Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (http://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
Journal of Biomedical Engineering and Technology
American Journal of Microbiological Research
Biomedical Science and Engineering

We are pleased to announce that submissions are now being accepted for peer review for all the journals across all our subject areas in SciEP.

Please submit your manuscript via our online submission system:
http://www.sciepub.com/author/signin

To unsubscribe from our mailing list, please click on the following link: unsubscribe

I am looking forward to hearing from you.

Kind regards,

David Rain
Email:join@sciepub.com
Science and Education Publishing (http://www.sciepub.com)

Natural Radioactivity in Soil Samples in Nineveh Province and the Associated Radiation Hazards

Laith A. Najam*, Shaher A. Younis, Fouzey H. Kithah

Physics Department, College of Science, Mosul Univ., Mosul, IRAQ

Abstract: The natural radioactivity due to presence of ²²⁶Ra, ²³²Th and ⁴⁰K in soil of Nineveh zone, Nineveh province, Iraq were measured by using gamma-ray spectrometry based on high-purity germanium detector. The specific activity of soil samples ranged from 16.21 to 38.83 Bq/kg with an average of value of 32.52±6.48 Bq/kg, 8.53 to 28.37 Bq/kg with an average of 20.30±5.36 Bq/kg, 236.03 to 613.11 Bq/kg with an average of 378.93± 123.29Bq/kg, and 2.18 to 17.92 Bq/kg with an average of 8.17± 5.55 Bq/kg for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs respectively. The study also examine some radiation hazard indices such as Radium equivalent activity (Raeq), Absorbed gamma dose rate (D), External hazard index (Hex), Internal hazard index (Hin) and gamma index (Iγ). These calculated hazard indices to estimate the potential radiological health risk in soil. The radium equivalent activity average (Raeq) was less than the permitted value (370 Bq/kg). The average absorbed dose rate value also less than the permissible limit of 55 nGy/h. The external hazard index, internal hazard index and gamma index of soil samples were less than unity.

Keywords: soil radioactivity, high-purity germanium detector, absorbed dose rate, activity concentrations, external hazard index

Received April 03, 2015; Revised April 12, 2015; Accepted April 15, 2015

Citation: Laith A. Najam, Shaher A. Younis, Fouzey H. Kithah, Natural Radioactivity in Soil Samples in Nineveh Province and the Associated Radiation Hazards. International Journal of Physics, 3 (3). 126-132. January 2015. doi:10.12691/ijp-3-3-6

1. Introduction

Radiation is present everywhere and man is knowingly or unknowingly being continuously exposed to radiations present in environment (natural). The natural radiations surrounding the life on earth can either be terrestrial or extraterrestrial (cosmic) origin. The ionizing radiations a, b and c emitted from various terrestrial materials (soil, rocks, and etc.) coming from naturally occurring radionuclides such as uranium, thorium etc., their isotopes, their decay products and some singly occurring radionuclides such as ⁴⁰K, ⁸⁷Rb contribute to the terrestrial radiations [1]. Natural radioactivity can be found, in low concentrations, throughout the geology of the planet. It is naturally occurring in many rocks, soils, and waterways. Phosphate rocks are one of the matrices that contain higher levels of natural radioactivity than the background. As the world population continues to grow, so does the world’s need for food. The increased demands of food production have led to a steady increase in the use of phosphate fertilizers [2,3]. Natural radioactivity exists widely in the terrestrial environment. There are many sources of radiation and radioactivity in the environment.

Gamma radiation emitted from naturally occurring radionuclides, also called terrestrial background radiation, represent the main external source of irradiation of the human body. It is located in different geological formations such as the surface of the earth, rocks, water, plants and even the air. The concentration of the natural radioactive materials depends on situation of geology and geography and appears at different level in soils of each different geological region [4,5].

The exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. For most individuals, this exposure exceeds that from all man-made sources combined. External exposures outdoors arise from terrestrial radionuclides present at trace levels in all soils. The specific levels are related to the types of rock from which the soils originate. Natural environmental radioactivity and the associated external exposure due to gamma radiation conditions, and appear at different levels in the soils which the soils originate [4,6]. The applications of radiations have become part and parcel in human life. We receive radiation emitted from the floor and walls of our homes, food we eat and drink and the air we breadth. The concept of technologically enhanced natural radioactivity (TENORM) was introduced in the mid-seventies. It represents the unintentional exposure to natural sources of radiation which would not exist without the technological activity. The natural radioactivity in the environment is the main source of radiation exposure for human body. Natural radionuclide in coal, soil and water contribute a significant amount of background radiation exposure to the population through inhalation and ingestion as well as through direct external exposure [4,7].

Natural radioactivity is widespread in the earth environment and it exists in various geological formations such as earth crust, rocks, soils, plants, water and air. Terrestrial radioactivity and the associated external exposure due to gamma radiation, depends primarily on the geological formation and soil type of the location; and these factors (geology and soil type) greatly influence the dose distribution from natural terrestrial radiation [4,8]. Radiation is present everywhere and man is knowingly or unknowingly being continuously exposed to radiations present in environment (natural). The natural radiations surrounding the life on earth can either be terrestrial or extraterrestrial (cosmic) origin. The ionizing radiations a, b and c emitted from various terrestrial materials (soil, rock, sand etc.) coming from naturally occurring radionuclides such as uranium, thorium etc., their isotopes, their decay products and some singly occurring radionuclides such as 40K, 87Rb contribute to the terrestrial radiations [9]. Since the creation of our earth soil and sediment contain different radionuclides. At the present age of our earth, these terrestrial radionuclides are mainly members of the two natural radioactive series, namely uranium (²³⁸U) and thorium (²³²Th) series, and the isotope potassium (⁴⁰K).These natural radionuclides cause radiation exposure to us externally through gamma ray emission and internally as well, through inhalation and food chain [10,11]. The aim of the present work is determine the specific activity concentrations of 226Ra, 232Th, 40K and 137Cs, radium equivalent activity, absorbed gamma dose rate, external and internal hazard indices and gamma index in surface soil samples in some selected districts in Nineveh province by using high purity germanium (HPGe) detector.

2. Materials and Methods

2.1. Study Area

This study was carried out at Nineveh province, ten districts has been selected from the center of Mosul city(i.e. Al-Medan, Camp of Gazlany and college of Agriculture in Univ. of Mosul) and others from some small towns outside the center of Mosul city like(Sinjar, Rabeaa, Telfar, Al-Koosh, Telkaif, Al-Hamdanea and Bacheeka) as shown in Table 1.

Table 1. Names and codes of collected soil samples from Nineveh province

2.2. Collection and Preparation of Samples

A total of ten soil samples have been collected from ten districts of Nineveh area. These samples were crushed and dried in an oven at110 C◦ for 24 h to ensure than any significant moisture was removed from the samples. Later, they were grinded into fine powder to pass through a 2mm mesh and the homogenized sample was sealed in marinelli beaker. The samples were then stored and kept sealed for about a four- week period to allow radioactive equilibrium among the daughter products of radon (²²²Ra), thoron (²²⁰Ra) and their short lived decay products.

2.3. Gamma Ray Spectrometry

Each Sample was measured with gamma –ray spectrometry consisting of vertical HPGe setup and multichannel analyzer (8192) channel, with the following specifications: resolution (FEHM) at 1.33 MeV ⁶⁰Co is 2.0 keV, relative efficiency at 1.33 MeV ⁶⁰Co is 40%. The detector shield are with activity adequate to accommodate large samples. Shield has walls 10 cm lead, thick lined inside with graded absorber of Cd ~ 1.6 mm, Cu~ 0.4mm. This shield serves to reduce different background radioactivity. To minimize the effect of the scattered radiation from the shield, the detector is located in the center of the chamber. Then the sample was placed over the detector for at least 2h. The spectrum was evaluated with the computer software program Maestro(EG&G ORTEC). The energy regions selected for the corresponding radionuclides were 609 keV, 11120 keV for ²¹⁴Bi for ²²⁶Ra, 911keV and 969 keV of ²²⁸Ac for ²³²Th and 1460 keV for ⁴⁰K.

