Average Concentrations Of 226Ra Research Articles

The current status of natural and artificial radiation in İstanbul 36 years after chernobyl, preceding a potential nuclear threat

AbstractIn this study, the current status of natural and artificial radioactivity levels in soil samples from the Büyükçekmece and Silivri districts of Istanbul, as well as the Marmara Ereğlisi district in Tekirdağ, has been determined in anticipation of a potential nuclear leakage (e.g. the Zaporizhzhia Nuclear Power Plant). Twenty soil samples were collected from the study area, and the radioactivity concentrations of 226Ra, 232Th, 40K and 137Cs were measured using an HPGe detector. The average concentrations of 226Ra, 232Th, 40K and 137Cs were found to be 26 ± 2, 30 ± 2, 540 ± 29, 0.55 ± 0.07 Bq kg−1, respectively.

Assessment of natural and anthropogenic radioactivity levels and their radiological hazards in surface soil samples around oil refinery, Little Aden City, Yemen

The activity concentration of global fallout of 137Cs and naturally- occurring radioactive materials (NORM), which primarily due to the geological and geographical condition of soil. and maybe occur from oil and gas burring processes and consequently accumulate on surface soil around the oil refinery in Aden Assoghra city, Yemen were studied by use the gamma-ray spectrometer equipped with a high purity germanium (HPGe) detector and specially designed shield. The average concentrations of 226Ra, 232Th, and 40K expressed in (Bq kg−1) of the studied samples were (13 ± 0.44) Bq kg−1, (22.1 ± 0.64) Bq kg−1 and (509 ± 9) Bq kg−1, respectively. Low concentrations of 137Cs were noted from some sample in the study area, where ranged from (0.3 ± 0.2) to (1.7 ± 0.2) Bq kg-1. The average values of calculated radiological hazard indices were 40.6 nGy h−1 (absorbed dose rate outdoors), 0.05 mSv y−1 (annual effective dose outdoors), 0.279 mSv y−1 (annual effective dose indoors), 83.7 Bq kg−1 (radium equivalent), 0.23 (external hazard index), 0.26 (internal hazard index), 0.65 (representative level index), 0.174×10-3 (the excess lifetime cancer risk ELCR) and 0.292mSv y−1 (annual gonadal equivalent dose, AGED).

A window into the future: case study of long-term radiological risk modelling posed by unregulated mining waste repurposing activities.

The study aims to assess long-term radiological exposure risks and effects to both industrial workers and occupants living in the near vicinity of local tailing processing plants. The detrimental effects of licensing exemption were studied by comparing contaminated soil collected from 7 unlicensed-by the Atomic Energy Licensing Board-tailing processing plants with soil from control location. It was found that the average concentration of 226Ra, 232Th, and 40K for all seven processing plants fell between the range of 0.1 ± 0.0-7.21 ± 0.1 Bqg-1, 0.1 ± 0.0-16.34 ± 0.27 Bqg-1, and 0.18 ± 0.01-1.74 ± 0.01 Bqg-1, respectively, showing observable indication of soil contamination with Technologically Enhanced Naturally Occurring Radioactive (TENORM) material. The annual effective dose was calculated which showed that most samples exceeded the recommended value of the ICRP of 1 mSvy-1 for non-radiation workers. Assessment of radiological hazards in the environment was done by calculating the radium equivalent value; revealing the exposure risk posed by the contaminated soil is substantial. Using the relatable inputs, the RESRAD-ONSITE computed code revealed that the dose due to internal exposure via inhalation of radon gas contributes the most to the overall exposure. The covering of the contaminated soil with a clean layer is effective in reducing external dose but ineffective for radon inhalation. RESRAD-OFFSITE computer code also revealed that the contribution of exposure via contaminated soil in the neighbouring vicinity is below the recommended 1 mSvy-1 threshold but still contributes to a significant amount cumulatively when considering other exposure pathways as well. The study proposes the introduction of clean cover soil as a viable option in reducing external dose from contaminated soil as 1m of clean cover soil is able to reduce dose exposure by 23.8-30.5%.

