Background Ionising Radiation and Estimated Health Risk in Cereal Farmland in Uyo, Akwa Ibom State, Nigeria

Radionuclides are found in soils, plants, vegetables, fruits and in farmlands. These radionuclides contaminate the farmland, environment, the cereal, food products and could cause deleterious effect on both animals and human beings when ingested or inhaled. The farmland is owned by a government research institute with a mandate to develop improved varieties of some cereal plants. In situ measurement of the background ionising radiation was conducted with a radiation survey meter which measured the exposures in micro Seviert per hour and the expected health indicators risk on the workers evaluated.The mean BIR measured was obtained as 0.097µSv/hr. The annual equivalent dose rate of radiation obtained in the farm was range between 0.1033 to 0.3328 mSv/yr with a mean value of 0.1699 mSv/yr. The mean annual effective dose rate of 0.1190 mSv/yr was obtained while the mean calculated ECLR is 0.416 X 10-3. The AEDR obtained in this study is lower than the international commission on radiation protection recommended safety limit for the public but higher than values from many works in dumpsites. The ECLR value for this work is higher than the recommended safe value, an indication of potential health risk for the workers and inhabitant of the farmland. Therefore regulatory controls are necessary which include workers spending fewer periods in the farmland and decontamination of the farm. Keywords: Gamma radiation, occupational risk, Annual effective dose rate, National Cereal Institute, Uyo

Thermal Properties of Clay Soil from Uruan River Bank in Akwa Ibom State, Nigeria

Clay soils are widely used in Akwa Ibom State for various purposes that require cooling. It is made into pots for storage of drinking water and as walling material. Clay soils are used as a potential thermal insulator for shelters and there is need for the thermal properties of the clay sample to be investigated. The thermal properties of clay soils from selected parts of Akwa Ibom State have previously been investigated but clay from other parts are yet to be investigated; hence this study investigates the thermal properties of clay soil from Uruan local government area of the state. The result shows that the clay has a mean thermal conductivity of 0.393 Wm-1K-1; mean bulk density of 1.69 ×10-3 kg/m3; mean thermal diffusivity of 1.98m2s-1 and mean thermal resistivity is 2.55 mkW-1. The results show that the clay from Uruan, Nigeria has the lowest absorptivity compared to the clay samples from the areas studied so far.  The temperature predictor model also shows that the clay presents the least temperature value during the highest daytime of between 13 hours and 14 hours. The resistivity and thermal conductivity compares better with the values for kaolin obtained elsewhere showing that the clay sample from Uruan local government area, Nigeria contains kaolin. Keywords: Clay, thermal properties, Uruan, conductivity, resistivity     

Phytochemical and antimicrobial properties of Solanum macranthum Dunal

Extracts of leaves, stem bark, roots and fruits of Solanum macranthum Dunal were subjected to preliminary phytochemical screening for the presence of plant secondary metabolites and in vitro antibacterial and antifungal studies respectively. The results of the preliminary investigation revealed the presence of alkaloids, the steroidal nucleus, saponins, tannins, cardiac glycosides, flavonoids, reducing sugars and  anthraquinones. The in vitro antimicrobial activity was done using agar well diffusion technique. Six clinical strains of human pathogenic  microorganisms, comprising two Gram positive, two Gram negative bacteria and two fungi were utilized in the studies. The various plant extracts varied in their high inhibitory activity to Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli at 1000 mg/ml comparable to the  reference antibacterial drug, gentamicin at 2.5 mg/ml. High activity was exhibited against Bacillus subtilis whilst Candida albicans and Aspergillus niger were moderately inhibited even at 2000 mg/ml.Key words: Solanum macranthum, Solanaceae, antimicrobial activity, phytochemical screening

ARTISANAL FISH MARKETING IN AKWA IBOM STATE, NIGERIA: PROBLEMS AND PROSPECTS

This paper was set out to examine the problems and prospects of artisanal fish marketing in Akwa Ibom State, Nigeria. It was observed that artisanal fish is one of the most important sources of food and income to many people, especially in the riverine areas. Artisanal fisheries is labour-intensive and conducted by artisanal craftsmen whose level of income, mechanical sophistication, quantity of production, fishing range, political influence, market outlets, employment and social mobility and financial power depends on it. Artisanal fish marketing involves all activities undertaken in conveying fish from fishermen to consumers. The paper revealed that artisanal fish marketing in Akwa Ibom State involves a lot of problems which often times hinder the objectives of the fish harvesting and marketing business. The problems include inadequate funds, sea piracy, poor post-harvest fish management, high cost / lack of transportation facilities, lack of market facilities and poor interpersonal relations skills among the fishermen. The study concluded that the problems of artisanal fish marketing if solved can result in the enhancement of level of satisfaction in the harvesting, processing and marketing of artisanal fish to meet the need of the society and provide diversified employment opportunities in fishing communities, villages and settlements. It was therefore suggested among others that, Akwa Ibom State Government in collaboration with Federal Government should provide a well-developed landing and processing sites in all the fishing settlements to ensure hygienic and protected space for processing activities as well as proper facilities at processing sites for sanitation and storage. This will help to reduce fish contamination, and prevent microbial attack of harvested fish.  Article visualizations

Entrance Surface Air Kerma for Chest X-ray Examination in some Diagnostic Radiologic Facilities in Akwa Ibom State, Nigeria

