Manufactured nanoplastics

Manufactured nanoplastics

By AVICENN team – Last modified in May 2023

Different types of nanoplastics

More and more plastic nanoparticles are infiltrating soils (after spreading sludge from wastewater treatment¹Efficient STEPs with nanoplastics, Le Matin, February 5, 2019 in particular), rivers and oceans.

• Some nano-plastics come from the degradation of plastics (packaging, waste, etc.) into micro-particles, which then break down into nano-particles²See for example:-The slow fragmentation of plastics decipheredJulienne Fanon, The Conversation, October 2019 –Tea bags Infusions with microplastics and nanoparticles, Que Choisir, September 2019 –Plastic waste disintegrates into nanoparticles, study finds, Lund University, December 2018 and Nanoplastics formed during the mechanical breakdown of daily-use polystyrene productsEkvall MT et al, Nanoscale Adv., 1 : 1055-1061, 2019..
• Other micro- and nanoplastics are intentionally incorporated into mixtures used by consumers or professionals³See:
  – La nanofabrication : une réponse aux enjeux de la plasturgie et des composites, L’Usine Nouvelle, 16 août 2022
  – The manufacture of nanoplastics, summarized in the video below as part of the European research program OPTINANOPRO (2015-2018), focused on the packaging, automotive and solar energy sectors (summary in French here). The 25 polymer products created have been tested right through to composting. Citizen question to be documented: what will become of this fragmentation? Plastic nanoparticles containing nanoparticles? https://www.youtube.com/embed/enBRksBYc
  – Another European MINANO program completed in 2013 indicates the types of plastics incorporating nanoparticles: polypropylene (PP) for plastic nanocomposites and polyvinyl chloride (PVC) for wood-plastic nanocomposites and polystyrene foam (for building insulation). The functionalized nanoparticles added are magnesium dihydroxide (MDH) Mg(OH)2, nano zinc oxide ZnO, and nano silver.:
  • in cosmetic products (microbeads used for their exfoliating properties – banned in France since 2018)
  • in detergents and cleaning products
  • in paints, coatings and building materials
  • in pharmaceutical products
  • in plant protection products (e.g. fertilizer coatings for a slow release)
  • in the oil and gas sector.
    

A cascade of adverse effects?

Their release and diffusion in the ecosystems lead to a cascade of harmful effects, still insufficiently evaluated, that are affecting aquatic fauna and the other animals (including humans) that feed on them⁴Cf. Scallops suck in billions of plastic particles, National Geographic, December 5, 2018 (study abstract in English: Uptake, Whole-Body Distribution, and Depuration of Nanoplastics by the Scallop Pecten maximus at Environmentally Realistic Concentrations, Al-Sid-Cheikh M et al, ES&T, 52(24): 14480-14486, 2018. And Scientific Colloquium 25 “Microplastics and nanoplastics in food and feed”, EFSA, June 2020.

