A veritable ecological plague, microplastics are constantly colonizing our planet.
Even if the subject remained surprisingly little discussed compared to other ecological issues, microplastics have gradually established themselves as an increasingly concrete threat to ecosystems. And that also goes for those who might seem less exposed; researchers have thus just discovered significant quantities of microplastics… directly in samples of fresh snow in Antarctica.
This work was carried out by a team of New Zealand researchers from the University of Canterbury. They focused on a surface layer of two centimeters. They were thus seeking to obtain representative samples of the fresh snow. And their results are disturbing to say the least; they found microplastics in 100% of their samples from 19 different sites.
In this case, it was mostly PET. It is a plastic widely used in the four corners of the planet. It is used in particular to produce synthetic fibers and containers such as bottles. But it wasn’t the only one; in total, the researchers found particles from 13 different types of plastics. The average concentration (29.4 particles per liter) is fortunately quite low. But the conclusion is no less worrying.
The sad confirmation of a worrying phenomenon
“It’s incredibly sad, but finding microplastics in fresh Antarctic snow highlights the scale of this plastic pollution, even in the most remote parts of the world.”, explains Alex Aves, PhD student at the University of Canterbury and lead author of the study.
Previous studies had already noted the existence of microplastics in these frozen lands. But according to the researchers, this is the very first time that a study has confirmed their presence in fresh snow, with all that this implies for their presence in the atmosphere on a global scale.
According to the researchers, these microplastics have two distinct origins. Some of it was probably deposited there by atmospheric and oceanic circulation. But the scientists also found that the concentration of microplastics tended to increase near the few research stations located on site. They therefore concluded that scientific expeditions probably play a leading role in this plastic pollution.
The researchers now explain that this experiment should be repeated over a wider area. Ideally, it should even be done on a continental scale. This would make it possible to verify whether this phenomenon is restricted to a particular area, or whether it affects the continent as a whole.
These data will make it possible to clarify the hypotheses on the circulation of these microplastics, with the hope of finding ways to prevent it. And there is urgency, because today, we are still sorely lacking in hindsight on the real impact of these contaminants that are found absolutely everywhere, from Everest to the Mariana Trench passing through the blood of humans (see our article).
Consequences still poorly known to anticipate now
While the precise nature of their impact remains to be clarified, it is commonly accepted that the balance sheet is negative. The arrival of these particles in the food chains of many ecosystems could upset the physiology of certain species, and by extension, the delicate balance on which these ecological niches rest.
In the specific case of the oceans and Antarctica, the situation is even more problematic. The darkest microplastics can turn into small heat accumulators; they then oppose the role of “shield” of the Antarctic, whose snow and ice usually reflect the rays of the Sun.
This action is very important in climate dynamics; if this reflective surface disappears as a result of global warming, all the more energy will end its course directly on Earth instead of being sent back into space, with all that this implies for subsequent events. Microplastics could therefore accelerate the establishment of this vicious circle with serious consequences.
More than ever, it is becoming fundamental to tackle the global management of these materials; this already worrying phenomenon is probably only the tip of a gigantic plastic iceberg waiting for humanity at the turn.