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ASSESSMENT OF NATURAL RADIOACTIVITY IN POTATO AND THE HEALTH RISK ASSOCIATED WITH ITS CONSUMPTION IN ENUGU, NIGERIA
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The determination of the specific activity of radioactivity in food stuffs is an important tool in the evaluation of human internal radiation exposure through ingestion. In this regard, the activity of natural radionuclides 40 K, 238 U and 232 Th in potato samples from different markets in Enugu town were determined by means of gamma spectrometry using NaI(TI) detector. The activity concentrations of 40 K ranged from 327.65±17.49-725.30±38.66 Bq.kg-1 with mean value 526.39±135.98 Bq.kg-1 , those of 238 U ranged from BDL-13.94±1.73 Bq.kg-1 with mean of 8.55±4.67 Bq.kg-1 and those of 232 Th ranged from BDL-3.38±0.20 Bq.kg-1 with mean value of 1.14±1.11 Bq.kg-1. The average daily intake of 40 K, 238 U and 232 Th were found to be 20.70, 0.34 and 0.04 Bq.d-1 respectively. The mean annual effective doses to age groups 2-7 yr, 7-12 yr, 12-17 yr and >17 yr were estimated to be 0.240, 0.201, 0.246 and 0.085 mSv.y-1 respectively. These values indicate that individuals within the age group 12-17 yr in Enugu are at higher radiation risk from potato consumption.
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... The earlier studies by same authors on radionuclides concentrations in soil of paddy fields from the study areas had revealed higher levels of 40 K in the paddy soils [3,4,12,13], which might have resulted to it having higher portion of the total radioactivity levels in the investigated rice. Previous studies had also reported 40 K having higher fraction of total radioactivity levels in some food crops [5,6,16,18,21,22,39,[42][43][44]. Since potassium is a major constituent of fertilizers, application by the rice farmers as a means of boosting soil nutrient can also result to the noticeable levels of 40 K measured in the rice, owing to a higher uptake. ...
... The slightly high intake of 40 K is due to it having higher concentrations in the rice than the other nuclides. Since potassium forms part of the essential nutrients in human body system, the present rate of intake [43] estimated for potato consumed in Enugu metropolis is of order of two higher than the present values. Radiation doses from radionuclides accumulated inside the internal organs can lead to changes in physiological and biochemical processes, induction of genetic effects as well as cancer [43]. ...
... Since potassium forms part of the essential nutrients in human body system, the present rate of intake [43] estimated for potato consumed in Enugu metropolis is of order of two higher than the present values. Radiation doses from radionuclides accumulated inside the internal organs can lead to changes in physiological and biochemical processes, induction of genetic effects as well as cancer [43]. As a measure of limiting the radiation doses to "as low as reasonable achievable" the effective dose was incorporated into the framework of radiological protection [52]. ...
Rice is a major staple food consumed globally. Due to geology of the cultivated area, fertilizers inputs and planting cultural, radionuclides present in soil can be transfers to the rice grain. This can present some forms of health risk to human. Therefore, this study assessed the levels of natural radioactivity and committed effective dose due to 40K, 232Th and 238U in freshly harvested rice grains from three different paddy fields (F1, F2, and F3) in Ebonyi State, Nigeria using NaI(TI) gamma spectrometry. The average activity concentrations of 40K, 232Th and 238U in the sampled rice grains were measured to be 129.0 ± 13.0, 3.0 ± 1.3 and 11.7 ± 4.3 Bq kg–1 respectively in F1; 129.1 ± 18.5, 4.3 ± 1.6 and 8.5 ± 4.2 Bq kg–1 respectively in F2; and 89.2 ± 10.3, 4.5 ± 2.1 and 2.7 ± 1.0 Bq kg–1 respectively in F3. The total radioactivity content of the rice was attributed to 40K, contributing about 90% in F1 and 91% in both F2 and F3. The committed effective dose, estimated as 0.12, 0.11 and 0.06 mSv year–1 in the rice from F1, F2 and F3 respectively, together with the resulting cancer risks were within the acceptable limit for radiological risk. This indicates low chances of any radiological health threat to the general public upon consumption. Since the assessment is based on freshly harvested raw rice, concentrations of the radionuclides can still be modified during processing and cooking; thus the generated data of this study can serve as a valuable baseline for estimation of any modification as well as a vital reference data for the radiological food safety and policy framework of nuclear and radiation agencies and WHO/FAO in Nigeria and the rest of the world.
... It is reported that all foodstuffs consist of detectable amount of natural radionuclides and their various progenies [1]. Evidently, quite a sizeable amount of 40 K, 232 Th, 238 U, and 226 Ra has been detected in various food crops consume by humans [3][4][5][6][7][8][9][10][11][12]. Since humans cannot do without food, the habitual consumption of food can thus result to accumulation of the radionuclides in the internal organs of the body. ...
