Health and Medicine
PUBLISHED
When it was invented, one of the major selling points of plastic was its chemically inert nature, a material that could be used for everything from food packaging to chemical containers.
But there has been steadily growing evidence that plastic is not quite as benign as was first touted.
As the seemingly endless tide of plastics finds its way into the environment, a combination of actions causes it to begin degrading. Plastics are never broken down, only ever fragmented into ever smaller pieces.
And it is this fragmentation that is of major concern.
“As plastic fragments into smaller and smaller particles, its surface area increases enormously,” said Wei Min, a Columbia professor of Chemistry and Biomedical Engineering, in a statement.
“Then microplastics change the water that surrounds them, generating high-energy, reactive radicals (reactive oxygen species, ROS) that very likely contribute to biological damage that we see in animals and potentially in humans as a result of microplastic exposure.”
A wonder material, now ubiquitous pollution
As the tide of plastic continues to flow around the world, the last decade or so has seen an increase in focus on the effect that plastic is having on the environment.
From the tops of the highest mountain peaks to the literal depths of the oceans, there is no place on this planet that has not been contaminated in some form by plastic pollution.
This is having a range of impacts on the animals and plants that live there, whether it is whales found with flipflops in their bellies, seabirds feeding their newly hatched chicks a diet of plastic, or hermit crabs using discarded trash as their new homes.
But it is not just the physical effect that is of concern. As plastics break apart, particularly when exposed to water and sunlight, they can start to release a toxic cocktail of chemicals.
How these are then affecting animals – including humans – that ingest the plastics is still barely understood.
How plastics interact with water
This is what the team behind this latest paper were keen to investigate. They found that water particles in contact with plastic generate what are known as reactive radicals.
“Our research found that when microplastics interact with water, as they do when they’re in bottled water, or when they’re absorbed into our bloodstream, they spontaneously generate [these] high energy reactive radicals,” said Naixin Qian, a postdoctoral researcher in Min’s lab.
“These are textbook examples of the kinds of molecules that can damage animal and human tissue.”
The fact that microplastics have been observed in a range of human tissues, including the blood which is predominantly made up of water, could be a cause for concern. Ultimately, more research is needed to fully understand these effects.
It is important to note that these results were obtained in laboratory conditions and not within the human body. Whether or not the same action is occurring in, for example, human blood is still not known.
In addition to this, the researchers were able to identify the radicals, but again did not test the impact that they might have on biological tissues. This means that any potential impact they might have on health is, at the moment, still speculative.
Ultimately, more research is needed to fully understand these effects. And with the level of plastics showing no sign of slowing, it couldn’t come soon enough.
The study is published in the journal Nature.
