Koffi Marcellin Yao

Centre de Recherches Océanologiques | CRO · Abidjan

The physicochemical parameters and trace metal concentrations were measured in the water of ten major river mouths along the coastline in Cote d’Ivoire. Sampling was performed during the dry season of 2020. The results showed that the river mouths have good water quality characteristics, with average values of temperature (25.5 ± 1.86 °C), and pH (...

Total concentrations of trace metals Hg, Cd, and Pb, and metalloid As were measured monthly (December 2014 to November 2015) in two fish species, Chrysichthys nigrodigitatus and Sarotherodon melanotheron at five sites in the western part of the Ebrie Lagoon (Côte d’Ivoire). Results indicated that Chrysichthys nigrodigitatus muscle accumulated signi...

Nutrient contamination assessments in the three West African tropical Comoé, Bandama, and Bia Rivers (Côte d'Ivoire) were performed from March 2016 to March 2018. Five stations per river were sampled. Nutrients spatio-temporal distributions were mapped and showed nitrogen concentrations (nitrite 0.001 to 0.025 mg/L NO2−-N, and nitrate 0.26 to 3.60...

The close relationship between the anthropocene and metal pollution prompted a study to improve and inform the reduction of lagoon ecosystem degradation. The objectives of this study were to evaluate the spatial distribution of trace elements Hg, As, Cd, and Pb in the sediments of the Aby Lagoon a transboundary lagoon in West Africa, including thei...

The purpose of this study was to investigate the mobility, spatial distribution, possible sources, and potential ecological risks associated with trace metals Cu, Mn, and Ni in sediments around industrial and artisanal gold mines in northern Côte d'Ivoire. The sampling was conducted in industrial and artisanal (Korhogo), and artisanal (Tengrela) go...

Despite increasing human activities, such as agriculture, little information is available on the status of trace metals contamination in rivers in developing countries including Côte d'Ivoire (West Africa). The aim of this study was study chemical fractions of Cu, Pb, Zn, and Ni, to identify mobility, sources and to evaluate ecological risks of tra...

Metallic contamination of the environment by mining activities constitute a major problem, regarding the exposure risks of the populations and wildlife. Unfortunately, few data are available on metallic contamination of water resources in West Africa. The present study aims to understand the distribution, mobility and potential toxicity of some tra...

Un Aquathon a été organisé les 20 et 21 novembre 2019 à Abidjan (Côte d’Ivoire) sur le thème des déchets plastiques dans l’océan. Trente participants de 18 structures publiques et privées ont expérimenté les outils et méthodes collaboratifs de l’innovation ouverte pour proposer des solutions. Il en ressort que les déchets plastiques doivent être él...

Rare earth elements (REEs) are increasingly critical to the high-technology and low-carbon economy. With a shift to sustainable socioeconomic development that aims to be less fossil fuel dependent, global demand for REEs continues to rise, despite their uncertain supply chain and high environmental impact of production. Here, we review recent resea...

Agbaou is one of the most recent gold mine exploitation sites in Côte d’Ivoire. Little studies are discussed on the geochemical baseline concentration of trace metals in the wetland sediments around Agbaou gold mine. The main objectives of this study were to establish geochemical baseline values and to assess the pollution status of antimony (Sb)....

Pesticides’ contamination status was determined in water samples at the Bia, Tanoé, and Comoe Rivers’ mouths to understand their occurrences and the potential ecological and human health risks in Cote d’Ivoire, West Africa. A total of 26 out 30 pesticides measured including five organophosphates, eleven N-substituted ureas, nine triazines, and one...

RESUME Les éléments traces métalliques s'accumulent dans les systèmes aquatiques et peuvent dégrader la qualité des eaux et présenter une menace pour la santé humaine et la faune. Cependant peu d'étude existe sur la concentration totale des métaux dans les cours d'eau ivoiriens impactées par les activités agricoles. Pour contribuer à la mise en pla...

The impact of uncontrolled municipal dumping sites on metal contamination in the surrounding waters, sediments, and soils are of great concern in many developing countries. Total concentrations of trace metals Cd, Zn, Cu, Pb, Ni, and Co were measured in 33 sediments collected in the vicinity of the Akouedo dumpsite (Abidjan, Cote d’Ivoire) and in a...

This study examined the concentrations of arsenic (As), cadmium (Cd), and mercury (Hg) in rice grains grown in wetlands associated with gold mining in central-southern of Côte d’Ivoire to evaluate potential health risks exposure via rice consumption. In total, 30 rice grains were sampled around Agbaou and Bonikro gold mines. Arsenic and cadmium con...

The purpose of this study was to investigate the spatial distribution, possible sources, and potential ecological risks associated with traces metals Cu, Mn and Ni in sediments around gold mine areas in northern Côte d’Ivoire. The sampling was conducted in industrial and artisanal and small-scale gold mining sites in Korhogo and Tengrela. Analysis...

