Is the toxicity of nanosized polymethylmethacrylate particles dependent on the exposure route and food items?

The environmental effects of nanoplastics-NPLs have been addressed mainly through short-term exposures to a few types polymers, neglecting other NPLs that are economically relevant like polymethylmethacrylate - PMMA. This work aimed assess long-term PMMA-NPLs on the marine primary consumer Brachionus plicatilis, evaluating influence different exposure routes (waterborne, foodborne and both) food items (Nannochloropsis gaditana Tetraselmis chuii). Rotifers were 21 days exposed to: a) control, with clean medium food-CTR; b) contaminated (8.1 mg PMMA-NPLs/L) algae-MC; c) algae (pre-incubated for 96 h 8.1 PMMA-NPLs/L)-AC; and, d) algae–MC/AC. Mortality (lx), total number organisms (TN), fecundity (mx), populational growth rate (r), generational time (gt), feeding rates assessed. Effects r mx found after days. Organisms from AC had higher than MC. MC/AC performed better control in all endpoints. Overall fed N. TN, those T. chuii. In treatments, rotifers mx. Results highlight route type may modulate NPLs’ effects, supporting need standardization assays.