Vol 5 _1_ - Cont. J. Environ. Sci. - Wilolud Journals

Okoro I.A. and Abii T: Continental J. Environmental Sciences 5 (1): 13 - 19, 2011of cadmium in this fraction in high concentration downstream makes cadmium less available that could pose athreat to water quality of this local stream.The mobility factor calculated for Iron, Selenium, Zinc, Lead and Calcium in the sediments of Anya stream asreported in Tables 1 and 2 was obtained using the equation below:MF = F 1 + F 2 /(F 1 + F 2 + F 3 + F 4 + F 5 ) * 100 (1)Where;F 1 is the exchangeable metal fractionF 2 is the carbonate bound metal fractionF 3 is the Fe – Mn oxide called the reducible metal fractionF 4 is the organic bound metal fractionF 5 is the residual metal fraction.Equation 1 because the mobility of metals in sediments may be expressed based on absolute and relativecontent(s) of the fractions weakly bound to sediment components. The relative index of Iron, selenium, zinc,lead and cadmium in the sediments from the Anya – stream was calculated as the mobility factor using equation1 as reported in Table 3 (Terus (1995), Ahumada et al, (1999) and Karezewska (1996)). A high MF value for ametal in the sediments is an indication of high lability and biological availability (Ahumada, et al (1999), A.Karezewska (1996), Ma et al 1997), Narwal et al, (1999), Kabia et al(2001)).From table 3, the trend in the mobility factor value for lead and cadmium was MS > DS > NS and US > DS >US respectively. Anya stream is a cause for environmental concern as this is an indication of toxicity of thismetal due to its bioavailability for uptake by aquatic organisms, plants and ingestion by local natives as thestream is the local source of water for cooking, laundry and irrigation (Kabia et al (2001), Salibu et al, (1998)).CONCLUSIONThe combination of chemical speciation and mobility factor is a useful analytical tool for predicting the degreeof contamination of sediments of any stream, river. When the Iron, Selenium, Zinc, Lead and Cadmium level inthe sediments of Anya stream is compared values obtained by other researchers, stream is not polluted.These findings are in agreement with the anthropogenic activities, going on along this Anya stream as thestream flow through the serene environments of the National Root Crop Research Institute and the FederalUniversity of Agriculture, Umudike in Ikwuano L.G.A in Abia State in the South-eastern Nigerian.ACKNOWLEDGEMENTWe acknowledge the assistance given to us by Rivers State Science and Technology Department by makingavailable to us the AAS instrument.REFERENCESAdriano D.D.C. (1986). Trace element in Terrestrial Environment, Springer – Verlag New York. Pp 10 – 12.Ayodele J T and Abubakar M(1998). Trace element contamination of rain water in semi-arid region of KanoNigeria, Environs, Man and Health, 9, 174-196Angelone M and Bini C (1992). Trace Element concentration in soils and plants of Western Europe, in D.C.Adriano (ed), Biogeochemistry of trace elements, Press Boca Raton fl, pp 19 – hazards, 2, 1 – 5.Ahumada I, . Mendoza Jand . Ascar L (1999). Sequential extraction in soil irrigation with waste water,Communication in Soil Science and plant Analysis, 30, 1057-1519..Brandy N C (1994). Radionuclide, the nature and properties of soil, Macmillan Publishers New York, Pp 570 –572.Barbara F. Stephen K K and William W (2002). Speciation and characterisation of heavy metals contaminationsoil using computer-controlled scanning electron microscope Environmental forensic 3,131-143.17