The complementarity of PIXE and PIGE techniques: A case study of size segregated airborne particulates collected from a Nigeria city.

The Proton Induced X-ray Emission (PIXE) technique is a reliable ion beam analytical tool for the characterization of thin aerosol samples, but it can underestimate the lightest measurable elements (such as Na, Mg, Al and Si) owing to the absorption of their X-rays inside the sample. The Proton Induced Gamma-ray Emission (PIGE) technique could be employed as avalid means to determine corrections for such an effect. Hence, in this study, Fine (PM(2.5)) and Coarse (PM(10-2.5)) particulate matter samples collected at Ikeja, Lagos-Nigeria, using a double staged 'Gent' stacked sampler were analyzed for their elemental concentrations using an external beam set-up for simultaneous PIXE and PIGE measurements. The measured PIXE concentrations as well as the PIGE correction factors for Na and Al detected in the PM(10-2.5) samples (collected on polycarbonate Nuclepore membranes) are reported. The concentrations of 24 elements (Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Se, Br, Rb, Sr, Zr, Cs and Pb) detected in both fractions were displayed, discussed and likely sources of these elements were also identified.

Effects of fungicide residues on the physico-chemical characteristics of soils of a major cocoa-producing area of Nigeria.

The effects of copper-based fungicide residues on some physico-chemical properties of soils in some cocoa-producing areas of Nigeria were investigated. The results show that the fungicide residues cause significant increases in the soil pH, organic matter and copper concentrations while lowering the concentrations of inorganic nitrogen, available phosphorus, exchangeable potassium and sodium. Slight increases were also observed for the cation exchange capacity (CEC) and exchangeable Ca2+ and Mg2+ but there are no significant changes in the Zn, Fe and Mn concentrations with fungicide treatment. It is concluded that the copper-based fungicide residues predispose the soils to nitrogen, phosphorus and potassium (N, P and K) deficiencies and perhaps copper toxicity if not properly managed.

Trace elements in bottled and soft drinks in Nigeria--a preliminary study.

The levels of Co, Cu, Zn, Cd, Pb, Cr, Se and Ni were determined in bottled waters and soft drinks in Nigeria. The mean levels of the elements ranged between 0.52 microgram/l for Co and 14.8 micrograms/l for Mn in the bottled waters and 3.10 micrograms/l for Co and 82.4 micrograms/l for Mn in the soft drinks, respectively. Comparison of the elemental concentrations in the water samples with WHO limits showed the mean levels of all the elements investigated in all the samples were below the WHO maximum allowable concentrations for drinking waters.

Trace elements in drinking and groundwater samples in southern Nigeria.

The levels of Al, Sn, Cs, Rb, Sr, Br, Cr, Mo, Co, Ba, Cu, Zn, Cd, Pb, Mn, Se, As, V and Ni were determined in drinking water supplies (public taps, domestic taps and treated water from public water sources) and groundwater supplies (boreholes and shallow wells) in some parts of Southern Nigeria. The water samples were analysed using inductively coupled plasma mass-spectrometry (ICP-MS). The mean levels (microgram/l) of all the elements ranged between 0.35 microgram/l for Cs and 87.3 micrograms/l for Zn in the drinking waters and between 0.54 microgram/l for Co and 420.3 micrograms/l for Ba in the groundwaters. A comparison of the elemental concentrations with WHO guidelines showed that with the exception of violations of Cd, Cr and Se limits in some of the drinking water samples, the levels of all the other elements investigated were below the WHO maximum allowable concentrations.

Environmental impact of vehicular traffic in Nigeria: health aspects.

Blood lead levels were analysed and pulmonary function tests were performed on Nigerian traffic wardens, comprising sixty from Lagos (ages 24-52 years; 27 +/- 6), thirteen from the sparsely populated university town of Ile-Ife (ages 22-40 years; 27 +/- 8) and a control group of twenty-four subjects (age 19-55 years; 31 +/- 8). Perkin-Elmer Zeeman 3030/HGA 600 AAS was used for blood analysis. The mean lead level in Lagos wardens was 18.1 +/- 6.4 micrograms/dl, which was significantly higher than the level of 10.2 +/- 2.7 micrograms/dl in Ife wardens and 12.9 +/- 7.0 micrograms/dl obtained in the controls (P < 0.001). However, there was no significant difference between the levels of blood lead in Ife traffic wardens and normal controls. Significant differences (P < 0.0005) in spirometric measurements--peak flow rate (PEFR), forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)--were observed between traffic wardens and control subjects. The noise levels measured along traffic roads exceeded the threshold for hearing damage.

Elemental composition of head hair and fingernails of some Nigerian subjects.

In this article, we present the elemental concentrations determined by INAA for 30 elements measured in some or all head hair samples of 100 Nigerian subjects and 20 elements in the fingernails of some of the same subjects. Measurements of the skewness of the distribution of each element in both tissues confirm previous reports that many tend toward a log-normal distribution. Thus, their concentrations in the tissues may not be under any homeostatic control. The ranges of elemental concentrations together with the medians, and the arithmetic and geometric means, with their respective standard deviations are presented and compared with literature values for other populations. Correlations between elements detected in hair are also sought.

Correlations between trace element levels in head hair and blood components of Nigerian subjects.

Elemental concentrations in head hair and blood (whole-blood, erythrocytes and plasma) of 28 Nigerian subjects were determined using instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE) techniques. Correlations found between different elements in hair and blood are reported. Hair levels of both zinc and chlorine were found to be significantly correlated with their levels in erythrocytes.

Trace element distribution in the hair of some sickle cell anemia patients and controls.

Hair samples of some young sickle cell anemia (SCA) and control patients in Nigeria were analyzed for 12 elements, viz, Se, Hg, Cr, Fe, Zn, Co, Cu, Br, As, Sb, Na, and Sc, using Instrumental Neutron Activation Analysis (INAA). With the exception of Cu, which was found to be significantly higher in the hair of SCA patients (at the 0.05 level of the t-test), there were generally no significant differences in elemental concentrations within the two groups. A preliminary study of the elemental contents of the fingernails of the same subjects showed a higher abundance of most of the elements in nail than in hair. These preliminary results were compared with similar studies from some other parts of the world.