Radiation Risk Among Children due to Natural Radioactivity in Breakfast Cereals

Breakfast cereal is one of the common foods for children’s nutrition. It is made from sugar, barley, calcium carbonate, salt, maize, peanuts, molasses, and honey. Therefore, assessing the levels of radioactivity in breakfast cereal is essential for children’s health. Gamma-ray spectrometry NaI(Tl) was used to measure the radiation hazard in ten samples collected from the Iraqi market. The corresponding radiation dose quantities and hazard indices were also calculated. The average concentrations of 226Ra, 232Th, and 40K were found to be 18.195, 20.965, and 796.500 (Bq.kg-1). The annual effective dose equivalent (AEDEin), annual ingestion dose (AID), and the risk of cancer incidence (ELCR) were all seen to be within the accepted levels, except the annual gonadal equivalent dose (AGED). Radiation hazard index values (i.e., Iγ, Iα, and Hin) were noticed to be lower than unity, except Iγ was much higher than the internationally permissible limits for the samples of BGF5, BGF6, and BGF7 recommended by UNSCER2000. Therefore, the study findings reveal that this type of cereal can be considered a safe feeding material for children’s health.

MEASUREMENT OF THE CONCENTRATION OF 226RA, 232TH, 40K IN THE SOIL IN SETTLEMENTS ON THE COASTLINE OF LAKE VAN, TURKEY.

In this study, the natural radioactivity level and its effects on the environment of Lake Van, which is the largest lake in Turkey, were investigated extensively. Initially, 254 soil samples have been collected from the districts (Tusba, Edremit, Gevas, Tatvan, Ahlat, Adilcevaz, Ercis) located around the coastline of Lake Van in eastern Turkey. A Na(TI) detector was used to detect activity concentrations of radium (226Ra), thorium (232Th) and potassium (40K) in each collected soil sample. The obtained average results were compared with available data from Turkey and international data base. The average activity in soil samples was measured as 28.0 ± 3.7-43.6 ± 2.2 Bq/kg for 226Ra, 27.3 ± 4.1-55.4 ± 4.8 Bq/kg for 232Th and 377 ± 42- 706 ± 40 Bq/kg for 40K. It was observed that the average concentrations of 226Ra, 232Th, 40K (43.6 ± 2.2, 55.4 ± 4.8, 706 ± 40 Bq/kg, respectively) for Tatvan district and (37.0 ± 3.5, 51.4 ± 4.2, 479 ± 41 Bq/kg, respectively) for Ahlat district were higher than both national and international average value. In addition, radiological effect parameters originating from terrestrial natural radionuclides for the study area; gamma dose rate (Dout), annual effective dose equivalent (AEDE), and lifetime cancer development probability (LCR) were calculated. The Dout, AEDE, LCR (83.0 ± 3.9 nGy/h, 0.102 ± 0.005 mSv/y, 0.36 ± 0.02 x 10-3, respectively) parameters in Tatvan district were found to be above the international allowable value.

Activity concentrations and bioconcentration factors (BCFs) of natural radionuclides (40K, 226Ra, and 232Th) from cultivated substrates to mushrooms.

This study examined 42 mushroom samples and corresponding cultivated substrates. The radionuclide activity concentrations and bioconcentration factor (BCF) from substrate-to-mushroom were determined. The substrate activity concentrations were 59.1-727.5, 4.5-37.6, and 4.0-53.0Bq/kg dw (dry weight) for 40K, 226Ra, and 232Th, respectively. The average 40K concentrations were 1546.5, 1115.7, and 749.3Bq/kg dw; the BCFs were 2.49, 3.56, and 5.58 for A. bisporus, F. velutipes, and L. edodes, respectively. The 40K concentrations were insignificantly correlated with each species' corresponding substrate concentration. The 40K BCFs had a significantly negative correlation with the substrate concentration for each species. Each mushroom species' 40K concentration was almost stable, suggesting that 40K has a regulated homeostasis for a given species. The average 226Ra concentrations were 5.5, 5.4, and 3.4Bq/kg dw; the BCFs were 0.58, 0.17, and 0.50 for L. edodes, A. bisporus, and F. velutipes, respectively. The average 232Th concentrations were 4.7, 4.7, and 3.0Bq/kg dw; the BCFs were 0.50, 0.11, and 0.53 for L. edodes, A. bisporus, and F. velutipes, respectively. The 226Ra and 232Th concentrations in mushrooms had a weak to moderate correlation with the cultivated substrate concentrations. The absorption of the 226Ra and 232Th from substrate-to-mushroom was similar to the hypothesis of the linear model that mushroom concentration yields a positive correlation with substrate concentration.

