الفهرس 
titelOnly 14 pages are availabe for public view
 |  | from | 176 |  |  |
| | | from | 176 | | |
Abstract
In present work a survey was carried out to determine activity
concentration levels and associated hazard indices from the naturally
occurring radionuclides 226Ra, 232Th and 40K in four different areas affected
to varying degrees by TENORM activity and evaluated the ability to use
Eucalyptus globulus leaves to act as bio-monitor for environmental
radionuclides air and soil pollution. The accumulation features of
radionuclides (226Ra, 232Th and 40K) in the leaves of camphor trees
(Eucalyptus globulus Labill) growing in areas near Al-Nasr quarry for
phosphate production, Upper Egypt during the physical year 2016 have been
considered. The activity concentration of 226Ra, 232Th and 40K in samples of
soils, plant leaves and deposited dust have been compared. These activities
were measured using high resolution gamma-spectroscopy (Hyper Pure
Germanium detector) with consideration for the background level. from the
accumulated spectra, the average activity concentrations was varied for each
measured radionuclide and also between them, according to, sites, sample
types and season. The mean values of radium equivalent (Req), absorbed dose
rate (Dout) and Effective dose rate (Deff) at the different area was varied
significantly between the studied areas. Internal (Hin) and external (Hex)
hazard indices were calculated. In addition, the total effective dose from
external, internal exposure and ingestion from uranium series (226Ra) and
thorium series (228Ra) of different areas received by characteristic individuals
of humans were estimated. Leaves of E. globulus exhibited different
accumulation coefficients according to the distance from the quarry. The
relationship between the incorporated radionuclides concentrations within
leaf and those of each leaf deposited dust and soil samples was estimated by
Pearson Coefficients to resolve two main mechanisms of radionuclide
ABSTRACT
VIII
accumulation, atmospheric deposition and root uptake. E. globulus growth and eco-physiological responses due to radionuclides stress were determined.