title: Zinc, copper, cadmium, and lead concentrations in water, sediment, and Anadara senilis in a tropical estuary.
abstract: Spatial and seasonal contaminations of zinc, copper, cadmium, and lead were assessed simultaneously in water, sediment, and in the bivalve Arca senilis from the Milliardaires Bay (Cote d'Ivoire) between February and October 2008. The metal load in sediments doubled from the dry season to the rainy season. On the contrary, metal concentrations in waters decreased significantly from the dry season to the rainy season. Zn and Pb concentrations in A. senilis showed similar seasonal variation with sediments. On the other hand, A. senilis regulated Cu concentrations by eliminating about twelve times the concentration accumulated during the dry season. Apparent Zn, Cu, Cd, and Pb concentration gradients were observed, but no significant differences between stations for sediment, water, and A. senilis. Concentrations in sediment increased from stations close to Abidjan Harbor towards farther stations, while concentrations in A. senilis showed a reverse gradient. The distribution gradient of A. senilis indicates pollution from local sources, but a transplant experiment is needed to better understand the observed spatial trend. Zn and Cu concentrations may pose little risk to human health and the environment, but they are the highest on the regional scale. On the contrary, Cd and Pb concentrations in A. senilis exceeded the maximum allowable limits set by the European Commission. Complementary studies including chemical speciation should be considered to provide a more accurate assessment of the risk of heavy metals to the environment.
authors.affiliation: Centre de Recherches Océanologiques (CRO), BP V18, Abidjan, Côte d'Ivoire.
authors.forename: Inza
authors.initials: I
authors.lastname: Bakary
authors.affiliation: Centre de Recherches Océanologiques (CRO), BP V18, Abidjan, Côte d'Ivoire. markcelklindr@gmail.com.
authors.forename: Koffi Marcellin
authors.identifier: http://orcid.org/0000-0002-7520-2585
authors.initials: KM
authors.lastname: Yao
authors.affiliation: Laboratoire de biologie et cytologie animales, Université Nangui Abrogoua, 02 BP 801, Abidjan 02, Côte d'Ivoire.
authors.forename: Olivier Assoi
authors.initials: OA
authors.lastname: Etchian
authors.affiliation: Centre de Recherches Océanologiques (CRO), BP V18, Abidjan, Côte d'Ivoire.
authors.forename: Metongo Bernard
authors.initials: MB
authors.lastname: Soro
authors.affiliation: Laboratoire de Chimie Physique, Université Félix Houphouët Boigny, 22 BP 582, Abidjan, Côte d'Ivoire.
authors.forename: Albert
authors.initials: A
authors.lastname: Trokourey
authors.affiliation: Laboratoire de Chimie Physique, Université Félix Houphouët Boigny, 22 BP 582, Abidjan, Côte d'Ivoire.
authors.forename: Yobou
authors.initials: Y
authors.lastname: Bokra
mesh_terms: D000818:Animals; D049893:Arcidae / Q000737:chemistry*; D002104:Cadmium / Q000032:analysis; D003300:Copper / Q000032:analysis; D007560:Cote d'Ivoire; D004784:Environmental Monitoring; D063366:Estuaries; D005843:Geography; D019015:Geologic Sediments / Q000032:analysis*; D007854:Lead / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis*; D012621:Seasons; D014867:Water; D014874:Water Pollutants, Chemical / Q000032:analysis*; D015032:Zinc / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D002104:Cadmium; D014867:Water; D007854:Lead; D003300:Copper; D015032:Zinc
keywords: Heavy metals; Molluscs; Pollution; Sediment; Water