
and workers from collected samples of rocks and soil, using Solid
State Nuclear Track Detector (SSNTDs) of CR-39 as a tool to study
222Rn emanation for 238U prospection of the subsurface of rocks and
soil distributed in the area , measure the radon exhalation rate and
estimation of 222Rn and radioelement measurements in well water &
plants in the investigated area.
The techniques used in measurements have been carried out as
follows: direct gamma dose measurements using (RDS-100) gamma
survey meter, radon gas concentration in subsurface soil using closed
cup technique, radon exhalation rate using closed can technique,
Abstract
xvi
radiometric measurements for soil and plants using NaI(Tl) gamma
spectrometry, radon gas concentration in water using Alpha
spectroscopy (SARAD GmbH RTM1688 ) and finally analysis of
environmental pollutants by Atomic absorption spectrophotometer.
The results obtained from this work is useful for establishing a
data baseline on the radon and gamma background radiation levels in
Wadi Sahu, and represent a basis to assess any further changes in the
radioactivity background levels due to various geological processes or
any artificial influences around the area under considerations . Also,to
prepare radioelement maps for geological study and mineral resource
assessment.
The results showed that ;
- The average results of gamma dose rate was (0.9)μSv/h which did
not exceed the recommended action limit (10) μSv/h .
- The average radon concentration in the four regions were higher
than the permissible limit for radon in the air outside (1-100( Bq/m3
as the first region (R1) were higher than other regions (19.84)
KBq/m3.
- The radon exhalation rate in the first region (R1) is higher than the
rest of the other regions,
-The average dose rate was (164.71 n Gy /h). and that average is
greater than the world dose rate(70 n Gy /h).
- The Average effective dose rate was (0.21 m Sv /y) and it is less
than the world effective dose rate (0.5 mSv / y).
- The average value of Raeq was (482.52) and it is higher than the
recommended maximum value (370 Bq / kg).
-The average External Hazard was (1.3) and it is greater than the
world internal hazard (unity (1)).
- The average Internal Hazard was (2.33) and it is greater than the
world internal hazard (unity (1)).
Abstract
xvii
-The average level index I-gamma was (3.27) and it is less than the
world level index I-gamma (6).
- The average (ELCR) was (0.73 × 10-3) and it is greater than the
standard (ELCR) value (0.29 × 10-3) .
- The average P-factor was (0.92) and it is less than the allowable
limit (1). It has been observed that, without exception the first region
(R1) was higher than the permissible values in all the hazard indices. -
- The average radon concentration in well water was (86.6 Bq/m3)
and it is lower than the maximum contaminant level (MCL) of (11.1 k
Bq m-3) for public water supplies .
- The concentration of cadmium was with value of (1.51 mg/l) higher
than the permissible limit of cadmium in drinking water (0.01 mg/l)
that present cadmium hazards to humans.
- The concentration of lead was with value of (0.28 mg/l) higher than
the permissible limit for lead in drinking water (0.05 mg/l).
Form present data one may conclude;
1- Radon gas concentration and radon exhalation rate in region
(R1) was higher than the other regions so we advised that the
soil of this region are not safe to be used in the construction
and paving works and recommend further studies on this region
in the coming periods.
2- Well water in Wadi Sahu is not safe for drinking or irrigation
because they contain high levels of lead and cadmium
concentrations that have hazard effects to humans, animals and
plants.
3- The soil to plant transfer factor data obtained from this study,
could be possibility used as a natural bio-indicator for
radioactive contamination in cases of accidents of unplanned
releases of radioactivity to the environment.