DOI: https://doi.org/10.55373/mjchem.v27i5.233

Keywords: Microplastics; fishes; lake; Laser Direct Infrared Imaging (LDIR); Yuehai Lake

Abstract

Microplastic (MP) pollution in freshwater ecosystems poses growing threats to biodiversity and human health. This study employed laser direct infrared imaging (LDIR) to analyze MP contamination in gills and gastrointestinal tracts (GIT) of five fish species (n=100) from Yuehai Lake, China. Results revealed significantly higher MP loads in omnivorous species compared to carnivorous counterparts, with GIT containing greater MP abundance than gills. MP characteristics exhibited tissue-specific patterns: fibers dominated gill samples (64.32%) while fragments prevailed in GIT (50.50%). Size distribution analysis showed >80% of MPs measured 20-100 μm. Polymer composition differed markedly between tissues, with fluoroelastomer (FKM, 17.87%) and polyvinyl chloride (PVC, 17.79%) predominant in gills, versus polyethylene terephthalate (PET, 18.74%) and chlorinated polyethylene (CPE, 17.63%) in GIT. Pollution indices (11) confirmed significant ecological contamination. These findings provide crucial evidence of MP pollution pathways in freshwater food webs and highlight potential risks to ecosystem integrity and public health.