Analysis of natural and artificial radioactive emission pattern in Qarasu River catchment in Gorgan Bay, northern Iran

Knowledge of distribution and emission pattern of natural and artificial radioactive elements and their radiation level in the environment is very important to assess its effects on human health and living organisms. In this study, the specific activity of natural and artificial radioactive elements for 30 soil and sediment samples collected from upstream and the outlet of Qarasu River to Gorgan Bay as well as sediments in the eastern part of Gorgan Bay were measured using High-Purity Germanium detector and their distribution map with using SURFER and GIS software was drawn. Specific activity of 226Ra, 232Th, 40K and 137Cs was obtained from 8.80 to 31.92, from 11.16 to 43.19, from 183.77 to 562.88 and from 0.83 to 12.72 in Bq/kg respectively. Upstream of the Qarasu River, the average concentration of 226Ra, 232Th, 40K and 137Cs in the soil samples beside the Qarasu River was higher than the sediments of the river, which indicates the washing of sediments and the transport of radioactive elements by water flow and transfer of these elements to lower areas. In Qarasu estuary and Gorgan Bay, 232Th and 40K distribution patterns are almost similar and the highest concentrations of 226Ra, 232Th and 40K elements are related to Qarasu estuary sediments. The concentration of 137Cs in the mouth of Qarasu River has the lowest value and increases with its distance from the mouth to the middle parts of Gorgan Bay, which indicates a high mobility and a tendency to sediment in calmer places for 137Cs. The measured values for radiological parameters and risk indices due to nuclear radiation in this study are within the allowable range and the amount of available nuclear radiation does not threaten the health of the inhabitants of the region‎‎‎.‎

LEVELS OF NATURAL AND ANTHROPOGENIC RADIONUCLIDES IN SEDIMENTS OF SOME MOROCCAN COASTAL AREAS AND DOSE ASSESSMENT BASED ON ERICA TOOL.

In this work, we considered the concentrations of natural and anthropogenic radionuclides (namely the 40K, 210Pb, 226Ra, 137Cs, 234Th, 228Th and 228Ra) in sediments from Moroccan coast areas by considering estuaries (Sebou and Loukkos) and marine ecosystems (M'diq Bay and three Lagoons: Moulay Bousselham, Sidi Moussa and Oualidia). Sediment samples were analyzed using Gamma spectrometry. The objective was to establish radioactivity levels in Moroccan coastal areas as well as radiological risk assessment by using the ERICA tool. The software allows the estimation of dose rates to biota (a set of reference organisms by default). The highest activity concentrations were found in sediment samples of Sidi Moussa Lagoon, possibly due to the anthropogenic activities, while the lowest levels were reported in Sebou estuary, attributed most probably to a flooding event that occurred in the same year of sampling. Also, 210Pb and 40K have the most significant concentrations, while 137Cs has the lowest concentrations with a great resemblance with similar works. The World Wide Average concentration of 226Ra was exceeded in the three lagoons and that of 40K only exceeded at Sidi Moussa Lagoon. The application of ERICA tool allowed the assessment of total dose rates that are mainly due to internal exposure with strong contribution of 226Ra mainly for phytoplankton in the case of marine ecosystems and insect larvae, mollusc-bivalve, mollusc-gastropod and zooplankton for estuary ecosystems. The total dose rates were far lesser than the admissible dose rate proposed by ERICA tool (10 μGy h-1) and, therefore, unlikely to cause harmful effects to organisms.

