Tag Archives: nanoplastic particles

Rapid formation of micro- and nanoplastics in the environment

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Image: Nora Meides.

A June 18, 2021 news item on phys.org announces the results of research into how materials made of plastic break down into micro- and nanoplastic particles in the environment,

Most microplastic particles in the environment originate from larger pieces of plastic. In a long-term study, an interdisciplinary research team at the University of Bayreuth has simulated how quickly plastic breaks down into fragments under natural influences. High-tech laboratory tests on polystyrene show two phases of abiotic degradation. To begin with, the stability of the plastic is weakened by photo-oxidation. Then cracks form and more and more and smaller fragments are released into the environment. The study, published in the journal Environmental Science & Technology, allows conclusions to be drawn about other plastics that are common in the environment.

A June 17, 2021 University of Bayreuth press release, which originated the news item, provides more detail,

Polystyrene is an inexpensive plastic that is often used for packaging and thermal insulation, and is therefore particularly common in plastic waste. As part of their long-term study, the Bayreuth researchers for the first time combined analytical investigations, which were also carried out on polystyrene particles at the atomic level, with measurements determining the behaviour of these particles under mechanical stress. On the basis of this, they developed a model for abiotic degradation, i.e. degradation without the influence of living organisms.

“Our study shows that a single microplastic particle with a diameter of 160 micrometres releases about 500 particles in the order of 20 micrometres – i.e. 0.02 millimetres – over the course of one and a half years of being exposed to natural weathering processes in the environment. Over time, these particles in turn break down into smaller and smaller fragments. An ecocorona can form around these tiny particles, possibly facilitating penetration into the cells of living organisms. This was discovered a few months ago by another Bayreuth research group,” says first author Nora Meides, a doctoral student in macromolecular chemistry at the University of Bayreuth.

n the water, the microplastic particles were exposed to two stress factors: intense sunlight and continuous mechanical stress produced by agitation. In the real-world environment, sunlight and mechanical stress are in fact the two main abiotic factors that contribute to the gradual fragmentation of the particles. Irradiation by sunlight triggers oxidation processes on the surface of the particles. This photo-oxidation, in combination with mechanical stress, has significant consequences. The polystyrene chains become ever shorter. Furthermore, they become increasingly polar, i.e. centres of charge are formed in the molecules. In the second phase, the microplastic particles begin to fragment. Here, the particles break down into smaller and smaller micro- and nanoplastic fragments.

“Our research results are a valuable basis for investigating the abiotic degradation of macro- and microplastics in the environment – both on land and at the surface of water – in more detail, using other types of plastic as examples. We were surprised by the speed of fragmentation ourselves, which again shows the potential risks that could emanate from the growing burden of plastics on the environment. Especially larger plastic waste objects, are – when exposed to sunlight and abrasion – a reservoir of constant microplastic input. It is precisely these tiny particles, barely visible to the naked eye, that spread to the remotest ecosystems via various transport routes,” says Teresa Menzel, PhD student in the area of Polymer Engineering.

“The polystyrene investigated in our long-term study has a carbon-chain backbone, just like polyethylene and polypropylene. It is very likely that the two-phase model we have developed on polystyrene can be transferred to these plastics,” adds lead author Prof. Dr. Jürgen Senker, Professor of Inorganic Chemistry, who coordinated the research work. 

The study that has now been published is the result of the close interdisciplinary cooperation of a working group belonging to the DFG Collaborative Research Centre “Microplastics” at the University of Bayreuth. In this team, scientists from macromolecular chemistry, inorganic chemistry, engineering science, and animal ecology are jointly researching the formation and degradation of microplastics. Numerous types of research technology are available on the Bayreuth campus for this purpose, which were used in the long-term study: among others, ¹³C-MAS-NMR spectroscopy, energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and gel permeation chromatography (GPC).

Here’s a link to and a citation for the paper,

Reconstructing the Environmental Degradation of Polystyrene by Accelerated Weathering by Nora Meides, Teresa Menzel, Björn Poetzschner, Martin G. J. Löder, Ulrich Mansfeld, Peter Strohriegl, Volker Altstaedt, and Jürgen Senker. Environ. Sci. Technol. 2021, 55, 12, 7930–7938 DOI: https://doi.org/10.1021/acs.est.0c07718 Publication Date: May 21, 2021 Copyright © 2021 The Authors. Published by American Chemical Society

This paper is behind a paywall.

In six hours billions of plastic nanoparticles accumulate in marine organisms

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For the sake of comparison, I wish they’d thought to include an image of a giant scallop that hadn’t been used in the research (I have an ‘unplastic’ giant scallop image at the end of this posting),

Caption: These are some of the scallops used as part of the current research. Credit: University of Plymouth

But, they did do this,

A scan showing nanoplastic particles accumulated within the scallop’s gills (GI), kidney (K), gonad (GO), intestine (I), hepatopancreas (HP) and muscle (M). Credit: University of Plymouth [downloaded from https://phys.org/news/2018-12-billions-nanoplastics-accumulate-marine-hours.html]

A December 3, 2018 news item on phys.org announces the research,

A ground-breaking study has shown it takes a matter of hours for billions of minute plastic nanoparticles to become embedded throughout the major organs of a marine organism.

The research, led by the University of Plymouth, examined the uptake of nanoparticles by a commercially important mollusc, the great scallop (Pecten maximus).

After six hours exposure in the laboratory, billions of particles measuring 250nm (around 0.00025mm) had accumulated within the scallop’s intestines.

However, considerably more even smaller particles measuring 20nm (0.00002mm) had become dispersed throughout the body including the kidney, gill, muscle and other organs.

