Fifty-year sedimentary record of heavy metal pollution in the lagoon of Oualidia (Moroccan Atlantic coast)

Sedimentary records of anthropogenic contribution to heavy metal content in Oum Er Bia estuary (Morocco)

“…137 Cs is present at low activities throughout the cored depth of sediment (although it is below detection limits in many depth intervals), but clear subsurface maxima related to periods of peak 137 Cs input (e.g., the 1986 fallout maximum from atmospheric Chernobyl accident). Similar 137 Cs (and 210 Pb) profiles to that of Oum Er Bia estuary have been observed in areas where vigorous mixing and reworking of sediments takes place, or where very rapid sediment accretion rates occur (Zourarah et al 2007). The sedimentation rates calculated in the present study were based on: (1) the identification of the 137 Cs peak, which usually occurred in the lower part of CO-1 core and has been identified worldwide with the fallout from the Chernobyl accident that took place in 1986; and (2) the recognition of an exponential trend in Pb-210 activity in the vibrocore sediments.…”

“…The correlation of chromium with others elements was less significant (r \ 0.60). Dated sediment profiles could provide a reasonable estimation of past natural and anthropogenic environmental conditions and the changes in specific areas (Förstner and Wittmann 1979;Von Gunten et al 1997 andZourarah et al 2007). …”

“…The enrichment of surface sediments of NW Oum Er Bia estuary withy organic carbon, and trace elements most likely results from the high surface area of fine-grained material (Zourarah et al 2007). …”

“…Higher This source of pollution in these stations appears to be the main contributor for Pb, Zn, Cu, Hg, Fe and Cr. Many studies had demonstrated that municipal and/or industrial wastewater discharges into coastal zones are the most important sources for contamination of water and sediment with heavy metals (Zourarah et al 2007;Maanan 2007).…”

Evolução sedimentar do estuário do rio Capibaribe (Recife-PE) nos últimos 200 anos e suas relações com a atividade antrópica e processo de urbanização

“…Impactos antrópicos modificam o equilíbrio ambiental natural de várias maneiras como o desenvolvimento urbano, a agricultura e as mudanças hidrológicas que causam alterações na composição sedimentar e na introdução de poluentes (ZOURARAH et al, 2007;TRAINI et al, 2015). Estas interferências antrópicas são registradas durante os processos de sedimentação nos ambientes costeiros (JHA et al, 2003;SWARZENSKI et al, 2008, DÍAZ-ASENCIO et al, 2009).…”