In this work, the specific activities of natural radionuclides, namely 238U series, 232Th series and 40K, have been measured in collected sedimentary phosphate deposits samples from El-Hamraween, El-Quser and Safaga phosphate mines in Egypt. HPGe γ-spectrometry was used. This study was undertaken to estimate the radiation hazard indices in phosphate mining at the studied mines on their occupational workers, to establish correlation relationships between the some measured heavy metals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determinate the biomarkers in the blood workers such as malondialdehyde (MDA) and superoxide dismutase (SOD). The phosphate mine sample of El-Hamrawein has the lowest activity concentration of 226Ra, 232Th and 40K in comparison to the phosphate mine samples of El-Quseir and Safaga (El-Hamrawein < El-Quseir < Safaga). The activity concentrations for the radionuclide’s considerably were fluctuated; for 226Ra activity concentrations varied from 222.4 to 255.8 Bq· kg- 1 , 122.4 to 188.3 Bq · kg-1 and 115.4 to 165.8 Bq · kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 232Th activity concentrations varied from 135.6 to 212.3 Bq · kg-1 , 112.8 to 167.4 Bq · kg-1 and 132.8 to 188.6 Bq · kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. For 40K activity concentrations varied from 225.2 to 312.8 Bq · kg- 1, 168.7 to 268.9 Bq · kg-1 and 95.2 to 155.8 Bq · kg-1 for Safaga, El-Quseir and El-Hamrawein, respectively. The workers of old ages have higher concentration of the investigated heavy metals than those of young ages. There is a good relation between the concentration of the investigated metals in phosphate mine samples and their concentration in blood of the occupational workers in these mines.
Studies of natural environmental radiation and radioactivity are of great importance and interest for environmental chemistry as well as many other disciplines. Environmental radiation originates from a number of naturally occurring and human-made sources. The estimation of exposure to ionizing radiation is an important goal of regulatory authorities and radiation protection scientists. Thus knowledge of the background radiation level is of paramount importance [
This work aims to measure the specific activities of natural radionuclides, namely 226Ra (238U) series, 232Th series and 40K, in collected sedimentary phosphate deposits samples from El-Hamraween, El-Quser and Safaga phosphate mines in Egypt and to establish correlation relationships between some heavy metals such as As, Cd and Pb in blood workers and their concentration in phosphate rock ores and to determinate the biomarkers in blood of occupational workers such as malondialdehyde (MDA) and superoxide dismutase (SOD) in addition to the hematological parameters (Hemoglobin concentration, red blood count, white blood count and platelets count). This work can be considered as a step toward investigating natural radioactivity in phosphate hills in Egypt which is considered as the main part of radiological baseline map in Egypt. The experimental results will be used as guides for decision makers in solving some natural environmental problems which may be found in those areas of phosphate mines. On the other hand, the radiation safety measures and radiation safety standers should be taken into account for workers and environmental ecosystems in phosphate mines areas
In Egypt, phosphate formations are established in different sites. Three locations of open-pit phosphate mines have been selected for this study. These samples were collected by services partner (Baltic Control Company). El-Hamrawein (35˚12'E 26˚15'N), El-Quseir (34˚17'E 26˚06'N) and Safaga (33˚57'E 26˚44'N) locations. Phosphate sampling was carried out in the months of April, May and December 2014.Twelve samples were collected from each mine; four samples were collected from the subsurface phosphate horizon (subsurface samples), four samples were collected from the exposed lower phosphate horizon (surface samples lower bed) and four samples were collected from the exposed upper phosphate horizon (surface samples upper bed). The collected samples were transferred to labeled polyethylene bags, closed and transferred to the laboratory for preparation and measurements. The collected samples were dried at room temperature for a week. The quartering technique was used to get a representative sample for each horizon. So, there are three representative samples for each mine. The Phosphate samples were prepared and analyzed as reported in [
