Multi-model analysis of the combined toxic effects of ultrafine carbon black and amisulbrom on A549 Cells

Black carbon (BC), a typical nanoscale component of PM₂.₅, is environmentally persistent and prone to forming composite pollutants. Amisulbrom, a widely used pesticide, can migrate synergistically with atmospheric contaminants, yet their combined health risks remain unclear. This study evaluated the individual and combined toxicities of ultrafine carbon black (UFCB) and amisulbrom in A549 cells. Both agents induced dose-dependent cytotoxicity, with 24 h IC₅₀ values of 19.79 and 54.45 μg/mL, respectively. Multiple models including Bliss independence, weighted quantile sum, and Bayesian kernel machine regression consistently showed an additive effect rather than synergism or antagonism, with UFCB as the main contributor. Combined exposure significantly increased intracellular ROS and apoptosis, but glutathione and malondialdehyde showed no synergistic changes. Measured indicators were comparable to theoretical values, further verifying the additive joint effect.