Gift IGUISI

Microplastic (MP) contamination of freshwater ecosystems is a significant environmental and public health concern globally. The paucity of data on MP contamination in Chrysichthys nigrodigitatus from the Ikpoba River, Benin City, Nigeria, warranted this investigation. This study determined the levels, types, and estimated daily intake (EDI) of microplastics in C. nigrodigitatus from three stations along the river over three months (July-September), using visual identification and Fourier Transform Infrared (FTIR) Spectroscopy for polymer confirmation. The mean levels of MPs in fish ranged from 0.0113 in August at Station 3 to 0.0163 in September at Station 2, with no significant difference (p>0.05) between months at each station. The plastic load (particles/fish) ranged from 0.00103 in September at Station 1 to 0.00136 in September at Station 2, showing significant temporal variation (p<0.05) at Station 1. The frequency of occurrence (FO) of MPs ranged from 0.33 in July at Station 1 to 1.00 in September at Stations 1 and 3. Physical classification revealed that fragments were the most dominant MP type (39.29%). FTIR analysis confirmed the presence of polyethylene, identified by characteristic absorbance wave numbers at 2925 cm⁻¹, 2850 cm⁻¹, 1430 cm⁻¹, and 710 cm⁻¹.The estimated daily intake (EDI) of MPs for humans through the consumption of C. nigrodigitatus was calculated to be low. The findings confirm the prevalence of microplastics in Ikpoba River and their ingestion by a commercially important fish species. It is recommended that continuous monitoring, effective waste management policies, and public enlightenment campaigns be implemented to mitigate plastic pollution and protect the river's ecosystem and associated public health