Research is being conducted on the subject in France⁵Among the thirty-four projects selected by Anses within the framework of the National Environment-Health-Work Research Program in 2020, the “Transplast” project aims to study the effects of micro- and nanoplastics on the activity of membrane transporters of xenobiotics (it is coordinated by M. Fardel (IRSET/INSERM) and elsewhere⁶ See for example:
– The Mobility of Plastic Nanoparticles in Aqueous and Soil Environments: A Critical Review, Brewer A et al, ACS EST Water, 2020
– Plastic pollution also threatens plants (and by the way, our food), Marcus Dupont-Besnard, June 23, 2020
–Differentially charged nanoplastics demonstrate distinct accumulation in Arabidopsis thaliana, Xiao-Dong Sun et al, Nature Nanotechnology, 22 June 2020
– Micro- and nanoplastics in our environment: Understanding exposures and impacts on human health, Call H2020-SC1-BHC-2018-2020
– Focus on Nanoplastic, Nature Nanotechnology, April 2019
– Emergence of Nanoplastic in the Environment and Possible Impact on Human Health, Lehner R et al., About. Sci. Technol., 2019
– Quantifying ecological risks of aquatic micro- and nanoplastic, Besseling E et al, Critical Reviews in Environmental Science and Technology, 2019
– Biological Effects and Implications of Micro- and Nanoplastics in the Aquatic Environment, Rist S, thesis, Technical University of Denmark, 2019
– Closing the gap between small and smaller: towards a framework to analyse nano- and microplastics in aqueous environmental samples, Mintenig, SM et al, Environ. Sci.: Nano,5: 1640-1649, 2018
– Nanoplastics in the Aquatic Environment, Mattsson K et al, in Microplastic Contamination in Aquatic Environments – An Emerging Matter of Environmental Urgency, 379-399, 2018
– Ingestion of micro- and nanoplastics in Daphnia magna – Quantification of body burdens and assessment of feeding rates and reproduction, Rist S et al, Environmental Pollution, 228: 398-407, September 2017 to evaluate their effects on the environment (eco-toxicity), but also their role in the dissemination of other pollutants that cling to their surface⁷See for example Transport of micro- and nanoplastics in the environment: Trojan-Horse effect for organic contaminants, Critical Reviews in Environmental Science and Technology, 52(5), 2022 (we speak of the “Trojan Horse” effect) and in the occurrence of “cocktail effects” triggered by the association with other nanoparticles or undesirable substances⁸See for example:
– Nanoplastics enhance the toxic effects of titanium dioxide nanoparticle in freshwater algae Scenedesmus obliquus, Das S et al, Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 256, June 2022
– Are gold nanoparticles and microplastics mixtures more toxic to the marine microalgae Tetraselmis chuii than the substances individually?, Davarpanah E, Guilhermino L, Ecotoxicology and Environmental Safety, 181: 60-68, October 2019.

Towards restrictions on manufactured nano and microplastics?

In August 2022, the Commission finally presented a proposal to restrict intentionally added microplastics⁹Cf. https://ec.europa.eu/transparency/comitology-register/screen/documents/083921/1/consult?lang=en, fulfilling a commitment made in 2017.

The restriction proposal does not set a lower limit for the size of microplastics, and includes all small plastic particles, including nanoplastics.

On April 26, 2023, the European Commission’s REACH Committee voted in favor of the European Commission’s proposal to restrict manufactured microplastics¹⁵See: https://rethinkplasticalliance.eu/news/rethink-plastic-alliance-welcomes-the-eu-restriction-of-intentionally-added-microplastics-urges-faster-implementation/. This is the broadest chemical ban in the European Union, covering all intentionally added micro- and nanoplastics in all sectors (detergents, medical devices, cosmetics, sports grounds, etc.). In addition to marketing bans, it also lays down further information and labeling requirements.

The European Parliament and the Council of the EU have a three-month review period, after which the regulation should come into force immediately.

This text has been welcomed by NGOs (Rethink Plastic, ClientEarth, Surfrider, BEE) who have been working on this restriction for years. On April 19, 2023, in anticipation of the REACH Committee meeting on April 26, 32 NGOs co-signed an open letter calling once again for the adoption of the text, while insisting on the need for Member States to implement additional measures to better prevent and reduce emissions of micro- and nanoplastics¹⁶Cf. https://eeb.org/wp-content/uploads/2023/04/20230420-REACH-Committee-letter.pdf.

However, this regulation still has a number of shortcomings.

Transition times too long

The deadlines for eliminating micro-plastics from cosmetics (12 years) and sports grounds (8 years) are still disproportionately long¹⁷Cf. https://www.clientearth.org/latest/press-office/press/green-groups-welcome-microplastics-restriction-but-warn-of-shortcomings/ and unjustified, despite warnings from European NGOs and calls from certain cosmetics brands to speed up the process¹⁸See: https://rethinkplasticalliance.eu/news/plastic-soup-foundation-rethink-plastic-alliance-and-20-cosmetic-brands-express-crucial-necessity-for-complete-ban-for-intentionally-added-microplastics-as-eu-vote-is-upcoming/.

A temporary exemption for nanoplastics from this restriction

Although this text provides for the restriction of all microplastics, irrespective of their size (therefore including nanoplastics < 100 nm), it also provides for a temporary exemption from application of the regulation for particles smaller than 0.1 µm and those in the form of fibers, smaller than 0.3 µm in length¹⁹Cf. Article 3 https://ec.europa.eu/transparency/comitology-register/screen/documents/083921/6/consult?lang=en . This exemption supposedly guarantees the application of the text, in a context where existing analysis methods are not “sufficient” to detect and analyze particles of this size.