Study of primordial radionuclides and radon/thoron exhalation rates in Bageshwar region of Kumaun Himalaya, India

The measurements of primordial radionuclides (226Ra, 232Th and 40K) and radon exhalation rates in soil samples were performed in Bageshwar region of Kumaun Himalaya, India using gamma-ray spectrometry and scintillation detector based radon monitor, respectively. The average concentrations of 226Ra, 232Th and 40K in the investigated region were found to be 36 Bq kg−1, 50 Bq kg−1 and 1595 Bq kg−1, respectively. The average values of radon and thoron mass exhalation rates were observed to be 29 mBq−1 kg−1 s−1 and 256 mBq−1 kg−1 s−1, respectively. The average value of thoron surface exhalation rates was observed to be 2281 mBq−1 m−2 s−1. The external exposure to 226Ra, 232Th and 40K is estimated in terms of different hazard assessment indices and dose quantities. The high values of 232Th content in soil samples indicate the presence of thorium mineralization in the vicinity of study area. The methodology adopted and results obtained are discussed in details.

Dosimetric impact of natural terrestrial radioactivity on residents of lower Himalayas, India.

A comprehensive radio-ecological evaluation of soil samples of Solan and Shimla districts of Himachal Pradesh has been carried out for risk and dose assessment. Twenty-six randomly selected environmental soil samples were analysed for natural radionuclide concentrations (226Ra, 232Th and 40K) using NaI(Tl) scintillator detector. The average concentration of 226Ra, 232Th and 40K was observed as 37, 59 and 430Bqkg-1, respectively, which exceeded the worldwide average of 33, 45 and 412Bqkg-1 reported by UNSCEAR (Sources and effects of ionizing radiation. Report to the general assembly with scientific annexes, New York, 2008). Radium equivalent activity (Raeq), hazard indices (Hex, Hin) and radioactivity level indices (Iϒr, Iα, AUI) and Clark value were checked against their threshold limits, and their mean values were safely below the recommended criteria. This confirms the soil applicability for construction purposes. Indoor and outdoor dose rates (Ḋ), age-dependent annual effective doses (AED), organ-specific doses and lifetime attributable cancer risk (both cancer incidence and cancer mortality) were also computed. Strong positive correlation was established between radon/thoron exhalation rate and their parent radionuclides. Multivariate statistical technique was employed to explore spatial distribution of radionuclides and homogeneity between various radiological parameters.

Some physicochemical parameters and 226Ra concentration in groundwater samples of North Guilan, Iran

The 226Ra concentration and some physicochemical parameters have been measured in thermal spring waters used for medical therapy and drinking purposes in the Astara basin of North Guilan, Iran. The radon emanation method was performed using the AB-5 photomultiplier tube to measure the 226Ra concentration in water samples. Also, the physicochemical parameters of the water were measured in situ using a portable multimeter-VWR multi. The average concentrations of 226Ra were ranged between 3.4 ± 0.06 to 38.2 ± 0.08 mBq l−1. For all samples, the 226Ra concentration values range is lower than the maximum admissible value recommended by the WHO report. The relation between the physicochemical parameters and 226Ra activity concentration of groundwater was assessed. The results indicate a significant correlation coefficient between 226Ra concentration and T, as well as acidity pH. Anomalously high 226Ra concentrations in groundwater are preferentially found in high temperate and electric conductivity along with the acidic environment.

