Coastal ecosystems are characterized by various human activities with potential adverse impacts. This study aimed to evaluate the potential oxidative stress effects in representative aquatic biota deployed in situ at a sawmill wastes dump (test site) and reference site in a coastal ecosystem for a short term (28 days) period. PAHs and OCPs were analysed using GC-FID and GC-MS respectively in surface water and sediments.
View Article and Find Full Text PDFWhen evidence-based policymaking is so often mired in disagreement and controversy, how can we know if the process is meeting its stated goals? We develop a novel mathematical model to study disagreements about adequate knowledge utilization, like those regarding wild horse culling, shark drumlines and facemask policies during pandemics. We find that, when stakeholders disagree, it is frequently impossible to tell whether any party is at fault. We demonstrate the need for a distinctive kind of transparency in evidence-based policymaking, which we call transparency of reasoning.
View Article and Find Full Text PDFThe use of herbicides for increased food production may pose risk to non-target organisms. This study evaluated the acute toxicity, genotoxic, biochemical, and histological biomarkers of subacute concentrations of paraquat and glyphosate in Oreochromis niloticus (Nile Tilapia) for 28 days following standard methods. Glyphosate (96 hLC50 value-1.
View Article and Find Full Text PDFThe Okobaba area of the Lagos Lagoon, Nigeria, is characterised by sawmilling activities which are potential threats to resident aquatic organisms. This study was aimed at evaluating the effect of sawmilling activities on the environmental quality of the Lagos lagoon at Okobaba area, Lagos, Nigeria. Surface water, sediment, macrobenthic invertebrates, and fish species were sampled monthly from six stations for 3 months (July-September 2018).
View Article and Find Full Text PDFAntimicrobial additives in personal care products (PCPs) such as triclosan (TCS) and triclocarban (TCC) are of environmental concern due to their potential toxicity in non-target aquatic organisms. In this study, the histological, genotoxic (micronucleus assay), and embryotoxic effects of sublethal and environmentally relevant concentrations of TCS and TCC were evaluated in Clarias gariepinus (the African sharptooth catfish) over a period of 28 days. The 96 hLC values of TCS and TCC against fingerlings of C.
View Article and Find Full Text PDFAbattoirs are positioned close to freshwaters in most developing countries where untreated wastewaters are discharged into with potential risk to aquatic life such as fish and ultimately human health. We assessed physicochemical parameters, antibiotics (oxytetracycline and diclofenac) and algal load of effluent collected from a major abattoir in Nigeria. Furthermore, liver function enzymes, genotoxic and haemotoxic effects of subacute concentration (10% of 96 hLC value) of the wastewater were evaluated over a period of 28 d in Clarias gariepinus (The African Sharptooth Catfish).
View Article and Find Full Text PDFEnviron Anal Health Toxicol
September 2020
Non-target aquatic organisms such as fish may be impacted by agricultural activities through the run-off of pesticides from farms into aquatic ecosystems. In this study, the genotoxic (erythrocytic micronuclei) and histological effects of sublethal concentrations (1% and 10% of 96-h median lethal concentration (LC50) values) of two pesticides (dichlorvos and paraquat) were evaluated in Clarias gariepinus (the African Sharptooth Catfish) for 28 days. The 96-h LC50 of dichlorvos and paraquat against fingerlings of C.
View Article and Find Full Text PDFThe physicochemical parameters and 16 priority PAHs in surface water, porewater and sediment at a sawmill wastes-impacted and High-Rise study sites on the Lagos lagoon in Nigeria were assessed. Further, the embryotoxic effects of sediment organic and porewater extracts from the study sites were evaluated in Clarias gariepinus (African sharptooth catfish) embryos for 26 h. High molecular weight PAHs dominated the PAHs profile especially in the sediment.
View Article and Find Full Text PDFThe ecological risk assessment (ERA) of polycyclic aromatic hydrocarbons (PAHs) is imperative due to their ubiquity and biological effects in aquatic organisms. We evaluated the seasonal levels and ERA of 16 priority PAHs in surface water, sediment and fish from four (4) anthropogenic-impacted zones of the Lagos lagoon, Nigeria. PAHs were analysed using GC-FID and standard guidelines were utilized for the ERA.
View Article and Find Full Text PDFThe discharge of untreated effluents into aquatic ecosystems poses potential adverse effects to aquatic organisms. In this study, the physico-chemical characteristics of abattoir effluent from Kara Cow Market, Ogun State, Nigeria, surface water and sediments from the Ogun River were evaluated. Fish species and macrobenthic fauna diversity in the river were also examined.
View Article and Find Full Text PDFBackground: Dispersants are first order response strategies for oil spill cleanup in an aquatic environment. However, their effects on the biodegradation capacity of indigenous hydrocarbon-degrading microorganisms are little known.
Objectives: The influence of a dispersant (DS/TT/066) on the type(s) and growth of hydrocarbon-degrading bacteria (HDB) and hydrocarbon-degrading fungi (HDF) in a crude oil-contaminated medium (water) was investigated in the laboratory for 28 days.
An expansion of anthropogenic activity around Lagos lagoon, Nigeria, has raised concerns over increasing contaminants entering the lagoon's ecosystem. The embryotoxicity, teratogenicity and genotoxicity of sediment organic extracts from four sampling zones around Lagos lagoon, Ilaje, Iddo, Atlas Cove and Apapa, as well as the dominant polycyclic aromatic hydrocarbons (PAHs) identified in water measured during the wet season (naphthalene, phenanthrene, pyrene, benzo[a]pyrene and a mixture of these), were assessed with Danio rerio embryos. Embryos were exposed to varying concentrations of toxicants from 0-72 h post-fertilization (hpf).
View Article and Find Full Text PDFThis study investigated the biomarker responses of the earthworm, Eudrilus eugeniae, exposed to sublethal concentrations of benzene, toluene and xylene (BTX) for a time span of 28 days. Lipid peroxidation (LPO) and histopathological alterations were examined. Toxicological evaluations of BTX were carried out against E.
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