Tag Archives: plastic nanoparticles

Nanoplastics accumulating in marine organisms

I’m starting to have a collection of postings related to plastic nanoparticles and aquatic life (I have a listing below). The latest originates in Singapore (from a May 31, 2018 news item on ScienceDaily),

Plastic nanoparticles — these are tiny pieces of plastic less than 1 micrometre in size — could potentially contaminate food chains, and ultimately affect human health, according to a recent study by scientists from the National University of Singapore (NUS). They discovered that nanoplastics are easily ingested by marine organisms, and they accumulate in the organisms over time, with a risk of being transferred up the food chain, threatening food safety and posing health risks.

A May 31, 2018 NUS press release (also on EurekAlert), which originated the news item, expands on the theme,

Ocean plastic pollution is a huge and growing global problem. It is estimated that the oceans may already contain over 150 million tonnes of plastic, and each year, about eight million tonnes of plastic will end up in the ocean. Plastics do not degrade easily. In the marine environment, plastics are usually broken down into smaller pieces by the sun, waves, wind and microbial action. These micro- and nanoplastic particles in the water may be ingested by filter-feeding marine organisms such as barnacles, tube worms and sea-squirts.

Using the acorn barnacle Amphibalanus amphitrite as a model organism, the NUS research team demonstrated for the first time that nanoplastics consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.

“We opted to study acorn barnacles as their short life cycle and transparent bodies made it easy to track and visualise the movement of nanoplastics in their bodies within a short span of time,” said Mr Samarth Bhargava, a PhD student from the Department of Chemistry at the NUS Faculty of Science, who is the first author of the research paper.

“Barnacles can be found in all of the world’s oceans. This accumulation of nanoplastics within the barnacles is of concern. Further work is needed to better understand how they may contribute to longer term effects on marine ecosystems,” said Dr Serena Teo, Senior Research Fellow from the Tropical Marine Science Institute at NUS, who co-supervised the research.

Studying the fate of nanoplastics in marine organisms

The NUS research team incubated the barnacle larvae in solutions of their regular feed coupled with plastics that are about 200 nanometres in size with green fluorescent tags. The larvae were exposed to two different treatments: ‘acute’ and ‘chronic’.

Under the ‘acute’ treatment, the barnacle larvae were kept for three hours in a solution that contained 25 times more nanoplastics than current estimates of what is present in the oceans. On the other hand, under the ‘chronic’ treatment, the barnacle larvae were exposed to a solution containing low concentrations of nanoplastics for up to four days.

The larvae were subsequently filtered from the solution, and examined under the microscope. The distribution and movement of the nanoplastics were monitored by examining the fluorescence from the particles present within the larvae over time.

“Our results showed that after exposing the barnacle larvae to nanoplastics in both treatments, the larvae had not only ingested the plastic particles, but the tiny particles were found to be distributed throughout the bodies of the larvae,” said Ms Serina Lee from the Tropical Marine Science Institute at NUS, who is the second author of the paper.

Even though the barnacles’ natural waste removal pathways of moulting and excretion resulted in some removal of the nanoplastics, the team detected the continued presence of nanoplastics inside the barnacles throughout their growth until they reached adulthood.

“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them. In addition, plastics are capable of absorbing pollutants and chemicals from the water. These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health,” said marine biologist Dr Neo Mei Lin from the Tropical Marine Science Institute at NUS, who is one of the authors of the paper.

The team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.

Next steps

The NUS research team seeks to further their understanding of the translocation of nanoparticles within the marine organisms and potential pathways of transfer in the marine ecosystem.

“The life span and fate of plastic waste materials in marine environment is a big concern at the moment owing to the large amounts of plastic waste and its potential impact on marine ecosystem and food security around the world. The team would like to explore such topics in the near future and possibly to come up with pathways to address such problems,” explained Associate Professor Suresh Valiyaveettil from the Department of Chemistry at the NUS Faculty of Science, who co-supervised the research.

The team is currently examining how nanoplastics affect other invertebrate model organisms to understand the impact of plastics on marine ecosystems.

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

Fate of Nanoplastics in Marine Larvae: A Case Study Using Barnacles, Amphibalanus amphitrite by Samarth Bhargava, Serina Siew Chen Lee, Lynette Shu Min Ying, Mei Lin Neo, Serena Lay-Ming Teo, and Suresh Valiyaveettil. ACS Sustainable Chem. Eng., 2018, 6 (5), pp 6932–6940 DOI: 10.1021/acssuschemeng.8b00766 Publication Date (Web): March 21, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

Other plastic nanoparticle postings:

While this doesn’t relate directly to aquatic life, the research focuses on how plastic degrades into plastic nanoparticles,

That’s it for now.