The activity concentration of the natural 238Useries, 232Thseries and 40K in the investigated samples were determined using a high-resolution HPGe γ-spectrometry system with 30% counting efficiency. These investigations were carried out in the Laboratory of Egyptian Nuclear and Radiological Regulatory Authority. This was performed by taking 250 cm3 counting vials filled up to a height of 7 cm, which correspond to 170 cm3. The measurement duration was up to 80,000 sec. The obtained spectra were analyzed. The determination of the presence radionuclides and calculation of their activities were based on the following gamma-ray transitions (in keV): the 226Ra activities (or 238U activities for samples assumed to be in radioactive equilibrium) were estimated from 234Th (92.38 keV, 5.6%), while γ-energies of 214Pb (351.9 keV, 35.8%) and 214Bi (609.3, 45%), 1764.5 keV, 17% ) and 226Ra (185.99 KeV, 3.5% )were used to estimate the concentration of 226Ra. The Gamma- ray energies of 212Pb (238.6 keV, 45%), and 228Ac (338.4 keV, 12.3%), (911.07 keV, 29%), (968.90 keV, 17 %) were used to estimate the concentration of 232Th. The activity concentrations of 40K were measured directly by its own gamma rays (1460.8 keV, 10.7%). In order to determine the background distribution due to naturally occurring radionuclides in the environment around the detector, an empty polystyrene container was counted in the same manner as the samples. The activity concentrations were calculated after measurement and subtraction of the background. The activities were determined from measuring their respective decay daughters. The activity concentrations were calculated from the intensity of each line taking into account the mass of the sample, the branching ratios of the γ-decay, the time of counting and the efficiencies of the detector [
Atomic absorption Spectrophotometer (AAS) is a simple and well available technique for the determinations of heavy metals in the soil samples. Heavy metals in sediments were determined according to [
Whole blood (1 ml) was transferred into screw capped polypropylene tubes and 5 ml nitric acid solution was added. After 10 minutes; it diluted with 5 ml deionized water, digested was continued in a microwave oven. In this digestion procedure, the temperature was increased gradually from 85˚C to 230˚C through 15 minutes. The sample preparation was completed with addition of 5 ml deionized water and 3 ml HCl 70% conc. Inductively-Coupled Plasma-Mass Spectroscopy (ICP-MS) (Agilent 7700X, USA) at (National Research Center, Cairo, Egypt) was used for the analysis of metals in collected samples. The standards for ICP-MS were prepared from stock solutions of lead, cadmium, arsenic at 10 mg/L concentrations obtained from Sigma-Aldrich, Australia, and labeled as Fluka Trace Cert Ultra Plasma with purity was higher than 99.999%. Calibration was performed by aqueous multi-element standard solutions. The method was validated by analysis of certified reference materials (Seronorm Trace Elements, Billingstad, Norway). Accurate results were obtained for all elements according to [
