Yield and Nutrient Depletion of Tomatoes by Radio-Frequency Radiation Exposure from Base Transceiver Stations in Ogbomoso, Nigeria

Major concerns are increasingly being raised about the effects of radiofrequency radiation (RFR) on different compartments of the biosphere. A major source of RFR currently being widespread is the base transmission station (BTS) of mobile telephone network, involving transceiver antenna. Soils inclusive of farmlands are likely being affected by the continuous exposure to RFR. The extent of soil depletion brought by RFR from BTS was assessed in this study. The effects of RFR were determined from evaluation of hybridized tomatoes planted on soil collected at different distances away from the BTS under the same agro-climatic conditions. The variation noticed in the tomato yield of the exposed group at the nearest distance and the contents of magnesium and potassium of the exposed groups at all the distances were significantly different when compared with the control group. It is imperative from this study to state that significant effect of RFR from BTS was noticed in plant, thus suggesting that regulations be put in place to check the proliferation of BTS close to residential buildings. Keywords: radiofrequency radiation, base transceiver stations, tomato, exposed group, control grou

Anatomy and Specific Gravity of Wood Samples from Six Nigerian Tree Species in Relation to their Diagnostic X-ray Shielding Capabilities

The basic principle of protection against nuclear radiation is to keep radiation exposure as  much as possible below the maximum permissible dose equivalent (MPD). In order to redress the dependence on costly shielding materials such as lead, steel, glass and gypsum, cheaper and readily available  materials  such as wood have been brought under focus as potential resources for shielding hazardous radiations. Making use of the relative transmission of 60 kVp X-rays by the wood of six Nigerian tree species as reference data, this study examined the wood anatomy of the tree  species (i.e Syzygium guinense (Willd.) DC., Tectona grandis L., Afzelia pachyloba Harms., A.  africana Pers., Gmelina arborea Roxb. and Daniellia oliveri (Rolfe) Hutch. & Dalziel with a view to providing information on the wood anatomical basis for their X-ray shielding capabilities. T. grandis and G. arborea were  the two most fibrous of  the six species studied, with their fibre-to-non-fibrous tissue ratios (F/NF) being 1.24 and 1.01 respectively. Incidentally, these two species transmitted  the least amounts of radiation at an average wood thickness of 5 cm.   Tyloses were observed in the wood of all but G. arborea and D. oliveri, and the % of vessels with tylose ranged  from 20.64 to 50.36.  At  0.05 level of probability, the reference data on relative X-ray transmission showed significant positive correlation  with % axial parenchyma content (r = 0.754), but significant negative correlations with % fibre content (-0.734), %  of vessels with tylose (-0.864), vessel diameter (-0.757), vessel lumen width (-0.753) and F/NF (-0.742). The diagnostic X-ray attenuation capability of the  wood samples examined can therefore be anatomically explained by these six  parameters, and their evaluation in prospective wood samples for shielding hazardous radiations can be useful. Key words: Gmelina arborea, hardwood, hazardous radiation, Tectona grandis, tylose,  wood anatomy, X-ray

Evaluation of soil-gas radon concentrations from different geological units with varying strata in a crystalline basement complex of southwestern Nigeria

The aim of this study is to determine the variation of soil-gas radon concentrations from different rock formations in Ogbomoso, southwestern Nigeria. The radon concentrations at different five geological domains in Ogbomoso are determined with respect to depth. The measurements varied from the surface (0 cm) to 100 cm depth, with an interval of 20 cm. At all the geological domains (Porphyroclastic, Granite, Quartzite, Migmatite and Banded gneiss), radon has its minimum emission over migmatite at 0 cm, while its maximum emissions occured over granite and banded gneiss at 80 cm. The overall soil-gas radon concentrations in Ogbomoso varied from 0.06 to 26.5 kBq/m3, which is within the natural limit of 0.4 to 40 kBq/m3 based on the International Commission on Radiological Protection’s recommendation. An F-ratio of 6.989 and a p-value of 0.001 were obtained for the first inferential hypothesis, while an F-ratio of 2.489 and a p-value of 0.076 were obtained for the second inferential hypothesis using ANOVA test. The post hoc (using Tukey HSD and Duncan) tests revealed that at 60 + cm, depth controls the level of radon concentrations being emanated from the subsurface. The pollution index in Ogbomoso is of level 1 at 80 cm and level 0 (safe limit) at other depths. In conclusion, the soil-gas radon emission depends on the local geology and lithological sequences (depths). Cracks that could act as passage for indoor radon at the floors of the buildings around the polluted zones should be avoided in order to have a sustainable city