Radiological and heavy metals analysis in soil and water at the former tin mining site in the urban area (Danau Kota Lake, Kuala Lumpur)

Former mining sites are known to be concentrated with enriched naturally occurring radioactive materials (NORM) and heavy metals, as a result of past mining activities. A number of the sites are reclaimed as an open area, which in turn raised concerns regarding public safety. Thus, it is crucial to evaluate the safety of the public engaging in activities around the former tin mining areas. A study is carried out to determine the concentrations of NORM and heavy metals in soil and water collected from Danau Kota Lake, Kuala Lumpur, known as a former mining site. Both NORM and heavy metals were analysed using gamma spectrometry and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The average concentration of 226Ra and 232Th in water collected was 0.7 ± 0.2 Bq/L and 0.1 ± 0.03 Bq/L, respectively. 40K, however, was not detected in the water. The average activity concentration of 226Ra, 232Th, and 40K in soil was 60.8 ± 2.3 Bq/kg, 42.9 ± 1.4 Bq/kg, and 338.4 ± 11.7 Bq/kg, respectively. From the values obtained, it is observed that the activity concentrations for both soil and water are still within the range limit reported by WHO and UNSCEAR. In regards to heavy metals analysis, manganese concentration was the highest in both water and soil with a value of 1.18 µg/L and 147.7 mg/kg, respectively. To evaluate the radiological hazard, the radium equivalent activity index (Req), gamma index (Iγ), absorbed dose rate (D), effective dose rate (Deff) and external hazard index (Hex) are calculated and valued at 148 Bq/kg, 1.1 Bq/kg, 69 nGy/h, 0.1 mSv/year and 0.4, respectively. All radiological hazard indices are found to be below the safety limits. Therefore, the lake area is considered safe for public activities except for Iγ.

Multivariate statistical investigations of natural radioactivity and radiological hazards in building materials mainly used in Amman Province, Jordan

ABSTRACTThirty-two samples of seven types of building materials were collected from different locations (Manufacturers) of Amman-Province, Jordan, and analyzed using a gamma spectroscopy system. From the results, the values observed in the specific activity concentrations of 226Ra, 232Th, and 40K range from 1.88 Bq/kg (bricks) to 69.8 Bq/kg (granite) for 226Ra, 0.78 Bq/kg (limestones) to 88.0 Bq/kg (granite) for 232Th and 2.00 Bq/kg (bricks and limestones) to 950.6 Bq/kg (granite) for 40K. The average concentrations of 226Ra, 232Th and 40K were found to be 17.23 ± 14.56, 13.68 ± 22.19 and 139.71 ± 216.29 Bq/kg, respectively. Different radiological hazard indices were also determined. The results showed that the average radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose equivalent (AEDE), the external hazard index (Hex), the internal hazard index (Hin), activity utilisation index (AUI), the external gamma index (Iγ), and the internal alpha index (Iα) were: 65.62 Bq/kg, 59.20 nGy/h, 0.073 mSv/y, 0.177, 0.246, 0.418, 0.243 and 0.111, respectively. Multivariate statistical methods were applied to determine the existing relationship between radionuclides and radiological health hazard parameters and to assign the maximum contribution of these radionuclides in radioactivity. The estimated mean values of all different hazard indices in this study were in good agreement with that of the international values; therefore, it is concluded that the buildings constructed from such materials are safe for the inhabitants. The measured activity concentrations for these radionuclides were compared with the reported data obtained from similar materials used in other countries.

Annual effective dose and excess life time cancer risk assessment from tobacco plants

Cigarette smoking is one of the pathways that might cause radiation exposure due to the presence of radioactive elements in tobacco leaves used in the manufacture of cigarettes. From the health point of view, the knowledge of radioactivity content of the various radionuclides in tobacco leaves and their derivative products is important to assess the radiological effects associated with tobacco smoking for smokers. In this work, naturally occurring radionuclides 226Ra, 232Th and 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometry. Results show that the average concentrations of 226Ra, 232Th and 40K vary from 4.30±0.2 to 11.85±0.7 (average 8.17), 1.35±0.1 to 16.12±0.9 (average 6.08), and 565.6±15.5 to 1235.81±35 (average 908.09)Bqkg−1, respectively. 137Cs activity concentrations were ranged from 0.15±0.01 to 0.67±0.9 (average 0.44)Bqkg−1. The most important radiological parameters, including radium equivalent (Raeq), total annual effective dose (AED) and excess lifetime cancer risk (ELCR) were calculated. For smokers, the total AED resulting from activity concentrations of 226Ra, 232Th and 40K in tobacco samples ranged from 0.44 to 2.29 (average 1.39)mSvy−1, while of 137Cs varied from 0.01 to 0.04 (average 0.025)μSvy−1 and so very little is contributing to the total dose due to inhalation to smokers. ELCR was higher than the world's average of 1.45×10−3 for tobacco and coal samples. The excess lifetime cancer risk ranged from 1.55×10−3 to 8.01×10−3 with an average value of 4.88×10−3 for all tobacco samples under investigation.

