In this article we present lead concentrations and isotopic compositions from analyses of cocoa beans, their shells, and soils from six Nigerian cocoa farms, and analyses of manufactured cocoa and chocolate products. The average lead concentration of cocoa beans was ≤ 0.5 ng/g, which is one of the lowest reported values for a natural food. In contrast, lead concentrations of manufactured cocoa and chocolate products were as high as 230 and 70 ng/g, respectively, which are consistent with market-basket surveys that have repeatedly listed lead concentrations in chocolate products among the highest reported for all foods. One source of contamination of the finished products is tentatively attributed to atmospheric emissions of leaded gasoline, which is still being used in Nigeria. Because of the high capacity of cocoa bean shells to adsorb lead, contamination from leaded gasoline emissions may occur during the fermentation and sun-drying of unshelled beans at cocoa farms. This mechanism is supported by similarities in lead isotopic compositions of cocoa bean shells from the different farms (206Pb/207Pb = 1.1548–1.1581; 208Pb/207Pb = 2.4344–2.4394) with those of finished cocoa products (206Pb/207Pb = 1.1475–1.1977; 208Pb/207Pb = 2.4234–2.4673). However, the much higher lead concentrations and larger variability in lead isotopic composition of finished cocoa products, which falls within the global range of industrial lead aerosols, indicate that most contamination occurs during shipping and/or processing of the cocoa beans and the manufacture of cocoa and chocolate products.

This study assessed the quality street vended food and water as well as the effects of environmental pollution on them in 3 local government areas (LGAs) representing low, medium and high income areas in Lagos State in coparison to samples collected from 5 locations in Ogun, Oyo and Osun States being previously established as places of origin of most migrants to Lagos. Street vended roasted plantain and maize as well as water samples were collected as composites from each of the sample locations. All samples were analysed for physico-chemical as well as microbiological parameters. The study revealed that roasted plantain in the low income area had the highest level of contaminants such as Pb, Cd, Zn and Fe. The lowest value was in the high income area. Lead levels ranged between 0.2 -125 µg/g with the highest value observed at the low income, high population density and high traffic area. Cd, Zc and Fe levels also followed a similar trend in the other three States. They ranged between 0.48 -18.3 µg/g, 2.0 -4.5 µg/g and 0.4 -13.5 µg/g respectively. It is opined that the pollution sources for the roasted plantain and maize include those from emissions from leaded gasoline. The aerobic mesophilic organisms, mould and Staphylococcus aureus were present in all the water samples. These results imply that government and its agencies should attend to the problem of unavailability of potable water and calls for greater monitoring and control of the environment where roadside foods are prepared. @ JASEM

A lot of work has shown that despite the effectiveness of the traditional electrokinetic remediation (EKR) technology in decontaminating soils with different types and amounts of contaminants, it can be enhanced by a number of strategies for extra effective performance. This work presents the effect of ethanol and acetone cosolvents in enhancing EKR of crude oil contaminated soil (COCS), collected at a depth of 1 m from a petroleum pipeline and storage company, Kaduna Nigeria using graphite electrodes to pass 1 V DC/cm across EKR setups enhanced by incorporating 20% ethanol and 20% acetone separately as cosolvents in the anode compartments of the setups. The total petroleum hydrocarbon results showed that the crude oil content of 78,600 mg/kg present in the COCS exceeds permissible limits for soils. Average removal efficiencies of 74.61% and 67.79% obtained from 20% ethanol and 20% acetone cosolvents enhancements respectively showed that 20% ethanol, with higher removal efficiency, is a better cosolvents for COCS than 20% acetone. Although 20% ethanol has been shown to be a better cosolvents compared to 20% acetone, either of them can be incorporated into EKR technology for enhancing the remediation of COCS.