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.

Radiological dispersion study is a key element in safety analysis report (SAR) of every nuclear facility for the purpose of emergency response planning. In this work, computational approach was used to determine the total effective dose and ground deposition at critical positions onsite and offsite of the Nigerian Research Reactor-1 (NIRR-1) facility which will be useful in the ongoing development of final SAR for NIRR-1 Low Enriched Uranium (LEU) core. In the methodology used, NIRR-1 LEU core was depleted with TRITON module of SCALE 6.2.3 code and the fission inventory in the core was calculated after a continuous operation at full power of 231.931MWD/MTU for 918 Effective Full Power Days (EFPD) at an operation regime of 3 h per day, 3 days per week and 48 weeks per year. Hot Spot was employed for atmospheric transport and dose calculations with consideration of different accidental scenarios in which 20%, 30%, 60% and 100% gaseous inventory was hypothetically released into the atmosphere. From the results obtained, the total effective dose to maximum exposed workers at 10 m and maximum exposed members of public at 300 m from the reactor were 3.10 mSv and 0.43 mSv respectively for the worst-case scenario with 100% release while the maximum ground deposition was 5.5 x 10(6) Bq/m(2) with corresponding maximum ground shine dose rate of 7.5 x 10(-4) mSv/hr. This results are at least one order of magnitude below the dose limits recommended by the International Commission on Radiological Protection (ICRP) and indicate that the present LEU core of NIRR-1 is unlikely to cause any detectable health effect on workers and members of public in the event that 100% of its gaseous inventory is released into air in the environment. Hence it could unequivocally be said that the population is safe from the operation of NIRR-1 in its present location.

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.

In this study, the end of lifetime for the Nigeria Research Reactor-1 high enriched uranium and the low enriched uranium fuelled core were analysed. The SCALE 6.2.3 computational sequences, CSAS6 and TRITON coupled with KENO-VI code were employed for Eigen value and depletion calculations respectively. The study was carried out to demonstrate the advantage of conversion of miniature neutron source reactor from high enriched uranium to the low enriched uranium fuel. The results obtained showed that the clean cold core excess reactivity values of the high enriched uranium and the low enriched uranium fuelled cores were comparable with the experimental data and indicate the suitability of the computational approach used in this study. Similarly, the integral worth of top beryllium shims was greater in the high enriched uranium core in comparison with the low enriched uranium fuelled core and could be attributed to the increased neutron leakage caused by hardening of the neutron spectrum due to higher inventory of U-238 in the low enriched uranium core. Furthermore, the lifetime of the low enriched uranium fuelled core was found to be higher when compared to the high enriched uranium core and could also be attributed to the higher loading of U-235 and U-238 in the low enriched uranium core. The longevity of the low enriched uranium fuelled core in comparison to the high enriched uranium indicate an advantage for its longer time of utilization in neutron activation analysis and underscore the importance of conversion from high enriched uranium to low enriched uranium fuel.

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.

Mining in the studied area is carried out without any precautionary measure.The radiological implication of this activity was reported in this work.Soil samples were collected from the gold mines and analyzed for activity concentration of naturally occurring radioactive materials (NORMs) using NaI (Tl).The average specific activity of 238 U, 232 Th and 40 K were 62.73, 90.66 and 411.27Bq/kg respectively.The radiological parameters D (nGy/h), AED (mSv/y) and Raeq had average values of 100.89, 0.13 and 224.04 respectively.Furthermore, the radiological hazard indices Hex, Hin, Iγ and Iα had average values of 0.61, 0.78, 0.86 and 0.31 respectively, which were lower than the United Nations Scientific Committee on effects of atomic radiation (UNSCEAR) recommended limit of unity.Finally, the total cancer risk due to NORMs in soil was 7.35 × 10 for the whole populations which was within the USEPA acceptable range of 1.00 × 10 to 1.00 × 10 .Therefore, the gold mining activity poses no significant radiological hazard to the members of the public.

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.

No Abstract.

Quantification of heavy metals pollution levels in an environment is a powerful tool for converging raw heavy metals concentrations to a comprehensive level that could easily be interpreted by decision makers, managers and the public. In this work, the heavy metals concentrations were obtained using atomic absorption spectrophotometry. Element specific pollution was assessed by contamination, ecological risk, enrichment and geo-accumulation indices; Pollution load, average pollution, risk and Nemerow pollution load integrated indices were used to quantify the overall pollution level of the studied area. All the single indices computed indicated that both the soil, water and plants were polluted at different levels by all the studied heavy metals. Pollution load index, Risk index, Average pollution index and Nemerow pollution load index were estimated at 3.5, 232.0, 23.9,172.7 respectively for soils, 2.9, 964.8, 24.2, 173.1 respectively for water, 2.2, 1166.9, 14.9, 172.5 respectively for plants. These integrated indices classified the soil and water in the studied area as polluted and under strongly high ecological risk, which calls for immediate remediation measures to be implemented by appropriate authorities to at least minimize these levels.

