Toxicity to humans of ingested micro and nanoplastics combined to metallic environmental contaminants – PLASTOX
Due to their attractive properties and low cost, plastics are widespread used in daily products. One of their most interesting property is their low degradability, but it becomes a drawback when plastics are released in the environment, because it leads to substantial and long-term accumulation of plastic waste in all compartments of the ecosystems, where they progressively fragment into micro- and nano- plastic particles (MNPLs). When exposed to environmnental conditions, including UV light, high temperatures, mechanical, biological and chemical stresses, MNPL physico-chemical properties evolve and their surface reactivity may increase. Owing to their large specific surface area, MNPLs adsorb some environmental pollutants on their surface, which contribute to their toxicity. Among those are metals, which encounter MNPLs during their stay in soils and surface waters. The toxicity towards Humans of such MNPL/metal combination has been rarely studied so far, especially in realistic environmental conditions that may alter their surface and enhance their metal adsorption potential. Human exposure occurs mainly via inhalation of polluted air and ingestion of contaminated food, especially seafood. This leads to intestinal exposure and potential adverse outcome on both intestinal epithelial cells and the immune system.
The objective of PLASTOX is to gain understanding on the toxicity towards humans of MNPLs, both plain and contaminated by metal. Chromium (Cr), nickel (Ni), copper (Cu) and methylmercury (MeHg) have been chosen as metal models, since they are ubiquitous environmental contaminants posing problems in terms of food safety. PLASTOX will focus on MNPLs that greatly contribute to the contamination of the food-chain, i.e., MNPLs released from polyethylene, polystyrene and polytetrafluoroethylene, which are among the most produced plastics in the world. Our industrial partner, in an effort to ensure that the tested items are real-life products, will provide some of these plastics. The plastic particles will be aged in a climatic chamber mimicking realistic environmental conditions, via the use of ISO standards, and will be digested in vitro using a model of human digestion. The sorption/desorption of metals on pristine and weathered MNPLs will be monitored. The impact of such plastic/metal combinations will be evaluated on in vitro and in vivo models of the human intestinal and immune system, using a combination of targeted and omics studies aiming at addressing both their hazard and the mechanisms underlying such impact.
PLASTOX will provide a better understanding of the plastic particle – metals interaction in environmentally relevant conditions, as well as an in-deep analysis of their toxic impact upon ingestion. It will deliver valuable information for a better MNPL risk assessment.
Madame Marie Carriere (Commissariat à l'Energie Atomique et aux Energies Alternatives)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
CEA-SyMMES Commissariat à l'Energie Atomique et aux Energies Alternatives
Inserm - IRSD Institut National de la Santé et de la Recherche Médicale
RHODIA OPERATION RHODIA OPERATION
CNRS-LCBM Centre National de la Recherche Scientifique
CEA-LITEN Commissariat à l'Energie Atomique et aux Energies Alternatives
Help of the ANR 649,184 euros
Beginning and duration of the scientific project: April 2022 - 48 Months