No abstract

The human body uses oils and fats in the diet as an energy source, as a structural component and to make powerful biological regulators. The significance of trace metals and toxicological effects of heavy metals on human health and nutrition have been increasingly studied in recent years. Micronutrients play a role in cellular defences, acting both as 'sinks' for free radicals or by being involved in the activity of the enzymes required to deal with the oxidative products e.g. zinc and copper in superoxide dismutase. Presence of metals in edible oil could be from soil or during the manufacturing process. In this present study, the levels of some metals were determined in vegetable oils sold in Zaria, Nigeria. The concentration ranged from 19.

Dutsen dan Libya is a rock material used in traditional medicine for the treatment of a myriad of ailments like cold, fever, stomach disorder, diarrhea and Jaundice. To evaluate the scientific basis for the use of the rock, the antimicrobial activities of its water extract was studied against some common gram positive and gram negative bacteria and fungi. The antimicrobial activity of the aqueous extract was evaluated by determination of the diameter of zone of inhibition using the paper disk diffusion method. Results showed sensitivity to Pseudomonas aeruginosa, Streptococcus pyogenes, Staphylococcus aureus, Corynebacterium ulcerans, Klebsiella pneumoniae and Candida albicans. Bacillus subtilis, Salmonella typhi, Escherichia Coli and Neisseria gonorhoea were resistant. Studies on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the rock-extract solution on the test organisms showed the lowest MIC at the dose level of 1.25mg/ml and MBC at the dose level of 2.50mg/ml respectively against Pseudomonas aeruginosa and Streptococcus pyogenes. The highest MIC (2.5 mg/ml) and MBC (5.00mg/ml) were exhibited against staphylococcus aureus, corynebacterium ulcerans, klebsiella pneumoniae and Candida albicans.

The heavy metal composition of some commercial fertilizers and soil supplements used in Zaria were analysed. The fertilizers analysed include Liquid Organic fertilizer, Palette Organic fertilizer, Urea, Super phosphate, NPK, some of the soil supplements analysed are cow dung and chicken droppings. Using Atomic Absorption Spectrophotometer (AAS) the following range of heavy metal concentrations were obtained: Cu 3.92-38.14mg/l, Mn 0.057-199.17mg/l, Cr 0.19-2.207mg/l, Zn 1.35-83.12mg/l, Fe 5.00-514.18mg/l, Ni 0.063-149mg/l, Pb 9.86-15.52mg/l, Co 0.26-2.87mg/l.. Super phosphate had the highest abundance of Iron (514.18mg/l). These values were compared to standards for heavy metals in fertilizers and supplements for other countries and were found to be below the limits. Like other countries, it will be important for Nigeria to have set standards for heavy metals levels for fertilizers used in the country.