No abstract

No abstract

Neutron Activation Analysis (NAA) was used for the determination of metal concentrations of sediments sampled at specific locations of the Kubanni River in Nigeria. The sedimentation process was assessed by examining the variation of the concentrations of the metals in different cores with sediment depths. Fifteen metals: arsenic (As), cerium (Ce), europium (Eu), iron (Fe), gadolinium (Gd), hafnium (Hf), holmium (Ho), potassium (K), lanthanum (La), lutetium (Lu), samarium (Sm), scandium (Sc), thorium (Th), uranium (U), and ytterbium (Yb) were detected from the sediments in substantial concentrations; higher than the parts per million (µg g -1 ) value in some cases. Our results showed contamination of the surface sediments by U and Th, suggesting contributions from phosphate fertilizers used in farmlands around the basin as potential sources of these pollutants. Aeolian depositions emanating from the uranium-rich region of Air (Niger) in the Saharan desert were considered to be other possibilities.

No abstract

To assess the impact of long-term feeding of fungicides on sperm quality, mice were fed a daily diet containing a mixture of maneb and zineb, at concentrations of 30, 300, and 3000 ppm, respectively. Employing epididymal sperm suspended in a medium permitting in vitro capacitation, the intracellular free Ca2+ concentration, [Ca2+]i, was determined with a fluorescent Ca2+ indicator, Fura-2. Regardless of the fungicide dosages applied, [Ca2+]i was about 50 percent higher in treated animals relative to a value of 123 nM [Ca2+]i in the control group. Fungicide-treated mice were mated to mature, non-treated females; as in the control, the litter sizes were the same. In conclusion, the observed elevation in [Ca2+]i seems to reflect cellular adaptation responses to toxic stress at moderate fungicide doses.

No abstract

No abstract

Energy Dispersive X-ray Fluorescence (EDXRF) technique has been used to determine the concentrations of lead(Pb) and other heavy metals in local cooking salts (LCS) from Akwana village, Middle Benue Trough, Nigeria. The comparison of the distribution of these metals in LCS, 'fake' salt (FS) and the usual common salts (CS) are given. Lead was found to be enriched in LCS by factor exceeding 200 times compared to the other salts. The origin of Pb contamination in the LCS is examined and its effects on the inhabitants of the village are considered.