Theoretical tool for understanding the fate of nano- and microplastic in rivers

An Oct. 17, 2016 news item on Nanowerk announced work being accomplished at Wageningen University (Netherlands),

Very tiny plastic particles of micro and nano size are difficult to measure in the environment to assess exposure risks. Researchers of Wageningen University & Research now provide the first mechanistic modelling study on the behaviour and fate of nano- and microplastic in surface waters.

Plastic debris has been detected in the oceans, in soils, sediments and surface waters worldwide. Emissions are expected to increase by an order of magnitude in the coming years. Fragmentation leads to smaller and smaller particles, eventually reaching the submicron scale. At these very small sizes, plastic particles may pose unforeseen risks. Yet they are hard to measure in the environment so that exposure assessments have to rely on modelling.

Wageningen researcher Ellen Besseling: “We already knew that microplastics are transported in rivers and can reach the sediment, potentially affecting aquatic life. Now we have a theoretical tool that helps us to understand why/how this happens and that helps us to explain what we see. This is important in order to design mitigation strategies for plastic debris of all sizes, and to predict emissions of plastics to our oceans.”

An Oct. 17, 2016 Wageningen University & Research press release, which originated the news item, provides more detail,

In their recent pioneering study published in the journal Environmental Pollution, Ellen Besseling and co-workers simulate the concentrations of plastic particles between 100 nm up to 10 mm for the hydrological flow regime of a real river. The model accounted for direct transport of the particles, but also for aggregation of the particles with natural suspended solids, and the transport and settling of the resulting so-called heteroaggregates. The model also accounted for the presence of biofilm on the plastics, and model scenarios were calculated for plastics of different density. “This provides very insightful results on where in the river bed the ‘hot spot’ locations for presence of nano- and microplastic can be expected,” says project leader Prof Bart Koelmans. No earlier models accounted for all of these processes, and some counterintuitive results were obtained. Settling to the sediment for instance, was important for nano- and microplastics smaller than one micrometer due to settling of aggregates, and for plastic particles bigger than fifty micrometer due to direct settling, but much less for sizes in between. This means that these particles are expected to be exported to sea to a larger extent.

Attachment efficiency
A key parameter in the model is the attachment efficiency, which is the chance that a colliding plastic and natural solid particle actually stick together. Because this parameter was not known, literature values were used taking non-polymer nanoparticles as a proxy for microplastic. These values, however, were used in combination with – also for the first time – new measured values for actual nano- and microplastics. These experimental data for aggregation of nano- and microplastic with suspended particles in natural freshwater appeared to fairly agree to the literature data. Whereas these first results are promising, the research team emphasizes that more research is needed to study the aggregation behaviour of nano- an microplastic in fresh and marine waters.

Risk assessment of plastic debris
The problem of plastic debris is high on the agenda of policymakers and the public, and society calls for an assessment of the risks of plastic debris to man and the environment. A risk assessment for nano- and microplastic requires an assessment of exposure, and of the effects caused by plastics, which then can be compared in a characterisation of actual risks for man and the environment. As long as analytical methods to detect plastic particles are still under construction, models provide invaluable tools to assess exposure to plastic of all sizes. Models can also be used to design monitoring networks and optimize sampling strategies by indicating ‘hot spot’ locations based on first principles. At Wageningen University & Research, several projects aim to develop tools for the risk assessment of plastic debris in marine as well as freshwaters, for instance the new STW-project TRAMP.

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

Fate of nano- and microplastic in freshwater systems: A modeling study by Ellen Besseling, Joris T.K. Quik, Muzhi Sun, Albert A. Koelmans. Environmental Pollution http://dx.doi.org/10.1016/j.envpol.2016.10.001 Available online 13 October 2016

This paper is behind a paywall.

Implications of nanoplastic in the aquatic food chain

As plastic breaks down in the oceans into plastic nanoparticles, they enter the food chain when they are ingested by plankton. Researchers in Sweden have published a study about the process. From a May 23, 2016 news item on ScienceDaily,

Plastic accounts for nearly eighty per cent of all waste found in our oceans, gradually breaking down into smaller and smaller particles. New research from Lund University in Sweden investigates how nanosized plastic particles affect aquatic animals in different parts of the food chain.

“Not very many studies have been done on this topic before. Plastic particles of such a small size are difficult to study,” says Karin Mattsson.

