In this study, we evaluated the negative impacts of tire leachate on the monogonont rotifer Brachionus manjavacas by analyzing both acute and chronic endpoints. Tire leachate was produced using tire-wear particles for which the chemical composition, including metal and polycyclic aromatic hydrocarbon (PAH) contents, had been characterized in our previous study. were examined. The survival rate was decreased in a dose-dependent manner for 24 h, with a 24-h LC50 value of 0.56 g L-1. Exposure to three concentrations of tire leachate (0.1, 0.2, and 0.3 g L-1) significantly increased intracellular reactive oxygen species levels at 24 h with an elevation in malondialdehyde content. Activities of key antioxidant defense enzymes, including superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, were also induced at 24 h at these same concentrations of tire leachate. Chronic exposure to 0.1 g L-1 tire leachate for 10 days significantly reduced survival, lifespan, and fecundity in B. manjavacas. Taken together, these findings indicate that tire leachate induces significant acute toxicity by triggering oxidative stress in the marine rotifer, and long-term exposure can alter its population structure.

• Jaehee Kim(Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon 22012, Republic of Korea)
• Jae-Sung Rhee(Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon 22012, Republic of Korea, Research Institute of Basic Sciences, Core Research Institute, Incheon National University, Incheon 22012, Republic of Korea, Yellow Sea Research Institute, Incheon 22012, Republic of Korea) Corresponding author
• Chang-Bum Jeong(Department of Marine Science, College of Natural Sciences, Incheon National University, Incheon 22012, Republic of Korea, Research Institute of Basic Sciences, Core Research Institute, Incheon National University, Incheon 22012, Republic of Korea, Yellow Sea Research Institute, Incheon 22012, Republic of Korea) Corresponding author