Periodic Reporting for period 1 - PlasticsFatE (Plastics fate and effects in the human body)
Período documentado: 2021-04-01 hasta 2022-09-30
The performance of spectroscopic, thermo-analytical and fractionation techniques to detect, identify and quantify MNP particles in complex matrices (like human tissue, food, water and air) was also tested, to determine how particle properties may change in exposure and hazard test media, or during sample preparation. A new dispersion approach was developed with stock and working dispersions for particle characterization and hazard and exposure assessment. The influence of several dispersants has been tested on particle behaviour (sedimentation, flotation) in abiotic and biotic test media assessed, including body fluids that mimic main exposure routes (inhalation, ingestion and translocation in blood). A protocol for dispersion of MP particles in biological media was successfully developed.
The current knowledge on human exposure and fate of MNP in the human body was critically reviewed to guide the analytical and experimental work and first studies initiated to detect and quantify MNP in food, drinks, air, and personal care products (PCP), and suitable digestion and analytical techniques tested for MNP in food and human tissues, to understand how particles translocate from primary organs (intestine, lung, skin, blood) into surrounding tissues and secondary organs (kidney, lymph nodes, liver, brain). To predict exposure to MNP after inhalation and ingestion, new fate and physiologically based pharmacokinetic (PBPK) models are being developed and tested.
First studies on hazard assessment have been carried out with particles of different size, shape and composition (Eu-doped PS, PE, PET and PP with sizes < 10 µm), and by testing and using various in vitro cell lines and biomarkers that represent main exposure routes and effects (see Figure 'Human exposure to MNPs'). Effects measured included cell viability, cytotoxicity, effects on barrier integrity, cellular uptake, bioaccumulation and immune-responses. In vivo studies will verify these in vitro studies.
No significant effects of acute exposure to MNP on cell viability was observed. Also, cell membrane integrity was not significantly affected. While data on bioaccumulation is still processed, first uptake experiments with Eu-doped PS proved positive in plants (lettuce) and human cells. A small induction of inflammatory response was observed and may indicate a potential risk, as it may trigger a cascade of events that can culminate in severe cell and tissue damage. Preliminary adsorption experiments showed particle internalization, but further investigation is needed, also to test the use of non-synthetic homologues, such as starch, as natural controls to distinguish between particle or polymer driven effects.
All data and methods developed and validated are feeding into a new integrated human and environmental risk assessment strategy that also uses a new prospective screening tool, specific IATAS (Integrated Approaches to Testing and Assessment) and decision trees to guide end-users during early design and production. The data produced will be made FAIR and stored in a central data repository within the eNanoMapper database to allow their reuse by stakeholders.
To demonstrate the applicability of the developed methodology under real conditions, case studies are performed that include occupational and environmental situations, and various monitoring activities at plastic packaging, production and recycling sites, to monitor exposure of workers through inhalation and early indicate inflammation or oxidative stress by a panel of new biomarkers. Also studies on long-term effects of MNP in food and their role as vectors for human pathogens have been established.