Agricultural practices have continued to make substantial addition to the natural radionuclides contents of cultivated soil, thus leading to elevated levels and consequent transfer to plants. The present study thus assess the levels of 238U, 232Th and 40K, related radiological hazards and their transfer to rice grains in cultivated paddy soil of College of Agricultural Sciences (CAS) campus of Ebonyi State University, Abakaliki, Nigeria. Topsoil soil samples were collected before planting (BP), after planting (AP) and during harvesting (DH) stages and were analyzed for the activity concentrations of the radionuclides using NaI(TI) detector. The activity concentrations of the radionuclides in the soil during the harvesting stage are of significant magnitude than the other stages which follows this order of DH > BP > AP for 232Th and DH > AP > BP for both 238U and 40K. The weighted average activity concentrations of the radionuclides in the rice indicated this order 40K > 232Th > 238U, which are within bearable limits of UNSCEAR and therefore radiologically safe for consumption. The radionuclides transfer factors indicated higher values for 40K in this order of 40K > 238U > 232Th, implying higher tendencies of 40K uptake by the rice plant. The evaluated soil radiological hazard indices predicted a radiological risk to exposed farmers only during harvesting.
The soil-to-orange fruit transfer factor of naturally occurring radionuclides was investigated. The temporal evolution of the three identified radionuclides, Ra-226, Th-232, and K-40, concentration was also examined throughout the growth period of the orange fruits until they reached maturity. A mathematical model was developed to predict the soil-to-fruit transfer of these radionuclides during the development of orange fruits. The results were found to agree with the experimental data. The experimental and modeling results revealed that the transfer factor for all radionuclides showed a similar exponential decline with the growth of the fruit and reached its minimum value when the fruit was ripe.
Dietary exposure of the Valencian Region population to lead, cadmium, inorganic arsenic (iAs), chromium, copper, tin and methylmercury (meHg) was assessed in a Total Diet Study carried out in the Region of Valencia in 2010-2011. A total of 8100 food samples were collected and analysed. Occurrence data were combined with consumption data to estimate dietary exposure in adults (>15 years of age) and young children (6-15 years of age). The estimated intake was calculated by a probabilistic approach. Average intake levels (optimistic scenario) for lead, inorganic arsenic (iAs), chromium and tin were 0.21, 0.08, 1.79 and 1.87 µg kg⁻¹bw day⁻¹ respectively; for Cd and meHg average intake levels were 0.77 and 0.54 µg kg-1bw week⁻¹, respectively and for Cu, 1.60 mg day⁻¹. In terms of risk characterisation, the results showed that 2.84% of the adult population may exceed the BMDL10 (Benchmark dose lower confidence limit) value established for Pb which is linked to renal effects; whereas 28.01% of the young children population may exceed the BMDL01 related to neurodevelopment effects. In addition 8.47% of the adult population and 12.32% of young children exceeded the meHg tolerable weekly intake (TWI).
p>Twenty two potato accessions from USA were evaluated for nutrient contents. Two Bangladeshi varieties were also included for comparison. Nutritional analyses were performed in the Department of Agricultural Chemistry, BAU during November, 2014 to April, 2015. Considering macro nutrient content, the highest values of N, P, K and S were found in the accession AC 10062 whereas Ca and Mg contents were found highest in Bangladeshi variety Cardinal and USA accessions AC 10073, respectively. In case of micro nutrient, the maximum amounts of Cu, Mn, B and Zn were observed in accession AC 10110, AC 10069, AC 10073 and AC 10109, respectively. Significant positive correlations were observed between N-P, N-K and K-Mn contents while K-Mg, Mn-B and Cu-B contents were negatively correlated. Considering all the parameters studied, the USA accession AC 10062, AC 10069 and AC 10110 were nutritionally superior to Bangladeshi variety Diamant and Cardinal. The accession AC 10062 was found as the best USA accession to produce nutrient rich potato in Bangladesh.
