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This study assessed the mineralogical and geochemical characteristics of geophagic clays sold in some markets in Cameroon to ascertain their provenance, contamination status and human health risk. To achieve this, 40 samples from 13 markets in Cameroon were purchased and analysed using X-ray diffractometry, X-ray fluorescence and laser ablation inductively coupled plasma mass spectrometry for their mineralogy and geochemistry, respectively. The geophagic clays were dominantly made up of kaolinite and quartz. Their chemistry was dominated by SiO2, Al2O3 and LOI with means of 48.76 wt%, 32.12 wt% and 13.93 wt%, respectively. The major, trace and rare earth elements data showed that these geophagic clays were predominantly derived from felsic rocks. The contamination assessment indicated no enrichment of metals from anthropogenic sources, except for Zn in samples from Acacia, Madagascar and Mfoudi markets. The index of geo-accumulation indicated no contamination to moderate contamination of the clays. The non-carcinogenic index values for Fe, Co, Cr, Cu, Ni, Pb and Zn were generally less than 1, suggesting no non-carcinogenic risk exposure to children and adults consuming the geophagic clays from these metals. The carcinogenic risk index (TCR) for Ni and Cr were above 10−6, which implies that children and adults are vulnerable to minimal carcinogenic health risk. The TCR values from Ni posed the highest risk, especially to children consuming clays from some markets.
Georges-Ivo Ekosse; George Nkeng; Nenita Bukalo; Olaonipekun Oyebanjo. Geophagic Clays from Cameroon: Provenance, Metal Contamination and Health Risk Assessment. International Journal of Environmental Research and Public Health 2021, 18, 8315 .
AMA StyleGeorges-Ivo Ekosse, George Nkeng, Nenita Bukalo, Olaonipekun Oyebanjo. Geophagic Clays from Cameroon: Provenance, Metal Contamination and Health Risk Assessment. International Journal of Environmental Research and Public Health. 2021; 18 (16):8315.
Chicago/Turabian StyleGeorges-Ivo Ekosse; George Nkeng; Nenita Bukalo; Olaonipekun Oyebanjo. 2021. "Geophagic Clays from Cameroon: Provenance, Metal Contamination and Health Risk Assessment." International Journal of Environmental Research and Public Health 18, no. 16: 8315.
This paper presents a sequence-stratigraphic interpretation from the lithologic data and palynological and palynofacies analyses of four shallow boreholes (Badore-1, Epe-1, Ikoyi-1, and Olokonla-1) within the upper Eocene-lower Oligocene interval of the Dahomey Basin. Three lithofacies, namely sandstones, shaly sands, and sandy shales were delineated. Sandstones and shaly sands could probably serve as reservoir rocks, while sandy shales could probably serve as source and seal rocks. Two major broad palynological zones were identified, i.e., the Verrucatosporites usmensis and Magnastriatites howardi Pan-tropical, which correlated to P500 and P400 zones. These zones were further subdivided into the P470 and P480, and P520 and P540 subzones. First occurrences (FOs) of Achomosphaera alcicornu, Homotryblium plectilum, and Adnatosphaeridium multispinosum and last appearance datum (LAD) of Homotryblium tenuispinosum were palynostratigraphic events that defined upper Eocene and lower Oligocene boundary in the four boreholes. Two and four depositional sequences were delineated in Epe-1 and Badore-1 boreholes, respectively, and three each were recorded in Olokonla-1 and Ikoyi-1 boreholes. Seven maximum flooding surfaces (38.8Ma, 37.5Ma, 36.5Ma, 35.0Ma, 32.0Ma, 29.0Ma, and 27.5Ma) and sequence boundaries (39.5Ma, 38.0Ma, 37.0Ma, 36.0Ma, 33.0Ma, 30.0Ma, and 28.4Ma) were identified in the four boreholes. The findings in this present study will be useful in understanding the significance of strata horizons and their respective ages, and system tracts sediment packages in the petroleum system.
Moshood Adegboyega Olayiwola; Ernest Uzodimma Durugbo; Olugbenga Temitope Fajemila; Moses Olaonipekun Oyebanjo. Sequence stratigraphy of subsurface upper Eocene-lower Oligocene deposits, Dahomey Basin, Southwestern Nigeria: palynological and palynofacies approach. Arabian Journal of Geosciences 2021, 14, 1 -19.
AMA StyleMoshood Adegboyega Olayiwola, Ernest Uzodimma Durugbo, Olugbenga Temitope Fajemila, Moses Olaonipekun Oyebanjo. Sequence stratigraphy of subsurface upper Eocene-lower Oligocene deposits, Dahomey Basin, Southwestern Nigeria: palynological and palynofacies approach. Arabian Journal of Geosciences. 2021; 14 (15):1-19.
