NORM in Instant Noodles (Indomie) Sold in Iraq

Natural Radioactivity elements are distributed everywhere in the environment with different concentrations. Their concentrations depend on the local geological condition and they vary from one place to another. It is necessary to monitor the release of radioactivity into the environment in order to provide an appropriate protection for humans [1]. Radionuclides in soil are absorbed by plants and will be available for further redistribution within food chains. These plants may be involved directly in human food [2]. Much work is reported on radioactive food contamination in the environment and its transfer or pathway mechanism to plants, animals and human population [3]. Ingestion of natural radionuclides depends on the consumption rate of food, water and the radionuclide concentrations. Naturally occurring radio nuclides enter the human body mainly by ingestion of primordial radio nuclides and their progeny 40K, 238U and 232Th series. The ingested radio nuclides may be concentrated in certain parts of the body, for example 40K is accumulated in muscles, 238U is in human kidney and lungs, and 232Th is in liver and skeleton tissue [4]. In Iraq, neither surveys of radioactivity in Instant Noodles were carried out nor for concentration of natural and anthropogenic radioisotopes. Therefore, the establishment of radioisotope concentrations will prove meaningful information that contribute to realize the population exposure and to the setting up of original base data, IAEA [5]. Moreover, numerous studies were conducted worldwide to investigate natural radionuclides in consumed food at different parts of the world [6-9]. Instant noodles played a pivotal role in addressing food issues, especially when the world population is anticipated to reach 10 billion by 2050 because it is cheap, tasty, storable and easy to cook [10], therefore studied Instant noodles in all scientific research such as natural radioactivity is important. Because Instant Noodles is popular among all ages, the current study focuses for investigating natural radioactive content in Instant Noodles. Study aim is to estimate radiation hazard indices from consumption of Instant Noodles among various types brand name in Iraqi markets.


Introduction
Natural Radioactivity elements are distributed everywhere in the environment with different concentrations. Their concentrations depend on the local geological condition and they vary from one place to another. It is necessary to monitor the release of radioactivity into the environment in order to provide an appropriate protection for humans [1]. Radionuclides in soil are absorbed by plants and will be available for further redistribution within food chains. These plants may be involved directly in human food [2]. Much work is reported on radioactive food contamination in the environment and its transfer or pathway mechanism to plants, animals and human population [3]. Ingestion of natural radionuclides depends on the consumption rate of food, water and the radionuclide concentrations. Naturally occurring radio nuclides enter the human body mainly by ingestion of primordial radio nuclides and their progeny 40 K, 238 U and 232 Th series. The ingested radio nuclides may be concentrated in certain parts of the body, for example 40 K is accumulated in muscles, 238 U is in human kidney and lungs, and 232 Th is in liver and skeleton tissue [4]. In Iraq, neither surveys of radioactivity in Instant Noodles were carried out nor for concentration of natural and anthropogenic radioisotopes. Therefore, the establishment of radioisotope concentrations will prove meaningful information that contribute to realize the population exposure and to the setting up of original base data, IAEA [5]. Moreover, numerous studies were conducted worldwide to investigate natural radionuclides in consumed food at different parts of the world [6][7][8][9]. Instant noodles played a pivotal role in addressing food issues, especially when the world population is anticipated to reach 10 billion by 2050 because it is cheap, tasty, storable and easy to cook [10], therefore studied Instant noodles in all scientific research such as natural radioactivity is important. Because Instant Noodles is popular among all ages, the current study focuses for investigating natural radioactive content in Instant Noodles. Study aim is to estimate radiation hazard indices from consumption of Instant Noodles among various types brand name in Iraqi markets.

Samples collection and preparation
Thirteen Instant Noodles samples were collected from some supermarkets that available in Iraq Markets. The collection period between December 2014 to February 2015. To ensure a comprehensive and a wide-spread representation, 13 different brands that originated from 5 different countries were selected (Table 1). Enough quantity of food samples (Instant Noodles) were collected for the analysis and each sample underwent a pre-treatment that consisted of powdering. This step was crucial for achieving a homogeneous state for the sample. Because Instant Noodles come dried, the samples did not undergo any drying process.