Analyses were carried on Corchorus tridens Linn in order to ascertain its elemental composition using neutron activation analysis (NAA) and energy dispersive x-ray fluorescence analysis (EDXRF). Nineteen (19) of the detected and determined elements were either essential, trace or heavy (Al, Ba, Br, Ca, Co, Cr, Cu, Fe, Hf, K, La, Mn, Na Rb, Sm, Sc, Th, V and Zn) while ten (10) others (As, Cs, Dy, Eu, Lu, Mg, Ta, Ti, U and Yb ) were found at below detection limit (BDL) levels. Variations of the elemental concentrations from the two techniques and the different parts of the plant were compared using student’s t – test and ANOVA test. Translocation factor of the elements and their concentrations in the different parts of the plant were compared with normal concentrations in plants and recommended daily allowance (RDA) values. It was found that for some of the elements, pattern of distribution is in the order of roots u003e stems u003e leaves while for others there is no regular pattern of distribution. Also, the amounts of certain essential elements in C. tridens L. show that the plant can serve as a means of supplementation of required minerals for man and his animals. Keywords: NAA, EDXRF, C. tridens L., translocation factor and bioaccumulation

The X-ray machines used for radio-diagnostics are required to meet certain quality assurance (QA) measure. For the exposure of patient in diagnostics radiology, individual dose limit does not apply, but justification and optimization of radiological protection do. This paper reports radiological checks carried out in five hospitals in Zaria, Kaduna State, Nigeria. The radiological kVp accuracy, reproducibility and consistence checks on the X-ray machines were assessed. The Quality Control (QC) parameters were evaluated using quality control kitto check the optimal exposure conditions at the five hospitals. The assessment showed that, some of the X-ray machines are over aged and others need adjustment corrections for good radiographs so as not to have rejects that may lead to unnecessary and unwanted exposure. The reported methods can easily be implemented in any clinical situations where kVp accuracy, reproducibility and consistence optimisation check assessment in radiography is necessary. From the study, varying levels of adherence to guidelines were evident with no hospitals demonstrating complete compliance to(NNRA) standard guidelines that is needed to check possible over exposure of patients.

In radiography low-energy x-ray do not contribute to the quality formation of an x-ray image; but instead exposes the body to unwanted radiation. The process of removing this low-energy x-ray from the x-ray beam is known as filtration. Filtrations also increase the average energy (quality) of the x-ray beam. Evaluation of total filtration of xray tube is one of the radiological tests that determine the adequacy of filtration and it also reflects the penetration power of the beam. This research evaluate the Half Value Layer (HVL) of the X-ray in the radiology unit of some Hospitals in Zaria, Kaduna State and determined their homogeneity factor (HF)( whether it is polychromatic or monoenergetic in nature). Series of Aluminum sheets of different thickness in conjunction with ion chambser used to detect and indicate the integrate exposure to be read directly on the internal calibrated scale were used. It was found that some of the hospitals beam homogeneity factors is one (1) while some showed less than one (1). The HVL Aluminum sheet, homogeneity factor for all the hospitals showed little or no variance from the standard recommendations. The calculated first HVL of the hospitals A-E were found to be 0.032, 0.0119, 0.0045, 0.016 and 0.024 respectively. And, the HF 1, 0.98, 1.05, 0.53 and 1 respectively.

In order to determine the natural radionuclides in portable water, samples were collected from fifty locations in Northern part of Kaduna state and were subjected to the investigation of the presence of naturally occurring radionuclides. The radionuclides investigated are potassium-40, uranium-238 and thorium-232 using sodium iodide detector (NaI (Ti)). Results showed that potassium-40 concentration in the water samples has minimum and maximum concentration as 0.124 and 0.849 Bq/L, respectively. The mean value of potassium-40 concentration found in water is 0.416 Bq/L. Also, uranium-238 and thorium-232 investigated in the samples gave mean concentration of 0.0011 and 0.00006 Bq/L, respectively. The results obtained from these analysis shows that samples have radionuclides activity concentration below the recommended value for the radionuclides.

