Cell Biology and Toxicology
Our Research Approach:
Effects of Anthropogenic Molecules and Particles (Microplastics) on Marine Organisms.
Uptake and effects of microplastics
Our group has been among the first to demonstrate experimentally that microplastic particles (MPs) enter the cells of central metabolic organs. The filter feeding blue mussel was exposed High Density Polyethylene (HDPE) were applied in the size range of larger 0 to 80 mm.
Uptake routes into eukaryotic cells
- are evolutionary conserved
- particles traverse by diffusion selectively by the size of pores in cell membranes
- of which only 2% are large sized pores (400-nm pore radius);
- 30% of medium size (40 nm);
- and 68 % of small size (1.3-nm).
- Specialised coated vesicles transport particles smaller than 200 nm.
- In contrast, larger particles up to 40 micrometers are taken up by engulfment through endocytosis and phagocytosis.
- taken up into epithelial as demonstrated by polarized light microscopy and FT-IR-Spectroscopy
- are targeted to specific cell organells (lysosomes)
- cause a pronounced stress response (membrane disruption, inflammation)
- cause the formation of granulocytomas (similar to asbestosis)
A) Histological section of a digestive tubule stained with H6E; B) Visualisation of HDPE fluff in digestive tubule by polarized microscopy.
C) FT-Infrared Spectoscopy in collaboration with Martin Löder, AWI Helgoland until 2014, University of Bayreuth since 2015 WG Prof. Laforsch).
Public awareness of the plastic problem since many years based on entangling in fishing gears of turtles, whales or seals.
A far more hazardous impact have smaller particles from
- Degradation of larger plastic fragments and film in time (+-by UV radiation, mechanical forces, biological activity /Screwing, chewing, shredding by marine organisms)
- Direct release of micro-and nano plastic particles (z.B. Peeling, cosmetics, toothpaste and household products, industrial cleaning products such as "sand" plastic blasting, into the air, via sewage plants into waterways
- Loss of industrial plastic as fluff, powder or pellets during transport on waterways or groundwater by accidents or due to careless handling
- Deliberate shredding of ship sewage and relaase into the seas (under violation of the MARPOL Convention 73/78 Annex V, which forbids the release of plastic into the sea under all circumstances
Once, microplastic has been arbitrarily defined as all particles smaller than 5 mm , stiil easily to be recognised by blank eye. From particles smaller than 1 mm up to 5 mm it has been anticipated that they can be swallowed by animals (Arthur et al., 2009).
Possible deleterious consequences
- Physical/mechanic Injury
- Toxic compounds determining the plastic properties (Phtalates, Bisphenol A)
- Accumulation of persistent organic chemicals/metals Microplastics can function as passive samplers for endocrine disrupting chemicals such as plastiziser, brominated flame retardants or dioxine (Kershaw et al. 2009)
Analysis, detection and quantification methods according to the size of microplastic particles and intake of MPs along the foodnet modified after: GESAMP 40 SOURCES, “Sources, fate and effects of microplastics in the marine environment – a global assessment” ; IMO/FAO/UNESCO-IOC/UNIDO/WMO/IAEA/UN/UNEP/UNDP Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection GESAMP. Rep. Stud. GESAMP No. 90, 96 p.
Video (at the moment available in German only)
"Plastik: Fluch der Meere"