The activity concentration of ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs were calculated using the following relation [12]:

[picture] | (1)

Where A is the activity concentration in Bq/kg (CPS) net is the (count per second) and equal [(CPS) sample –(CPS) background], I is the intensity of γ-line in a radionuclide, is the measured efficiency of each γ- line observed, m is the weight of each sample and t is the sample counting time 7200 sec.

3. Results and Discussion

3.1. Activity Concentration in Soil Samples

From Table 2, it can be noticed that the highest value of specific activity concentration of ²²⁶Ra was found in (S1)(Sinjar) district which was equal to (38.83 Bq/kg), while the lowest value of specific activity concentration of ²²⁶Ra was found in (S9) (Al-Medan) district which was equal to (16.21 Bq/kg), with an average value of (32.52± 6.48 Bq/kg).The present results have shown that values of specific activity concentrations in the studied districts in Nineveh province were lower than value of specific activity concentration of ²²⁶Ra global limit which equal to (370 Bq/kg) [4]. The highest value of specific activity concentration of ²³²Th was found in (S2)(Rabeaa) district which was equal to (28.37 Bq/kg), while the lowest value of specific activity concentration of ²³²Th was found in (S9) (Al-Medan) district which was equal to (8.53 Bq/kg), with an average value of (20.30± 5.3 Bq/kg).The present results have shown that values of specific activity concentrations in the studied districts in Nineveh province were lower than value of specific activity concentration of ²³²Th global limit which equal to (45 Bq/kg) [4]. The highest value of specific activity concentration of ⁴⁰K was found in (S2)(Rabeaa) district which was equal to (613.11 Bq/kg), while the lowest value of specific activity concentration of⁴⁰K was found in (S10) (College of Agriculture) district which was equal to (261.81 Bq/kg), with an average value of (378.93± 123.29 Bq/kg).The present results have shown that values of specific activity concentrations in the studied districts in Nineveh province were lower than value of specific activity concentration of ⁴⁰K global limit which equal to (420 Bq/kg) [4] except Rabeaa and Camp of Gazlany districts (S2 and S8). The highest value of specific activity concentration of ¹³⁷Cs was found in (S8)(Camp of Gazlany) district which was equal to (17.92 Bq/kg), while the lowest value of specific activity concentration of ¹³⁷Cs found in (S5) (Telkaif) district which was equal to (2.18 Bq/kg), with an average value of (8.17± 5.55 Bq/kg).The present results have shown that values of specific activity concentrations in the studied districts in Nineveh province were lower than value of specific activity concentration of ¹³⁷Cs global limit which equal to (14.8 Bq/kg) [4] except Al-Hamdanea and Backeeka districts (S6 and S7).The results of the activity concentrations for ²²⁶Ra, ²³²Th, ⁴⁰K and ¹³⁷Cs were shown graphically in Figure 1, Figure 2, Figure 3 and Figure 4.

Table 2. Specific activity concentrations of ²²⁶Ra,²³²Th,⁴⁰K and ¹³⁷Cs for soil samples in Nineveh province

Figure 1. Activity concentration for ²²⁶Ra in soil samples

Figure 2. Activity concentration for ²³²Th in soil samples

Figure 3. Activity concentration for ⁴⁰K in soil samples.

