Research conducted by Associate Professor Monica Passananti can be utilised in legislation and official recommendations.
Nanoplastics are plastic particles, invisible to the naked eye, measuring about 1/50 of the thickness of a human hair. Very little is known about these and other nano-sized particles that end up in the environment - less than about microplastics, whose formation and spread have been investigated for much longer.
Associate Professor Monica Passananti from the University of Helsinki concentrates particularly on nanoplastics in the atmosphere. In her research, her aim is to collect diverse data on the topic. Among other things, it is important to know the quantity and location of nanoplastics in the environment, as well as the effects of nano-sized plastic particles on nature and humans.
"Our goal is to understand what kind of effects nanoplastics may have on the environment, which is why we are developing methods to study nanoplastics," Passananti says.
Use regulated when necessary
Detailed information is needed on nanoplastics to understand their effects and, when necessary, to regulate their spread and use. In the case of microplastics, research and practical measures have progressed much further, and the goal is to emulate this with nanoplastics.
"The European Chemicals Agency has used microplastics data produced by researchers to assess the risks, for us and the environment, resulting from the use of microplastics in various products. Based on this, the agency has proposed to restrict the use of microplastics in specific products. The European Commission will soon decide whether to accept these proposals."
Nanoparticles arise from everyday activity
Nanoplastics can be formed, for example, by particles of plastic fragmenting into smaller pieces either mechanically, through chemical reactions or in combinations thereof. The formation of nano- and micro-sized particles is strongly linked to everyday human activity, even though the full range of sources are yet to be identified.
"For example, both micro- and nanoscopic particles break off from car tyres when they touch the surface of the road. Some of these particles remain on the ground, but with runoff they easily end up in surface water. The lightest particles can float up into the atmosphere."
Clothes made of synthetic materials release both micro- and nanoplastics when washed, which end up in the drain. Some wastewater treatment techniques are able to capture a proportion of micro-sized plastics, but the screening of nanoplastics is more difficult.
Nanoplastics can also be involved in chemical reactions whose effects are yet to be investigated. When a plastic object is broken down into nanoscopic pieces, the combined surface area of the particles is much larger than that of the original object.
"For example, if you take a plastic bag and degrade it to nano-size particles, the area they cover is equivalent to ten tennis courts. Since many chemical reactions occur specifically on the surface of plastics, the significance of these reactions will increase as the surface area increases," Passananti says.
More understanding of risks and opportunities for impact
Monica Passananti is not against producing and using plastics as such. However, she stresses the need to understand the risks associated with their use.
"People live, produce and consume. This is why we need to know what is happening in our environment and what the effects are of, for example, nanoplastics on the environment."
In this, research has an invaluable role. The information and knowledge produced by research helps authorities and legislators perceive the harm caused to humans and the environment, and contribute to reducing it.
