Human Health Risk Assessment from the Ingestion of Clarias gariepinus (Burchell, ۱۸۲۲) and Oreochromis niloticus (Linnaeus, ۱۷۵۸) Contaminated with Micro- (Nano) Plastics (MNPs) from River Ngadda, Borno State – Nigeria

Introduction: Freshwater fish inhabiting polluted rivers are capable of bio-accumulating microplastics (plastic fragments measuring less than ۵ mm, and nanoplastics (particles with dimensions below ۱ µm) in their gastrointestinal tracts and occasionally in edible tissues, depending on species, size, and feeding ecology. Consumption of MNP-contaminated fish therefore represents a potential pathway of human exposure. Although dietary intake estimates vary by region and consumption patterns, aquatic bio-resources are recognized exposure routes alongside inhalation and other food sources. This study assessed the human health risks associated with consuming Clarias gariepinus and Oreochromis niloticus contaminated with micro- and nanoplastics (MNPs) from the Ngadda River, Borno State, Nigeria. Materials and Methods: C. gariepinus and O. niloticus were collected monthly from ۶ stations over eight months. Samples were processed and analyzed for MNPs using Fourier Transform Infrared (FTIR) Spectroscopy and Gas Chromatography–Mass Spectrometry (GC–MS) at Yobe State University, Damaturu. Results: Mean MNP abundance in C. gariepinus ranged from ۰.۲۴–۰.۳۹ pp/kg (Stations B–C), while O. niloticus ranged from ۰.۴۷–۰.۷۹ pp/kg. Estimated ingestion for children was ۷۰.۳۸–۱۱۷.۹۷ pp/week and ۸۴۴.۵۰–۱۴۱۵.۶۵ pp/year. Adult exposure ranged from ۲۱۱.۱۳–۳۵۳.۹۱ pp/week and ۲۵۳۳.۵۱–۴۲۴۲۶.۹۵ pp/year. Conclusion: O. niloticus exhibited higher bioaccumulation than C. gariepinus. Spatial variability reflected localized pollution sources. Dietary exposure levels for both children and adults were notable, highlighting the need for further studies on MNP retention and elimination in humans.

کلیدواژه ها:

Water Pollution ، Microplastics (MPs) ، Nanoplastics (NPs) ، Risk Assessment ، Environmental Exposure.