Chicago/Turabian StyleMoshood Adegboyega Olayiwola; Ernest Uzodimma Durugbo; Olugbenga Temitope Fajemila; Moses Olaonipekun Oyebanjo. 2021. "Sequence stratigraphy of subsurface upper Eocene-lower Oligocene deposits, Dahomey Basin, Southwestern Nigeria: palynological and palynofacies approach." Arabian Journal of Geosciences 14, no. 15: 1-19.
Detrital zircon grains within four (4) deposits including two (2) Cretaceous and two (2) Paleogene/Neogene kaolins in Nigeria were analysed using U–Pb LA-SFICP-MS to determine their provenance. The zircon textures were dominated by xenocrystic cores and oscillatory zoning in the Cretaceous and Paleogene/Neogene kaolins, respectively. The Th/U ratios obtained for the detrital zircon grains within the kaolins were predominantly within known values for rocks with magmatic origin. The age populations obtained for the detrital zircon grains were dominated by values from 529 to 978 Ma within the Neoproterozoic, followed by values from 1754 to 2497 Ma of the Paleoproterozoic. Detrital zircon ages obtained between 553.2 ± 6.2 and 583.5 ± 2.0 Ma represent part of the minimum provenance ages for the primary minerals that were kaolinised. The Cretaceous–Paleogene/Neogene kaolins were derived from parent rocks of Eburnean and Pan African ages within the Western and Northern Nigeria Basements.
Olaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. U–Pb ages of detrital zircons in Cretaceous–Paleogene/Neogene kaolins within Eastern Dahomey and Niger Delta Basins (Nigeria) as provenance indicators. Scientific Reports 2021, 11, 1 -12.
AMA StyleOlaonipekun Oyebanjo, Georges-Ivo Ekosse, John Odiyo. U–Pb ages of detrital zircons in Cretaceous–Paleogene/Neogene kaolins within Eastern Dahomey and Niger Delta Basins (Nigeria) as provenance indicators. Scientific Reports. 2021; 11 (1):1-12.
Chicago/Turabian StyleOlaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. 2021. "U–Pb ages of detrital zircons in Cretaceous–Paleogene/Neogene kaolins within Eastern Dahomey and Niger Delta Basins (Nigeria) as provenance indicators." Scientific Reports 11, no. 1: 1-12.
The demand for kaolinitic clays for various industrial applications is increasing globally. The present study evaluated the potential industrial applications of kaolins from the Eastern Dahomey and Niger Delta Basins, Nigeria. The colour, pH, electrical conductivity (EC), particle size distribution (PSD), plastic limits and liquid limits of the kaolins were determined. Mineralogical properties were assessed using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and differential thermal analysis (DTA). The chemical compositions of the kaolins were determined using X-ray fluorescence spectrometry (XRF). The kaolins were generally acidic, with pH less than 7 with low EC. The moderate plasticity indices (PI ≥ 10%) for the kaolins suggested their potential use in the manufacturing of structural clay products without extrusion. Kaolinite was the only kaolin mineral present with anhedral–subhedral–euhedral crystals. The platy morphology of the kaolinites in the Cretaceous kaolins are very important in paper production. Other minerals present in the kaolins were quartz, muscovite, anatase and goethite. The major oxide contents of the kaolins were dominated by SiO2, Al2O3, Fe2O3 and TiO2. Based on chemical specifications, the raw kaolins are not suitable for most industrial applications except for the Cretaceous Lakiri kaolins in the paper and ceramic industries (except for TiO2 and K2O content). The study concluded that the kaolin deposits would require beneficiation for large-scale industrial applications.
Olaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications. Minerals 2020, 10, 670 .
AMA StyleOlaonipekun Oyebanjo, Georges-Ivo Ekosse, John Odiyo. Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications. Minerals. 2020; 10 (8):670.
Chicago/Turabian StyleOlaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. 2020. "Physico-Chemical, Mineralogical, and Chemical Characterisation of Cretaceous–Paleogene/Neogene Kaolins within Eastern Dahomey and Niger Delta Basins from Nigeria: Possible Industrial Applications." Minerals 10, no. 8: 670.
