الفهرس 
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Abstract
The thesis deals with the occurrence of 238U-series, 232Th-series,40K, and 137Cs in all types of water (ground water, drinking water, and
Sabkha water), and also different types of soil (desert soil, agricultural soil, and sabkha soil) in Bahariya Oasis. The results of this study serve as a data base for radioactivity levels of the water, and soil in selected
sites at Bahariya Oasis. Also the distribution of evaporite minerals in El Bahariya sabkha indicated that most NaCl, CaCo3, and CaSo4 have
crystallized out, then the water become highly enriched in K, and Mg salts. The concentrations and distribution of radionuclides in Bahariya have been determined using high resolution gamma spectrometry to evaluate the environmental radioactivity.
The activity concentration of 222Rn was determined in all types of water with SSNTD (solid state nuclear track detector) CR-39 with
calibration factor 0.212tracks cm-2 d-1 per (Bq.m-3) which is calculated in this study, and is agreement with other studies. The hazard
parameters (dose rates, annual effective dose, external hazard, radium equivalent activity) are also calculated for water, and soil samples. In
order to reduce radiation exposure and avoid high doses, it is important
to examine the activity levels of natural radionuclides in groundwater.
The physicochemical parameters like pH, electric conductivity, T.D.S,
T.S.S, carbonate, bicarbonate, and alkalinity are determined for all types of water in this study because the physical and chemical characteristics controlling life in aquatic habitats, either saline or
brackish water, lead to the appearance of special types of biota.
Changes in climatic and hydrologic conditions may be lead to change in
physical-chemical and biological characteristics of lake water’s and they
are very important for aquatic system.
The average activity concentrations of 238U for all types of water in Bahariya Oasis is larger than the average recommended value is 4BqL-1 [GCD, 1996], and also the average activity concentrations of 234Th is
larger than the average recommended value is 20 BqL-1 [GCD, 1996]
for all types of water in all sites of Bahariya Oasis,and The activity ratio
238U/234Th for all types of water is go to unity which indicates that there
is a state of equilibrium between U-238 and its daughter 234Th in all
types of water in Bahariya Oasis. The average activity concentrations of
210Pb are 53.20BqL-1, and 47.895BqL-1 for groundwater and drinking water respectively, the activity concentration of 210Pb is higher than the recommended limit 0.1BqL-1 for groundwater, and drinking water. The sabkha water doesn’t have any concentration of 210Pb.
The activity concentrations of Ra-226, and its daughters 222Rn,214Pb, and 214Bi, and 228Ra isotope all are higher than the recommended
values are 0.61BqL-1, 183BqL-1, 1BqL-1, 1BqL-1, and 0.51BqL-1
respectively for all types of water in Bahariya Oasis due to water which
are closed to mines of Iron especially in El-Gedida area in Bahariya oasis. Activity ratio 226Ra/228Ra in all types of water in the studied area
there has been enrichment of 238U over 232Th for all the sites of water in this study because the places of water in Bahariya Oasis is closed to the
mines of iron in El-Gedida area this result was achieved by the previous study of Mineralogy by the Scanning Electron Microscope show that The percentage of iron in the El- Gedida mines is ranging from 40 to 60%, quartz grains (about 10%) carbonate (about 10%)and
evaporates (about 20%).
All correlations between 226Ra with both 222Rn, and 228Ra are poor for
all types of water in Bahariya Oasis, pointing out to the complexity of the processed involved in radionuclide accumulation together in
groundwater. The activity concentrations of 212P, and 40K are 2.63BqL-1,
and 11.85 BqL-1 respectively for drinking water and for Sabkha water are 2.17 BqL-1, and 227.10 BqL-1 respectively. Also for well groundwater, the average activity concentration of 212P and 40K are
2.38BqL-1, and 9.24 BqL-1 respectively. The activity concentration of 40K
for Sabkha water greater than its concentration for drinking, and well ware this is due to the composition of Sabkha, where the source of 40K in water is the chemical weathering of shale, clay, and arkosic
sandstones which are present in the surrounding rocks. The effective dose for three types of water in Bahariya Oasis, which well groundwater, and drinking water are lower than the recommended value of effective dose (0.29mS/Y)[UNSCEAR,B. 2000], but Sabkha
water is higher than the recommended value.
