Evaluation of Background Ionization Radiation Level in Some Selected Dumpsites in Delta State, Nigeria

This paper reports on the evaluation of background Ionization radiation level (BIR) in some selected Dumpsites in Uvwie, Udu and Ughelli North Local government area of Delta State, Nigeria. Background ionization radiation measurements were carried out in five Dumpsites. An in- situ measurement was done using a well calibrated nuclear radiation meters Radalert-100 and a geographical positioning system (GPS). Readings were taken once in a week for one month in ten different locations within each of the Dumpsites. The mean background Ionization radiation values in all the five Dumpsites ranges from 0.017±0.006mR/hr to 0.018±0.007mR/h. All the background ionization radiation level obtained values exceeded the normal world average BIR level of 0.013mR/h. The mean Absorbed Dose Rate values range from 1.430mSv/y to 1.541mSv/y. The results showed that all the dumpsites yearly absorbed dose rate exceeded the 1.0mSv/y maximum permissible limit recommend for the public and non-nuclear industrial environment by International Council on Radiological Protection (ICRP, 1999). This research work indicated that the Dumpsites environment may have been impacted radiologically. This will pose some long-term health side effects on the workers and residents. Keywords: Evaluation, Ionization, Radiation, Dose, dumpsites

Quantification of Activity Concentrations and Radiation Hazard Indices in the Solid Minerals Exploration Fields of Benue State, Nigeria with Multivariate Statistical Approach

The quantification of activity concentrations of radionuclides and the radiation hazard indices in the exploration fields of Benue State have been carried out. Samples of the environmental matrix (soil and minerals) were collected from five mining sites of barite, limestone, lead, coal and salt in Lessle, Gboko, Anyin, Owukpa and Akuana communities. The concentrations of radioactivity was analyzed using NaI (Tl) γ-ray spectroscopy. Results showed that the concentrations of activity of the primordial radionuclides 40K, 238U, and 232Th for soil samples obtained ranged from 11.42 (Salt) – 1491.47 (Lead) Bq/kg, 12.87 (Barite) – 452.32 (Coal) Bq/kg and 6.78 (Coal)–108.41 (Barite) Bq/kg respectively. The mean value activity concentration of the radionuclides in the minerals samples at the mining sites were 10.58 – 623.36 Bq/kg, 1.97 – 540.33 Bq/kg and 2.13 – 25.28 Bq/kg for 40K, 238U, and 232Th respectively. The radium equivalent activity (Raeq), external hazard index, Hex, internal hazard index (Hin), representative index (Ig) and excess lifetime cancer risk calculated for soil and minerals samples compared favourably with the precautionary limits set by UNSCEAR. The excess lifetime cancer risk estimated for soil which was fairly insignificant compared with 0.05 prescribed by ICRP for low level radiation. The multivariate statistical (Pearson’s correlation and cluster) analysis showed some positive significant among 40K, 238U and 232Th, and with other radiological parameters in some mine fields. The study indicated that the minerals and soil samples from the mining sites will pose no major health risk to the public if used for industrial activities except for the salt minerals consumption

Survey of Background Ionization Radiation Level in Some Selected Automobile Mechanic Workshops in Uvwie LGA Delta State, Nigeria

Environmental radiation measurement was carried out in automobile mechanic workshops in Effurun, Uvwie Local government area of Delta State, Nigeria. An in-situ measurement was done using a well calibrated nuclear radiation meter (Radalert-100) and a geographical positioning system (GPS). The mean background Ionization radiation value in all the automobile mechanic workshops is 0.0167±0.002mR/hr  while the mean Equivalent  Dose Rate value is 1.428±0.002mSv/y. Both the background ionization radiation and equivalent dose rate levels obtained values exceeded the normal world average background ionization radiation (BIR) level of 0.013mR/h and 1.0mSv/y respectively (ICRP, 1999). This study revealed that the automobile mechanic workshops environment may have been impacted, but there is no immediate health implication. However, it will pose some long-term health side effects on the workers, residents and the environment. Keywords: Survey, Ionization, Radiation, Dose, Automobile, Mechanic, Workshop

Natural Radioactivity Levels in Surface Soil of Ogba/Egbema/Ndoni Oil and Gas Fields

