Contaminants that have emerged as a result of human activity continue to reach even the most remote parts of the world, with scientists recently finding decades old nanoplastics in the north and south pole.
As the world continues to produce, use and dispose of plastics at a growing rate, the danger of plastic pollution is becoming increasingly clear.
Discarded plastics do not disappear. They pollute the environment for years and break down into small particles known as microplastics that range from 5 millimetres to 0.1 micrometres in size, and nanoplastics that are smaller than 0.1 micrometres.
These contaminants have been found to end up in the earth, water, and atmosphere - making their way to our tables and lungs - and travelling around the world.
Of particular concern is “the omnipresence of nanoplastics” in the words of Dusan Materic and colleagues, the researchers behind a recent study that traced nanoplastics in ice cores from Greenland and Antarctica.
Nanoplastics, owing to their minuscule size, can become airborne and be carried distances away from their original sources, travelling farther than microplastics to end up in virtually any part of the world.
What dangers are we facing?
So far, exposure to nanoplastics and microplastics have shown several adverse effects on humans and other organisms, and we still don’t have a sufficient understanding of the damage these particles can cause.
One known fact is that nanoplastics, in positive correlation with their increased mobility, are more toxic compared to microplastics.
Alarmingly, nanoplastics can cross into cells and even infiltrate the blood-brain barrier owing to their size, giving them the potential to cause brain damage.
It has been found that nanoplastics can lead to cell damage and inflammation in humans. Growth impairments, larval deformities and other toxic effects have also been observed in marine organisms.
Minuscule plastic particles also signal adverse effects for the environment when they are carried into the atmosphere. These particles can absorb and scatter radiation, thus leading to direct changes in the Earth’s climate.
Decades old nanoplastics in Earth’s poles
For their study published in January 2022 looking for nanoplastics in remote parts of the world, Materic and colleagues examined water samples from both the north and south poles.
Their samples were from a 14-metre-deep firn core from Greenland, and sea ice core from Antarctica.
A matter of interest is that they were not examining the surface - they were going down to the core - and still found nanoplastics, meaning that the particles got there decades ago.
In the sample from Greenland, the researchers found 13.2 nanograms of nanoplastics per millilitre (ng/mL), while the number was 52.3 ng/mL for the sample from the Antarctic.
The types of nanoplastics the researchers detected consisted of polyethylene (PE), poly-propylene (PP), polyethylene terephthalate (PET), polystyrene (PS), polyvinyl chloride (PVC), and Tire wear.
These were all identified in the Greenland sample, while the Antarctic sample only showed PE, PP and PET particles - all common types of plastic.
PE is found in single-use bags and containers, as well as houseware, pipes, and agricultural foils. PET is used in clothing and plastic bottles. PP, on the other hand, is also used in food and beverage packaging.
In total, the prevailing type of nanoplastics was PE, contributing to 49 percent of the nanoplastics mass in Greenland and over 50 percent of the mass in the Antarctic.
The researchers suggest that these nanoparticles most likely reached their distant locations through complex processes of global plastic circulation that includes re-emission from land and sea surfaces when plastic products are eroded in physical, chemical and biological processes.
It is likely that emitted plastic particles deposited at the sampling locations through atmospheric circulation by becoming airborne, or marine circulation via ocean currents.
These nanoplastics could have come from primary sources - hotspots where the plastic products are produced, used, and disposed of - or secondary sources such as microplastics that were already eroded from these primary sources.
Now that they have been found in the most remote places of the world, it is becoming clear that toxic nanoplastics can be everywhere, and we are not prepared to engage in an effective battle with them.
The threat of nanoplastics is yet another global issue that is in need of major international attention as we have just begun to face the repercussions.