TITLE:
Toxicity Evaluation of Pharmaceutical Wastewater to the Nile Tilapia (Oreochromis niloticus)
AUTHORS:
Scholastica Mnena Lan, Tam-Miette Dawari Briggs, Henry Ebele Obanya, Nnamdi Henry Amaeze, Adebayo Akeem Otitoloju
KEYWORDS:
Pharmaceutical Effluents, Oreochromis niloticus, Oxidative Stress, Transaminases
JOURNAL NAME:
Journal of Environmental Protection,
Vol.12 No.4,
April
29,
2021
ABSTRACT: This study assessed the levels of oxidative stress biomarkers in gills and liver, as well as the activities of transaminases in the liver of Nile tilapia (Oreochromis niloticus), exposed to pharmaceutical effluents. The pharmaceutical effluents were collected from two pharmaceutical industries in Lagos, Nigeria. The assessment of physicochemical characteristics of the effluents indicated that some parameters were not in accordance with NESREA limits. The acute toxicity studies showed that 96hrLC50 values of “effluent A” and “effluent B” were 27.0 ml/L and 18.0 ml/L respectively. The juveniles of O. niloticus were exposed to 1/100th and 1/10th LC50s of the two effluents for a period of 14 and 28 days. These concentrations significantly increased the level of the lipid peroxidation product, malondialdehyde. There was also inhibition of the activities of superoxide dismutase and catalase as well as significantly lower levels of reduced glutathione after 28 days. The levels of the transaminases (aspartate aminotransferase and alanine transaminase) were elevated in the liver of the fish after the exposure to the effluents. The present findings showed that the wastewater caused oxidative stress and hepatocellular damage in the fish suggesting potential ecotoxicological risks of the wastewater to aquatic organisms.