Heavy metal pollution is a global issue of concern which results from both biogenic and anthropogenic activities. Hence, an investigation of soil pollution is pertinent because of its potential threat to human health. The present study examined the concentrations, contamination and pollution load index cum ecological risk factor for some heavy metals in soil samples collected from Borno Express (BOEXP), Tashan Kano (TASKP) and Tashan Bama (TASBP) motor parks within Maiduguri, Borno state of Nigeria. The data obtained showed mean concentration range of 0.34 - 1.18 mg/kg, 0.04 - 0.15 mg/kg, 0.07 - 0.41 and 0.18 - 0.29 mg/kg for Zn, Cr, Cd and Cu respectively. Nonetheless, lead was not detected in any and all samples analyzed. The increasing order of concentrations in the soils followed: Zn > Cu > Cr > Cd, Cu > Cd > Zn > Cr and Cd > Zn > Cu > Cr for BOEXP, TASKP and TASBP motor parks respectively. Notwithstanding, the results showed lower concentrations to the allowable limits of World Health Organization (WHO). Furthermore, the contamination factor of cadmium in the TASKP fell within the (0.10 – 0.25) category, indicative of slight contamination whereas in TASBP, the calculated value 0.5125 was within (0.51 -0.75) category implying severe contamination. The other heavy metals analyzed showed contamination factor as well as pollution index values < 0.1 indicative of very slight contamination.Keywords: Borno Express, Tashan Kano, Tashan Bama, Motor Parks, Contamination Index.

Three brands of chocolate and five varieties of bread samples were collected and subjected to acid digestion for evaluation of some heavy metals (Cu, Cr, Pb, Fe, Cd and Zn) using atomic absorption spectrophotometry. The concentrations of the studied heavy metals in the chocolate brands were in the range 0.02-0.20; 0.02-0.10 and 0.09-0.20 mg/kg for Cd, Zn and Cr respectively. whereas Pb was not detected in the study. As per the bread samples, the concentrations ranged 0.05-0.13; 0.60-2.24, 0.30-0.06 and 0.02-0.10 mg/kg for Cd, Zn, Cr and Pb respectively. This study indicates that the concentrations of the studied brands of chocolate and bread are within the allowable limits hence pose no potential health risk or hazard upon consumption. Keywords: Chocolate, Concentrations, Spectrometry, Acid digestion

The purpose of this study was to investigate the concentrations of PAHs in water samples from Dadin Kowa Dam, Nigeria and to evaluate the risk associated with the ingestion of the water from the Dam. The concentrations of PAHs varied with the sample site and season; and the levels of PAHs at all site are found to be significantly below the maximum allowable concentrations (MACs) of 0.005 to 3.0 mg/l. The carcinogenic risks were higher than 10−6 threshold values, and the water from Dadin Kowa Dam is considered to pose significant health effects to children and adult. However, the carcinogenicity risks rating decrease in the order of children > adult. The study further demonstrated that Dadin Kowa Dam requires a substantial PAHs pollution control program.

Anthropogenic activities inducing the accumulation of trace elements in Madaka village (between latitudes 6°00' E and 7°00' E, and 10°00' N and 10°04' N longitudes) of Rafi Local Government Area (Kagara, Niger State, Nigeria) have claimed many lives in the past. This study evaluated the accumulation of heavy metals and minerals in Butryospermum paradoxum and Parkia biglobosa and their soil rhizosphere at the lead polluted site around Madaka village of Rafi Local Government Area (Kagara, Niger State, Nigeria). Lead, arsenic, pH, nitrogen (%), organic carbon (%), organic matter (%), P, K, Na, Ca, Mg, N and cation exchange capacity were determined. Results showed significant differences (p < 0.05) between the Pb content in the soil from control (3.13 ± 1.010 mg/kg) and polluted sites (12.71 ± 1.010 mg/kg), and in the seeds of Butryospermum paradoxum from control (3.80 ± 0.09 mg/kg) and polluted sites (13.10 ± 0.10 mg/kg). A significant (p < 0.05) difference was also observed between the Pb content in Parkia biglobosa seeds from the control site (2.50 ± 0.10 mg/kg) and from the polluted site (14.10 ± 1.10 mg/kg). Overall, no significant differences (p > 0.05) were observed in the nutrient contents among all samples analysed. A significantly high concentration of Pb and As in these plants around the lead polluted site poses a great health concern. This calls for the public’s attention, both governmental and non-governmental organisations, to intervene by creating awareness of the likelihood of their bioconcentration in humans and animals that consume these plants.