Copper and Zinc Contents in Urban Agricultural Soils of Niger State, Nigeria

Study of the Cu and Zn contents in urban agricultural soils is paramount in order to assess concerning the possible potential risks they may pose at high concentrations to life and environment through the food chain. Levels of Cu and Zn in soil samples collected from cultivated farmlands in the vicinity of abandoned industrial sites at two cities of Minna and Bida in Niger State, were determined using flame atomic absorption spectrophotometry technique. The concentrations were in the following ranges; 12-89mgCukg-1 and 2.8-41mgZnkg-1 for Minna and 2.4-6.5mgCukg-1 and 0.57-36mgZnkg-1 for Bida. The accumulation of Cu in Minna cultivated farmlands was apparent, with a mean Cu content of 24 + 22ppm, which was almost five times that of the control soils, but other mean values were similar to the soilbackground average contents. Soil properties were also analysed, andobtained results for the cultivated farmland soils of the two cities were of the following ranges: - pH (5.0-7.5), Organic carbon (0.36-2.5)%, sand (46.4- 94.2)%, silt (2.3-20.0)% and clay (1.8-33.6)%. Cu and Zn positively correlated among themselves, Cu correlated with clay content and Zn correlated with pH and organic carbon in all the soils. Keywords: heavy metals, accumulation, environment, cultivated farmlands, abandoned industrial sites

Impact Of Municipal Solid Waste On Trace Metal Concentrations In Herbage And Soil Samples Of The Abuja Municipality

The impact of municipal solid waste on the levels of cadmium, copper, nickel, lead and zinc in herbage and soil samples within Abuja municipality was studied. The flame atomic absorption spectrophotometry was used in the determination of the metals. The average concentration of Cd, Cu, Ni, Pb and Zn in the herbage samples were 0.3 ± 0.1, 3.8 ± 1.2, 2.9 ± 0.8, 50.7 ± 14.3 and 34.7 ± 6.1 µg g-1 weight respectively. The concentrations of metal in the soil were higher than in the herbage samples and were in the order of Pb> Zn >> Cu > Ni> Cd. The concentrations of metal in the soil samples were higher than levels in normal farmlands. The levels of Cd and Pb in the soil samples were higher than levels in soil criteria of many countries suggesting that municipal wastes are contributing significantly to the metal concentrations in the herbage and soil samples. KEY WORDS: Solid waste, trace metals, environmental samples. Global Journal of Environmental Sciences Vol.3(1&2) 2004: 65-6