Arsenic and trace metal (Cd, Cu, Pb and Zn) concentrations in the liver, kidneys, and muscles of two fish species (Chrysichthys nigrodigitatus and Sarotherodon melanotheron) collected from three rivers (Bandama, Comoé, and Bia) in Côte d'Ivoire were examined from July to November 2016. A total of 102 fishes were sampled and measured by atomic absor...

Rivers and their watersheds play a key role in the global biogeochemical cycle of nitrogen and phosphorus in the biosphere. They are also important economic resources for humans. However, little information is available on eutrophication of West African coastal rivers due to costly analytical instruments and socio-economic difficulties. In this stu...

Les secteurs IV et V de la lagune Ebrié subissent une pression anthropique de plus en plus importante du fait de l’augmentation de la population et de l’intensification des activités agroindustrielles. L’objectif de cette étude est d’évaluer le niveau de contamination et les risques sanitaires des éléments (As, Cd et Pb) dans les eaux des secteurs...

Phosphorus and nitrogen pollution in groundwater, surface and marine waters results in tremendous economic, environmental and human health issues. This study examined phosphorus and nitrogen fate in sediments and the landfill leachate around the Akouedo landfill, the only landfill of the megacity Abidjan (Cote d’Ivoire, West Africa). The reactive p...

Purpose Trace metals accumulate in the food web and can pose high risks to human health and aquatic biota. We investigated seasonal and spatial variations of Cu, Zn, Pb, Co, and Ni mobility in surface sediments (0–5 cm) and their potential toxicity. Materials and methods The sampling was carried out in three embayments of the Ebrie Lagoon (Côte d’...

Correction to: Journal of Soils and Sediments https://doi.org/10.1007/s11368-018-2062-8 The article “The mobility of the trace metals copper, zinc, lead, cobalt, and nickel in tropical estuarine sediments, Ebrie Lagoon, Côte d’Ivoire”, written by N. L. B. Kouassi, K. M. Yao, N. Sangare, A. Trokourey, and B. S. Metongo, was originally published el...

Despite increasing mining activities, and fertilizer and pesticide use in agriculture, little information is available on the status of metal(loid) contamination in rivers in West Africa. Sixty water samples were collected from three significant rivers (the Bandama, Comoé, and Bia Rivers) in Côte d’Ivoire, the world’s top cocoa producer, to examine...

Biomass wastes are potential low-cost and promising materials for removal of carcinogenic metals in contaminated waters. However, no information is available for cashew and shea nut shells that are abundantly grown in West Africa. We investigated lead and cadmium removal from aqueous solutions using activated carbons prepared from cashew and shea n...

The distribution patterns and sources of arsenic and trace metals (Cd, Pb, Cu, Zn, Cr, Co, Fe, Al, Mn, and Ni) were investigated in wetland sediments that may be impacted by industrial and artisanal gold mining, along with those from non-mining areas in Divo (Bonikro and Agbaou sites) and Aboisso (Afema site) Departments, central-southern and south...

This data article is issued from the research article ‘’Distribution trends and ecological risks of arsenic and trace metals in wetland sediments around gold mining activities in central-southern and southeastern Côte d’Ivoire’’ [1]. It presents arsenic and trace metal Cd, Pb, Cu, Zn, Cr, Co, Fe, Al, Mn, and Ni loadings in surface sediments collect...

This data article is issued from the research article ‘’Distribution trends and ecological risks of arsenic and trace metals in wetland sediments around gold mining activities in central-southern and southeastern Côte d’Ivoire’’ [1]. It presents arsenic and trace metal Cd, Pb, Cu, Zn, Cr, Co, Fe, Al, Mn, and Ni loadings in surface sediments collect...

The distribution patterns and sources of arsenic and trace metals (Cd, Pb, Cu, Zn, Cr, Co, Fe, Al, Mn, and Ni) were investigated in wetland sediments that may be impacted by industrial and artisanal gold mining, along with those from non-mining areas in Divo (Bonikro and Agbaou sites) and Aboisso (Afema site) Departments, centralsouthern and south-...

Water samples of leachates, pits and M’Badon Bay (Ebrié lagoon, Côte d’Ivoire) were collected from Akouédo Landfill area and a baseline site, Anna Lagoon, over June 2013 - January 2014 to assess water resources pollution by trace metals Cd, Pb, Cu, Zn, Fe and Co. The landfill water pollution index (LWPI) was calculated to examine the influence of t...

Factors controlling ocean acidification and its temporal variations were studied over the 1995–2011 period at the Dyfamed site at 10 m depth, in the North Mediterranean Sea. The results indicated a mean annual decrease of 0.003 ± 0.001 pH units on the seawater scale. The seasonal variability was characterized by a pH decrease during springtime and...

RESUME En Afrique, plusieurs familles de pesticides, susceptibles de nuire à la santé de l'homme et de l'environnement, sont utilisées contre les pestes et autres nuisibles. Cependant, la plupart des études menées se sont focalisées sur les organochlorés. La fréquence de détection et les concentrations des pesticides aldicarbe et crimidine ont été...

