Responses of Heterobranchus Longifilis to Environmental Contamination by Kemdrill

This study evaluated the hematological effects of KEMDrill, a water-based drilling fluid, on juvenile Heterobranchus longifilis exposed to sublethal concentrations. Following a 14-day acclimation period, 35 juveniles were subjected to 167, 333, 400, and 500 mg/L KEMDrill in a 21-day static renewal bioassay, alongside a control group. Post-exposure blood analyses revealed significant reductions in red blood cells (RBC), white blood cells (WBC), platelets, and hemoglobin levels in treated fish compared to controls. Differential leukocyte counts showed no significant changes in neutrophils, eosinophils, and monocytes; however, lymphocytes declined significantly at the highest concentration (7.98 ± 0.20 at 500 mg/L vs. 11.64 ± 0.21 in control, p < 0.05). These findings confirm the toxic effects of KEMDrill on fish hematology, highlighting potential environmental risks in aquatic ecosystems impacted by drilling fluid contamination. The study recommends careful use of KEMDrill under strict regulations and ongoing environmental monitoring to mitigate adverse effects on aquatic life