Man is continuously being exposed to radiation due to its presence everywhere on earth. This study is aimed at determining the radium equivalent activity from the soil samples collected from different locations around a superphosphate fertilizer factory in Nigeria. An efficiency and Energy calibrated high purity germanium detector was used to carry out the study while gamma vision software was used for the spectrum analysis. The Activity Concentrations of the soil samples collected from the different locations in the factory ranges from 48.99±7.47 to 520.37±20.46 BqKg-1 for 234U, 55.32±7.59 to 215.18±8.70 BqKg-1 for 232Th, and 101.32±13.34 to 476.04±28.07 BqKg-1 for 40K respectively. The radium equivalent activity was found to be within the range of 215.59 to 607.29 with most of the soil samples having values less than the world allowed value for radium equivalent activity which is 370 Bq/Kg. Hence radiologically the operation of the factory does not appear to pose immediate threat to the factory workers.

Senna occidentalis Linn was subjected to neutron activation analysis (NAA) in order to assess its major, minor, trace and ultra-trace contents. The results indicated that Al, Ca, Fe, Na and K have the highest concentration followed by Mn, Zn and Rb while Co, Rb, La, Sc, Sm and Th were in traces. The presence of toxic metals (such as As) in the plant at low levels and absence of others (e.g Cd and Pb) indicates that the plant can be consumed but bearing in mind that long consumption of the plant may lead to their bioaccumulation. The pattern of bioaccumulation of the elements did not follow any particular trend among the different parts of the plant. Key words: Senna occidentalis Linn and NAA.

This study presents result of external and Internal Hazard indices from the soils samples collected from different locations around a superphosphate fertilizer factory in Nigeria. An efficiency and Energy calibrated high purity germanium detector was used to carry out the study while gamma vision software was used for the spectrum analysis. The Activity Concentrations of the soil samples collected from the different locations in the factory ranges from 48.99±7.47 to 520.37±20.46 BqKg-1 for 234U, 55.32±7.59 to 215.18±8.70 BqKg-1 for 232Th, and 101.32±13.34 to 476.04±28.07 BqKg-1 for 40K respectively. The internal and external hazard indices for most of the locations are greater than unity which requires radiological attention for protection.

This study assessed the radiological levels from Awwal artisanal gold mining exercises in Kebbi State. Results show mean values of activities of 40K>226Ra>232Th numerically as 425.96±5.56, 23.85±2.01 and 18.80±1.21 Bq/kg, respectively. The average outdoor gamma dose was 34.26 nGy/h while the mean annual effective dose rate was 42.15 μSv/year (= 0.042 mSv/year), which is less than 0.07 mSv/year benchmark given in UNSCEAR (1993). Radio logically, the values obtained are low and do not imply any significant health concerns effects on the local population. However, the observed unprofessional practices such as lack of use of gas mask while working in the dust-filled mine cafes and at the mills could expose workers to possible risks from inhalation of respiratory crystalline silica as well as exposure to radon gas.

The amount of radioactivity in soils varies widely and man is continuously being exposed to radiation. This study presents result of outdoor absorbed dose rates and estimated effective dose from the soils samples collected from different locations around a superphosphate fertilizer factory in Nigeria. An efficiency and Energy calibrated high purity germanium detector was used to carry out the study while gamma vision software was used for the spectrum analysis. The Activity Concentrations of the soil samples collected from the different locations in the factory ranges from 48.99±7.47 to 520.37±20.46 BqKg-1 for 234U, 55.32±7.59 to 215.18±8.70 BqKg-1 for 232Th, and 101.32±13.34 to 476.04±28.07 BqKg-1 for 40K respectively. The calculated absorbed dose rate and outdoor annual effective dose from the soil samples ranges from 99.18 to 282.55nGy/hr and 0.120 to 0.342mSv/yr respectively. The mean annual effective dose was calculated to be 0.217mSv/yr. The result showed the radiation exposure level from the factory activities to the public is lower than the IAEA recommended value of 1mSv/yr. Hence radiologically the operation of the factory does not appear to pose immediate threat to the factory workers.

The activity concentrations of naturally occurring radionuclides ( 40 K, 226 Ra 232 Th) in nine organic fertilizers were measured using NaI (Tl) gamma ray spectrometry. The results show that 40 K mean activity concentration was 305.33±0.196Bqkg -1 ranging from 120Bq/kg to 907 Bqkg -1 , 232 Th mean concentration was 45.04Bqkg -1 ranging from 14.66 Bq/kg to 60.20Bqkg -1 . While 226 Ra mean concentration was 24.87±0.02Bqkg -1 with a range of 12.83 to 65.69Bqkg -1 . Radiological hazard indices were calculated and the mean air absorbed dose rate was 51.59nGyh -1 it ranged from 30.33 to 101.23nGyh -1 . The annual effective dose rate averaged 61.33µSvy -1 (0.061) which is lower than the world average (0.07µSvy -1 ) it ranged from 33.39 to 124.51μSvy -1 . The Raeq was 112.90Bqkg -1 which is far below the 370Bqkg -1 maximum.The Hex and Hin averaged 0.31 and