A December 3, 2018 University of Plymouth press release (also on EurekAlert), which originated the news item, adds more detail,

The study is the first to quantify the uptake of nanoparticles at predicted environmentally relevant conditions, with previous research having been conducted at far higher concentrations than scientists believe are found in our oceans.

Dr Maya Al Sid Cheikh, Postdoctoral Research Fellow at the University of Plymouth, led the study. She said: “For this experiment, we needed to develop an entirely novel scientific approach. We made nanoparticles of plastic in our laboratories and incorporated a label so that we could trace the particles in the body of the scallop at environmentally relevant concentrations. The results of the study show for the first time that nanoparticles can be rapidly taken up by a marine organism, and that in just a few hours they become distributed across most of the major organs.”

Professor Richard Thompson OBE, Head of the University’s International Marine Litter Research Unit, added: “This is a ground breaking study, in terms of both the scientific approach and the findings. We only exposed the scallops to nanoparticles for a few hours and, despite them being transferred to clean conditions, traces were still present several weeks later. Understanding the dynamics of nanoparticle uptake and release, as well as their distribution in body tissues, is essential if we are to understand any potential effects on organisms. A key next step will be to use this approach to guide research investigating any potential effects of nanoparticles and in particular to consider the consequences of longer term exposures.”

Accepted for publication in the Environmental Science and Technology journal, the study also involved scientists from the Charles River Laboratories in Elphinstone, Scotland; the Institute Maurice la Montagne in Canada; and Heriot-Watt University.

It was conducted as part of RealRiskNano, a £1.1million project funded by the Natural Environment Research Council (NERC). Led by Heriot-Watt and Plymouth, it is exploring the effects which microscopic plastic particles can have on the marine environment.

In this study, the scallops were exposed to quantities of carbon-radiolabeled nanopolystyrene and after six hours, autoradiography was used to show the number of particles present in organs and tissue.

It was also used to demonstrate that the 20nm particles were no longer detectable after 14 days, whereas 250nm particles took 48 days to disappear.

Ted Henry, Professor of Environmental Toxicology at Heriot-Watt University, said: “Understanding whether plastic particles are absorbed across biological membranes and accumulate within internal organs is critical for assessing the risk these particles pose to both organism and human health. The novel use of radiolabelled plastic particles pioneered in Plymouth provides the most compelling evidence to date on the level of absorption of plastic particles in a marine organism.”

Here’s a link to and a citation for the paper,

Uptake, Whole-Body Distribution, and Depuration of Nanoplastics by the Scallop Pecten maximus at Environmentally Realistic Concentrations by Maya Al-Sid-Cheikh, Steve J. Rowland, Karen Stevenson, Claude Rouleau, Theodore B. Henry, and Richard C. Thompson. Environ. Sci. Technol., Article ASAP DOI: 10.1021/acs.est.8b05266 Publication Date (Web): November 20, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

‘Unplastic giant scallop’

The sea scallop (Placopecten magellanicus) has over 100 blue eyes along the edge of its mantle, with which it senses light intensity. This mollusk has the ability to scoot away from potential danger by flapping the two parts of its shell, like a swimming castenet. Credit: Dann Blackwood, USGS – http://www.sanctuaries.nos.noaa.gov/pgallery/pgstellwagen/living/living_17.html Public Domain

Stunning, isn’t it?

Plastic nanoparticles and brain damage in fish

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Researchers in Sweden suggest plastic nanoparticles may cause brain damage in fish according to a Sept. 25, 2017 news item on phys.org,

Calculations have shown that 10 per cent of all plastic produced around the world ultimately ends up in the oceans. As a result, a large majority of global marine debris is in fact plastic waste. Human production of plastics is a well-known environmental concern, but few studies have studied the effects of tiny plastic particles, known as nanoplastic particles.

“Our study is the first to show that nanosized plastic particles can accumulate in fish brains”, says Tommy Cedervall, a chemistry researcher at Lund University.

A Sept. 25, 2017 Lund University press release, which originated the news item, provides more detail about the research,

The Lund University researchers studied how nanoplastics may be transported through different organisms in the aquatic ecosystem, i.e. via algae and animal plankton to larger fish. Tiny plastic particles in the water are eaten by animal plankton, which in turn are eaten by fish.

According to Cedervall, the study includes several interesting results on how plastic of different sizes affects aquatic organisms. Most importantly, it provides evidence that nanoplastic particles can indeed cross the blood-brain barrier in fish and thus accumulate inside fish’s brain tissue.

In addition, the researchers involved in the present study have demonstrated the occurrence of behavioural disorders in fish that are affected by nanoplastics. They eat slower and explore their surroundings less. The researchers believe that these behavioural changes may be linked to brain damage caused by the presence of nanoplastics in the brain.

Another result of the study is that animal plankton die when exposed to nanosized plastic particles, while larger plastic particles do not affect them. Overall, these different effects of nanoplastics may have an impact on the ecosystem as a whole.

“It is important to study how plastics affect ecosystems and that nanoplastic particles likely have a more dangerous impact on aquatic ecosystems than larger pieces of plastics”, says Tommy Cedervall.

However, he does not dare to draw the conclusion that plastic nanoparticles could accumulate in other tissues in fish and thus potentially be transmitted to humans through consumption.

“No, we are not aware of any such studies and are therefore very cautious about commenting on it”, says Tommy Cedervall.

Here’s a link to and a citation for the paper,

Brain damage and behavioural disorders in fish induced by plastic nanoparticles delivered through the food chain by Karin Mattsson, Elyse V. Johnson, Anders Malmendal, Sara Linse, Lars-Anders Hansson & Tommy Cedervall. Scientific Reports 7, Article number: 11452 (2017) doi:10.1038/s41598-017-10813-0 Published online: 13 September 2017

This paper is open access.