Figure 4. Activity concentration for ¹³⁷Cs in soil samples

Figure 5. Bar graph showing the Radium equivalent activity Raeq (Bq/kg) of soil samples in different districts

3.2. Gamma Radiation Parameters

3.2.1. Radium Equivalent Activity (Raeq)

The distribution of ²²⁶Ra, ²³²Th and ⁴⁰K in soil is not uniform. Uniformity with respect to exposure to radiation has been defined in terms of radium equivalent activity (Raeq) in Bq/kg to compare the specific activity of the material containing different amounts of ²²⁶Ra, ²³²Th and ⁴⁰K.It is calculated through the following relation [13]:

[picture] | (2)

Where ARa, ATh and AK are the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in Bq/kg, respectively. While defining Raeq activity, it has been assumed that 370 Bq/kg of ²²⁶Ra or 259 Bq/kg of ²³²Th or 4810 Bq/kg of ⁴⁰K produce the same gamma dose rate. The results of radium equivalent activity shown graphically in fig.5.

3.2.2. Absorbed Gamma Dose Rate(D)

The external outdoor absorbed gamma dose rate due to terrestrial gamma rays from the nuclides ²²⁶Ra, ²³²Th and ⁴⁰K at 1m above the ground level were calculated as follows outlined by [14]:

[picture] | (3)

Where ARa, ATh and AK are the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in Bq/kg. Fig.6 shows graphically the results of absorbed gamma dose rate.

Figure 6. Bar graph showing the Absorbed gamma dose rate D(nGy/h) of soil samples in different districts

3.2.3. External and Internal Hazard Indices (Hex and Hin)

Local soil of the area is used for the construction of houses. These soils will contribute to the external gamma dose rate in these houses. The external hazard index (Hex) can be defined as follows [15]:

[picture] | (4)

Where ARa, ATh and AK are the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in Bq/kg, respectively. When the value of this index is less than unity then the radiation received by occupants will be < 1.5 mGy/y. The internal exposure to ²²²Rn and its radioactive progeny is controlled by the internal hazard index(Hin), which is calculated by the relation [16]:

[picture] | (5)

Hin should be <1 for safe use of soil.

The results of Hin and Hex shown graphically in Figure 7.

Figure 7. Bar graph showing the External and Internal hazard indices (Hex& Hin) of soil Samples in different districts

3.2.4. Gamma Index (Iγ )

Another radiation hazard called the representative level index Iγ, is defend as follows [17,18]:

[picture] | (6)

Where ARa, ATh and AK are the activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in Bq/kg, respectively.

Iγ varied from 0.388 in S9 (Al-Medan district) to 0.940 in S2 (Rabeea district), with an average value of 0.65± 0.16.

Figure 8. Bar graph showing the Gamma index ( Iγ) of soil samples in different districts

This index value must be less than unity in order to keep the radiation hazard to be in significant. Fig.8 shows graphically the results of gamma index.

The results of radium equivalent activity( Raeq ), Absorbed dose rate(D), External and Internal hazard indices (Hex,Hin) and Gamma index (Iγ) are listed in Table 3.

Table 3. Radium equivalent activity(Raeq), Absorbed dose rate (D), External and Internal hazard indices(Hex,Hin) and Gamma index(Iγ) for soil samples in selected districts in Nineveh province

4. Conclusion

The evaluation of radiation hazard indices of soil samples in Nineveh province (IRAQ), has been conducted. The values obtained when compared with the various world permissible values world were found to be below the standards for such environment and soil from this area will pose no significant health threat to human lives and the environment is said to be radiogically hazard safe.

