Abstract

Investigations of Cu, Cd, Co, Zn, Cr, Ca, Fe and Pb in raw cow milk samples were carried out in this study. Samples of raw cow milk used were in part, obtained from Benin City, Uromi and Auchi all in Edo State; then from Agbor, Asaba and Warri, the latter three cities are in Delta State. Both states are located in the southern part of Nigeria. Samples collections were carried out during the dry season and sterile plastic containers were used. The collected raw milk samples were homogenized and subsequently, subjected to wet digestion using concentrated tri-acid (HNO3 -H2 SO4 -HClO4 ) as digestion mixture. The respective digests were thereafter, spectrophotometrically examined for their Cu, Cd, Co, Zn, Cr, Ca, Fe and Pb contents, using atomic absorption spectrophotometer (Buck Scientific Model 410). Additionally, data obtained were statistically analysed, using International Business Machine (IBM) statistical package for social sciences (SPSS). With respect to the analysed digests of samples collected from studied cities in Edo State, findings indicate the following mean total levels of occurrence for the examined mineral elements: Ca (120.274mg/kg); Zn (2.888mg/kg); Cu (0.102mg/kg); Fe (0.680mg/kg); Cr (0.060mg/kg); Co (0.083mg/kg); Pb (0.014mg/kg) and Cd (0.048mg/kg). The corresponding mean total of the examined mineral elements in digests of samples obtained from Delta State were: Ca (119.797mg/kg); Zn (2.817mg/kg); Cu (0.102mg/kg); Fe (0.606mg/kg); Cr (0.063mg/kg); Co (0.078mg/kg); Pb (0.013mg/kg) and Cd (0.048mg/kg). Variations were noted to occur in the respective values of the examined mineral elements. The observed variations were found to be statistically significant (P<0.05) with respect to the different examined mineral elements, but not with sampling locations. It is nutritionally desirable that the examined dietary relevant mineral elements occurred in the studied milk samples. It is however of concern, that Pb and Cd both of which are highly toxicologically relevant, also occurred in all the milk samples investigated. There is need to put in place, measures that will prevent further increase in the levels of these toxicologically relevant mineral elements in milk obtained from the studied locations.