A May 23, 2016 Lund University press release, which originated the news item, provides more detail,

“We tested how polystyrene plastic particles of different sizes, charge and surface affect the zooplankton Daphnia. It turned out that the size of the nanoparticles that were most toxic to the Daphnia in our study was 50 nanometers”, says Karin Mattsson.

Because zooplankton like Daphnia are also food for many other aquatic animals, the researchers wanted to study the effect of plastic particles higher up in the food chain. They found that fish that ate Daphnia containing nanoplastics experienced a change in their predatory behaviour and poor appetite. In several studies, researchers also discovered that the nanoparticles had the ability to cross biological barriers, such as the intestinal wall and brain.

“Although in our study we used much larger amounts of nanoplastic than those present in oceans today, we suspect that plastic particles may be accumulated inside the fish. This means that even low doses could ultimately have a negative effect”, says Karin Mattsson.

Plastic breaks down very slowly in nature, and once the microscopically small plastic particles reach lakes and oceans they are difficult to remove. Plastic particles also bind environmental toxins that can become part of the food chain when consumed accidentally.

“Our research indicates the need for more studies and increased caution in the use of nanoplastics”, she says.

Karin Mattsson is a physicist and her research project was produced in collaboration between the Centre for Environmental and Climate Research, the Division Biochemistry and Structural Biology and the Division of Aquatic Biology at Lund University. Karin Mattsson is also affiliated with NanoLund, where several studies are currently conducted to evaluate the safety of nanoparticles.

Here’s a link to and a citation for a paper published online in 2014 and in print in 2015,

Altered Behavior, Physiology, and Metabolism in Fish Exposed to Polystyrene Nanoparticles by Karin Mattsson, Mikael T. Ekvall, Lars-Anders Hansson, Sara Linse, Anders Malmendal, and Tommy Cedervall. Environ. Sci. Technol., 2015, 49 (1), pp 553–561 DOI: 10.1021/es5053655
Publication Date (Web): November 07, 2014

Copyright © 2014 American Chemical Society

More recently, Karin Mattson has published her PhD thesis on the topic (I believe it is written in Swedish).

What is the effect of nanoscale plastic on marine life?

A Nov.27, 2015 news item on Nanowerk announces a new UK (United Kingdom) research project designed to answer the question: what impact could nanoscale plastic particles  have on the marine environment?,

As England brings in pricing on plastic carrier bags, and Scotland reveals that similar changes a little over a year ago have reduced the use of such bags by 80%, new research led by Heriot-Watt University in conjunction with Plymouth University will look at the effect which even the most microscopic plastic particles can have on the marine environment.

While images of large ‘islands’ of plastic rubbish or of large marine animals killed or injured by the effects of such discards have brought home some of the obvious negative effects of plastics in the marine environment, it is known that there is more discarded plastic out there than we can account for, and much of it will have degraded into small or even microscopic particles.

It is the effect of these latter, known as nano-plastics, which will be studied under a £1.1m research project, largely funded by NERC [UK Natural Environment Research Council] and run by Heriot-Watt and Plymouth Universities.

A Nov. 25, 2015 Herriot-Watt University press release, which originated the news item, provides more details,

The project, RealRiskNano, will look at the risks these tiny plastic particles pose to the food web including filter-feeding organisms like mussels, clams and sediment dwelling organisms. It will focus on providing information to improve environmental risk assessment for nanoplastics, based on real-world exposure scenarios replicated in the laboratory.

Team leader Dr Theodore Henry, Associate Professor of Toxicology at Heriot-Watt’s School of Life Sciences, said that the study will build on previous research on nano-material toxicology, but will provide information which the earlier studies did not include.

“Pieces of plastic of all sizes have been found in even the most remote marine environments. It’s relatively easy to see some of the results: turtles killed by easting plastic bags which they take for jelly fish, or large marine mammals drowned when caught in discarded ropes and netting.

“But when plastics fragment into microscopic particles, what then? It’s easy to imagine that they simply disappear, but we know that nano-particles pose their own distinct threats purely because of their size. They’re small enough to be transported throughout the environment with unknown effects on organisms including toxicity and interference with processes of the digestive system.

An important component of the project, to be investigated by Dr Tony Gutierrez at Heriot-Watt, will be the study of interactions between microorganisms and the nanoplastics to reveal how these interactions affect their fate and toxicology.

The aim, said Dr Henry, is to provide the information which is needed to effect real change.“We simply don’t know what effects these nano-plastic particles may pose to the marine environment, to filter-feeders and on to fish, and through the RealRiskNano project we aim to provide this urgently needed information to the people whose job it is to assess risk to the marine ecosystem and decide what steps need to be taken to mitigate it.”

You can find the RealRiskNano website here.