This study evaluated patient doses in diagnostic radiology facilities in Akwa Ibom State. Patient doses were evaluated using equations and software. One thousand five hundred and forty one (1541) patients took part in the study. Eight hundred and six (52.3 %) were female while six hundred and thirty five were male patients. Sixty  percent (60 %) patients were of mean  age group below 50 years, and 40 % of the patients were of mean aged above 50 years, their mean body thickness  range between 6.5-8.0 Kg/m, their height range between 1.5-1.7 cm and mean body mass range between 43.2-82.0 Kg. The ESAK value obtained from the software ranged between (0.38-1.69) mGy for male and  female ESAK ranged (0.37-1.69) mGy while  0.015 – 0.091mGy for male nd 0.015- 0.095 mGy for female were obtained from equation. This study shows that, 6 facilities representing 66.6 % of the facilities recorded mean ESAK values that are within the UK range while only 3 facilities representing 33.3 % recorded ESAK higher than the UK range but within the Montenegro and Serbian range.  Mean ED (mSv) values obtained for the examinations in the different facilities show ED ranges of (0.03-0.12) mSv. The differences in mass and height of patients affect the ESAK value from equation because body thickness of the patient depends on body mass and height. Other reasons for this dose variation are chiefly human factor

ROOT GROWTH AND MOISTURE UTILIZATION BY COWPEA (Vigna unquiculata) GROWN ON CRUDE-OIL POLLUTED SOIL

Daily and cumulative root elongation (Re

Need for Prior Geotechnical Engineering Studies for Foundation Design: Cases of Collapsed Buildings in Port Harcourt and Environs, Nigeria

Cases of collapsed buildings have been on the increase in the city of Port Harcourt and environs in Rivers State, in particular and other major cities in Nigeria in recent times. A critical evaluation of the modes of failures indicates that absence of and / or inadequate subsurface geotechnical investigations have been responsible for these building foundation failures. Case histories of four major building foundation failures within the municipality of Port Harcourt and environs in the southern Niger Delta sub-region of Nigeria in recent times are presented and discussed in this paper. The first case history involves a five-storey building that collapsed because it was constructed across a river channel that had sand and gravels as major subsurface materials beneath the building site. As a result of excessive increase in groundwater table during the rainy season and the attendant excessive pore water pressures build-up that led to a rapid loss of the bearing strength of the subsurface materials, it collapsed in the form of a “punching failure”. The second case was a bearing capacity failure due to rapid construction that did not leave enough time for the dissipation of pore water pressures to allow the foundation soils gain shear strength. It collapsed soon after construction was completed. The third case failed as a result of lack of sufficient time to allow for curing of the block materials used for the building. This was a case of structural failure. The fourth case failed as a result of a complete lack of soil investigations that prevented a detailed foundation design for the residential buildings near the banks of a creek at Opobo town, a suburban settlement along a tidal creek. The paper presents and discusses in details the geology, hydrogeology and modes of failures of these four structures and draws attention to the need to carry out detailed subsurface investigations and abide within the building codes (if any)

Physico-Chemical Evolution, Gill Mda Concentration And Histology Of Tilapia Exposed To Mixed Effluent In Okrika River, Rivers State, Nigeria

The physico-chemical evaluation and histological studies on Tilapia (Oreochromis niloticus) exposed to mixed effluent (industrial, domestic and municipal) from Okrika River were investigated. Tilapia samples were collected at about 500 meters from point of entry of mixed effluent into the River (downstream) and about 1.5 kilometers from the point of entry of mixed effluent into the River (upstream) while Tilapia from a fish pond affiliated to Rivers State Sustainable Development Authority (RSSDA) was used as control. Malondialdehyde (MDA) concentration was assayed in the gill homogenates in the Tilapia fish blood serum. It was observed that the biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), conductivity, chromium and cadmium were significantly higher in concentrations in the Okrika River exceeding FEPA regulations in Nigeria. Aside chromium whose concentration was more upstream of the river, BOD, TDS, TSS, conductivity and cadmium show more concentration downstream of the river. Results showed an increase in gill MDA concentration upstream samples (0.00±0.00 to 1.51± 0.24nm/mg), downstream samples (1.51±0.24 to 2.32±0.66nm/mg) and the control samples (2.32±0.66 to 2.70±0.89nm/mg). No significant change was also observed in gill MDA concentration of both downstream and upstream samples when compared with the control. Histology of the gill showed vacuolar degeneration, focal areas of necrosis and aggregation of inflammatory cells between the hepatocytes. From the investigation, the mixed effluents discharged into the river are toxic to the marine environment. Key words:  Physico-chemical, Histological, Effluent, Malondialdehyde and Tilapia

Assessing Image Classification Accuracy with Principal Component Analysis Algorithm Case Study: Odeda LGA of Ogun State, Southwest Nigeria

The aim of this study is to assess image classification accuracy using the instrumentality of Principal Component Analysis (PCA). It is focused on evaluating the accruable benefits of Principal Component Analysis as part of an image preprocessing procedure for image classification. Land use land cover (LULC) and accuracy assessment datasets were obtained with remote sensing and geographic information system’s software. The principal component analysis was statistically used to assess the level of correlation amongst bands in Landsat 8. The image classification was premised on the Maximum Likelihood classifier for land use land cover analysis. To ascertain the accuracy of the classified images, the Producer’s accuracy, User’s accuracy and Kappa coefficient derivatives of accuracy assessment was calculated. The results revealed that the first three PCs of the raw Landsat data accounted for 99.37 % variance of the original Landsat data, while the last three PCs represented only 0.63% of the original data. The results of land use land cover based on raw bands composite were Forest (41%), Shrubs (33%) and Built-up (26%) respectively. On the other hand, land use land cover based on Principal Component Analysis showed Forest (39%), Shrubs (39%) and Built-up (22%) respectively. Comparing the results of Kappa coefficients of both LULC of raw bands’ composite was 0.88 while that of PCA was 0.91. Conclusively, there is a significant level of difference in the classification outputs of PCA derived classification and that of raw Landsat bands’ composite