New research from the Swiss Federal Laboratories For Materials Science And Technology (EMPA), Utrecht University, and the Austrian Central Institute for Meteorology and Geophysics showcase the scale and huge range of pollution carried through the atmosphere.
The findings suggest that around 3,000 tons of nanoplastic particles are deposited in Switzerland every year, including the most remote Alpine regions. Most are produced in cities around the country, but others are particles from the ocean that get introduced into the atmosphere by waves. Some of these travel as far as 2000 kilometers through the air before settling, the team explains, originating from the Atlantic.
Such results build on a previous body of research showing that plastic pollution has become ubiquitous on Earth, with nano- and microplastics, in particular, being pervasive on the planet.
Although we're confident that the Earth has a plastic problem, judging by the overall data we have so far, the details of how nanoplastics travel through the air are still poorly understood. The current study gives us the most accurate record of plastic pollution in the air to date, according to the authors.
For the study, the researchers developed a novel chemical method that uses a mass spectrometer to measure the plastic contamination levels of different samples. These samples were obtained from a small area on the Hoher Sonnenblick mountain in the Hohe Tauern National Park, Austria, at an altitude of around 3100 meters from sea level. This area was selected as an observatory of the Central Institute for Meteorology and Geodynamics and has been in operation here since 1886.
The samples were collected on a daily basis, in all types of weather, at 8 AM. They consisted of samples of the top layer of snow, which were harvested and processed taking extreme care not to contaminate them with nanoplastics from the air or the researchers' clothes. According to their measurements, about 43 trillion miniature plastic particles land in Switzerland every year -- equivalent to around 3,000 tons.
In the lab, the team measured nanoplastic content in each sample and then analyzed these particles to try and determine their origin. Wind and weather data from all over Europe were also used in order to help determine the particles' origins. Most of the particles were likely produced and released into the atmosphere in dense urban areas. Roughly one-third of the particles found in the samples came from within 200 kilometers. However, around 10% of the total (judging from their level of degradation and other characteristics) were blown to the mountain from over 2000 kilometers away, from the Atlantic; these particles were likely formed in the ocean from larger debris and introduced into the atmosphere by the spray of waves.
Plastic nanoparticles are produced by weathering and mechanical abrasion from larger pieces of plastic. These are light enough to be comparable to a gas in behavior. Their effect on human health is not yet known, but we do know that they end up deep into our lungs, where they could enter our bloodstream. What they do there, however, is still a mystery.
The current study doesn't help us understand their effects any better, but it does put the scale of nanoplastic pollution into perspective. These estimates are very high compared to other studies, and more research is needed to verify them -- but for now, they paint a very concerning picture.
The paper "Nanoplastics transport to the remote, high-altitude Alps" has been published in the journal Environmental Pollution.