Heavy Metal Pollution Monitoring in Vulnerable Ecosystems: A Case Study of the Lagos Lagoon, Nigeria

This comparative analysis was carried out to monitor heavy metal concentrations in the Lagos Lagoon over the last 2 decades. Surface water and sediment samples were collected from stations on the Lagos Lagoon based on their suitability for comparative analysis and future monitoring. Heavy metal content in samples was determined using Flame atomic absorption spectrophotometry (FAAS). The concentrations in the samples were compared to those obtained by Don-Pedro et al. (West African Journal of Applied Ecology 5:103-114, 2004) in previous studies from the same sampling zones. Results show that concentration of most heavy metals analysed has reduced significantly (p < 0.05) in the past 2 decades. However, the concentration of Cadmium (Cd) was found to have increased significantly (p < 0.05) over the same period. Increased concentration of Cadmium poses a threat to ecosystem health thus, it is imperative that safe limits for heavy metal discharge in waste streams should be revised and implemented.