Heavy metals are widely known for their potential to cause carcinogenic and non-carcinogenic health risks. In this work, the carcinogenic and non-carcinogenic health risks associated with heavy metals in the vicinity of schools and auto mechanic workshops close to busy roads in Kaduna state was assessed using NEX CG EDXRF MODEL with brand name RIGAKU situated at a UTM Laboratory, Malaysia. The obtained heavy metals concentrations were used to estimate the health effects that might result from exposure to carcinogenic and non-carcinogenic chemicals for both the population ages using US EPA methodology. Findings indicated that in some locations the carcinogenic and non-carcinogenic hazards associated with exposure for residents was greater than the US EPA acceptable thresholds of 10-4 and 1 respectively. This indicated that the heavy metals may result to unacceptable carcinogenic and non-carcinogenic risks, which is an issue of concern in public health especially looking at the way school children play around these areas. The present study therefore provides scientific basis for strategies required to protect human and environmental health in schools and automobile workshops.

Heavy metals are metallic elements with high density compared to other metals and are toxic even at minute concentrations. The concentration of these metals around schools and automobile workshops near frequented roads in Kaduna State, Nigeria, was reported in the present work. Soil samples were collected at varying distances from the major roads (0 – 10m) and at different depths (0 – 60cm). The elemental composition of the samples was determined using Next-Generation Cartesian Geometry Energy Dispersive X-Ray Fluorescence Spectrometer (NEX CG EDXRF) and the statistical correlation and clustering analysis were carried out using SPSS and Mini tab, respectively. The heavy metals Sn, Hf, Ta, V, Cr, Zn, Ir, Pt, Au, Mn, Fe, Co, Ni, Cu, Pb, Th, Ga, As, U, and Zr were considered in the analysis, and their concentrations were presented as Average ± standard deviation. Pearson correlation coefficient indicated different levels of relationships among the heavy metals, while Clustering analysis grouped the soil samples into three major clusters, further confirming the interrelationship among the samples. The concentrations of As, Pb, Cd, Co, Ni were found to be of serious health concern, considering that in almost all the zones in Kaduna state, their average concentrations were greater than the threshold provided by WHO/FAO. Findings from this study indicated that it is unsafe for children to play near schools /auto-mechanic workshops located along highways.

A total number of 166 average measurements were taken using a handheld radiation meter. The mean terrestrial gamma radiation dose rate (TRD) was 32 nGy h−1 which is less than the world average value of 59 nGy h−1. Kaura Namoda has the highest TRD with a value of 38 nGy h−1, while Bakura has the lowest TRD with a value of 28 nGy h−1. The mean activity concentrations of 226Ra, 232Th and 40 K in soil samples were measured using HPGe and were found to be 18 ± 2 Bq kg−1, 22 ± 3 Bq kg−1 and 251 ± 7 Bq kg−1, respectively. Highest activities of 226Ra, 232Th and 40 K were all found to be in Zurmi local government area with respective values of 31 ± 3 Bq kg−1, 34 ± 3 Bq kg−1 and 419 ± 10 Bq kg−1. The radiological hazards indices associated with the measured activity concentrations were determined as 69 Bq kg−1, 0.2, 0.24, 32 nGyh−1 and 0.05 mSvy−1 for radium equivalent (Raeq), external hazard index (Hex), absorbed dose rate (DR) and annual effective dose (AED), respectively. It can be concluded that despite the illegal mining activities within the area, the radiation exposure level in the area is normal and will not pose any immediate radiation effect to humans and their environs.

Radon concentration in water is one of the major problems of radiation protection in recent years. This work assessed the radon concentration in water sources from Sabon Gari, local government area, Kaduna State. The water samples were collected and analyzed using Liquid scintillation counter (Tri-Carb-LSA1000). The overall mean radon concentration of the waters samples was found to be 14.9 BqL-1, which is higher than the maximum permissible limit of 11.1 BqL-1 by USEPA and the world average value of 10 BqL-1 by UNSCEAR and WHO. The overall Annual effective dose (AED) due to inhalation of radon is calculated to be 37.6 μSvy-1. This value is less than the permissible limit of 100 μSvy-1 set by WHO. Also, the overall AED due to ingestion is estimated as 109.0, 154.2, and 180.4 μSvy-1 respectively for both Adult, children and Infant, which is slightly higher than the WHO permissible limit of 100 μSvy-1 for adults and less than the permissible limit of 200 μSvy-1 for children. This result shows that the inhabitants of Sabon Gari local government are safe from any radiological health related effects that may result from the inhalation of radon gas. Also, both Children and Infant are safe from any immediate radiological health risk, but for Adults, consuming any of the water sources (Well, Borehole and Surface) over a prolong period of time is not completely safe and may result in radiological health hazard