Ninety phosphates mine workers were taken from the three studied sites (Safaga site, El-Hamrawein site and El-Quseir site) in addition to a control group worker for investigations. All workers were divided according their age into three groups (first group 20?30 years, second group 30 - 40, third group 40 - 50 years) and 10 people as a control group was selected from non-phosphate mine workers (mean age 30 years). Hematological assessment Blood samples (5 mL) were collected by venepuncture of the cubital vein in the antecubital fossa by using a 5 mL disposable syringe. A part of the blood sample was then transferred to sterile vacuum tubes containing an anticoagulant Ethylene Diamine Tetraacetic Acid (EDTA), for whole blood analysis. The remaining blood was collected in sterile vacuum tubes with no added anticoagulant and was kept at room temperature for 2 h, where it was allowed to clot, as this was designated for serum separation for superoxide dismutase (SOD) and Malondialdehyde (MDA). The tubes were transported to a laboratory (Biomedical Lab, National Research Center, Egypt ) for analysis by using hematological investigations consisting of the Hemoglobin (Hb) concentration, RBC count, WBSc, platelets count, hematological investigations were estimated in an automated blood counting machine (SYSMEX XE-2100; Sysmexbiomedical Lab, National Research Center, Egypt). Accurate results were obtained for all elements according to [
Superoxide dismutase (SOD) activity determination and Malondialdehyde (MDA) determination were performed at Biomedical Lab, National research center, Egypt. SOD determined according to the method of [
Activity concentrations of the natural radionuclides (226Ra, 232Th and 40K) were measured for the investigated phosphate mines samples by HPGe gamma spectrometry. According to the International Atomic Energy Agency, one kilogram of soil typically contains the following amounts of the following three natural radioisotopes 370 Bq of 40K (typical range 100 - 700 Bq), 25 Bq of 226Ra (typical range 10 - 50 Bq), 25 Bq of 238U (typical range 10 - 50 Bq) and 25 Bq of 232Th (typical range 7 - 50 Bq) (IAEA, 2000).The activity concentrations of these radionuclides in different layers of the investigated samples are shown in
Samples | The selected natural radionuclide’s in phosphate mine at Safaga (33˚57'E 26˚44'N) ( Bq∙kg−1) | activity of the investigated radionuclide’s at El-Quseir (34˚17'E 26˚06'N) (Bq∙kg−1) | activity of the investigated radionuclide’s at El-Hamrawein (35˚12'E 26˚15'N) ( Bq∙kg−1) | ||||||
---|---|---|---|---|---|---|---|---|---|
226Ra | 232Th | 40K | 226Ra | 232Th | 40K | 226Ra | 232Th | 40K | |
Subsurface samples | 222.4 ± 7.2 | 135.6 ± 4.7 | 225.2 ± 11.5 | 122.4 ± 5.8 | 112.8 ± 7.3 | 168.7 ± 6.5 | 115.4 ± 5.9 | 95.2 ± 4.8 | 132.8 ± 6.8 |
Surface samples upper bed | 235 ± 7.8 | 198.2 ± 7.1 | 264.7 ± 12.3 | 154.6 ± 7.1 | 132.7 ± 6.2 | 212.5 ± 9.7 | 135.2 ± 6.2 | 122.7 ± 8.3 | 145.2 ± 7.8 |
Surface samples lower bed | 255.8 ± 9.3 | 212.3 ± 9.2 | 312.8 ± 12.8 | 188.3 ± 7.6 | 167.4 ± 8.4 | 268.9 ± 10.2 | 165.8 ± 6.6 | 155.8 ± 9.4 | 188.6 ± 8.7 |
siderably fluctuated; for 226Ra activity concentrations varied from 222.4 to 255.8 Bq∙kg−1, 122.4 to 188.3 Bq∙kg−1 and 115.4 to 165.8 Bq∙kg−1 for Safaga, El-Quseir and El-Ha- mrawein, respectively and these concentrations are 5 to 10 times higher than that value recommended by IAEA 2000. For 232Th activity concentrations varied from 135.6 to 212.3 Bq∙kg−1, 112.8 to 167.4 Bq∙kg−1 and 132.8 to 188.6 Bq∙kg−1 for Safaga, El-Quseir and El-Hamrawein, respectively and these concentrations are 5 to 8 times higher than that value recommended by IAEA 2000. For 40K activity concentrations varied from 225.2 to 312.8 Bq∙kg−1, 168.7 to 268.9 Bq∙kg−1 and 95.2 to 155.8 Bq∙kg−1 for Safaga, El-Quseir and El-Hamrawein, respectively and these concentrations are lower than that value recommended by IAEA 2000.Also the obtained results indicate that the phosphate mine sample of El-Hamrawein has the lowest activity concentration of 226Ra, 232Th and 40K in compared to the phosphate mine samples of El-Quseir and Safaga (El-Ha- mrawein < El-Quseir < Safaga). This can be discussed in the light of increasing concentration of P2O5 as shown in
In this study the concentration of some famous hazardous heavy metals reflected the impacts on their environmental sites. Phosphate mines rocks ores and phosphate industry phopsphgysoium make them directly affected with these products into human, plants and ecosystem.