Assessments of 226Ra and 222Rn concentration in well and tap water from Sik, Malaysia, and consequent dose estimates

The ingestion of 226Ra, inhalation, and ingestion of 222Rn in water is considered the primary health risk for lungs and stomach. This study presents the concentrations of 226Ra and 222Rn in well and tap water collected from Sik, Malaysia, using HPGe and RAD7 detectors. Maximum average concentrations of 226Ra and 222Rn were found 47.6 ± 3.6 mBq/l and 9.3 ± 1.4 Bq/l in well water, respectively, and minimum were found 17.1 ± 3.6 mBq/l and 1.6 ± 1.0 Bq/l in tap water, respectively. A positive correlation (R=.88) was found between 226Ra and 222Rn determined by HPGe and RAD7 detectors, respectively. Infants in the age group of 0–1 y appeared to be at risk with respect to the annual effective doses from 226Ra and 222Rn as compared to the other age groups. However, annual effective doses for all three age groups from intake of 226Ra and 222Rn in well and tap drinking water were found below the World Health Organization (WHO) recommended level of .1 mSv/y.

Radioactivity Measurements and Radiation Dose Assessments in Ground Water of Al-Baha Region, Saudi Arabia

Twenty samples of ground water were collected from different wells in Al-Baha region which is located at south-east of Saudi Arabia. Gamma spectrometer based on HPGe crystal was applied to determine activity concentrations in Bq·L-1 of the natural radio nuclides: Radium-226 and Thorium-232 series also Potassium-40. The measured results indicate that the average concentrations of 226Ra, 232Th and 40K in the studied samples were 0.85, 0.43, and 2.84 Bq·L-1, respectively. The average annual estimated effective dose was found to be 0.058 mSv/y which is lower than the annual limit of the dose allowed by WHO Thus, it has no harmful effects on health.

Natural radionuclide transfer from soil to plants in high background areas in Oyo state, Nigeria

The activity concentrations of naturally-occurring radioactive materials present in soil, vegetables, and food crops and their transfer factor (TF) in some high background areas of northern parts of Oyo state, Nigeria, were measured using gamma spectrometry. The average concentration of226Ra,228Ra, and40K in soil is 25.3 ± 7.1, 26.2 ± 5.0 and 381.8 ± 16.0 Bq/kg, respectively in Agbaaru; 25.4 ± 3.1, 39.5 ± 3.8, and 401.9 ± 25.4 Bq/kg in Abuja; 26.5 ± 3.3, 39.2 ± 7.4, and 394.9 ± 18.6 Bq/kg in Arget; and 26.5 ± 3.5, 38.8 ± 2.5, and 389 ± 18.6 Bq/kg in Igbeti. The soil-to-vegetables TF for226Ra,228Ra, and40K is 0.123, 0.058, and 0.215, respectively, in Agbaaru; 0.065, 0.040, and 0.185 in Abuja; 0.093, 0.035, and 0.243 in Arget; and 0.080, 0.050, and 0.265 in Igbeti. Furthermore, the TF from soil to food crops is within the recommended value. Therefore, consumption of these vegetables and food crops will not pose any radiation health concerns to the consumers and the general population.

