Activity concentrations of natural radionuclides in the sediments of Ogun River, Southwestern Nigeria

2011 ◽  
Vol 147 (4) ◽  
pp. 555-564 ◽  
Author(s):  
N. N. Jibiri ◽  
I. C. Okeyode
2021 ◽  
Author(s):  
Oladele Ajayi ◽  
Olusegun Omogunloye

Abstract Activity concentrations of natural radionuclides in some river waters in southwestern Nigeria were measured using high-purity germanium (HPGe) detector. The activity concentrations ranged from 0.12 to 2.31, 0.17 to 2.85, and 7.86 to 65.51 Bq l-1 for 226Ra, 228Ra, and 40K respectively. The calculated mean of the total annual effective dose were 9.86, 2.46, 1.71, 2.43, 5.74 and 0.99 mSv y-1 for age groups ≤1y, 1-2y, 2-7y, 7-12y, 12-17y, and >17y respectively. Estimated cancer mortality and morbidity risks ranged from 0.04x10-3 to 0.77x10-3 with a mean of 0.42x10-3 and 0.04x10-3 to 0.80x10-3 with a mean of 0.44x10-3 respectively for 226R while they ranged from 0.11x10-3 to 1.89x10-3 with a mean of 0.96x10-3 and 0.16x10-3 to 2.66x10-3 with a mean of 1.38x10-3 respectively for 228Ra. The lifetime average daily dose (LADD) of 226Ra and 228Ra ranged from 9.39x10-14 µg kg-1 d-1 to 181.01x10-14 µg kg-1 d-1 with a mean of 100.06x10-14 µg kg-1 d-1 and 4.82x10-16 µg kg-1 d-1 to 80.70x10-16 µg kg-1 d-1 with a mean of 40.90x10-16 µg kg-1 d-1 respectively.. Radiological hazard indicator of radium is of concern in these drinking river water samples.


2018 ◽  
Vol 14 (2) ◽  
pp. 1-14
Author(s):  
I C OKEYODE ◽  
N N JIBIRI ◽  
R BELLO

This work was aimed at generating a model using least square approximation technique to predict values of activity concentrations of 226Ra in any location along Ogun river in Nigeria using experimental data. Sediment samples were collected in thirty two locations along the river of about 400 km in length. NaI(Tl) gamma-ray spectrometer system was used to obtain activity concentrations of 226Ra.The aver-age value of activity concentration of 226Ra in the sediment samples from the upper region through the middle to the lower region of the river was found to be 12.65 ± 3.48 Bq/kg, having values ranging from 5.57 ± 2.36 Bq/kg (at Ekerin) to 20.40 ± 4.52 Bq/kg (at Sokori). From this work, it was observed that the generated model and experimental data could be used to predict values of activity concentrations of 226Ra in any location along the river once the latitude and longitude (position) are known. Statistical tests on the model also showed that there were no significant differences between the experimental and predicted data of 226Ra and that 98.70% of the experimental data were predicted by the model.


2017 ◽  
Vol 15 (1) ◽  
pp. 82-93
Author(s):  
O O ALATISE ◽  
Y S AKINSANYA

In this work, the presence of natural radioactivity in bottled waters from parts of south-west Nigeria was investigated. The activity concentrations of 226Ra, 232Th and 40K in the water samples were ob-tained using a high-purity germanium detector. The ranges of activity concentrations obtained for 232Th, 226Ra and 40K were 0.15 to 1.25Bq l-1, 0.02 to 2.94Bq l-1 and 6.96 to 46.47 Bq l-1, respectively. 40K has the highest activity concentration in the bottled water samples while 232Th has the least value. The activity concentrations obtained together with ingested dose conversion factors, were used to calculate the annual effective doses for six age groups ranging from < 1 to >17 years. The calculated total annual effective doses (mSvy-1) ranged from 0.01 to 4.16 and the values are age dependent (highest for < 1year and lowest for 7-12years age groups). The results showed that the average annu-al effective dose for 35% of the bottled water brands were below the World Health Organization (WHO) recommended level of 0.1 mSvy-1 for drinking water. Furthermore, out of the remaining 65% that were higher than the WHO recommended level, 9% were higher than 1 mSvy-1, which is the radia-tion exposure limit for the general public according to the recommendation of the International Com-mission on Radiological Protection. Consequently, consumption of some of the bottled water brands investigated in this study could constitute radiological hazard especially for the < 1 and 12-17years age groups.