Artisanal gold mining activities in Shanono and Bagwai local governments of Kano state Nigeria is a serious threat to the quality of drinking water in the area. This work was carried out to assess the radon, gross alpha and gross beta radioactivity in drinking water sources from artisanal gold mining villages in Shanono and Bagwai local government areas of Kano state, Nigeria. Water samples were collected and analysed for gross alpha and beta radioactivity using a non-gas proportional counter with model protean instrument corporation MPC 2000DP single channel and for Rn-222 using liquid scintillation counter (Tri-Carb-LSA1000). Rn-222 , gross alpha and beta radioactivity had average concentrations of 36.101, 0.142 and 0.285 Bq/L respectively. The annual effective dose for the ingestion of Rn-222 , gross alpha and beta radioactivity were 0.264, 0.228, 0.457mSv/year for adults; 0.395, 0.114, 0.229mSv/year for children and 0.461, 0.057 and 0.114mSv/year for infants respectively. These values were higher than the ICRP, WHO, UNSCEAR and USEPA recommended safety limits, indicating that the water is not safe for drinking and domestic purposes in terms of radiological consequences.

This work was aimed at estimating the carcinogenic and non-carcinogenic health risks due to heavy metals on children and adults living in the vicinity of Shanono and Bagwai gold mining environs, Kano state, Nigeria. Flame atomic absorption spectrophotometry was used to obtain the concentrations of the heavy metals Zn, Cu, Cd, Cr, Pb, As, Cr, Mn, Fe and Ni in (40) soils, (8) drinking water and (8) edible plant samples from artisanal gold mining villages within Shanono and Bagwai environs. The obtained concentrations were used to estimate the non-cancer and cancer risks due to exposure from these metals using models provided by the United State Environmental protection Agency for the population ages. The overall hazard index was found to be 0.125 for children and 0.810 for adults and was largely contributed by Cr, As and Co. The overall total excess lifetime cancer risk was majorly contributed by Cr and As and was estimated as 5.77E-06 for children and 7.07E-06 for adults. The overall hazard index and Excess lifetime cancer risks were below the USEPA threshold limit for non-carcinogenic and carcinogenic risks respectively. Therefore, the exposed population ages are unlikely to experience any adverse carcinogenic or non-carcinogenic risks. (C) 2019 The Author(s). Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative.

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In this work liquid scintillation analysis was used to measure the concentration of 222 Rn in three sources of water around Ririwai Artisanal Tin mine. The annual effective dose due to 222 Rn concentration in surface water source and Domestic water were also determined. The result shows that the tailing bearing water has the highest 222 Rn concentration of 3.04±0.14 Bq/L followed by surface water source with 222 Rn concentration of 2.51±0.13 Bq/L while the Domestic water has the lowest 222 Rn concentration of 2.23±0.11 Bq/L. The results also indicated that the annual effective dose due to the 222 Rn concentration is higher in surface water with 13.05±0.55 mSv/year than in Domestic water with 11.11 ± 0.44mSv/year. The mean 222 Rn concentration obtained in this work is lower than 10.00Bq/L recommended by WHO and UNSCEAR. Also in this study the annual effective dose obtained is lower than the maximum permissible of 0.1mSv/year recommended by UNSCEAR. Keywords: Radionuclide, activity concentration and annual effective dose

