Environmental Health Status of Some Aquatic Ecosystems in Badagry Division, Lagos, Nigeria

Abstract

The status of Agboju, Ajegunle, Topo and Gbaji water bodies in Badagry Division of Lagos State, Nigeria was evaluated between April and November 2018 in order to determine the suitability of the ecosystem to biota and safety of the aquatic resources for human consumption. Some environmental variables such as alkalinity, temperature, biochemical oxygen demand (BOD), conductivity, total dissolved solid (TDS), carbon (iv) oxide (CO2), total hardness, chemical oxygen demand (COD), turbidity, phosphate, dissolved oxygen (DO), pH, salinity, sulphate and nitrate, and some heavy metals (Fe, Cu, Zn, Pb, Cd and Cr) in water, sediment, aquatic plant (Eichhornia crassipes) and fish (Ethmalosa fimbriata) were measured using standard procedures. The results showed that BOD, COD, total hardness and turbidity values were above the standard permissible limits. Cd in water column of Agboju and Ajegunle, and Pb recorded from Agboju, Ajegunle and Topo, exceeded standard permissible limit. Cu (0.56±0.54), Zn (5.45±0.89), Pb (0.54±0.47) and Cr (0.455±0.375) contents in E. fimbriata (from Ajegunle) was slightly above permissible limits while Cd and Fe contents in the fish across the four stations were above permissible limits. Contamination factor, Index of geochemical accumulation and enrichment factor showed moderate degree of contamination of cadmium and Fe in the sediment. This preliminary study could be concluded that the biota can still survive in the ecosystems despite high contamination of the water bodies with metals. However, human consumption of several of E. fimbriata and water could cause health hazard. Therefore, urgent effort should be made by all users of the ecosystem to decline in discharging untreated waste into these water bodies.