The physicochemical properties of groundwater from various locations in Bichi Local

Sub-Saharan Africa is seeing rapid urbanization, with the population of cities such as Lagos and Nairobi growing at a rate of 3–4% a year. The region is extremely under-sampled for all air pollutants, particularly VOCs, which are useful markers for source apportionment as well as toxic in their own right. There are many contributors to air pollution in the region, and studies examining fine particulate pollution implicate traffic as the primary source in urban areas. In this pilot study, VOCs were analysed at a selection of roadside and urban background locations in Nairobi and Lagos, and 74 VOCs were quantified. GC×GC–MS/FID analysis revealed all locations were dominated by hydrocarbons typical of vehicle emissions, with the aromatic hydrocarbons benzene and toluene among the most abundant VOCs. Typical personal exposure scenarios for citizens of the cities were calculated to far exceed those of a resident in a city in Europe/US. Finally, the calculated ozone forming potential of the VOCs measured was found to be similarly high to other large cities studied with similar air pollution problems. Further study is therefore essential to determine the full extent of VOC pollution in the region and its impact on tropospheric chemistry.

No abstract

Vegetable cultivation is increasing because of its health benefit. However, in areas with limited fresh water, irrigation is from industrial and domestic wastewaters. Consumption of crops with high heavy metal content poses concern to health. A comparative analysis was conducted using AAS (Atomic Absorption Spectrophotometer) to determine the concentration of heavy metals in some vegetables irrigated with industrial effluent, domestic wastewater, and water from natural dams in Kano State. The results indicated that for all the sites, Fe and Zn had mean concentrations above the WHO/FAO permissible limits for edible vegetables with ranges 115-4041 mg/kg and 0.00-621 mg/kg. There was no mean significant difference at the p < 0.05 level within all the sites for Fe but, Zn showed significant variations between industrial and natural sites. Cr and Ni had a mean significant difference within all the sites and Ni had mean value below the allowable limit, Cr only had below for natural site. The mean concentration for Mn and Cu were below the permissible limit and there was mean significant difference between natural and domestic sites for Mn but, there was none for Cu. Vegetables cultivated from natural dams were relatively safe from contamination. The results highlight the need for the remediation of heavy metal contamination in irrigation waters from domestic and industrial sources to reduce the associated health hazards in the long run.