A total of 38 different samples of Kohl comprising of 23 indigenous mined products and 15 imported products as control and were analyzed for general elemental composition but with particular interest in those reported to be of relevance (As, Cd, Hg, Ni, Co and Sb) in cosmetics. Energy dispersive X-ray Fluorescence Analysis EDXRA was used for the assay. Only Pb, As, Ni and Cr were detected among the elements of interest. Mean Pb concentrations of 277300 ppm; Ni at 2256 ppm concentration; and As at 810 ppm which are considerably higher than their safety limits (20 ppm p<0.01) were obtained in both the indigenous and imported products. The same risk was statistically observed to be involved following the use of both local and imported kohl products. Again Pb concentrations in excess of what was claimed on the labels of the imported kohl products were observed (p<0.01), hence the need for scrutiny of imported products by the relevant agency. The high concentration of Cr (7460 ppm, p<0.05) in the imported samples signifies its presence as colorant and the need for chromium control for the brands concerned. Also the observed presence of Th in the indigenous (local) samples suggests that Nigerian products may be of radiological effect to health. Measurements were made of gross alpha and beta count of indigenous mined and imported kohl samples The results reveals that all the forms of kohl products assayed, emit both particles but with β’s count substantially higher than the α’s (p<0.5) at a mean β count 4695×10-3 cpm and α count as 283×10-3 cpm. One of the samples from Zamfara State of Nigeria (known for Pb poisoning due to mining activities) shows an exceptionally high count in both α = 8998100 cpm and β = 9315700 cpm which reveals that products from Zamfara State, need a special attention. Application of this product is therefore very much likely to produce radiation damage to the cornea due to low penetration of α and to the internal tissue of the eye due to the relatively high penetration of β s. However, the non-existence of defined safety limits for these particles in Kohl as cosmetic, suggests the need for further research.

This study presents result of outdoor absorbed dose rate and estimated annual effective dose rate from the naturally occurring radionuclides 238 U, 232 Th and 40 K around BirninGwari artisanal goldmine using Instrumental Neutron Activation Analysis (INAA). The results showed that the mean absorbed dose rate is 96.52 nGy/h with a standard deviation of 33.3 nGy/h and the standard error of 9.62 nGy/h the range falls between 26.67-123.85 nGy/h. The mean effective dose rate was estimated to be 0.675 mSv/year with a standard deviation of 0.234 mSv and standard error of 0.068 mSv and in range between 0.183-0.867 mSv. The mean annual effective dose rate from this work is lower than the 1mSv/year recommended by ICRP for public radiation exposure control.

The effects of biomass particle size and addition of binder on the high calorific values (HCVs) of five (5) selected biomass briquettes is studied. Analyses of the experimental results show that finely grinded particles (about 1.75mm and 2.00mm) had low calorific values as the grinding resulted in a loss of some heat and made the sample vulnerable to air oxidation.Addition of gum Arabic binder greatly inceases the high calorific value of all samples followed by starch and top-glue binder tend to decerease the HCVs for the range of biomass tested in the order 25.3201> 23.2985>20.0023 respectively.Thus indicating gum Arabic and starch improves the caloric value while top glue and polyvinyl Chloride (PVC) decreases the calorific value of the samples. An extensive investigation on the PVC dissolved in Toluene compound(organic) as chemical binder was observed to decrease the calorific values of all the briquette samples except those made of coconut shell and rice husk. Keywords: Biomass, Biofuel, Binder, Briquette, High heating value

The detector in experimental physics is an instrument that converts radiation energy into an electrical signal, and this is achieved basically either by ionization or excitation. The choice for any type of a detector (gas-filled, scintillation or semiconductor) for any application depends upon the x-ray of gamma energy range of interest. A working model is therefore developed which is capable of describing the overall NaI(Tl) detection efficiency as a function of several known parameters. The algorithms of this model permit the evaluation of a large variety of sample shapes, sizes, and single initial detector calibration. Therefore, based on the model, on the assumption that the thickness of the detector, T, is 1.0mm, the geometry of the detector, the absorption coefficient, μ, the penetration, ρ, the effective radius in the detector, r, and the distance from source to effective zone of interaction, d, were calculated to be 0.28863054 radian, 0.103198386 ± 0.016841325cm, 0.004999135 ± 2.20454 x 10-8cm, 2.417012326±0.001689568cm and 3.140217836 ± 0.000142627cm respectively and finally, the efficiency, e, was found to be 28.62791552± 7.69750264 at x = 1.00cm