Correlation between radon and radium concentrations in soil and estimation of natural radiation hazards in Namom district, Songkhla province (Southern Thailand)

The purpose of this work was to investigate the correlation between concentrations of radon (222Rn) and radium (226Ra) in soil and to estimate the potential natural radiation hazard indices in Southern Thailand, Songkhla province, Namom district. In this study, the concentration of radon was measured by RTM1688-2 radon monitor and radium content was made using a high-resolution gamma spectrometer. A positive correlation coefficient between exhaled radon in soil gas and radium concentrations has been observed. Average concentrations of 226Ra, 232Th and 40K in soil samples were (108 ± 26), (114 ± 22) and (1081 ± 278) Bq kg−1, respectively. These values were used to estimate the radiological health hazard indices using standard analytical methods. The estimated absorbed dose rate, annual effective dose equivalent, gamma radiation hazard index and excess lifetime cancer risk are higher than world permissible limit. These values show a significant health risk due to radiation pollution in Southern Thailand.

Natural Radioactivity and Heavy Metals Measurement in Rice and Flour Consumed by the Inhabitants in Saudi Arabia

The natural radionuclides ²²⁶Ra, ²³²Th and ⁴⁰K and some heavy metals (Fe, Cd, Zn, Cu, Mn, Ni and Pb) were measured in samples of rice and flour consumed in Saudi Arabia. Gamma ray spectrometry was utilized to determine the activity concentration of the three nuclides. Heavy metals were analyzed by an inductively coupled plasma optical emission spectrophotometer (ICP-OES).The findings indicated that the average concentration of 226Ra, 228Th and 40K in the rice samples were 1.08, 1.19 and 83.08 Bq/kg, respectively. While, in the flour samples, the average concentrations were1.65, 1.61 and 171.31 Bq/kg, respectively. The ingestion doses were calculated to be 0.224 &muSv/Y for the rice and 0.471 &muSv/Y for the flour samples which are below the recommended 1mSvlimit. The concentration of heavy elements (Fe. Cd, Mn, Ni and Pb) in the rice and flour samples were below the detection limits. Whereas, the mean contents of Cu were 3.75 and 3.6mg/kg of the rice and the flour samples, respectively. The mean values of Zn in the rice and the flour samples were 19.42 mg/kg and 17.3 mg/kg, respectively. The daily intake of Cu and Zn through the rice and the flour samples were lower than the tolerable daily intakes by FAO/WHO; this indicates that there is no risk of intaking these foodstuffs by people.

Lifetime Cancer Risk of Gamma Radioactivity Results from Smoking

Smoking is one of the causes of heart attack, lung cancer and cancers of mouth and larynx. The latter could be arises from exposure of those sensitive organs to a combination of both chemical carcinogenic and radiological exposure results from naturally occurring radionuclides in tobacco leaves. Coal is also used in smoking some types of tobacco products that could be carcinogenic due to presence of a high percentage of an organic matter with inorganic matter such as minerals and trace elements. Varieties of commonly available tobacco products as well as coal samples were examined for their radioactivity content using gamma ray spectroscopy and calculate associated radiological hazards. Results shows that the average concentrations of 226Ra, 232Th, and 40K in tobacco samples vary from 2.6±0.2 to 8.9±0.7 (average 5.4), 1.9±0.1 to 9.5±0.8 (average 4.5), and 517.4±15.5 to 2401.2±72 (average 1360.4) Bqkg-1. Measured activity concentration for coal samples ranged from 10.8±1.1 to 64.4±2.1 (average 40.2), 3.5±0.1 to 28.3±0.3 (average 15.7), and 49.2±0.4 to 301.2±9.5 (average 215) Bqkg-1 for 226Ra, 232Th, and 40K respectively. 137Cs activity concentrations in cigarettes and coal samples were ranged from 0.1±0.01 to 1.3±0.02 (average 0.5) and 2±0.01 to 5.8±0.8 (average 3.1) Bqkg-1 respectively. Radium equivalent, total annual effective dose and excess lifetime cancer risk were calculated. ELCR was higher than world's average of 1.45x10-3 for tobacco and coal samples. In Egypt no special and clear regulations for monitoring radioactivity content in imported coal and tobacco leafs or its products, which appear to be necessary.