No abstract

The concentration of respirable dust at seven sampling stations in Jos metropolitan area, was measured weekly for three consecutive months (October 2012 to December 2012). Characterization of the dust particles shows that the concentration of fine dust (<2.5 µm) ranged from 55.0-124.9 µg/m 3 while the coarse dust (2.5-10 µm) varied from 20.0-124.4 µg/m 3. FAAS analysis of the respirable dust shows that the concentrations of heavy metals ranged from 0.121-0.832 mg/kg Pb, 0.019-0.111 mg/kg Cr, 0.171-1.081 mg/kg Fe, 0.002-0.056 mg/kg Mn, 0.002-0.438 mg/kg Cd, 0.696-1.712 mg/kg Zn, 0.025-0.571 mg/kg Cu, and 0.021-0. 478 mg/kg Ni, across the sites studied. The main sources of these heavy metals in the sampled area could be attributed to anthropogenic activities like open incineration of waste and vehicular traffic. The concentrations of Cd, Mn and Ni were found to be far above the standard limits prescribed by the WHO for respirable dust. These results convey the health risk the inhabitants in the study area are exposed to. We therefore recommend that measures be taken to regulate these anthropogenic activities

River Benue, the second largest river in Nigeria, serves as the major source of municipal water supplies for towns and villages along its course. Water samples from the river were collected at ten stations in the Makurdi metropolitan area (7°44(') N, 8°32(') E) in Benue State, Central Nigeria, for 12 months and analyzed for their heavy metals concentration, along with other water-quality parameters such as turbidity, pH, total dissolved solids and total solids. The results revealed that the mean concentrations of heavy metals in the river was in the following ascending order, Cd < Cu < Zn < Mn < Pb < Cr < Fe. The levels of most of the parameters determined, with the exception of Cd, Cr and Pb were, generally, within acceptable limits for drinking water. From the present study, it is concluded that the River Benue is only moderately contaminated with regard to heavy metals, in the Makurdi metropolitan area.

Hair samples of individual were analysed for heavy metals (Cd, Cr, Pb and As) across gender and various occupational distributions by Atomic Absorption Spectrophotometric technique (AAS). The results of replicate analysis shows the following mean concentrations (mg/kg): Cd = 27.8 ± 8.0, Cr = 2.70 ± 0.7, Pb = 73.8 ± 42.3 and As = 222 ± 34.1. The coefficients of variation for the total distribution is; Cd = 28%, Cr = 26%, Pb = 57% and As = 15%. The distribution of the metals follows the series in decreasing order of As ˃ Pb ˃ Cd ˃ Cr, while their coefficients of variation is in the order of Pb ˃ Cd ˃ Cr ˃ As. The result shows the presence of all the metals in relatively large amounts with As having the highest concentration between the two genders. The difference between male and female concentration could be due to individual differences in exposure to heavy metal load as a result of habitual or environmental factors.

Analysis of six heavy metals (Cr, Mn, Ni, Cu, Zn and Mo) in human scalp hair was carried out among various occupational distributions to ascertain their heavy metal burden, using energy dispersive x-ray fluorescence technique (ED-XRF). The result of the analysis shows that mean concentrations (mg/kg) of heavy metals obtained were as follows: Cr = 17.1 ± 12.7; Mn = 3.11 ± 0.50; Ni = 11.3 ± 9.3; Zn = 451 ± 128; Cu = 83.3 ± 35.8 and Mo is 9.16 ± 9.1.While the mean concentrations of Cr, Cu, and Mo were higher in the females, that of Mn, Ni and Zn were more in the males. Statistical analysis of the results for both genders at 0.05 probably shows significant difference for Ni, Zn and Mo while Cr, Mn and Cu showed no significant difference. The relationships between age, body mass, height, and heavy metal concentrations were also investigated. Statistical analysis of the results indicates that there was no correlation between the body mass (R2 ≤ 0.048), height (R2 ≤ 0.002) and heavy metal concentration in hair. Zn showed the highest deviation among other elements in the individual samples for both genders which reflect the individual variation in the concentration of Zn