The activity concentrations of naturally occurring radionuclides $(^{238}U, ^{232}Th$ and $^{40}K)$ were investigated in gold ore mined from Birnin Gwari Artisanal Goldmine in Kaduna state Nigeria using Instrumental Neutron Activation Analysis (INAA) technique. Twelve samples were collected from pits at different depths and the locations of pits were marked out using Global Positioning System (GPS). The measured activity concentration due to $^{238}U$ range from 6.18±3.7 to 66.69±4.9 Bq/Kg with mean value 37.36±5.45, Bq/Kg $^{232}Th$ range from 16.65±0.8 to 87.29±1.2 Bq/Kg with mean value of 62.69±6.33 and $^{40}K$ range from 85.13±4.5 to 1564.69±57.9Bq/Kg with a mean value of 997.52±11 9.97 Bq/Kg. The value compared well with published data from other countries and all values from this study are higher than the world average values and other countries with the exception of $^{232}Th$ concentration from India and Malaysia that are slightly higher than the mean value of $^{232}Th$ obtained in this study.

The relationship between the high heating values (H HV’s) and total elemental hydrogen and carbon conte nts of fourteen (14) selected biomass briquettes is studie d. Analyses of the experimental results shows that, the HHV’s of the biomass tested are not linearly related to thei r total hydrogen contents but, directly related to their total Carbon contents. HHV’s calculated from emperical correlati ons using the elemental contents of C, H, N,S and O compared well with that of the American Standard of Testing Materials (ASTM) results and also in good agreement with the widely reported values in the acceptable range of 1 7-21MJ/Kg. The investigation of the effect of parti cle size on the HHV’s indicates that finely ground particles (about 125µm) had low calorific values as the grinding re sulted in a loss of some heat and made the sample vulnerable to air oxidation.

Thermal Activation cross-sections for the (n, γ) reaction were experimentally measured using NIRR-1 facilities. The irradiated target isotopes were 71Ga, 109Ag, 55Mn 94Zr; 96Zr; 238U, 74Se, 75As and 48Ca. In order to obtain reliable activation cross sections, careful attention was paid to neutron irradiation and to the measurement of induced activity. The values obtained for the ten (n, γ) reactions were compared against the comprehensive evaluated values listed in Mughabghab, (2003) and other evaluated data libraries. The values were found to compare well with values evaluated by Mughabghab and those from other libraries.

Analysis of chemical composition and concentration of three Nigerian minerals have been carried out with the research reactor (GHARR-1) at Ghana Atomic energy commission Kwabenya Accra, in order to analyze their gamma photon shielding prospects using WINXCOM software. The physical densities of Serpentinite rock from Katsina/ Zamfara state, Hematite rock from Kogi state and Barite from Benue states of Nigeria were measured, and their moisture content analyzed with the Am-Be neutron source irradiation facility at Centre for Energy Research and Training (CERT) A.B.U. in Nigeria Qualitative and quantitative evaluation of gamma ray spectra of the residual radio nuclides of the rock samples were performed using the SPAN 5.0 software. The result of the chemical composition was observed to have a good elemental correlation with the well known neutron shields (concrete), but indicative of a better substitute to ordinary concrete when, in addition, the moisture retention capabilities, refractive properties and, most importantly, their densities are taken into account. The knowledge of the elemental composition is a requirement for calculating the shielding characteristics using WINXCOM. For an increase in photon energy by a factor of 0.21keV the mass attenuation in Serpentinite decreased by 2.0cm2/g; Hematite had a decrease of 5.0cm2/g; Barite also decreased by 5cm2/g while concrete had its mass attenuated by only 1.3cm2/g. Keywords: Transmission, Reflection, Mineral rock, Thermal neutrons, Fast neutrons, Moisture

For the utilization of the NIRR-1 to include the k0-standardization method, the following neutron spectrum parameters in one inner and one outer irradiation channels were determined using the “Cd-ratio for multi-monitor method”: The thermal to epithermal flux ratio, f, and the epithermal flux shape factor, α. These parameters determined in the inner irradiation channel A1,are: α = - 0.046 ± 0.005 and f = 18.4 ± 0.34 and for the outer irradiation channel A2 α = + 0.024 ± 0.002 and f = 49.5 ± 0.96. The results compare well with reported values obtained from other reactor facilities with similar core configuration such as the Slowpoke and Miniature Neutron Source Reactor facilities available in literature.