Abstract:Recent studies have shown that strong acid digestions for the determination of heavy metals in soils and sediments can be misleading when assessing environmental effects. Therefore, this study adopted the use of modified community bureau of reference (BCR) sequential extraction scheme in order to overcome the limitation. The physicochemical properties of the soil such as pH, cation exchange capacity (CEC) and soil organic matter (SOM) were determined. The pH, CEC and SOM were found to be 5.90, 0.0023 cmol/kg and 99.8% respectively. The concentrations of the heavy metals in the solution were also measured using atomic absorption spectrophotometry. Pseudo total metal content in the soil (aqua-reqia digestions) for cadmium, lead, chromium, nickel, zinc and copper were 0.12, 0.74, 0.48, 0.26, 15.9 and 11.0 mg/kg respectively. These concentrations are within the World Health Organization (WHO) permissible limit in agricultural soils. The heavy metals were partitioned into four fractions (exchangeable, reducible, oxidizable and residual fractions) in the soil using modified BCR sequential extraction. Cd, Zn and Cu were predominantly in the first two fractions, thus, mobile and bioavailable for plant uptake, while Pb, Cr and Ni were found in the last two fractions (less mobile and immobile residual fractions). Thus, Cd, Zn and Cu may pose high environmental risk. The results indicate the reliability of the Modified BCR scheme in risk assessment of heavy metals in soils.

This study was aimed at the evaluation of the influence of freezing on the meat/fish storage of cow, ram, goat, tilapia and catfish within a period of thirty (30) days. Samples were obtained from Kaduna North and South Local Government, Kaduna State, Nigeria. The protein content of all the meat samples were analysed using kjehdahl method and values was recorded before slaughter and the observed storage period. Among the meat category, the goat meat had the highest protein content at 46.37%, while the tilapia had the highest protein content of 45.50% in the fish category. The research showed that goat meat had more protein content than all the analysed samples, followed by tilapia and ram meat had the least protein content. After the thirty (30) days freezing and storage period, the protein content of both the goat and tilapia had dropped to 38.93% and 37.62%. Amongst all the samples, ram meat had the slowest protein content diminishing effect as storage period increased. The research also showed that as storage time increases via freezing, the protein content of the analysed samples also reduces with time. The protein content in all the meat and fish samples did not meet the benchmark for protein content values but were enough for consumption.