Geoelectrical Investigation Of Aquifer Problems In Gosa Area Of Abuja, North Central, Nigeria

The study of aquifer problems in Gosa area of Abuja, North-central Nigeria, has been undertaken. Abuja, the capital city of Nigeria, is underlain by Precambrian basement rocks. Vertical electrical sounding (VES) was carried out at twelve locations within and around the Gosa area. The interpretation of the data obtained from the sounding revealed that six non-aquiferous geoelectrical layers overlie the unfractured basement. The first layer with average thickness of about 0.5 m and resistivity of 83 Ohmm. The thickness of the second layer is about 0.7 m and resistivity of 438 Ohm-m. The third layer is about 3.4 m thick and resistivity of about 63 Ohm-m. The fourth layer with average thickness of about 16.0 m and resistivity, 236 Ohm-m. The fifth layer with average thickness of 42.7 m and resistivity of about 68 Ohm-m. The thickness of sixth layer varies from 42.7 m to infinity and resistivity of about 2067 Ohm-m. Eight boreholes of varying depths, 45 to 70 m were drilled. Other areas were drilled with good yield of static water level of about 3.7 m, whereas Gosa aquifers were found dried. It could be attributed to basaltic intrusion that shattered the aquifer bearing rocks thereby devoid water in the zone after pronouncing from geophysical investigation

Assessment of natural radioactivity levels in the Ajali Formation, Enugu, South Eastern Nigeria

Activity concentrations of the radionuclides (238U, 232Th and40K) were analysed using high resolution co-axial HPGe gamma ray spectrometer system to know the implication where groundwater is sourced from Enugu, South-East Nigeria. The activity concentration of 238U ranges from 37 ± 4 to 74 ± 6 Bq kg-1 with the highest value of 74 ± 6 Bq kg-1 noted in the thin coal sample. The 232Th activity level in the rock samples ranges from 58 ± 5 to 85 ± 7 Bq kg-1 with the higher value of 89 ± 7 Bq kg-1 reported in the coal sample. For 40K, the activity concentration varies from 140 ± 19 to 293 ± 25 Bq kg-1 with the highest value of 293 ± 25 Bq kg-1 reported in coal samples whereas lowest value of 140 ± 19 Bq kg-1 was noted in Ajali sandstone in the study area (Enugu State). The higher activity levels of 238U, 232Th and 40K reported in coal samples may be due to the closer clusters of weathered surface of Ajali sandstone that overlays the thin coal layer with an escarpment being spread out, implying higher permeability towards deeper direction. All the values are within the recommended level when compared with United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR, 2000). Further research on groundwater activity concentration and rock geochemistry is required within the study area. This will allow for a comprehensive conclusion to be drawn on the level of exposures to the inhabitants relying on groundwater for consumptio

MEASUREMENTS OF SEASONAL VARIATIONS OF RADIOACTIVITY DISTRIBUTIONS IN RIVERINE SOIL SEDIMENT OF ADO-ODO OTA, SOUTH-WEST NIGERIA: PROBABILISTIC APPROACH USING MONTE CARLO

The radioactivity levels were measured using a hand-held gamma-ray survey meter and NaI (Tl) based gamma spectroscopy to evaluate the seasonal variation of radioactivity levels in the riverine area of Ado-Odo Ota. The measured iso-dose map reported higher gamma dose rate of 79 nGy/h, approximately 34% higher than the world average of 59 nGy/h. The values for U-238, Th- 232 and K-40 activity levels ranged between 29.9 and 21.6; 103.2 and 31.2; 802.2 and 233.5 with mean values of 26.1, 55.6 and 499.3 Bq/kg, respectively. According to the mean, 5th and 95th percentiles of the probabilities using theMonte Carlo simulation, the Radium equivalent activities and the absorbed dose rates are within their respective recommended limits of 370 Bq/kg and 84 nGy/h. This study could be used to monitor dose rates and radiological risks for the areas covering the small area (Ado-Odo Ota) to the larger area (West African Region) as baseline data

