Plastic waste has been accumulating in the oceans for several decades. It undergoes various degradation processes leading to its fragmentation into small particles. Microplastics (MP) are defined as fragments smaller than 5 mm that are persistent and ubiquitous in all ocean compartments (water, sediment, organisms). It has recently been shown that plastic fragmentation does not stop at PM and also generates sub-micron sized particles: nanoplastics (NP). However, while their abundance could be higher than that of PM, no studies have been carried out on the presence of NP in the environment. Indeed, to date, sampling of plastic fragments smaller than a few dozen µm has never been carried out. However, NPs have their own characteristics (high specific surface, nanometric size) that make them particularly reactive and potentially more toxic because of their capacity to pass through the biological membranes more easily than PM. It is therefore essential, while continuing research on PM, to study NPs from a physical, biological and chemical point of view.
This project has five main objectives:
(i) to understand the processes leading to the fragmentation of plastic debris in the marine environment;
(ii) develop a methodology for sampling and characterising the smallest PM and NP;
(iii) obtain data on their distribution in environmental samples (seawater, sediments, marine organisms);
(iv) gain knowledge on the fate of PM/NP in the marine environment and assess their toxicity to marine life;
(v) to assess the transfer of PM/NP in the marine food chain and the potentially associated health risks to consumers.
This project will also involve an awareness programme to inform the general public about the issue of PM/NP.