Distribution of Microplastic in Egypt Wastewater Using Aquatic Insects as Bioindicators

The environment’s microplastic (MP) contamination is heavily influenced by nearby industrial and human activity. Great attention has been given to understanding the MP distribution, composition, and effect on aquatic biota in different freshwater systems. In this study, the concentration and characterization of MPs in sediment, water, and Chironomus sp. larvae were investigated in a wastewater basin in Upper Egypt, Sohag Governorate. The mean abundance of MPs in sediment was 385 ± 38 particles/kg dry wt. and 2.05 ± 0.53 particles/L in water. Meanwhile, the mean MP load was 107 ± 36 particles/g wastewater in Chironomus sp. larvae. All detected MPs were found to be fibers. Blue was the predominant color, with different proportions in different samples. Most detected fibers were <500–3,000 μm in length. Polyester was the only polymer found, suggesting that domestic sewage may be the only source of MPs in the current basin. We can conclude that the Chironomus sp. larvae were the best qualitative and quantitative bioindicators for MP contamination. However, further research should be done on their applicability as MP bioindicators in various freshwater environments throughout the world.