J. Bangladesh Agril. Univ. 13(2): 207-214, December 2015</p
Activity concentrations of radionuclides in water, soil and tuber crops of a major food-producing area in Ghana were investigated. The average gross alpha and beta activities were 0.021 and 0.094 Bq/L, respectively, and are below the guidelines for drinking water and therefore not expected to pose any significant health risk. The average annual effective dose due to ingestion of radionuclide in water ranged from 20.08 to 53.45 μSv/year. The average activity concentration of (238)U, (232)Th, (40)K and (137)Cs in the soil from different farmlands in the study area was 23.19, 31.10, 143.78 and 2.88 Bq/kg, respectively, which is lower than world averages. The determined absorbed dose rate for the farmlands ranged from 23.63 to 50.51 nGy/year, which is within worldwide range of 18 to 93 nGy/year. The activity concentration of (238)U, (232)Th, (40)K and (137)Cs in cassava ranges from 0.38 to 6.73, 1.82 to 10.32, 17.65 to 41.01 and 0.38 to 1.02 Bq/kg, respectively. Additionally, the activity concentration of (238)U, (232)Th, (40)K and (137)Cs in yam also ranges from 0.47 to 4.89, 0.93 to 5.03, 14.19 to 35.07 and 0.34 to 0.89 Bq/kg, respectively. The average concentration ratio for (238)U, (232)Th and (40)K in yam was 0.12, 0.11 and 0.17, respectively, and in cassava was 0.11, 0.12 and 0.2, respectively. None of the radioactivity is expected to cause significant health problems to human beings.
Vegetable is an essential daily diet item for the people of Malaysia. This work addressed the radiation and heavy metal exposure scenarios through the consumption of vegetables. Kuala Selangor is located in Sungai Selangor estuary in the west coast of Peninsular Malaysia, which is susceptible to pollution load due to the presence of large-scale industrial and human activities. Radioactivity and heavy metals level in human diet is of particular concern for the assessment of possible radiological and chemical hazards to human health. Therefore, a comprehensive study was carried out to determine the radioactivity levels ((226)Ra, (228)Ra and (40)K) and heavy metal concentrations (Cr, As, Cd, Mn, Mg, Al, Sr, Rb, Sb, Ba, Hg, Fe, Ni, Zn, Cu, Bi and Pb) in 10 varieties of vegetable collected from different farmlands in Kuala Selangor region. The committed doses for (226)Ra, (228)Ra and (40)K due to consumption of vegetables were found 16.6±1.3, 23.6±1.7 and 58±5 µSv y(-1), respectively, with a total of 98±8 µSv y(-1). This dose imposes no significant threat to human health. The estimated cancer risk shows that probability of increase in cancer risk from daily intake of vegetables is only a minor fraction of International Commission on Radiological Protection values. The concentrations of heavy metal were below the daily intake recommended by the international organisations.
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Radioactivity distribution and transfer factor (TF) in plants are crucial parameters used to assess radioactive contamination in the environment and its risks to humans. In this study, the activities of 226Ra, 232Th, and 40K were successfully measured via gamma-ray spectrometry on rice plant components (root, straw, husk, and grain) and on corresponding soil samples collected from paddy fields in Penang, Malaysia. Soil physico-chemical characteristics (pH, citation exchange capacity, electrical conductivity, organic matter, and soil texture) were also analyzed for their estimated effects on soil–grain TF. A major fraction of the total 226Ra and 232Th activities measured at 47% and 57%, respectively, were concentrated in the roots, whereas only about 9% and 8% were distributed in the grains, correspondingly. 40K activity accumulation was about 59% in the straw and 7% in the grains. Rice soil–grain TFs were observed in the ranges of (0.06–0.36) × 10−1 for 226Ra, (0.04–0.14) × 10−1 for 232Th, and (0.74–4.72) × 10−1 for 40K. Results showed that the selected radionuclide distributions in rice are dependent on component type, and their grain concentrations are not linearly related to their soil concentrations. These findings indicated that uptake predominantly depends on soil physico-chemical characteristics.
Activity concentration of natural radionuclides in surface water and sediment from waterfall site, Erin-Oke, Osun State, Nigeria has been determined by gamma spectrometry. The mean activity of ⁴⁰K, ²²⁶Ra and ²³²Th, gives 61.015 ± 15.5 and 172.023 ± 35.433 Bq/kg, 8.165 ± 2.05 and 19.282 ± 4.95 Bq/kg, 5.24 ± 1.57 and 17.089 ± 4.37 Bq/kg in water and sediment respectively. Total annual effective dose ingested by an individual ranges from 10.73 ± 3.36 to 15.18 ± 4.44 mSv/y, 2.50 ± 0.80 to 3.58 ± 0.96 mSv/y and 2.30 ± 0.72 to 3.23 ± 0.93 mSv/y, with mean values of 13.25 ± 3.89, 3.10 ± 0.90 and 2.83 ± 0.83 mSv/y for infants, children and adults respectively. These values are greater than ICRP and WHO recommended limit of 1.0 and 0.1 msv/y respectively. Mean activity concentrations in sediment is 172.023 ± 35.433, 19.823 ± 4.95 and 17.089 ± 4.37 Bq/kg for ⁴⁰K, ²²⁶Ra and ²³²Th respectively, with mean absorbed dose of 26.91 nGyh⁻¹. This value is lesser than UNSCEAR world average value of 55 nGyh⁻¹. Health hazard index and radium equivalent for sediments showed lower values than absorbable limits.