The activity concentrations and the gamma-absorbed dose rates of the terrestrial naturally occurring radio nuclides viz. 226Ra, 232Th and 40K were determined in soil samples collected from twelve oil fields and their host communities, using gamma ray spectrometry. The soil activity ranges from 10.10 to 41.23 Bq/kg for 226Ra, 7.42 to 30.31 Bq/kg for 232Th and 92.42 to 482.79 Bq/kg for 40K with mean values of 19.16, 21.26 and 224.29 Bq/kg, respectively for host community soil. In the field soil sample, the activity concentration ranges from 16.27 to 52.19 Bq/kg for 226Ra, 9.72 to 34.13 Bq/kg for 232Th and 134.50 to 395.15 Bq/kg for 40K with mean values of 29.61, 17.41 and 262.63 Bq/kg, respectively. The concentrations of these radionuclides are compared with the values of the control samples and the UNSCEAR, 2000 standards of 35.0, 30.0 and 400 Bq/kg for 226Ra, 232Th and 40K respectively. The measured activity concentration of 226Ra, 232Th and 40K in soil is lower than the world average except in two oil fields that 226Ra and 40K exceeded the world average. Radium equivalent activities are calculated from the results to assess the radiation hazards arising due to the use of these soil samples in the construction of dwellings. All the soil samples have radium equivalent activities lower than the limit set in the UNSCEAR report (370 Bq/kg). The overall mean outdoor Absorbed Dose rate are 32.17 and 35.45nGy•h−1 respectively for host community soil and field soil samples. The corresponding effective dose calculated has mean values less than 1.0 mSvy-1, the limit set by WHO (2008). The hazard indices calculated were all less than unity (1) showing that all the soil/sediment samples sampled are still safe for building purpose since their radiological impact is minimal. The percentage contribution of each of these radionuclide are; 64.77% for radium-226, 3.13% for thorium-232 and 32.10% for potassium-40. The entire radiation hazard indices are within the acceptable limit therefore, no immediate health risk as a result of these radionuclide but continuous exposure may result to a significant health impact

Monitoring of specific activities of long-lived radioactive elements along the Mini- Okoro/Oginigba Creek, Port Harcourt

Presence and concentrations of radionuclides could be as a result of natural and human activities. This  study examined the associations and differences  among soil, sediment and water specific activities of long-lived radioactive element (LLRE). Gamma spectroscopy was used to measure the concentration of  the LLRE along the Mini Okoro/Oginigba Creek, Port Harcourt. Specific activities of three selected LLRE were derived. Correlation analysis was carried out to  examine associations among the specific activities across different substrates. A strong and a significant negative correlation exists between the specific  activities of Water 40K and Soil 232Th (r =-0.721, p<0.05); Water 238U and Soil 238U (r = -0.717, p<0.05) and Water 40K and Sediment 238U (r=-0.69,  p<0.05). Comparison using Mann-Whitney U test shows that, soil and sediment are similar in their specific activities with Z values of -0.408, -1.209 and  -1.021 (p > 0.05) for 40K, 232Th and 238U respectively. The concentration of solid samples (soil and sediment) is different from the liquid (water) samples. These associations can be attributed to some specific underlying factors. And in other to understand them there is need for more studies. © JASEMKeywords: Radionuclide; environmental monitoring; Niger Delta; Gamma spectroscopy; Environmental managemen

Determination of Radionuclide Levels in Soil and Water around Cement Companies in Port Harcourt

The study of the radionuclide concentration levels in soil and water samples in Eagle, Atlas and rock cement companies in Port Harcourt was carried out. Soil and water samples collected from the respective premises were analyzed using the gamma -ray spectrometry. The average absorbed dose rates of the soil samples were 49.27nGy/h, 45.21nGy/h and 42.33nGy/h for Eagle, Atlas and Rock cements respectively while the water values were 22.16nGy/h, 20.75nGy/h and 19.37nGy/h for the respective companies. Mean dose rate equivalents of 0.18mSv/y and 0.39mS/y were obtained for the water and soil samples. These results are lower than the International Commission on Radiological Protection (ICRP) maximum permitted limit and therefore, have no significance radiological health burden on the environment and the populace. @JASE

Assessment of Gamma-Radiation Levels in Selected Oil Spilled Areas in Rivers State, Nigeria

A prelude radiological impact assessment of oil spillage on the oil spilled environment, those saddled with the responsibility of cleaning the spilled crude and the host/nearest communities residents in Rivers State Nigeria has been examined in-situ, using radiation meters (Digilert 100 nuclear radiation meter) and a geographical positioning system (GPS). Readings were taken twice in a month for three months in the five different oil spilled site and one measurement taken at a control site where there is no oil spillage but within oil bearing community. The average radiation values in all the oil spilled site is 0.019±0.006mRh-1, this is far above the 0.011±0.003mRh-1obtained for the control and ICRP 0.013±0.005mRh-1 world background levels. The average equivalent dose rate obtained in all the five studied site is 1.6mSvy-1 while the dose rate in the control is 0.93mSvy-1. The results showed that all the oil spilled sites yearly equivalent dose rate exceeded the 1mSvy-1 maximum permissible limit recommend for the public and non-nuclear industrial environment by International Council on Radiological Protection (ICRP,1999). All the oil spilled environment radiation levels exceeded the normal world average BIR level of 0.013mRh-1and other reported values in similar environment. This shows that the oil spilled environment have been impacted radiologically. This will pose some long-term health side effects on the clean-up workers and residents of the host communities. Interim proactive measures are recommended while further and a detail study is ongoing

