IMAGINE

Studies investigating the effects of nanoplastics (NPs) on aquatic organisms used concentrations between 2 to 7 order-of-magnitudes higher than those predicted in the open ocean. These studies divided the community between those sounding the alarm due to the observed ecotoxicological effects, and those predicting that NP concentrations in the environment are far below any threshold-effect. Most experiments were inadequately designed, and thus the results unsatisfying. Fit-to-purpose experimental designs have been hindered by a lack of appropriate NP models, analytical methods, and monitoring strategies for predicted NP concentrations. Using [14C]NPs and conventional nuclear techniques, I have recently modelled that scallops, chronically exposed (> 1 y) to environmentally realistic NP concentrations (15 .........g/L) might accumulate and reach NPs body burden where effects are observed by those sounding the alarm. Astonishingly, this suggests that NPs might already be beyond threshold-effects in organisms and harming the marine biota. Here, I propose an innovative approach that will overcome the analytical limitations to correlate potential local biological responses with mapping and quantification of NPs under realistic environmental settings. By developing [14C]NPs of the most produced plastics, and combining then with the analytical power of the accelerator mass spectrometry, ion beam analysis and mass spectrometry imaging, IMAGINE will answer whether NPs in the oceans are already beyond "threshold-effect" concentrations? This novel analytical approach will provide a unique insight into the potential effects of NPs following chronic exposures and will: 1) provide key intrinsically radiolabelled NP models; 2) develop an analytical suite to generate spatially-resolved toxicokinetic and metabolomic data; 3) perform chronic NPs exposures at predicted NPs concentrations; 4) answer whether key NPs accumulate and induce local biological responses at predicted concentration