L’accumulation des Hydrocarbures Aromatiques Polycycliques (HAP) dans l’environnement est une préoccupation mondiale du fait de leur persistance et de leur toxicité. l’Union Européenne a ainsi jugé seize HAP comme « préoccupants », parmi lesquels le benzo(a)pyrène est l’un des plus toxiques. La dépollution du benzo(a)pyrène contenu dans les eaux a...

L'influence de la décharge d'Akouédo sur la contamination des eaux environnantes par les éléments traces métalliques (Cd, Pb, Cu, Zn, Fe et Co) et les risques sanitaires pour l'Homme ont été évalués respectivement à partir des indices de pollution de décharge (LWPI : Landfill Water Pollution Index) et de risque (HI : Hazard Index) de Juin 2013 à Ja...

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 wa...

Les métaux plomb (Pb) et cadmium (Cd) s’accumulent dans les réseaux trophiques aquatiques et peuvent présenter une menace pour la santé humaine et la faune. Une littérature relativement abondante existe sur la concentration totale de ces métaux dans les lagunes ivoiriennes. Cependant, aucune information n’est disponible pour prédire leur toxicité p...

Metal (Cu, Zn, Pb, Cd, Ni, Co, and Fe) contamination in sediments from a tropical estuary (Ébrié Lagoon, Ivory Coast) was assessed using pollution indices, multivariate analyses and sediment quality guidelines (SQGs). The results demonstrate that increased input of the studied metals occurred over the past 6 years compared to that from 20 years ago...

Metal (Cu, Zn, Pb, Cd, Ni, Co, and Fe) contamination in sediments from a tropical estuary (Ebrie Lagoon, Ivory Coast) was assessed using pollution indices, multivariate analyses and sediment quality guidelines (SQGs). The results demonstrate that increased input of the studied metals occurred over the past 6 years compared to that from 20 years ago...

The impact of urban wastewaters on total metal concentrations in the Ebrié Lagoon (Côte d'Ivoire) is unknown. Physical and chemical parameters (temperature, conductivity, dissolved oxygen, salinity, pH, and redox hydrogen potential) and total metal concentrations (Fe, Cu, Cd, Pb, Cr, and Zn) were measured in water samples from Cocody Bay and wastew...

Cadmium is a toxic metal often found with a strong enrichment factor in coastal sediments. The sequential extraction procedure proposed by the BCR (Community Bureau of Reference) was applied for partitioning of Cd in tropical estuary sediments. The method showed satisfactory recoveries. The repartition of Cd in different phases of sediment was cont...

Interactions of mercury (Hg) with different molecular weight fractions of humic substances (HS) play an important role in controlling distribution, diffusion, speciation, and bioavailability of Hg in natural systems. This study suggests that Hg prefers to associate with higher molecular weight fractions of HS and this association particularly predo...

Cadmium is a toxic metal often found with a strong enrichment factor in coastal sediments. The sequential extraction procedure proposed by the BCR (Community Bureau of Reference) was applied for partitioning of Cd in tropical estuary sediments. The method showed satisfactory recoveries. The repartition of Cd in different phases of sediment was cont...

Arsenic totals and species were found to vary during a one year period in the surface sediments of Godavari estuary (the third largest river in India). This study suggests that increasing salinity of overlying water column of sediments may alter the mobility of arsenic complexes in an estuarine system. The higher salt (NaCl) concentrations result i...

Since the beginning of the industrial era, humankind consumption of fossil fuels at increasing rates has led to increases in atmospheric CO2 concentrations by approximately 105 ppm. In the same time, the Mediterranean coastal regions experienced a brutal population growth, from 94 million habitants in 1950 to 274 million in 2000, generating a stron...

RESUME Suite à l'explosion démographique et au déversement de déchets hautement toxiques dans la métropole d'Abidjan, la qualité physico-chimique de cinq baies fermées de la lagune Ebrié en face d'Abidjan a été évaluée de 2006 à 2008. Plusieurs paramètres (température, pH, salinité, oxygène dissous, matières oxydables et sels nutritifs) ont été mes...

The metal contamination of the Ebrié lagoon sediments (Côte d'Ivoire) was assessed using lead, copper and zinc. The study was about three stations far from the urban direct thrusts: station st4 (4°04 W, 5°15 N), R1 (3°42 W, 5°16 N) and R2 (3°43 W, 5°13 N) and 6 stations left in the most polluted lagoon bays. The average contents (in mg/kg dry weigh...

The metal contamination of the Ebrié lagoon sediments (Côte d'Ivoire) was assessed using lead, copper and zinc. The study was about three stations far from the urban direct thrusts: station st4 (4°04 W, 5°15 N), R1 (3°42 W, 5°16 N) and R2 (3°43 W, 5°13 N) and 6 stations left in the most polluted lagoon bays. The average contents (in mg/kg dry weigh...

Bulletin d'Informations de la Société Ouest Africaine de Chimie (2009) N°06 ; 71 -82 71 Caractérisation physico-chimique des sédiments de la zone urbaine d'une lagune tropicale (lagune Ebrié, Côte d'Ivoire). Abstract: The physico-chemical quality of the sediments of the estuarine part of the Ebrié lagoon opposite Abidjan had been given. The sedim...