Heavy-Metals as Environmental Health Indicator of the Lagos Lagoon Complex, Nigeria

Abstract

The study was conducted on heavy metals contents of water, fish tissues and sediment from Lagos lagoon complex, Nigeria. The aim was to assess the current environmental health/pollution status of the lagoon from three sample stations: Ologe lagoon [1], Badagry creek [2] and Lagos island [3]; each having three (3) hotspots. In all, twelve (11) heavy metals were determined between June and November, 2018. Heavy metals: Zn, Fe, Pb, Cu, Na, Potassium, Ca, Mn, Cd, Hg and Nickel were determined using Atomic absorption spectrophotometer (AAS). Results of mean Heavy metals in fish tissues were: Zn (0.741±0.38), Fe (5.59±8.32), Pb (0.12±0.17mg/l), Cu (0.16±0.25), Na (9.38±0.25), Ca (116.68±41.53), Mn (0.76±0.96), Pb (0.01±0.0), Cd (0.02±0.0), Potassium (12.09±2.34), Ni (0.02±0.02) and Hg (0.01±0.0). Statistical analysis showed variations in the distribution of Heavy metals which are mostly within recommended limits of WHO, FME, & LASEPA. Except for iron (Fe), which was found in excess in fish tissues, and other metals (lead), found in higher conc. in sediments than in water and fish tissues combined. This is indicative of heavy metals bio-accumulation in the study area.