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New research has found it takes less than six hours for plastic nanoparticles to be absorbed throughout the major organs of a marine organism.
The study, led by the University of Plymouth, involved scientists from the UK and Canada.
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.
Among them was Ted Henry, Professor of Environmental Toxicology at Heriot-Watt University, who was responsible for reviewing and interpreting the findings of the research.
He 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.”
Scientists examined the uptake of nanoparticles by a commercially important mollusc, the great scallop (Pecten maximus).
After six hours exposure in the laboratory, particles measuring 250nm (around 0.00025mm) had accumulated within the scallop's intestines.
However, even smaller particles measuring 20nm (0.00002mm) had become dispersed throughout the body including the kidney, gill, muscle and other organs.
The study is the first to explore the uptake of nanoparticles at environmentally relevant conditions, with previous experiments having been conducted at far higher concentrations than 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.”
The study 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.