Billions of
nanoplastics accumulate in marine organisms within six hours
University of Plymouth
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.
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."