This exemption is problematic, as it effectively excludes nanoplastics from the scope of the regulation, at a time when the development of detection methods is progressing rapidly²⁰See for example: https://microplastics.springeropen.com/articles/10.1186/s43591-022-00051-1. It could encourage companies to continue using nanoplastics and delay efforts to eliminate or substitute them.

No specific measures for nanoplastics

All the more relevant since, although nanoplastics share many characteristics with microplastics, their interactions with their environment generate additional specific risks²⁴See European Commission, Directorate-General for Environment, Nanoplastics: state of knowledge and environmental and human health impacts, Publications Office of the European Union, 2023, https://data.europa.eu/doi/10.2779/632649. Brewer, Dor and Berkowitz (2020)²⁵See Brewer, A., Dror, I. and Berkowitz, B. (2020) The mobility of plastic nanoparticles in aqueous and soil environments: a critical review. ACS ES&T Water, 1(1): 48-57 elaborate on what distinguishes them from larger particles, namely :

• their ability to penetrate more numerous and varied biological barriers
• their capacity to absorb large quantities of other pollutants
• their greater reactivity due to their smaller size
• the fact that they are too small to be disposed of using existing plastic disposal methods.
• …

In a brief produced for the European Commission in April 2023 “Nanoplastics: state of knowledge and environmental and human health impacts” , the authors conclude that an inclusive categorization where microplastics also includes nanoplastics will avoid leaving “a gaping hole” in the regulatory regime for intentionally added nanoplastics, in a context where the “regulatory response lags behind the rate of release of nanoplastics and their abundance in the environment”.

What research has been done on the subject?

In August 2019, following the publication of an analysis of the state of research on microplastics in drinking water the World Health Organization (WHO) called for more research on micro- and nanoplastics and strong action against plastic pollution²⁶Cf. WHO calls for more research on microplastics and strong action on plastic pollution, WHO, 22 August 2019.

Anses announced at the end of 2021 that it would fund four projects on the study of micro and nanoplastics under its National Environment-Health-Work Research Program (PNR EST).

At the European level, more than a dozen projects are in progress to improve our understanding of the behavior of nanoplastics and the associated risks²⁷Five projects (POLYRISK, AURORA, IMPTOX, PLASTICHEAL, PlasticsFatE – 2021-2025), for a total of €30 million EU funding, have been funded.

Harmonized methods and protocols specific to nanoplastics are currently being developed for assessing risks to health and ecosystems²⁸En octobre 2023, des chercheurs publie dans la revue Nature Protocols un protocole de recherche pour évaluer la toxicité des nanoplastiques dans les sols et les écosystèmes aquatiques, voir : Exposure protocol for ecotoxicity testing of microplastics and nanoplastics, Abdolahpur Monikh, F., Baun, A., Hartmann, N.B. et al., Nat Protoc (2023).

To be continued…

What recommendations exist?

In August 2020, a report²⁹Cf. Global Summit on Regulatory Science 2019 Nanotechnology and Nanoplastics, JRC & GCRSR, Publications Office of the European Union, 2020 from the Joint Research Center (JRC) and the Global Coalition for Regulatory Science Research (GCRSR) was published; it summarized the discussions of a conference on the topic of nanoplastics that brought together nearly 200 stakeholders from 36 different countries in 2019. Some of the recommendations made were:

• a coordination effort on terminology, definitions, sampling, characterization, and hazard and exposure assessment of nanoplastics to produce reference materials, as well as “robust” standards, guidance and regulations
• an information and exchange platform on nano- and microplastics
• collaboration between stakeholders, building trust through data transparency³⁰Other more general recommendations include:
  -Increased efforts to ensure that testing of nanomaterials, especially those used in nanomedicine, is rigorous, reproducible and comparable across samples and situations throughout the development pipeline
  – harmonization of methods, standards and reference materials
  – the intensification of ongoing international efforts to address the potential health and environmental hazards of nanomaterials
  -The development of collaborations and continuous communication on scientific research on the regulation of nanomaterials, as well as the appropriate harmonization of legal and regulatory structures.