Occurrence of selected pharmaceuticals in industrial wastewater, receiving waters and fish

Abstract

Data on pharmaceutical contamination of African waterbodies are scarce. Therefore, this research aimed to quantify the occurrence of selected pharmaceuticals in wastewater from pharmaceutical industries, receiving waters and fish. Water and fish samples were collected from waterbodies close to two pharmaceutical manufacturing companies, here refered to as “Company A” and “Company B” and processed for chemical analyses. High-performance liquid chromatography (HPLC) Agilent 1100 series was used to quantify metronidazole and tetracycline HCl in wastewater, the receiving water and fish for Company A, whereas caffeine, diazepam and ibuprofen were assessed in the same sample matrices for Company B. Metronidazole, tetracycline HCl, caffeine, diazepam, and ibuprofen concentrations in wastewater were 8.04 ± 0.56 μg l⁻¹, 5.77 ± 0.98 μg l⁻¹, 7.53 ± 0.56 μg l⁻¹, 25.89 ± 2.47 μg l⁻¹, and 37.99 ± 0.83 μg l⁻¹, respectively. The risk quotients of the concentrations of ibuprofen in the wastewater and the receiving water were >1 and therefore could be of environmental concern. The concentrations of the pharmaceuticals in fish from the receiving waters ranged from 1.29 to 95.27 ng g⁻¹. This study has revealed the accumulation of pharmaceuticals in fish tissues in Nigeria and the risk assessment showed ibuprofen could pose environmental risks. There is a requirement for studies on the acute and chronic toxicity tests of these emerging contaminants on aquatic organisms native to Africa to determine their ecotoxicological implications on African waters.

Keywords: aquatic contamination, bio-accumulation, industrial effluent, pharmaceuticals, toxicity testing