Effects of Nanoplastics, Lithium, and Their Mixtures on Corbicula fluminea: Preliminary Findings

The effects of polystyrene nanoplastics (NP), lithium (Li), and their mixtures were investigated using the exotic invasive bivalve Corbicula fluminea as test organism for ethical reasons. In a 96 h laboratory bioassay, groups of bivalves were exposed to water (control), 0.8 mg/L NP, 3.2 mg/L NP, 1 mg/L Li, 4 mg/L Li, 0.8 mg/L NP + 1 mg/L Li (Mix1) or 3.2 mg/L NP + 4 mg/L Li (Mix2). Effect criteria were filtration rate (FR), lipid peroxidation levels (LPO), and the activity of the enzymes cholinesterases (ChE), isocitrate dehydrogenase (IDH), octopine dehydrogenase, glutathione S-transferases and glutathione reductase. Bivalves exposed to NP alone or in mixture had IDH activity inhibition (22%), and LPO reduced by 33%. Bivalves exposed to Li alone or in mixture had 22% of ChE inhibition. Bivalves exposed to Mix2 had FR induction (twofold). These results suggest that the NP tested may decrease the cellular energy production by anaerobic pathways despite providing some reduction of lipid oxidative damage that Li has anticholinergic effects, and that NP and Li may cause toxicological interactions in bivalves exposed simultaneously to the two substances. Further studies are needed to understand potential toxicological interactions between NP and Li under different abiotic conditions and exposure periods.