Radiometric Survey of Aluu Landfill, In Rivers State, Nigeria

A key component of the Millennium Development Goals is a call to halve by the year 2015 the proportion of persons without sustainable access to safe drinking water and basic sanitation in developing nations. This paper reports a study of the terrestrial radioactivity around Aluu landfill in Obiakpor Local Government Area of Rivers State, Nigeria.  Measurements were carried out in the North, South, East and West directions of the Aluu landfill. An in- situ measurement was done using two well calibrated nuclear radiation meters (Radalert-100 and Digilert-50) and a geographical positioning system (GPS). Ten readings were taken in each direction of the landfill at intervals of ten (10) meters away from the landfill making a total of forty (40) sampling points. The mean site radiation levels all the four cardinal points ranges from 0.0123  0.0026 mR/hr (1.034mSv/y) to 0.0151± 0.0012mR/h (1.270mSv/y).  The equivalent dose has an average value range of 1.001mSv/y to 1.270mSv/y which is slightly above the recommended dose limit of 1.0mSv/y for the general public. Comparison of the measured radiation level of site locations with the normal background levels show 21 locations representing 53% of the sampled area exceed the normal background level of 0.013mR/h. This study indicates that there is no immediate radiological health hazard for the general public, however there may be long-term health challenges. Keywords: Assessment, Dose equivalent, Landfill, Millennium, Radalert, Digilert

Gross \u3b1 and \u3b2 Activity Concentration and Estimation of Adults and Infants Dose intake in Surface and Ground Water of Ten Oil Fields Environment in Western Niger Delta of Nigeria

The oil and gas rich Niger Delta region of Nigeria is characterized by environmental degradation leading to environmental pollution from oil and gas activities. This study examined the gross \u3b1 and \u3b2 activity in thirty (river/stream, well and tap) water samples collected from ten oil fields in the Western Niger Delta region of Nigeria. The counting system employed in this analysis is the Gas-flow proportional counter {Eurisys Measure IN20 low- background multiple (eight) channel counter}. Gross alpha activity concentration range from 0.01\ub10.002 to 0.7\ub10.01 (0.15\ub10.003) Bql-1, 0.01\ub10.003 to 0.5\ub10.01 (0.1\ub10.003)Bql-1 and 0.02\ub10.001 to 35.1\ub11.1 (4.1\ub10.1) Bql-1 while beta activity concentration ranged from 1.1\ub10.04 to 13.2\ub10.1 (6.0\ub10.1) Bql-1, 0.7\ub10.1 to 54.7\ub11.3 (8.9\ub10.2)Bql-1 and 0.7\ub10.03 to 151.2\ub11.8 (40.1\ub10.9)Bql-1 for well, tap and river waters respectively. Correlation value between \u3b1 and \u3b2 activities in well, tap and river water is 0.025, 0.047 and 0.512 respectively. The results show that except for the alpha activity in the tap water samples, the average natural activity concentrations of \u3b1- and \u3b2-emitting radionuclides in the samples are slightly above the WHO recommended limit. For all samples the gross \u3b2 activities are higher than the corresponding gross \u3b1 activities. The mean effective equivalent dose intake per year due to alpha activity in the water samples for adults and infants are: 76.4\ub11.8 and 20.9\ub155\u3bcSvy-1, 54.6\ub11.3 and 14.9\ub10.4\u3bcSvy-1, and 2118\ub170 and 584\ub119.2\u3bcSvy-1 in well, tap, and river water samples respectively. The results obtained for dose intake are below the WHO recommended reference level of 0.1mSvy-1, except for the water sample from Uzere river. This study indicates that the water sources evaluated, especially the rivers, are contaminated radiologically. @JASE

Radiological impact of oil and Gas Activities in selected oil fields in Production Land Area of Delta State, Nigeria

A study of the radiological impact of oil and gas exploration activities in the production land area of Delta State has been carried out in-situ using two synchronized and calibrated radiation meters (Digilert 50 and 100) and a geographical positioning system (GPS). Ten oil field facilities were studied. At each facility, nine sampling locations and their host communities were evaluated making a total of 100 study points. Measured exposure rate in the oil field facilities ranged from 0.011\ub10.003mRh-1 in Evwreni camp site to 0.031\ub10.01mRh-1 at the Otorogu gas plant. Mean field exposure rates/equivalent dose rates ranged from 0.016\ub10.006mRh-1(0.839\ub10.34mSvy-1) to 0.0213\ub10.008mRh-1(1.134\ub10.44mSvy-1). In the host communities the values ranged from 0.0115\ub10.003mRh-1 (0.612\ub10.16mSvy-1) in Evwreni community to 0.021\ub10.007mRh-1 (1.117\ub10.37mSvy-1) in Otujeremi town, while for the control study area the value obtained was 0.009\ub10.002mRh-1(0.479\ub10.11mSvy-1). The results show that the radiation levels for the Ughelli East, Kokori, Eriemu, Evwreni, Eriemu, Oweh, Olomoro-Oleh oil and gas fields are within the 1mSvy-1 maximum permissible limit recommended for the public and non-nuclear industrial environment, while the levels for the fields at Otorogu, Ughelli West, Afiesere and Uzere West and East and the host communities of Olomoro, Uzere and Emeragha exceeded the maximum recommended value, an indication that the oil fields and host communities environment have been impacted radiologically. However, these results obtained may not have immediate health hazard, but will pose some long-term health side effects on the staff working in the facilities and residents of the host communities. Interim proactive measures are recommended @JASE