Tiny plastic particles also find their way into the brain
Mechanism for breaching the blood-brain barrier described for the first time
Peer-Reviewed PublicationThe study was carried out in an animal model with oral administration of MNPs, in this case polystyrene, a widely-used plastic which is also found in food packaging. Led by Lukas Kenner (Department of Pathology at MedUni Vienna and Department of Laboratory Animal Pathology at Vetmeduni) and Oldamur Hollóczki (Department of Physical Chemistry, University of Debrecen, Hungary) the research team was able to determine that tiny polystyrene particles could be detected in the brain just two hours after ingestion. The mechanism that enabled them to breach the blood-brain barrier was previously unknown to medical science. "With the help of computer models, we discovered that a certain surface structure (biomolecular corona) was crucial in enabling plastic particles to pass into the brain," Oldamur Hollóczki explained.
Researching impact on health
The blood-brain barrier is an important cellular barrier that prevents pathogens or toxins from reaching the brain. The intestine has a similar protective wall (intestinal barrier), which can also be breached by MNPs, as various scientific studies have demonstrated. Intensive research is being conducted on the health effects of plastic particles in the body. MNPs in the gastrointestinal tract have already been linked with local inflammatory and immune reactions, and the development of cancer. "In the brain, plastic particles could increase the risk of inflammation, neurological disorders or even neurodegenerative diseases such as Alzheimer's or Parkinson's," said Lukas Kenner, pointing out that more research is needed in this area.
Restrict the use of MNPs
Nanoplastics are defined as having a size of less than 0.001 millimetres, while at 0.001 to 5 millimetres, some microplastics are still visible to the naked eye. MNPs enter the food chain through various sources including packaging waste. But it is not just solid food that plays a role, but liquids too: according to one study, anyone who drinks the recommended 1.5-2 litres of water per day from plastic bottles will end up ingesting around 90,000 plastic particles a year in the process. However, drinking tap water instead can – depending on the geographical location – help reduce this figure to 40,000. "To minimise the potential harm of micro- and nanoplastic particles to humans and the environment, it is crucial to limit exposure and restrict their use while further research is carried out into the effects of MNPs," Lukas Kenner explained. The newly discovered mechanism by which MNPs breach protective barriers in the body has the potential to advance research in this area decisively.
JOURNAL
Nanomaterials
ARTICLE TITLE
Micro- and Nanoplastics Breach the Blood–Brain Barrier (BBB): Biomolecular Corona’s Role Revealed
ARTICLE PUBLICATION DATE
19-Apr-2023
Arctic ice algae heavily contaminated with microplastics
Melosira arctica has ten times higher concentration of plastic particles than surrounding seawater
Peer-Reviewed PublicationIMAGE: ON A POLARSTERN EXPEDITION IN THE ARCTIC, RESEARCHERS LED BY BIOLOGIST MELANIE BERGMANN FROM THE ALFRED WEGENER INSTITUTE ARE INVESTIGATING HOW MUCH MICROPLASTIC IS IN AGGREGATES OF THE ICE ALGA MELOSIRA ARCTICA AND THE SEAWATER DIRECTLY NEXT TO ICE FLOES. view more
CREDIT: ALFRED-WEGENER-INSTITUT / MARIO HOPPMANN
The alga Melosira arctica, which grows under Arctic sea ice, contains ten times as many microplastic particles as the surrounding seawater. This concentration at the base of the food web poses a threat to creatures that feed on the algae at the sea surface. Clumps of dead algae also transport the plastic with its pollutants particularly quickly into the deep sea - and can thus explain the high microplastic concentrations in the sediment there. Researchers led by the Alfred Wegener Institute have now reported this in the journal Environmental Science and Technology.
It is a food lift for bottom-dwelling animals in the deep sea: the alga Melosira arctica grows at a rapid pace under the sea ice during spring and summer months and forms metre-long cell chains there. When the cells die and the ice to whose underside they adhere melts, they stick together to form clumps that can sink several thousand metres to the bottom of the deep sea within a single day. There they form an important food source for bottom-dwelling animals and bacteria. In addition to food, however, these aggregates also transport a dubious cargo into the Arctic deep sea: microplastics. A research team led by biologist Dr Melanie Bergmann from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) has now published this in the journal Environmental Science and Technology.
“We have finally found a plausible explanation for why we always measure the largest amounts of microplastics in the area of the ice edge, even in deep-sea sediment,” Melanie Bergmann reports. Until now, the researchers only knew from earlier measurements that microplastics concentrate in the ice during sea ice formation and are released into the surrounding water when it melts. „The speed at which the Alga descends means that it falls almost in a straight line below the edge of the ice. Marine snow, on the other hand, is slower and gets pushed sideways by currents so sinks further away. With the Melosira taking microplastics directly to the bottom, it helps explain why we measure higher microplastic numbers under the ice edge”, explains the AWI biologist.
