South-West Benin Coastal Lagoon: Waters and sediments’ toxicity and contents in heavy metals during high water period (Togbin to the Mono Mouth)

The uncontrollable population growth is reaching Benin's rivers, especially the coastal lagoon, raising then thorny problem of pollution, which considerably accentuated by malevolent behavior populations. aim this paper to characterize degree contamination water and sediments lagoon in heavy metals (Cd, Cr, Zn, Cu, Pb Fe) through dosage with molecular absorption spectrophotometer type DR 3900. At same time, a cytotoxicity test Allium cepa will be carried out order evaluate toxic potential pollutants responsible for degradation lagoon. Cd, Cu Zn contents far exceed accepted standards at almost all stations. Pollution Index (PI) geo-accumulation index (Igeo) indicate existence polymetallic pollution sediments, extremely strong dominated decrease abundance by: Cd>Zn>Cu>Pb. results highlight acute toxicity on 82% stations surveyed. poor states indexed study, impose application urgent measures participative management, preservation sanitation zone