Radioactivity measurements
Radioactivity counting: Gamma-ray spectrometer equipment's is used. It is consists of scintillation detector NaI(Tl) of ("3×3") crystal dimension (Model No. 802 series, Canberra Inc.), supplied by (Alpha Spectra, Inc.-12I12/3), coupled with a multi-channel analyzer (MCA) (ORTEC -Digit Base, Model No. 1104) with range of 4096 channel joined with ADC (Analog to Digital Convertor) unit, through interface. Resolution value of the detector is about 7.9% for 0.662 MeV of a 137 Cs standard source; therefore it is capable of distinguishing the gamma ray energies considered during these measurements. The detector in this study was calibrated using a set of standard γ-ray 1-μCi active 137 Cs, 60 Co, 54 Mn and 22 Na sources. Moreover, it was shielded by a cylindrical lead shield in order to achieve the lowest background level. The relative efficiency for each of the peaks can be calculated with the mentioned energy depending on N p (net peak area (count/ sec) at E γ ), N p ( net peak area (count/ sec) at E γ ), I γ ( intensity of emitted gamma ray (%)) and A( activity of standard source in (Bq)) by the following equation [11]: The samples of Instant Noodles were placed symmetrically on top of the detector and counting for each sample was done for a period of 5 hr (18,000 s). The net area counts under the photo peaks for each radionuclide that was analyzed using the ORTEC Maestro-32 data from the memory of the MCA which subtracts counts due to back-ground

Abstract
The Radioactivity is invisible, tasteless and not mentioned on food labels, therefore it must be measured the Radionuclides levels in all samples food, we selected the important food that it is widely used in world Instant Noodles. Natural Radioactivity and Some Radiological Parameters of 13 instant noodles samples that available in Iraq supermarkets was determined using Gamma-ray Spectroscopy method. The results showed the range of specific activity for Ra-226 from (2.382 ± 1.128) Bq/kg to (31.918 ± 3.374) Bq/ kg with an average (14.98231) Bq/kg, for Th-232 from (1.509 ± 0.297) Bq/kg to (9.269 ± 0.716) Bq/kg with an average (3.4421538) Bq/kg and K-40 from (113.069 ± 6.854) Bq/ kg to (392.453 ± 8.482) Bq/kg with an average (234.9235) Bq/kg, while the average results of Radium equivalent activity and Internal hazard indices were (37.99370015 Bq/kg and 0.143116) respectively. All specific activity (Ra-226, Th-232 and K-40) investigated in the noodle samples occurred within the threshold limit of UNSECR, (2000) standard (35, 30 and 400) Bq/kg, also Radium equivalent activity and Internal hazard indices were lower than the worldwide average (370 Bq/kg and 1) respectively. All the samples of fast noodles (Indomie) that are available in the Iraqi market are edible for all people, but caution should be taken for accumulation over the time of this natural radioactivity especially in samples where they appeared near the threshold limit amount.
Page 2 of 4 effects from the total area. The Radium-226 and Thorium-232 activities were determined indirectly through the secular equilibrium with their decay products. NaI(Tl) detector was made basing on the fact that it has a poor resolution. Hence, the peaks of interest to be considered would be sufficiently discriminated and intense. The activity of 226 Ra was estimated by the gamma transition lines of 214 Bi (1.760 MeV), while the activity of 232 Th was determined using gamma transition lines of 208 Tl (2.614 MeV) and the activity of 40 K was determined directly from the peak areas at 1.460 MeV. These peaks are clean, reasonably and strongly with very low continuum.
Radioactivity determination: Specific Activity of natural radioactivity in the Instant Noodles samples was computed by the net area count after background corrections in each photo peak, using the expression [12][13][14]: Where: C is the Specific activity of the radionuclide in the sample.
C n is the count rate under each photo peak due to each radio nuclides.
ε is the detector efficiency of the specific gamma ray. I γ is the absolute transition probability of the specific gamma ray. M s is the sample mass in (kg).

