title: Aneugenicity and clastogenicity in freshwater fish Oreochromis niloticus exposed to incipient safe concentration of tannery effluent.
abstract: Conventional effluent bioassays mostly rely on overt responses or endpoints such as apical and Darwinian fitness. Beyond the empirical observation, laboratory toxicity testing needs to rely on effective detection of prognostic biomarkers such as genotoxicity. Indeed, characterization of tannery effluent requires slotting in of genotoxic responses in whole effluent toxicity testing procedures. Hence, the prime objective of the present experimental investigation is to apply the technique of biological assay as a tool of toxicity testing to evaluate the induction of micronuclei (MN) in peripheral erythrocytes, and exfoliated cells of gill and kidney of O.niloticus exposed to Maximum tolerable concentrations (MTCs) of composite Modjo tannery effluent (CMTE) and to compare the sensitivity of each cells origin to the induction of MN. After 72h of exposure, cellular aberrations were detected using MN and nuclear abnormality (NA) tests. The induction of MN was significantly higher in exposed groups (P<0.05) when compared to the control group; moreover the tissue specific MN response was in the order, gill cells>peripheral erythrocyte>kidney. Total NA was found to increase significantly (P<0.05), when compared to the non-exposed group. NA was also further ramified as blebbed (BL), bi-nucleated (BN), lobbed (LB) and notched (NT) abnormalities. The result of each endpoint measured has demonstrated that at a concentration of total chromium (0.1, 0.73 and 1.27mg/L), a perceptible amount cellular aberration was measured, further implicating somber treat of genotoxicity to fishes, if exposed to water contaminated with tannery effluent. This further highlight that conventional effluent monitoring alone cannot reveal the effects expressed at cellular and genetic levels further demanding the incorporation of effluent bioassays in risk assessment and risk management/abatement programs.
authors.affiliation: Ethiopian Public Health Institute, Department of Environmental Public Health Research, Ethiopia. Electronic address: abelweldetinsae@gmail.com.
authors.forename: Abel
authors.initials: A
authors.lastname: Weldetinsae
authors.affiliation: Addis Ababa University, Center for Environmental Sciences, Ethiopia.
authors.forename: Mekibib
authors.initials: M
authors.lastname: Dawit
authors.affiliation: Addis Ababa University, Department of Zoological Sciences, Ethiopia.
authors.forename: Abebe
authors.initials: A
authors.lastname: Getahun
authors.affiliation: Addis Ababa University, Center for Environmental Sciences, Ethiopia.
authors.forename: H S
authors.initials: HS
authors.lastname: Patil
authors.affiliation: National fish and other aquatic life research center, Ethiopia.
authors.forename: Esayas
authors.initials: E
authors.lastname: Alemayehu
authors.affiliation: Ethiopian Public Health Institute, Department of Environmental Public Health Research, Ethiopia.
authors.forename: Melaku
authors.initials: M
authors.lastname: Gizaw
authors.affiliation: Ethiopian Public Health Institute, Department of Environmental Public Health Research, Ethiopia.
authors.forename: Moa
authors.initials: M
authors.lastname: Abate
authors.affiliation: Ethiopian Public Health Institute, Department of Environmental Public Health Research, Ethiopia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Abera
mesh_terms: D024422:Aneugens; D000818:Animals; D002467:Cell Nucleus / Q000187:drug effects*; D002857:Chromium / Q000633:toxicity; D023681:Cichlids / Q000235:genetics*; D004249:DNA Damage; D004912:Erythrocytes / Q000187:drug effects; D005880:Gills / Q000166:cytology; D007220:Industrial Waste; D007668:Kidney / Q000166:cytology; D015162:Micronucleus Tests; D009153:Mutagens; D013633:Tanning; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D024422:Aneugens; D007220:Industrial Waste; D009153:Mutagens; D014874:Water Pollutants, Chemical; D002857:Chromium
keywords: Maximum tolerable concentration; Micronuclei; Nuclear abnormality; Oreochromis niloticus; Tannery effluent