Histopathological investigation of some facial cosmetic products mixture exposed to fingerlings of mud catfish <i>(Clarias gariepinus</i>)

Abstract

Cosmetics are one of the major pollutants in the aquatic ecosystem due to the quantum of production to meet the astronomical demand of users that eventually becomes harmful to organisms. Changes in physic-chemical parameters such as potential of hydrogen (pH), Electrical conductivity (EC), Temperature (T oC) Dissolved oxygen (DO) were investigated at the beginning and after 96 hours of cosmetic exposure. This study also investigated the effects of four facial cosmetic products (Powder, foundation, concealer, and primer) histopathologically in fingerlings of Clarias gariepinus (gills) exposed to binary, trinary, and quaternary mixtures in o laboratory bioassays for 48 hours and 96 hours. The results of pH, T C, EC and DO ranged from 6.21 - 6.64, o 25.40 - 26.70 oC, 0.04 - 0.14 mS/cm, and 10.00 -12.00 mg/l respectively. The joint action toxicity evaluation of the binary, trinary, and quaternary mixtures of the cosmetics prepared based on an equitoxic ratio against the test organism was in concordance with the model of synergism. Results showed the prevalence of severe lamellar necrosis in the gills of C. gariepinus which was observed across all combinations except in the combinations of Powder + Primer as well as Powder + Foundation + Concealer + Primer. Moderate lamellar necrosis and hypertrophied epithelium were observed in fish exposed to a mixture of Powder + Foundation + Concealer. The results obtained in this study suggested that the presence of facial cosmetics in the aquatic ecosystem could be dangerous to fish and subsequently human health via biomagnification. Therefore, there is an urgent need for environmental regulators to enforce safety standards for the emission of these selected cosmetics wastes into the waterways to prevent damage to aquatic organisms and public health issues.