A sample collection mission was carried out in the fall of 2021 on alpine glaciers by two IPGP researchers, with the aim of tracing the distribution and the sources of particles of nanometric size in areas supposedly preserved. This expedition follows on from the NanoTrack project, funded by the Université de Paris IdEx, on the study of nanoparticles and their effects on humans and the environment.
Last fall, two IPGP researchers, Yann Sivry and Sophie Coural, were able to lead a scientific mission organized as part of the INSIDE THE GLACIERS project, conducted by Italian, French and Swiss scientific teams, including the Spélé'Ice Exploration Association and the IPGP-Université de Paris. Several expeditions took place between August and December 2021 by various teams, on eight different glaciers on the northern side of the Alps, including glaciological and microbiological studies. The samples taken by all these missions will allow IPGP scientists to obtain a complete data set and a global vision that is essential for tracing the sources of nanoparticles, the objective of the study.
This high-risk mission, carried out on and inside the Zinal and Moiry glaciers, in Valais (Switzerland), allowed IPGP scientists to take samples of ice at different depths, but also of the runoff waters and sediments, in order to find the chemical composition of nanoparticles deposited over time in successive layers of ice. The objective is to determine whether this chemical composition is specific to a natural source or if it is linked to a human source following transport and then deposition by the atmosphere (snow, rain, wind deposition). Like the Grand Paris Nanoparticles Observatory project (NanObs, carried by the IPGP and supported by the Université de Paris Foundation), the objective here is to trace the distribution and the sources of nanometric-sized particles in supposedly remote and unspoiled areas.
Contrary to the usual scientific expeditions where the cores are carried out from the surface to the depths, the scientists this time descended directly into the "moulins", these crevasses widened by the meltwater, accompanied by speleologists and high mountain guides. Small horizontal cores of 20 cm allowed then access to the different layers of ice.
The different samples will now be analyzed at the IPGP in order to measure the precise chemical composition of these particles and distinguish anthropogenic nanoparticles from geogenic ones.
One of the main limitations of nanometrology is the multitude of nanomaterials present in natural systems: while a minority are manufactured nano-objects, many other nanoparticles (NPs) produced by natural or anthropogenic processes are present in the natural environment. Existing analytical tools are not yet able to distinguish natural NPs from anthropogenic and/or artificial NPs, at the low concentrations expected in environmental matrices. The lack of effective tools still limits the prediction and management of risks, in a context of important environmental and societal challenges. The development of new technologies for innovative measures is a key point in ensuring, over time, the monitoring of the effects of nanoparticles on consumers, workers and the environment.
The Nanotrack project aims to break down this barrier by discriminating between geogenic and anthropogenic nanoparticles, through the combined use of the most recent innovative tools such as non-traditional stable isotopes, high-resolution ICPMS and time-of-flight ICPMS used in single particle counting mode, as well as asymmetric flow-force fractionation. This project is not only one of the first studies dedicated to the discrimination between anthropogenic and geogenic nanoparticles in environmental systems, but also the first to combine all of these three cutting-edge tools, to understand, quantify and predict fate of nanoparticles on a larger scale.
The new knowledge acquired in this project will be crucial not only for the implementation of regulations and laws dedicated to nanotechnologies but also for the information and protection of the general public regarding the different sources of nanoparticles.
If the results of the work carried out during this mission in the Alps are conclusive, the IPGP researchers will then be able to consider studies in more remote areas (Greenland, Patagonia) with sampling plans on a larger scale.