Aristeidis Tsagkaris, PhD, post-doc works at the University of Chemistry and Technology in the Czech Republic. He has an extensive expertise in the field of contaminants analysis, development and validation of both targeted and non-targeted methods.
See his publications here: https://www.researchgate.net/profile/Aristeidis-Tsagkaris-2
How would you describe the task of your Work Package and your role within it?
University of Chemistry and Technology in Prague (UCT) is involved in two working pages, WP2 and WP3. Our main task, in both WPs, it is to deliver robust, sensitive and high throughput chromatographic methods for the detection of plastic additives in various matrices, namely, soil, earthworms, water and cereal matrices. This is a great analytical challenge as the aforementioned matrices have absolutely different composition indicating the need for the development of individual analytical strategies on each occasion.
Tell us a bit about the article in your own words; what motivated you to write this article on micro- and nanoplastic pollution and its impacts on food safety and security?
Our recently published paper, https://doi.org/10.1016/j.trac.2023.116993, it is a result of a fruitful collaboration with partners from Australia (Commonwealth Scientific and Industrial Research Organisation, CSIRO) and the UK (Queen’s University Belfast, QUB). These are connections we had already established in UCT through a successful participation in a different EU-funded project, http://www.foodsmartphone.eu/. Our colleagues, led by Dr. Joost Nelis, https://people.csiro.au/N/J/jordi-nelis, have been also working in the assessment of micro- and nano-plastic (MNP) pollution and this was a great chance to combine our activities on PAPILLONS with our internal agenda. In late 2021, they asked us to contribute with a comprehensive review on the analytical methods used for plastic additive analysis, and that’s what we did!
Can you explain briefly what micro- and nanoplastic pollution is, and how it enters the human food chain?
The extensive use of plastic materials in various sectors of everyday life and their waste mismanagement has resulted in the formation of MNPs, tiny polymer particles with under investigation impact on ecosystems and organisms. The entrance of MNPs in the food chain is a challenging question as research community still identifies the contamination sources. So far, we are confident to say that there are two main sources, namely, wastewater from urban areas, eventually ending in other water sources (rivers or oceans) and applied plastic mulch widely used in agriculture affecting the soil ecosystem.
What are some of the major research gaps in this area that are hindering the development of robust risk assessments of MNP pollution?
There are several grey areas, but I would like to highlight the following:
Trophic transfer of MNPs can occur for the small MP/NP section (<10 µM). The extent to which this occurs remains largely unquantified. Some effects (altered brain structure) of trophic transfer were shown on fish but much remains unknown.
Human MNP ingestion via food and beverage consumption is an important exposure factor, next to inhalation. Cross contamination through food handling and packaging may be a more major contributor to MP pollution of food as trophic transfer.
MNPs ingestion in livestock is understudied. Studies on larger grazers are scarce or non-existent. Such studies are needed since it is well known these animals ingest MNPs.
Plastisphere communities are insufficiently characterised. We need to understand if these communities are transient or specific and quantify the risk of pathogen/gene transport by MNPs into the food system. Studies on the effects of plastisphere communities on open ocean ecosystems and soil ecosystems are particularly needed.
Plastic additives are understudied. Studies quantifying leaching profiles of plastic additives from any plastic (be it pristine or weathered) in animal tissue/digestive systems or complex soils are scares or non-existent. Nonetheless, matrix related physicochemical factors govern leaching profiles and this must be understood to quantify the potential food safety risk of plastic additives.
Can you describe some of the emerging and current analytical methods that can help to close these research gaps and accurately quantify plastic additives generated through the MNP pollution risks?
Plastic additives are low molecular weight organic molecules and as such they can be efficiently and sensitively monitored by chromatographic methods. The majority of plastic additives can be measured by liquid chromatography whilst those that are volatile and thermostable can also be detected by gas chromatography. I would say that the golden standard for plastic additive determination is chromatographic separation hyphenated to tandem mass spectrometry. Such methods provide wide linear ranges, great accuracy and high-throughput in terms of analysed analytes per run. Employing high resolution mass spectrometry is expected to be used more in the upcoming years as this instrumentation is becoming less expensive (so more available) permitting new analytical capabilities, such as non-targeted screening, an analytical workflow in which no analytical standards are used.
What is the next step for you in the PAPILLONS research?
At the moment, we are developing and optimising our sample preparation protocols or in other words, how to efficiently extract the plastic additives from complex matrices, i.e., soil or cereals. Such matrices feature a diverse composition (e.g., organic matter, mineral content, sugars, lipids etc) and our aim is to selectively isolate the plastic additives and measure them by high-end instrumental methods, such as liquid chromatography tandem mass spectrometry. So far, it has been a very challenging task as many of the target compounds are used in plastic apparatus in the lab, resulting in contamination problems. However, we are confident that in the next the next few months, we will come up with a finalised method that will apply to analyse hundreds of samples collected around Europe.