On an expedition with the research vessel Polarstern in summer 2021, she and a research team collected samples of Melosira algae and the surrounding water from ice floes. The partners from Ocean Frontier Institute (OFI), Dalhousie University and the University of Canterbury then analysed these in the laboratory for microplastic content. The surprising result: the clumps of algae contained an average of 31,000 ± 19,000 microplastic particles per cubic metre, about ten times the concentration of the surrounding water. “The filamentous algae have a slimy, sticky texture, so it potentially collects microplastic from the atmospheric deposition on the sea, the sea water itself, from the surrounding ice and any other source that it passes. Once entrapped in the algal slime they travel as if in an elevator to the seafloor, or are eaten by marine animals,” explains Deonie Allen of the University of Canterbury and Birmingham University who is part of the research team.
Since the ice algae are an important food source for many deep-sea dwellers, the microplastic could thus enter the food web there. But it is also an important food source at the sea surface and could explain why microplastics were particularly widespread among ice-associated zooplankton organisms, as an earlier study with AWI participation shows. In this way, it can also enter the food chain here when the zooplankton is eaten by fish such as polar cod and these are eaten by seabirds and seals and these in turn by polar bears.
The detailed analysis of plastic composition showed that a variety of different plastics are found in the Arctic, including polyethylene, polyester, polypropylene, nylon, acrylic and many more. In addition to various chemicals and dyes, this creates a mix of substances whose impact on the environment and living creatures is difficult to assess. “People in the Arctic are particularly dependent on the marine food web for their protein supply, for example through hunting or fishing. This means that they are also exposed to the microplastics and chemicals contained in it. Microplastics have already been detected in human intestines, blood, veins, lungs, placenta and breast milk and can cause inflammatory reactions, but the overall consequences have hardly been researched so far,” reports Melanie Bergmann. “Micro and nano plastics have basically been detected in every place scientists have looked in the human body and within a plethora of other species. It is known to change behaviours, growth, fecundity and mortality rates in organisms and many plastic chemicals are known toxins to humans,” says Steve Allen, OFI Dalhousie University, a research team member.
Moreover, the Arctic ecosystem is already threatened by the profound environmental upheavals caused by the climate crisis. If the organisms are now additionally exposed to microplastics and the chemicals they contain, it can weaken them further. “So, we have a combination of planetary crises that we urgently need to address effectively. Scientific calculations have shown that the most effective way to reduce plastic pollution is to reduce the production of new plastic,” says the AWI biologist and adds: “This should therefore definitely be prioritised in the global plastics agreement that is currently being negotiated.” That is why Melanie Bergmann is also accompanying the next round of negotiations, which will begin in Paris at the end of May.
Original Publication:
Bergmann, M., Allen, S., Krumpen, T., Allen, D., 2023. High levels of microplastics in the Arctic ice alga Melosira arctica, a vector to ice-associated and benthic food webs. Environmental Science and Technology. DOI: https://doi.org/10.1021/acs.est.2c08010
Information for editorial offices:
EMBARGOED until 12:00 CEST (06:00 am US Eastern Time, 11:00 London Time) on Friday, 21 April 2023.
Printable images can be found in this collection until the end of the embargo: https://multimedia.awi.de/medien/pincollection.jspx?collectionName=738688f0fec1806bc1d0814218a705c7#1681817422433_2 and then in the online version of this press release at https://www.awi.de/ueber-uns/service/presse.html
Video footage of the sampling for the study can be found here: https://we.tl/t-9p7yre7Ro1
Your contact at the Alfred Wegener Institute is Dr. Melanie Bergmann (Tel.: +49 (0) 471 4831-1739, e-mail: Melanie.Bergmann@awi.de. At the cooperating institutes your contacts are: Dr. Deonie Allen, Research fellow at University of Birmingham, UK/ Canterbury University, New Zealand; email: deonie.castle@canterbury.ac.nz ; Phone: +64 (0)22 095 5171 and Dr. Steve Allen, Research fellow at Ocean frontiers Institute (Dalhousie University), Canada; Phone: +64 (0)22 095 5171; email: steveascotland@gmail.com.
In the press office of the Alfred Wegener Institute, Dr. Folke Mehrtens (Tel.: 0471 4831-2007; E-Mail: medien@awi.de) will support you.
Follow the Alfred Wegener Institute on Twitter (https://twitter.com/AWI_Media), Instagram (https://www.instagram.com/awiexpedition/) and Facebook (www.facebook.com/AlfredWegenerInstitute).
The Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) conducts research in the Arctic, Antarctic and oceans of the high and mid-latitudes. It coordinates polar research in Germany and provides major infrastructure to the international scientific community, such as the research icebreaker Polarstern and stations in the Arctic and Antarctica. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.
JOURNAL
Environmental Science & Technology
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
High levels of microplastics in the Arctic ice alga Melosira arctica, a vector to ice-associated and benthic food webs
ARTICLE PUBLICATION DATE
21-Apr-2023
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