ENVIRONMENTAL AND ECOLOGICAL RISK ASSESSMENT OF HEAVY METAL IN DREDGED SEDIMENTS IN LAGOS, NIGERIA: AN INDEX APPROACH ANALYSES
Abdulrafiu Majolagbe1, Abosed Yususf2, and Adebola Adeyi3
1Lagos State University, Nigeria, 2Lagos State University, Nigeria, and 3University Of Ibadan, Nigeria
The present study investigate the distribution of Heavy metals (Cadmium, Copper, Zinc, lead and Nickel) and potential ecological risk associated in surface sediments samples from six coastal communities (Ajah, Imore, Ilado, Ajindo, Ojo and Gbelejo) in Lagos, Nigeria. Composite samples were collected from ten (10) different locations in each of the communities and analysed of heavy metals using employing Atomic Absorption Spectrophotometer (AAS). The interim Sediment Quality Guidelines (ISQG) was applied to characterize the dredged sediments and assess the potential ecological risk on the environment through multivariate quality indices such as pollution index (Pi), pollution classification (Pc), geo accumulation index(I geo) and potential ecological risk index (RI). The concentration of zinc was observed higher in the sediments from commercially dredge areas (Ajah and Imore). The result obtained classified entire study area as polluted with respect of Pb and Ni, and as contaminated with (Cd, Cu, and Zn) respect of other metals investigated. The overall ecological risk for the six study areas revealed moderate potential risk (110 ? RI < 200), except Imore and Gbelejo which showed low potential risk (RI < 110). The need for regular monitoring by the relevant agencies cannot be overemphasized to ensure sustainable environment.
Ecological risk index, Dredged sediment, Interim Sediment Quality Guidelines, and Heavy metals