Arsenic and mercury levels in human hairs and nails from gold mining areas in Wassa West district of Ghana

Hair and nail samples obtained from inhabitants of Wassa West District, a major gold mining area in Ghana, were analysed for arsenic (As) and mercury (Hg) using instrumental neutron activation analysis. The samples were irradiated at a thermal neutron flux of 5 x 10P11 Pn cmP-2P sP-1P using the Ghana Research Reactor. Concentrati-on of Hg in the hairs ranged from 1.65 to 20.46 μg/g, which were below World health Organization (WHO) recommended level of 50.00 μg/gP Pfor human hair. Mercury concentrations in human nail samples ranged from 0.97 to 31.94 μg/g. Arsenic concentrations in human hairs ranged from 0.07 to 0.95 μg/g, while the levels in nail samples ranged from 0.08 to 3.90 μg/g. Generally, levels of As in the hair were less than WHO recommended value of 1.00 μg/g, however, the levels of As in 5 nail samples (FNB11B, FNB20B, FNB28B, TNB9B and TNB16B) were above the maximum WHO value of 1.08μg/g. The measurement precision specified by the relative standard deviation was within ± 3 %. The accuracy of determination evaluated by analysing certified standard human hair reference material GBW 09101 was within ± 4 % of the certified value. The levels of As in hair and nail samples of the experimental group were generally higher as compared to the control subject. Similarly, Hg levels in the hair and nail samples in experimental group were also higher compared to the control subject. However, the levels of the toxic elements determined were all below WHO recommended values

Menone, Spectrum of organochlorine pesticide Residues in L.J

Abstract: In this study, the levels of organochlorine pesticide residues in the Densu basin have been investigated using fish samples as a case study. Six fish species namely Heterotis niloticus, Channa obscura, Hepsetus odoe, Tilapia zilli, Clarias gariepinus and Chrysichthys nigrodigitatus were collected from the sampling towns, Weija and Nsawam along the Densu river basin in the Greater Accra Region of Ghana. Composite samples were homogenized, freeze dried and ground to obtain powdered samples. The powdered samples were extracted by soxhlet extraction procedure using (3:1) hexane: acetone mixture. The extracts were cleaned-up using florisil adsorbent and characterized for organochlorine content using Gas Chromatography (GC) equipped with Electron Capture Detector (ECD). The GC recoveries of spiked samples were between 80 to 96%. Fourteen organochlorines (OCs) namely gamma-HCH, delta-HCH, heptachlor, aldrin, gammachlordane, p,p'-DDE, alpha-endosulfan, dieldrin, endrin, endrin-aldehyde, endosulfan-sufate, p,p'-DDT, endrinketone and methoxychlor were identified and quantified. A 100% incidence was recorded for gamma-HCH, delta-HCH, heptachlor, aldrin, gamma-chlordane, alpha-endosulfan, dieldrin and p,p'-DDT, while 75% incidence was recorded for the metabolites, p,p'-DDE and endosulfan-sulfate. The concentrations of OCs ranged from 0.3 to 71.3 :g/kg and were however, below the Australian Maximum Residue Limits (MRL) of 50 to 1000 :g/kg for fresh water fish

Simultaneous cloud point extraction of low levels of Cd, Cr and Hg in seaweed species prior to neutron activation analysis

A one-step preconcentration cloud point extraction (CPE) method has been developed for the simultaneous determination of Cd, Cr, and Hg using a mixture of 1-(2-pyridylazo)-2-naphthol (PAN) and 1-(2-thiazolylazo)-2-naphthol (TAN) chelating agents and polyoxyethylene nonylphenylether-20 (PONPE-20) surfactant. The pH, concentration of PAN and TAN, concentration of PONPE-20, ionic strength and temperature affecting the sepa-ration were optimized. The recoveries of each of the elements under the optimum conditions of pH 8.6, [PAN/ TAN] = 1 x 10-4 M, [PONPE-20] = 0.1 % (m/v), ionic strength = 0.05 M KNO3, and temperature of 41 oC were > 98 %. The concentrations of the elements were determined by neutron activation analysis using the Dalhousie University SLOWPOKE-2 reactor (DUSR) facility. The detection limits of Cd, Cr, and Hg were 6.0, 3.6 and 1.2 ng g-1 respectively, and precision and accuracy of measurements were evaluated. The method was success-fully applied to the simultaneous determination of Cd, Cr, and Hg in fifteen Ghanaian seaweed species. Journal of Applied Science and Technology Vol. 13 (1 & 2) 2008: pp. 48-5