Groundwater in the Bahariya Oasis are nearly to acidic form with mean PH value is 7 with range of 6.70 to 7.62 along forty samples. PH values for drinking water is 6.99 with ranges of 6.65 to 7.40 this mean that the drinking water is neutral for two samples are (Dr1(6)& Dr1(23)) and is nearly to acidic PH less than 7 for samples (Dr1(3),
Dr1(43), Dr1(42), Dr1(28), Dr2(42),and Dr2(43)).The mean PH values for Sabkha water is 7.92 with average of 6.91 to 7.78 which indicated
that the Sabkha water is nearly in the basic form except two samples are(S1(30) & S2(30)). There are a strong relations between alkalinity, and HCo3 for well ground water (R2=0.86), drinking water (R2=0.68), and Sabkha water (R2=1.00), these strong positive relations are due to water with low alkalinity has low pH value (high acid) and all of its alkalinity in the
bicarbonate (HCO3) form, this interpretation is agreement with our
results because Carbonate (CO3) for all type of water in the studied areas is 0.00. Both TDS, and TSS for Sabkha water are high with means
of 130080 mg/l, and 48.67 mg/l. The mean values of TDS and TSS for drinking water are 251.15 mg/l, and 36.85 mg/l respectively. Also the
mean values of TDS and TSS for well groundwater in this study are 223.45 mg/l, and 30.74 mg/l respectively.
The conductivity had mean values are 0.35 mmhos/cm (0.23 to 0.867), 0.39mmhos/cm (0.248 to 1.021), and 203.25mmhos/cm (79.5
to240.00) in for well groundwater, drinking water, and Sabkha water
respectively for different sites in Bahariya Oasis. Heavy metal analysis on water was done to analyze cadmium (Cd), lead (Pb), copper (Cu),
cobalt (Co), and zinc (Zn), nickel (Ni). All concentrations of Heavy metals for all types of water well, drinking, and Sabkha water are fell
within the standard limits .Chemically uranium (U) has been analysed by Spectrophotometer colorimetric technique using Arsenezo III method for all types of water, and the relation between the chemically analysed uranium (U) and radiometric analysed uranium (eU) for all
types of water in Bahariya Oasis are deviated from unity either by decreasing or increasing. These results indicate a pronounced
disequilibrium with different grades.
The mean activity concentrations of 238U for desert, sabkha, and
agricultural soil in Bahariya Oasis are 57.58Bqkg-1, 70.07Bqkg-1, and
73.82 Bqkg-1, respectively, which 238U concentrations are higher than the recommended value (35Bqkg-1) for all types of soil in Bahariya Oasis, and The activity concentrations of 226Ra, 232Th, and 40K are below the recommended values are (35, 30, and 400Bqkg-1) respectively for all
types of soil in Bahariya Oasis. The anthropogenic radionuclide 137Cs
was found in most samples with an average of 4.51Bqkg-1 and ranges from 0.00-4.51 Bqkg-1 for all types of soil in Bahariya Oasis. The
estimated dose rates, and external hazard, are lower than the recommended values, for all types of soil in Bahariya Oasis but the mean radium equivalent activity, and annual effective dose are higher than the recommended values.
People have been exposed to radioactivity in this Oasis, Special radio ecological significance of the studied waters has been found. The radioactivity levels in drinking water supplies in the regions of Baharyia Oasis should be investigated. The data obtained in this study is a
baseline which can be used to evaluate possible future changes, and it should provide a good baseline for setting standards for water quality in
this Oasis.