2020 ◽  
Vol 27 ◽  
pp. 121
Author(s):  
Filothei K. Pappa ◽  
Christos Tsabaris ◽  
Dionisis Patiris ◽  
Georgios Eleftheriou ◽  
Effrossini G. Androulakaki ◽  
...  

Radionuclides are characterized by their nuclear and chemical behavior. Additionally, the geochemical characteristics of radionuclides result in their accumulation in the sediments via sorption processes. In this work the radionuclide activity concentrations obtained by gamma-ray spectrometry (HPGe detector) were converted to metal concentrations as described in [1]. The results were compared with the measured metal concentrations obtained by atomic spectrometry (X-ray fluorescence system-XRF). The samples originate from the coastal environment of two Greek areas, characterized by elevated values of natural radionuclides (e.g. 226Ra) and metals. The preliminary study revealed a good agreement among the concentrations of potassium calculated via activity concentrations of 40K and those of XRF measurement, while a great divergence was observed for the thorium case. These differences can be attributed to the low statistics, as well as to the calibration set-up of Th XRF measurement.


2020 ◽  
Vol 35 (4) ◽  
pp. 347-353
Author(s):  
Sukai Zhuang ◽  
Xinwei Lu

The radiological hazard of building materials originating from clay, rock and other mineral wastes has attracted more attention because they contain natural radionuclides (226Ra, 232Th, and 40K). The activity concentration of radionuclides in red-clay brick samples obtained from three different brickyards in Shangluo, China waHs measured. Various indexes, including radium equivalent activities, Raeq, external hazard index, Hex, internal hazard index, Hin, indoor air absorbed dose rate, D, and annual effective dose, AED, of the aforementioned radionuclides in the bricks were used to assess the radiation hazard for people. The average activity concentrations of 226Ra, 232Th, and 40K were respectively 34.5 ? 1.9, 62.5 ? 2.1, and 713.7 ? 19.8 Bqkg?1 for the studied red-clay bricks. The Raeq values of the red-clay brick samples varied from 167.0 to 184.7 Bqkg?1, which are lower than the limit of 370 Bqkg?1. Moreover, the activity concentrations of natural radionuclides in unfired brick, clay and coal were also determined and the results were compared with that in the red-clay brick samples. This study shows that the red-clay bricks produced in Shangluo, China can be used safely in construction industries.


Author(s):  
N N Jibiri ◽  
S O Egwu ◽  
N E Adesiji

Abstract The natural radionuclides content and radiological assessment of sediments of the Ogunpa waste-water channel were evaluated to ascertain the radiological safety of the sediments as a building material. The mean activity concentrations of 40K, 226Ra and 232Th in Bq kg−1 were found to be 171 ± 69, 11 ± 5 and 10 ± 4, respectively. The overall mean radium equivalent 29 ± 13 Bq kg−1 was &lt;370 Bq kg−1 that can give the maximum recommended dose of 1 mSv to the general public. The activity concentrations of the radionuclides were all less than world average for soils and sediments. Thus, the use of the sediments from the Ogunpa water channel as building material is safe and would not pose any significant radiological health hazards.


2019 ◽  
Vol 184 (3-4) ◽  
pp. 391-396 ◽  
Author(s):  
Saïdou ◽  
Shinji Tokonami ◽  
Masahiro Hosoda ◽  
Ndjana Nkoulou II Joseph Emmanuel ◽  
Naofumi Akata ◽  
...  

Abstract Within the framework of a joint research project on natural radiation exposure and its health effects in Cameroon from 2014 to 2017, the Institute of Geological and Mining Research and the Hirosaki University worked together to carry out natural radiation survey in mining and ore bearing regions of Cameroon. Air kerma rates were measured using car-borne survey method. In-situ gamma spectrometry was used to determine activity concentrations of 238U, 232Th and 40K in soil. A total of 450 RADUET detectors and 350 thoron progeny monitors were deployed in dwellings of the study areas for 2–3 months, collected and analysed. Although natural radioactivity level seems to be normal in most of the surveyed areas, there are many points where activity concentrations of natural radionuclides are largely above the world average values. Indoor radon, thoron and thoron progeny results show the importance to put in place the national radon plan in Cameroon. It was also pointed out that thoron cannot be neglected when assessing inhalation dose.


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