Calculations of radiological parameters:
To arrive at a safe conclusion on the health impact of an environment, it is important to assess the gamma radiation hazards to human associated with the food used for eating of Instant Noodles. This is done by calculating the different radiation hazard indices. Radium equivalent activity can be defined on the basis of the preliminary estimation of the quantities of these radionuclides releasing the same gamma ray dose ( 226 Ra, 232 Th, and 40 K). Consequently, the following Radium Equivalent Activity (Ra eq ) of a sample in (Bq/kg) can be evaluated as [ where C Ra , C Th , and C k are the activity concentrations of 226 Ra, 232 Th, and 40 K in Bq/kg, respectively. Ra eq activity has been assumed as 370 Bq/kg (10 pCi/g) 226 Ra, 259 Bq/kg (7 pCi/g) 232 Th and 4810 Bq/kg (130 pCi/g) 40 K provide the same gamma ray doses. Widely hazard index used radon and its short-lived progeny are hazardous to the respiratory organs which is called the internal hazard index. The internal exposure to radon and its daughter progenies is quantified by the internal hazard index H in , which is given by the equation [15]: For the safe use of a material in the construction of dwellings, index H in should be less than unity. Table 2 shows the specific activity of 226 Ra, 232 Th, and 40 K of the collected Instant Noodles samples which is Sold in Iraq Supermarkets. The specific activity of radionuclide collected from samples under study from (2.382 ± 1.128) Bq/kg to (31.918 ± 3.374) Bq/kg for 226 Ra, (1.509 ± 0.297) Bq/kg to (9.269 ± 0.716) Bq/kg for 232 Th, and (113.069 ± 6.854) Bq/ kg to (392.453 ± 8.482) Bq/kg for 40 K. There is a variation in the specific activity of radionuclides in different Instant Noodles samples, for example (S11) which is China product has lowest 226 Ra concentration, while (S3) which is SAUDI ARABIA product has the maximum value, (S8) UNITED ARAB EMIRATES product has the lowest 232 Th concentration of maximum is (S3) SAUDI ARABIA product, and the lowest 40 K concentration is (S4) which is SAUDI ARABIA product and the maximum is (S2) also SAUDI ARABIA. The results show, (Figures 1-3) that the specific activity of 226 Ra, 232 Th and 40 K respectively in all Instant Noodles samples appeared lower than recommended limit of (UNSCEAR, 2000). From the specific activity of 226 Ra, 232 Th, and 40 K of Instant Noodles samples, the Ra eq and internal radiation hazard is calculated and the results are in (Table 3). The Ra eq is calculated and the value ranges from (15.189) Bq/kg to (67.629) Bq/ kg, which is very much lower than the recommended safe limit (370 Bq/kg) by Organization for Economic Cooperation and Development [16]. Also we found the internal hazard index is ranges from (0.052) to (0.268). All the calculated values are lower than the recommended safe limit (1) by Organization for Economic Cooperation and Development [16]. Correlation is a statistical measure for finding the degree of relationship between two or more variables. (Figure 4) shows the correlation between Ra eq and 226 Ra activity concentrations computed        Ra, 232 Th and 40 K have been measured in Instant Noodles samples that sold in Iraqi Markets using gamma-ray spectroscopy. The activity profiles of the radionuclides have clearly showed low activity for all samples under study. Some Radiological Parameters such as the Ra eq and the H in were calculated to assess the radiological hazards from eating of Instant Noodles. All the calculated parameters are lower than the recommended safe level. Thus, the result of this work showed that the natural radioactivity in each available noodles samples brands consumed in the Iraqi markets do not pose any health risks or effect of Radioactivity. But in the long term, accumulation of the radioactivity from some samples under study could lead to health issues [17][18][19].