Hair and nail samples were collected from different subjects with respect to sex, age of those working in iron welder workshop and liquor and non-liquor subject in Maiduguri Metropolis, Borno State, Nigeria for heavy metals determination. Sample collection and preparations were carried out using standard procedures. The levels of heavy metals (Copper (Cu), Zinc (Zn), Copper (Co), Manganese (Mn), Iron (Fe), Chromium (Cr), Cadmium (Cd) Arsenic (As), Nickel (Ni) and Lead (Pb)) were carried out using Atomic Absorption Spectrophotometer (AAS, Unicam 969). From the results of this study, Zn showed the highest concentrations while Cu showed the least levels. The results of the study showed that there was no contribution of liquor towards nail and hair metal concentrations. The levels of all the metals studied were significantly higher in the toenails compared to fingernails samples (p<0.05). Similarly, iron welding workers showed high concentrations of heavy metals when compared to liquor user. The levels of all the metals studied were statistically higher in male subjects compared to female subjects (p<0.05). The concentrations of heavy metals in nail samples were significantly higher when compared to hair samples. Significant levels of these metals in nail and hair samples indicate the presence of these metals in the environment and the workplace of the subjects. Since the present study reveals high levels of some heavy metals in hair and nail samples of iron welding worker volunteer. So there is instantaneous need for public awareness about the hazards of this occupation in order to enable these volunteer take necessary precautionary measures.

Effluent samples from tanneries and textile industries from Kano industrial area of Challawa, Bompai and Sharada industrial area were collected on quarterly basis from June to September, 2007 (Rainy season), November, 2007-February, 2008 (Harmattan season) and March-May, 2008 (Dry season) to reflect the seasonal factors. Effluents from ten industries were sampled and determined for physicochemical parameters. The physicochemical pollutants indicators determined include; Biological oxygen demand (BOD) and Chemical oxygen demand (COD) which all depend on the concentration of dissolved oxygen (DO) in effluent samples. Anions and trace elements were also determined. The above parameters were determined using standard procedures. From the results of the study, the concentrations of BOD, COD, DO, nitrate, nitrite, sulphate, phosphate, chloride and heavy metals were higher than the limits set by WHO for the discharged of tanneries and textile effluents into river. Result of analysis of variance (ANOVA) showed that variations between some industries were statistically significant (p≤0.05), but there were no marked seasonal variation in all the industries studied. Based on the high levels of the above parameters, it can be suggested that regular monitory of pollutants in the tannery and textile effluent are necessary to ensure proper discharge of these effluents into receiving river.

Heavy metal concentration in road side soils with its potential ecological effects draws much attention in the developing countries. This necessitates the study of their accumulation in the road side soils of Maiduguri (longitude 11° 13' N; latitude 13° 05' E), to ensure effective protection of soil from the potential loss of its fertility. In this study, roadside soil samples from major roads (Baga road, Bama road, Ngala road and Kano/Jos road) of Maiduguri were collected and determined the levels of heavy metals (As, Cr, Mn, Fe, Ni, Pb, Zn, Cd, and Cu) in the roadside soil using the Perkin-Elmer analyst 300 Atomic Absorption Spectroscopy (AAS). The results showed that in all the sampling locations, Mn, Zn, Fe and Pb have higher concentration of 137.4±0.04 mg/kg, 392.11±0.07 mg/kg, 13491.70±0.07 mg/kg and 928.50±0.04 mg/kg respectively in roadside soil as compared with Cd of concentration ranges from 0 to maximum of 0.87±0.04mg/kg in Ngala road. The concentrations of Pb and Cd in the soil samples were higher than the recommended value of 48 mg/kg and 5.0 mg/kg respectively. The higher concentration of these metals in the roadside soil samples may be attributed to human activities and traffic volume. Therefore, there is need to further study the concentrations of such heavy metals in agricultural soil, plants and vegetables grown in that area, animals that fed on the plants and any other source that directly or indirectly link to the source of food of the populace.