Neutron activation analysis for some toxic elements in the hair of some galamsée workers in Ghana

Hair samples of 26 workers involved in small scale gold mining, popularly called “Galamsée,” have been analysed using thermal NAA for mercury and other elements including As and Sb, all considered as toxic. The following elements have been found in these hair samples Hg. As, Sb, Sm, Ho, Zn, La, Na, K, Au and Br. Similarly, hair analysis of 10 non-galamsée workers, for control and comparison, using the same NAA technique yielded the following elements: Ho, Zn, Na, K and Br. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 2 No. 1 (2000) pp. 39-4

Determination of some wear elements in used car engine oil and oil filter paper using Neutron Activation Analysis

In the present investigation, wear elements in used car engine oil and in oil filter paper were determined using instrumental neutron activation analysis (INAA). The objective was to identify an effective and scientific method of monitoring car engine health. Results obtained from analysing blank and used samples of engine oil and of filter paper showed the presence of Al, Mn, Sb, V, and Zn, in both samples .The relatively higher concentration of some wear elements in the oil filter paper as compared to that of the used engine oil seem to suggest that used oil filter paper analysis using INAA is more effective in following wear trends than used engine oil analysis and could be adopted as scientific technique in monitoring car engine health in Ghana. However, this method does not present a drawback to the used engine oil analysis as in the case of aircraft engines. Used engine oil analysis using INAA still remains an effective, simple and scientific technique for determining wear in car engines. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 2 No. 1 (2000) pp. 53-5

A theoretical model for predicting neutron fluxes for cyclic Neutron Activation Analysis

A theoretical model has been developed for prediction of thermal neutron fluxes required for cyclic irradiations of a sample to obtain the same activity previously used for the detection of any radionuclide of interest. The model is suitable for radiotracer production or for long-lived neutron activation products where the background activities have half-lives ten times less than the activity of the radionuclide of interest. For selected irradiation conditions of timing of the repeated and single irradiation, the calculated results of thermal fluxes for various cycles and periods are discussed in the paper. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 2 No. 1 (2000) pp. 45-5

The nuclear fuel cycle associated with the operation of nuclear power plants

Electric power generation in Ghana is presently achieved through hydro and fossil fuel energy sources. However, recent energy crisis due to sporadic rainfall patterns has mandated the search for alternate and more secure electricity generating technologies. The nuclear power option has been mentioned as an alternative for Ghana but the issue of waste management worries both policy makers and the public. In this paper, the nuclear fuel cycle associated with the operation of nuclear power plants (NPPs) for electric power generation has been extensively reviewed. Different methods or schemes for dealing with the management of spent fuel arisings from the operation of these power plants have also been analyzed. Particular attention has been paid to providing answers to vital questions often asked by the public regarding the front- (nuclear fuel supply) and back- (spent fuel disposal) ends of the nuclear fuel cycle. Different strategies of the fuel cycle have been mentioned. The wet and dry storage methods of spent fuel management required for temporal storage of spent fuel at-reactor (AR) and away-from-reactor (AFR) sites have also been reviewed. Some recommendations have been made for the adoption of a nuclear power program in Ghana by concentrating on management and disposal of nuclear waste. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 2 No. 2 (2000) pp. 121-12

Arsenic and mercury levels in earthenware clays in otsew in gomoa west district of central region of Ghana using instrumental neutron activation analysis

Abstract: This study was conducted to investigate the occurrence and extent of potentially toxic heavy metals, As and Hg in earthenware clay deposits at Otsew in the Gomoa West District of the Central Region of Ghana using the Instrumental Neutron Activation Analysis (INAA) technique. Arsenic concentrations in the clay ranged from 1.55±0.23 to 18.47±2.60 :g/g at S 6 and S 10 respectively with a mean of 9.48 :g/g. Arsenic was not detected in sample S 3 . Mercury concentration in the clay ranged from 0.030±0.005 to 0.31±0.01:g/g in S 2 and S 3 respectively, with a mean of 0.14 :g/g. Mercury was however, not detected in S 10 . The precision and accuracy of the analytical technique (INAA) were assessed by simultaneous activation of reference material IAEA soil-7. The values obtained compared favourably well with the recommended values as Spearman's correlation coefficient was +0.99. The experimental samples were within ±5% of the recommended values. The measurement precision specified by the relative standard deviation was within ±4%