Site | P2O5 | SiO2 | Al2O3 | Fe2O3 | CaO | MgO | Na2O | K2O |
---|---|---|---|---|---|---|---|---|
El-Hamrawein | 28 | 14.5 | 0.74 | 4.2 | 45 | 0.9 | 0.8 | 0.9 |
El-Quseir | 30 | 15.3 | 0.52 | 3.1 | 47 | 1.1 | 0.6 | 1.3 |
Safaga | 33 | 11.2 | 0.33 | 2.3 | 41 | 0.8 | 1.1 | 1.2 |
phosphate samples | Heavy metals (ppm) | ||
---|---|---|---|
As | Cd | Pb | |
Safaga | 24.9 | 0.88 | 28.2 |
El-Quseir | 26.8 | 0.98 | 22.3 |
El-Hamrawein | 20.2 | 1.2 | 26.7 |
in Safaga site in compared to Al Quseir and EL-Hamrawein sites, as well as Cd in Al Quseir and Safaga sites in compared to Al Quseir site, these results were acceptable when compared to global ratio of heavy metals in phosphate rocks. The concentration of cobalt phosphate rocks widely, generally ranging from about 1 to 40 ppm [
The chemical analysis of phosphate samples were carried out for showing the correlation between oxides of heavy metals regarding phosphate mine and their hazardous on the occupational workers. As shown in
The obtained results revealed increasing of siliceous ores which have impact health hazards in workers. The workers exposures to these particles may have many artificial and hematological diseases. Inhalation of silica causes risk of tuberculosis, lung cancer and some autoimmune diseases such as scleroderma and rheumatoid arthritis. Freshly fractured silica dust appears to be more reactive and more hazardous than old or stale dust. This may be a consequence of a relatively higher surface charge on freshly formed particles [
The obtained results of investigated heavy metals in blood of occupational workers at phosphate mines are shown in
Heavy metal (µg/dL) | Control Mean ± SD n, 10 | Workers at Safaga | Workers at El-Hamrawein | Workers at El-Quseir | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | ||
As | 0.046 ± 0.011 | 0.076 ± 0.015 | 0.121 ± 0.019 | 0.128 ± 0.039 | 0.077 ± 0.007 | 0.116 ± 0.032 | 0.123 ± 0.040 | 0.078 ± 0.021 | 0.149 ± 0.016 | 0.152 ± 0.008 |
Cd | 0.086 ± 0.021 | 0.164 ± 0.027 | 0.162 ± 0.023 | 0.192 ± 0.060 | 0.181 ± 0.011 | 0.204 ± 0.018 | 0.224 ± 0.054 | 0.171 ± 0.025 | 0.194 ± 0.027 | 0. 214 ± 0.023 |
Pb | 0.362 ± 0.068 | 0.994 ± 0.105 | 1.244 ± 0.027 | 1.662 ± 0.180 | 0.882 ± 0.161 | 1.218 ± 0.075 | 1.196 ± 0.227 | 0.868 ± 0.077 | 1.121 ± 0.088 | 1.068 ± 0.171 |
Blood Parameters | control | Workers at Safaga | Workers at El-Quseir | Workers at El-Hamrawein | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | ||
Hemoglobin mg/dl | 12.55 ± 0.31 | 11.96 ± 0.21 | 11.02 ± 0.32 | 10.38 ± 3.3 | 12.46 ± 0.11 | 11.56 ± 0.33 | 10.4 ± 0.065 | 12.8 ± 0.14 | 11.27 ± 0.25 | 9.4 ± 0.13 |
Red cell count × 106/cmm3 mil | 5.21 ± 0.09 | 4.34 ± 0.05 | 4.04 ± 0.08 | 3.96 ± 0.06 | 4.3 ± 0.02 | 4.14 ± 0.04 | 3.72 ± 0.073 | 21.6 ± 0.23 | 3.71 ± 0.024 | 3.38 ± 0.042 |
Leucocytic count/cmm3 | 6450 ± 9.1 | 6744 ± 8.3 | 5830 ± 5.2 | 7300 ± 5.1 | 5819 ± 7.84 | 5770 ± 6.94 | 6360 ± 7.36 | 6970 ± 8.53 | 6750 ± 9.66 | 6300 ± 6.22 |
Platelet count × 103/cmm3 | 290 ± 3.8 | 185 ± 4.3 | 181.2 ± 2.3 | 152.2 ± 2.3 | 239 ± 2.48 | 187.6 ± 5.28 | 173.2 ± 4.22 | 237 ± 4.88 | 166 ± 2.85 | 115.4 ± 2.84 |
low concentrations of Pb than other workers at both of EL-Hamrawein and Safaga mines. The variation of the investigated heavy metals between the workers at the different sites agrees with their concentrations in the phosphate mines. The enhancement of As, Cd and Pb in blood workers could be due to their accumulation through the inhalation of phosphate dust which may be released into the environment during mining process.