References

[1]   | Rajeshwari T., Rajesh S., Kerur B.R., Anilkumar S., Krishnan Narayani, and Pant Amar D, (2014), Natural radioactivity studies of Bidar soil samples using gamma spectrometry, J Radioanal Nucl Chem, 300:61-65.
[2]   | Kapsimalis R, Landsberger S, and Reguigui N. (2009) Measurement of uranium in small quantities in phosphates by use of γ-ray spectrometry and the 1001 keV peak of 234 mPa, J. Radioanal Nucl Chem 280(2):293-298.
[3]   | Ajmal P. Y., Bhangare R. C., Tiwari M., Sahu S. K., and Pandit G. G., (2014), External gamma radiation levels and natural radioactivity in soil around a phosphate fertilizer plant at Mumbai, J Radioanal Nucl Chem, 300:23-27.
[4]   | UNSCEAR, (2000), Sources, Effects and Risks of Ionizing Radiation. Report to the General Assembly, New York SalehȦ Adel Mehdi, Al-Mashhadani Asia H., and SiyahḂ Murtdha Adhab,(2014),
[5]   | Natural Radioactivity Concentration and Estimation of Radiation Exposure in Environmental Soil Samples from Al-Sader City/Iraq, International Journal of Current Engineering and Technology,4(4), 2902-2906.
[6]   | Asgharizadeh F., Ghannadi M., Samani A. B., Meftahi M., Shalibayk M., Sahafipour S. A., and Gooya E. S.,(2013), Natural Radioactivity in surface soil samples from dwelling areas in Tehran city, IRAN, Radiation Protection Dosimetry, 156( 3), 376-382.
[7]   | Hasan M. Mehade, Ali M. I., Paul D., Haydar M. A., and Islam S. M. A.,(2013) Measurement of Natural Radioactivity in Coal, Soil and Water Samples Collected from Barapukuria Coal Mine in Dinajpur District of Bangladesh, Journal of Nuclear and Particle Physics, 3(4): 63-71.
[8]   | Faisal B. M. R., Haydar M. A., Ali M. I., Paul D., Majumder R. K., and Uddin M. J., (2014), Assessment of Natural Radioactivity and Associated Radiation Hazards in Topsoil of Savar Industrial Area, Dhaka, Bangladesh, Journal of Nuclear and Particle Physics, 4(4): 129-136.
[9]   | Ramola R.C., Gusain G.S., Badoni M., Prasad Y., Prasad G., Ramachandran T.V., (2008) J. Radiol Prot 28:379-385.
[10]   | IAEA (1989) Measurement of Radionuclides in Food & the Environment, A guide book, Technical Report Series No. 295, IAEA, Vienna.
[11]   | Rahman, M. M.A., Islam, A. T.A., Kamal M.B.,& Chowdhury M.I.B. (2012). Radiation hazards due to terrestrial radionuclides at the coastal area of Ship Breaking Industries, Sitakunda, Bangladesh. Science Journal of Physics, 2012(2), 1-6.
[12]   | Najam, L.A., Tawfiq, N.F. &Kitha F. H.,(2013), Measurement of Natural Radioactivity in Building Materials used in IRAQ, Australian Journal of Basic and Applied Sciences, 7(1): 56-66.
[13]   | Jose, A., Jorge, J., Cleomacio, M., Sueldo, V., &Romilton, S.(2005).Analysis of the ⁴⁰K Levels in Soil using Gamma Spectrometry. Brazilian Archives of Biology and Technology Journal, 221-228.
[14]   | Kessaratikoon, P. and Awaekechi, S.(2008), Natural radioactivity measurement in soil samples collected from municipal area of Hat Yai District in Songkhla Province, King Mongkut’s Institute of Technology Ladkrabang Science Journal, 8( 2), 52-58.
[15]   | Xinwei, L. (2005). Natural radioactivity in some building materials of Xi’an, China. Radiation Measurements, 40, 94-97.
[16]   | Berekta, J., & Mathew, P. J. (1985). Natural radioactivity in industrial waste and by product. Health Physics, 48, 87-95.
[17]   | NEA-OECD. (1979). Nuclear energy agency. exposure to radiation from natural radioactivity in building materials. Report by NEA Group of Experts NEA.
[18]   | El-Arabi, A. M., (2005). Gamma activity in some environmental samples in South Egypt. Indian J. Pure Appl. Phys. 43, 422-426.