title: Cytotoxic and genotoxic responses of the RTgill-W1 fish cells in combination with the yeast oestrogen screen to determine the sediment quality of Lagos lagoon, Nigeria.
abstract: Economic advancements in developing countries have seen an increase in urbanisation and industrialisation with a rise in the levels of discharge of effluents and municipal waste into aquatic ecosystems. Unfortunately, aquatic environmental regulations in these countries are often rudimentary and the development of environmental monitoring programmes will help identify ecological risks. As an example, the current study assesses the pollution status of 11 sampling sites in Lagos lagoon, Nigeria. The organic solvent sediment extracts were assessed for cytotoxicity and genotoxicity in rainbow trout gill-W1 cells. The induction of oestrogenic activities using the yeast oestrogen screen was also determined. The sediments were analysed for polycyclic aromatic hydrocarbons (PAHs) and other contaminants (polychlorinated biphenyls, organochlorine and organophosphate pesticides). Only sediments from three sites were cytotoxic at both 25 and 12.5mg eQsed/ml using the Alamar Blue cell viability assay. The alkaline Comet assay showed that all sites caused significant DNA damage at 7 mg eQsed/ml; the extent of the damage was site specific. The measure of oxidative damage to DNA via the formamidopyrimidine DNA-glycosylase-modified Comet assay revealed similar results. Toxicity to yeast cells was observed in extracts from six sites; of the remaining sites, only two exhibited oestrogenic activity. There was no strong consistent relationship between sediment PAH concentrations and the cell toxicity endpoints. The dynamic nature of Lagos lagoon with its tides and freshwater inputs are suggested as factors that make it difficult to link the sources of pollution observed at each site with PAH levels and toxic endpoints. The study has demonstrated that the Comet assay is a sensitive endpoint to identify sediments that possess genotoxic contaminants, and this in vitro bioassay has the potential to be incorporated into an environmental monitoring framework for Lagos lagoon.
authors.affiliation: Ecotoxicology Laboratory, Department of Zoology, Faculty of Science, University of Lagos, Akoka, 101017 Lagos, Nigeria, Nigeria, Division of Diabetes and Nutritional Sciences and Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Nnamdi H
authors.initials: NH
authors.lastname: Amaeze
authors.affiliation: Division of Diabetes and Nutritional Sciences and.
authors.forename: Sabine
authors.initials: S
authors.lastname: Schnell
authors.affiliation: Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Osman
authors.initials: O
authors.lastname: Sozeri
authors.affiliation: Ecotoxicology Laboratory, Department of Zoology, Faculty of Science, University of Lagos, Akoka, 101017 Lagos, Nigeria, Nigeria, Division of Diabetes and Nutritional Sciences and Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Adebayo A
authors.initials: AA
authors.lastname: Otitoloju
authors.affiliation: Ecotoxicology Laboratory, Department of Zoology, Faculty of Science, University of Lagos, Akoka, 101017 Lagos, Nigeria, Nigeria, Division of Diabetes and Nutritional Sciences and Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Rosemary I
authors.initials: RI
authors.lastname: Egonmwan
authors.affiliation: Analytical and Environmental Sciences Division, MRC-PHE Centre for Environment and Health, King's College London, Franklin Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
authors.forename: Volker M
authors.initials: VM
authors.lastname: Arlt
authors.affiliation: Division of Diabetes and Nutritional Sciences and nic.bury@kcl.ac.uk.
authors.forename: Nic R
authors.initials: NR
authors.lastname: Bury
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage / Q000235:genetics; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis* / Q000633:toxicity*; D004967:Estrogens / Q000032:analysis / Q000633:toxicity; D063366:Estuaries; D019015:Geologic Sediments / Q000737:chemistry*; D005880:Gills / Q000166:cytology; D009549:Nigeria; D017686:Oncorhynchus mykiss; D010755:Organophosphates / Q000032:analysis / Q000633:toxicity; D010078:Oxazines; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000633:toxicity; D014966:Xanthenes; D015003:Yeasts
chemical_list: D004785:Environmental Pollutants; D004967:Estrogens; D010755:Organophosphates; D010078:Oxazines; D011084:Polycyclic Aromatic Hydrocarbons; D014966:Xanthenes; C005843:resazurin; D011078:Polychlorinated Biphenyls