The prevalence of occupational health hazards for phosphat mine workers in Safaga, Al Quseir and EL-Hamrawein. The experimental study were designed according to three different age stage were start from (20 - 30 y), (30 - 40 y) and (40 - 50 y) male workers selected in three phosphate mine sites and were undergo to hematological studying and other biochemical studies. In this study the results in
In this study it is evident that phosphate miners were exposed to oxidative stress emitted
Parameters | Control Mean ± SD n, 10 | Workers at Safaga | Workers at El-Quseir | Workers at El-Hamrawein | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | Age of 20 to 30 (year) | Age of 30 to 40 (year) | Age of 40 to 50 (year) | ||
SOD U/g Hb | 4.22 ± 0.85 | 8.91 ± 2.63 | 10.44 ± 2.89 | 11.54 ± 3.1 | 12.48 ± 3.11 | 15.49 ± 3.22 | 18.22 ± 3.89 | 7.22 ± 0.46 | 8.24 ± 0.97 | 10.83 ± 2.33 |
MDA U/L | 10.22 ± 0.92 | 28.43 ± 2.32 | 32.58 ± 2.78 | 35.66 ± 2.98 | 24.35 ±0.57 | 32.58 ± 3.11 | 38.75 ± 2.13 | 40.66 ± 3.44 | 46.75 ± 3.22 | 42.83 ± 3.89 |
from the particles of heavy metals and radioncleads. The oxidative stress plays a role in damage of immune system and makes a hematological disorder for phosphate workers. These symptoms were very clear in oldest workers than youngest works. The results in
This study revealed that MDA and SOD were acting as smart biomarkers for determination types and category which had been related to the health impacts on phosphate miners workers during exposures to heavy metals and natural radioactivity. An increased serum MDA level in phosphate miners may indicate a general oxidant effect of phosphate heavy metals dust and natural radioactive nuclides. Also, decreased SOD activity in phosphate miner might be a marker of diminished antioxidant defense system which was caused by heavy metals and natural radioactivity.
The workers in phosphate mine plants are more susceptible to health problems. MDA, SOD and hematological tests acting specific tests to confirm the effect of phosphate mines’ pollutants can be carried out. This study also investigates occupational and heavy metals exposure in the phosphate mines. On the other hand, we need to implement radiation regulations and standards through improving the working conditions to reduce the occupational radiation exposure to the accepted levels recommended by ICRP-and IAEA-Safety standard.
Radiological and environmental safety should be considered in phosphate mines. Regulations should be issued and applied by the administration of these sites. Radiological follow-up should be a routine. Medical follow-up system should be applied. Occupational health monitoring should be take into account according to US EPA 2010 and WHO 2006 standard and regulation for health measurements in occupational mines.
The activity concentrations of the investigated radionuclides considerably fluctuated in the studied mines. The concentrations of 226Ra are 5 to 10 times higher than that value recommended by IAEA 2000. The concentrations of 232Th are 5 to 8 times higher than that value recommended by IAEA 2000. The 40K concentrations are lower than that value recommended by IAEA 2000. The concentrations of the investigated heavy metals (As, Cd and Pb) in old ages of the occupational workers are higher than those of young ages, while these metals are concentrating in all ages more than the control people sample.
RAtta, E.R., Zakaria, Kh.M. and Ibrahim, M.S. (2016) Assessment of the Heavy Metals and Natural Radioactivity in Phosphate Mines and Occupational Health Effects at Some Egyptian Regions. Journal of Environmental Protection, 7, 1657-1669. http://dx.doi.org/10.4236/jep.2016.711135