The deliberate consumption of earthly materials is a universally recognised habit with health benefits and risks to those that practice it. Thirteen (13) samples comprising of six (6) Cretaceous and seven (7) Paleogene/Neogene geophagic kaolinitic materials, respectively, were collected and analysed for trace element concentrations (V, Cr, Co, Ni, Zn, Pb, and Fe), and possible risk on consumers’ health. The trace element compositions were obtained using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and X-ray fluorescence spectrometry (XRF) analytical methods. Based on their average concentrations, Fe > V > Cr > Ni > Zn > Pb > Cu > Co and Fe > V > Cr > Zn > Cu > Pb > Ni > Co for the Cretaceous and Paleogene/Neogene geophagic clays, respectively. Iron concentrations were significantly higher in Paleogene/Neogene geophagic clays than in Cretaceous geophagic clays. The nutritional value of Cu and Zn were lower whereas, Cr and Fe were higher than the recommended dietary intake. The index of geoaccumulation (0 < Igeo ≤ 1) showed that the geophagic materials were uncontaminated to moderately contaminated by the trace elements. The overall hazard indices (HI) for non-carcinogenic effects showed that the geophagic clays pose threat to children (HI > 1) and no threat to adults (HI < 1) health. However, the carcinogenic risk indices (CRI) for Cr, Ni, and Pb were within acceptable cancer risks (10−6 < CRI < 10−4) for children and adults. Hence, based on the trace element s HI and CRI, this study concluded that the consumption of Cretaceous and Paleogene/Neogene geophagic kaolinitic clays poses no risks to adult health but children might suffer health risk if the geophagic clays are not beneficiated before ingestion.
Olaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. Health Risk Evaluation of Trace Elements in Geophagic Kaolinitic Clays within Eastern Dahomey and Niger Delta Basins, Nigeria. International Journal of Environmental Research and Public Health 2020, 17, 4813 .
AMA StyleOlaonipekun Oyebanjo, Georges-Ivo Ekosse, John Odiyo. Health Risk Evaluation of Trace Elements in Geophagic Kaolinitic Clays within Eastern Dahomey and Niger Delta Basins, Nigeria. International Journal of Environmental Research and Public Health. 2020; 17 (13):4813.
Chicago/Turabian StyleOlaonipekun Oyebanjo; Georges-Ivo Ekosse; John Odiyo. 2020. "Health Risk Evaluation of Trace Elements in Geophagic Kaolinitic Clays within Eastern Dahomey and Niger Delta Basins, Nigeria." International Journal of Environmental Research and Public Health 17, no. 13: 4813.
The geochemistry of the <2 μm fractions of Cretaceous-Tertiary Kaolins from Eastern Dahomey and Niger Delta Basins, Nigeria was investigated to infer their paleoenvironment, provenance, and tectonic settings using major, trace, and rare earth elements (REE). Twenty-eight (28) samples comprising of fifteen (15) Cretaceous and thirteen (13) Tertiary kaolins, respectively, were collected. Geochemical compositions of the <2 μm fractions were obtained using X-ray fluorescence (XRF) Spectrometry and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) analytical methods. Weathering indices such as chemical index of alteration (CIA, 96.98-99.39) and chemical index of weathering (CIW, 98.95-99.89) suggested intense chemical weathering under a wet tropical climatic condition. Ni/Co, V/Ni ratios and bivariate plot of V versus Ni indicated that they were deposited under marine oxygen-poor environment which is consistent with the horst and graben structural framework model of the Eastern Dahomey and Niger Delta Basins. The major, trace and REE data suggest that these deposits were derived from predominantly felsic source rocks with contributions from intermediate source rocks. The geochemical discrimination plots showed that the Cretaceous and Tertiary kaolins have been deposited in passive margin tectonic settings.
O.L.A.O.N.I.P.E.K.U.N. Oyebanjo; Georges-Ivo Ekosse; J.O.H.N. Odiyo. Geochemical characterisation of the <2 μm fractions of cretaceous-tertiary kaolins from eastern dahomey and Niger delta basins, Nigeria: Implications on paleoenvironment, provenance, and tectonic settings. Journal of African Earth Sciences 2018, 147, 402 -410.
AMA StyleO.L.A.O.N.I.P.E.K.U.N. Oyebanjo, Georges-Ivo Ekosse, J.O.H.N. Odiyo. Geochemical characterisation of the <2 μm fractions of cretaceous-tertiary kaolins from eastern dahomey and Niger delta basins, Nigeria: Implications on paleoenvironment, provenance, and tectonic settings. Journal of African Earth Sciences. 2018; 147 ():402-410.
Chicago/Turabian StyleO.L.A.O.N.I.P.E.K.U.N. Oyebanjo; Georges-Ivo Ekosse; J.O.H.N. Odiyo. 2018. "Geochemical characterisation of the <2 μm fractions of cretaceous-tertiary kaolins from eastern dahomey and Niger delta basins, Nigeria: Implications on paleoenvironment, provenance, and tectonic settings." Journal of African Earth Sciences 147, no. : 402-410.