Radiotoxicity risks of radium-226 (226Ra) on groundwater-based drinking at Dawaki, Kuje, Giri and Sabon-Lugbe area of Abuja, North Central Nigeria

In this study, 226Ra and heavy metal concentrations were studied to represent the radiotoxicity risk of groundwater of Abuja, North Central Nigeria. Groundwater samples were collected from five areas in Abuja, and measurements were taken by using inductively coupled plasma mass spectrometer. Radium (226Ra) concentrations were determined from 0.067 to 0.216 µg/L. The mean annual effective dose from the natural radionuclide of 226Ra for the inhabitants was estimated to be 2.2 × 10−5 mSv. In addition, life average daily dose and cancer mortality risk were calculated. As a result, radiological risks of 226Ra in groundwater are quite low, typically in the magnitude of 10−7 when compared with the international reference dose level

The CUPID (Cultural and Psychosocial Influences on Disability) study: methods of data collection and characteristics of study sample

Background: The CUPID (Cultural and Psychosocial Influences on Disability) study was established to explore the hypothesis that common musculoskeletal disorders (MSDs) and associated disability are importantly influenced by culturally determined health beliefs and expectations. This paper describes the methods of data collection and various characteristics of the study sample.Methods/Principal Findings: standardised questionnaire covering musculoskeletal symptoms, disability and potential risk factors, was used to collect information from 47 samples of nurses, office workers, and other (mostly manual) workers in 18 countries from six continents. In addition, local investigators provided data on economic aspects of employment for each occupational group. Participation exceeded 80% in 33 of the 47 occupational groups, and after pre-specified exclusions, analysis was based on 12,426 subjects (92 to 1018 per occupational group). As expected, there was high usage of computer keyboards by office workers, while nurses had the highest prevalence of heavy manual lifting in all but one country. There was substantial heterogeneity between occupational groups in economic and psychosocial aspects of work; three- to five-fold variation in awareness of someone outside work with musculoskeletal pain; and more than ten-fold variation in the prevalence of adverse health beliefs about back and arm pain, and in awareness of terms such as “repetitive strain injury” (RSI).Conclusions/Significance: the large differences in psychosocial risk factors (including knowledge and beliefs about MSDs) between occupational groups should allow the study hypothesis to be addressed effectivel

Dispersion of gamma dose rates and natural radionuclides in the coastal environments of the Unumherin community in Niger Delta

AbstractThe outdoor gamma dose rates and the activity concentrations of potassium-40, uranium-238, and thorium-232 within the study area were carried out using calibrated hand-held gamma detector (RS-125 gamma spectrometer) and NaI(Tl) gamma spectroscopy. The in-situ measurement results of the gamma dose rate indicate that the hotspot is at location 4 with a value of 100 nGyh-1. The results from the NaI(Tl) gamma detector revealed the highest activity concentrations of potassium-40, uranium-238, and thorium-232 to be 288.09, 96.49, and 136.12 Bqkg−1 for sediments and 257.31, 66.93, and 96.57 Bqkg for water, respectively. The highest mean activity concentration of potassium-40 and uranium-238 was observed in Catfish with values of 151.87 and 38.00 Bqkg−1, whereas the highest value for the activity of thorium-232 was observed in Tilo Fish with a value of 89.02 Bqkg-1. In comparison, all the observed values are higher than the population-weighted average of 420.00, 32.00, and 45.00 Bqkg−1 for potassium-40, uranium-238, and thorium-232 according to UNSCEAR. Geologically, this may be attributed to the marine incursion of regional tectonic subsidence during transgression. Statistically, the correlation results confirmed that the enhanced outdoor dose rates at the coastline environment were caused mainly by uranium-238, followed by thorium-232 and then potassium-40 in magnitude. The mean hazard indices calculated for the samples were also observed to be within the global average values recommended by ICRP