ECO-TOXICOLOGICAL EFFECTS OF POLYETHYLENE MICROPLASTICS ON DNA DAMAGE IN ERYTHROCYTES OF BARILIUS VAGRA IN THE SARDARYAB STRETCH OF THE KABUL RIVER, PAKISTAN

Abstract

In this study, genotoxic effects of polyethylene micro-plastics (PE-MPs) on a commercially and ecologically significant species of freshwater fish, Barilius vagra were evaluated in the stretch of the Kabul river, Pakistan. The fish were sampled from nine locations (S1 to S9) and held in controlled laboratory conditions for 7 and 14 days at different concentrations of PE-MPs (0, 5, 25 and 50 mg/L). The peripheral blood erythrocytes (PBE) were used for determination of DNA damage with the micronucleus (MN) assay. After 7 days of exposure, MN frequency increased from 4.8% in the control group to 24.0% at 50 mg/L. The genotoxic stress increased with concentration and time, with MN frequency increasing from 7.2% in the control to 27.4% at 50 mg/L after 14 days. Comparing data from the sampling stations revealed that the baseline MN frequencies of fish were significantly higher at downstream stations (S7–S9: 13.6–15.8%) than at upstream stations (S1–S2: 4.8–6.2%), indicating the overall increase in microplastic pollution in the river. The majority of the fibers, 80-92%, was the dominant type in all matrices, suggesting the presence of pollution from textiles and domestic wastewater. These results indicate ecological concerns due to micro-plastic pollution in the Kabul River basin and the need for more environmental regulations and monitoring approaches for particular species.